Hypotensive resuscitation during active hemorrhage: Impact on in-hospital mortality

Dutton RP, MacKenzie CF, Scalea TM,
R Adams Cowley Shock Trauma Center, and the Departments of Anesthesiology and Surgery,
University of Maryland School of Medicine, Baltimore, Maryland.

J Trauma 2002 June;52(6):1141-1146

Background: Traditional fluid resuscitation strategy in the actively hemorrhaging trauma patient emphasizes maintenance of a normal systolic blood pressure (SBP). One human trial has demonstrated improved survival when fluid resuscitation is restricted, whereas numerous laboratory studies have reported improved survival when resuscitation is directed to a lower than normal pressure. We hypothesized that fluid resuscitation titrated to a lower than normal SBP during the period of active hemorrhage would improve survival in trauma patients presenting to the hospital in hemorrhagic shock.

Methods: Patients presenting in hemorrhagic shock were randomized to one of two fluid resuscitation protocols: target SBP > 100 mm Hg (conventional) or target SBP of 70 mm Hg (low). Fluid therapy was titrated to this endpoint until definitive hemostasis was achieved. In-hospital mortality, injury severity, and probability of survival were determined for each patient.

Results: One hundred ten patients were enrolled over 20 months, 55 in each group. The study cohort had a mean age of 31 years, and consisted of 79% male patients and 51% penetrating trauma victims. There was a significant difference in SBP observed during the study period (114 mm Hg vs. 100 mm Hg, p < 0.001). Injury Severity Score (19.65 ± 11.8 vs. 23.64 ± 13.8, p = 0.11) and the duration of active hemorrhage (2.97 ± 1.75 hours vs. 2.57 ± 1.46 hours, p = 0.20) were not different between groups. Overall survival was 92.7%, with four deaths in each group.

Conclusion: Titration of initial fluid therapy to a lower than normal SBP during active hemorrhage did not affect mortality in this study. Reasons for the decreased overall mortality and the lack of differentiation between groups likely include improvements in diagnostic and therapeutic technology, the heterogeneous nature of human traumatic injuries, and the imprecision of SBP as a marker for tissue oxygen delivery.

Fluid resuscitation of the patient with major trauma

Fowler R, Pepe PE
University of Texas Southwestern Medical Center and
The Dallas Metropolitan Area Biotel (EMS) System,
Dallas, Texas, USA

Current Opinion in Anaesthesiology 2002 April;15:173-178

Current reviews and consensus documents now recommend a more discriminating approach to the traditional practices of delivering liberal infusions of intravenous fluid to all major trauma patients with suspected or known major hemorrhage. The evolving evidence suggests that aggressive fluid resuscitation prior to hemostasis leads to additional bleeding through hydraulic acceleration of hemorrhage, soft clot dissolution, and dilution of clotting factors.

Aggressive preoperative fluid infusion is still considered appropriate for unconscious patients without palpable blood pressure or for those with controllable hemorrhage (e.g. isolated extremity or head injury), However, the latest recommendations are to limit or delay intravenous fluid resuscitation preoperatively in those with uncontrollable hemorrhage (e.g. those with penetrating torso injuries), even if they are hypoperfusing.

Although most clinicians still generally support fluid resuscitation for multisystem blunt trauma, particularly with head injury, the most recent experimental data have begun to challenge this traditional practice as well, suggesting a ‘slow infusion’ approach when there is risk for uncontrolled internal bleeding. By providing oxygen delivery with slow, limited infusion, new hemoglobin-based oxygen carriers might help to resolve the current dilemma of having to limit preoperative resuscitation when there is risk of uncontrolled hemorrhage.

Matter for debate--Fluid resuscitation in pre-hospital trauma care: A consensus view

Greaves I, Porter KM, Revell MP
Selly Oak Hospital,
Birmingham, B29 6JD, UK

J.R.Coll.Surg.Edinb. 2002 April;47:2, 451-457

SUMMARY

Fluid administration for trauma in the pre-hospital environment is a challenging and controversial area. There is, as yet no equivocal answer or view, which can be supported by clear, well-documented and reliable evidence. Nevertheless, a careful evaluation of what evidence is available does allow some provisional conclusions to be drawn. We believe that the following represent the best possible current expert consensus on pre-hospital fluids in trauma. As future evidence brings clarity to this area, these guidelines can be modified, and further consensus statements will be issued taking into account such information.

When treating trauma victims in the pre-hospital setting:

• Cannulation should take place en route, where possible
• Only two attempts at cannulation should be made
• Transfer should not be delayed by attempts to obtain intravenous access
• Entrapped patients require cannulation at the scene
• Normal saline is recommended as a suitable fluid for administration to trauma patients
• Boluses of 250 ml fluid may be titrated against the presence or absence of a radial pulse (caveats; penetrating torso injury, head injury, infants)

Prehospital fluid resuscitation of the patient with major trauma

Pepe PE, Mosesso Jr JV, Falk JL
University of Texas Southwestern Medical Center at Dallas,
Emergency Medicine, MC 8579, 5323 Harry Hines Boulevard, Dallas, TX 75390-8579, USA.

Prehospital Emergency Care 2002 Jan-Mar;6:81-91

The most appropriate prehospital approach to resuscitative fluid interventions for trauma patients involves: determining the mechanism of injury (i.e., blunt versus penetrating versus thermal injury); identifying anatomic involvement (i.e., truncal versus isolated head injury versus isolated extremity injury); and staging the condition (i.e., hemodynamic stability versus instability versus moribund state). Based on available data, the liberal use of fluid infusions for presumed uncontrolled internal hemorrhage, such as that usually occurring after penetrating abdominal and thoracic injuries, is no longer advised. Although some infusion might be appropriate in patients with extremely severe hemorrhage (i.e., no palpable blood pressure, unconscious), the priority in such patients is rapid evacuation to definitive surgical intervention, with airway control and intravenous access provided en route. The data are less clear for patients with blunt injuries, particularly those with closed head injury. Most researchers would still recommend that patients with isolated extremity and head injuries, either blunt or penetrating, are candidates for immediate support of blood pressure through fluid infusions. However, the addition of potential intra-abdominal, intrapelvic, or intrathoracic injuries with uncontrolled hemorrhage confounds the decision-making process. Although conventional wisdom has been to provide aggressive blood pressure support under these circumstances through judicious use of isotonic, or perhaps hypertonic, fluid resuscitation, recent experimental data challenge even this philosophy. Use of new blood substitutes might help to resolve some of these issues by providing oxygen delivery with limited volume in the face of uncontrolled hemorrhage.

Continuous fluid resuscitation and splenectomy for treatment of uncontrolled hemorrhagic shock after massive splenic injury

Abu-Hatoum O, Bashenko Y, Hirsh M, Krausz MM,
Department of General Surgery and the Laboratory for Shock and Trauma Research,
Rambam Medical Center, and the Bruce Rappaport Faculty of Medicine,
Technion-Israel Institute of Technology, Haifa, Israel.

J Trauma 2002 Feb;52:253-258

Background: Using a standardized massive splenic injury (MSI) model of uncontrolled hemorrhagic shock, we studied the effect of continuous fluid resuscitation and splenectomy on the hemodynamic response and survival in rats.

Methods: The animals were randomized into seven groups: group 1 (n = 8), sham-operated; group 2 (n = 8), MSI untreated; group 3 (n = 8), MSI treated with 7.5 mL/kg/h of 7.5% NaCl (hypertonic saline [HTS]) for 1 hour; group 4 (n = 8), MSI treated with 7.5 mL/kg/h hydroxyethyl starch (HES-7.5) for 1 hour; group 5 (n = 8) MSI treated with 35 mL/kg/h Ringer’s lactate (RL) solution (RL-35) for 1 hour; group 6 (n = 8) MSI treated with 70 mL/kg/h RL for 1 hour (RL-70); and group 7 (n = 8), MSI treated with 105 mL/kg/h RL for 1 hour (RL-105). In all MSI groups, splenectomy was performed 45 minutes after injury.

Results: MSI in untreated group 2 resulted in a fall of mean arterial pressure from 105.9 ± 10.7 mm Hg to 27.0 ± 6.7 mm Hg (p < 0.001) in 60 minutes. Mean survival time after splenectomy in this group was 160.7 ± 29.7 minutes, and total blood loss was 34.8 ± 4.7% of blood volume. Continuous HTS infusion with splenectomy in group 3 was followed by a total blood loss of 38.7 ± 4.4% and mean survival time was 176.5 ± 23.2 minutes. HES-7.5 infusion and splenectomy was followed by a total blood loss of 39.6 ± 2.5% and survival time was 171.6 ± 19.5 minutes. Continuous infusion of increasing volumes of RL in groups 5, 6, and 7 was followed by increase in blood loss to 29.0 ± 4.1%, 50.2 ± 3.1% (p < 0.001), and 62.7 ± 7.1% (p < 0.002) of total blood volume, respectively. Mean survival time in groups 5, 6, and 7 was 233.5 ± 6.5 minutes (p < 0.04), 207.6 ± 17.0 minutes (p < 0.05), and 158 ± 26 minutes, respectively.

Conclusion: Continuous infusion of large-volume RL and splenectomy after massive splenic injury resulted in a significant increase in intra-abdominal bleeding and shortened survival time compared with small-volume RL infusion.

Low-volume fluid resuscitation for presumed hemorrhagic shock: helpful or harmful?

Stern SA.
Department of Emergency Medicine,
University of Michigan, Ann Arbor, Michigan

Current Opinion in Critical Care. 2001 Dec;7(6):422-30.

For the past 4 decades, the standard approach to the trauma victim who is hypotensive from presumed hemorrhage has been to infuse large volumes of fluids as early and as rapidly as possible. The goals of this treatment strategy are rapid restoration of intravascular volume and vital signs towards normal, and maintenance of vital organ perfusion. The most recent laboratory studies and the only clinical trial evaluating the efficacy of these guidelines however, suggest that in the setting of uncontrolled hemorrhage, today's practice of aggressive fluid resuscitation may be harmful, resulting in increased hemorrhage volume and subsequently greater mortality. This has been demonstrated in animal models representative of penetrating trauma as well as those representative of blunt trauma. The data strongly suggest that limited or hypotensive resuscitation may be preferable for the trauma victim with the potential for ongoing uncontrolled hemorrhage. Limited resuscitation provides a mechanism of avoiding the detrimental effects associated with early aggressive resuscitation, while maintaining a level of tissue perfusion that although decreased from the normal physiologic range is adequate for short periods. Large randomized clinical trials are necessary to confirm this new laboratory data. Future research should focus on developing resuscitation methods that may actually enhance tissue perfusion during limited resuscitation and therefore offset its potential detrimental effects.

Crystalloid and colloid resuscitation of uncontrolled hemorrhagic shock following massive splenic injury.

Krausz MM, Bashenko Y, Hirsh M.

Department of General Surgery, Laboratory for Shock and Trauma Research,
Rambam Medical Center, Haifa, Israel.

Shock. 2001 Nov;16(5):383-8.

Using a standardized massive splenic injury (MSI) model of uncontrolled hemorrhagic shock we studied the effect of vigorous crystalloid or colloid fluid resuscitation on the hemodynamic response, and survival in rats. The value of massive fluid infusion in uncontrolled hemorrhagic shock following intra-abdominal solid organ injury is still controversial. The effect of crystalloid and colloid infusion was studied following massive splenic injury.

The animals were randomized into six groups: group 1 (n = 8) sham-operated, group 2 (n = 12) MSI untreated, group 3 (n = 10) MSI treated with 41.5 mL/kg Ringer's lactate (large-volume Ringer's lactate, LVRL), group 4 (n = 14) MSI treated with 5 mL/kg 7.5% NaCl (hypertonic saline, HTS), group 5 (n = 10) MSI treated with 7.5 mL/kg hydroxyethyl starch (HES-7.5), and group 6 (n = 11) MSI treated with 15 mL/kg hydroxyethyl starch (HES-15).

Following MSI mean arterial pressure (MAP) in untreated group 2 decreased from 109.1+/-4.5 to 49.8+/-9.6 mmHg (P < 0.001) in 60 min. Mean survival time was 132.1 18.7 min, and total blood loss was 30.2+/-4.1% of blood volume. LVRL infusion resulted in an early rise in MAP from 59.7+/-7.3 to 90.0+/-11.3 mmHg (P < 0.01), which then rapidly dropped to 11.7+/-4.5 mmHg (P < 0.001) after 60 min. The mean survival time was 82.5+/-18.2 min (P < 0.01), and total blood loss was 53.7 2.9% (P < 0.01). Total blood loss following HTS infusion was 32.2 4.0% and survival time was 127.9+/-19.7 min. HES-7.5 infusion only moderately increased bleeding to 44.2+/-3.9% (P < 0.05), but mortality remained unchanged. HES-15 infusion resulted in an increase in blood loss to 47.8+/-7.1% (0.01), survival time dropped to 100.7+/-12.3 min (P < 0.05). Vigorous large volume infusion of Ringer's lactate or HES following MSI resulted in a significant increase in intra-abdominal bleeding and shortened survival time compared to untreated, small volume HTS, or HES-7.5-treated animals.

The hemodynamic response to crystalloid or colloid infusion in blunt abdominal trauma is primarily dependent on the severity of injury and the rate of fluid resuscitation.

Reviewer’s note:
Longest survival was in the group with no fluids, shortest survival with large volume infusion.

Permissive hypotension during primary resuscitation from trauma and shock

Kreimeier U, Prückner S, Peter K,

in Yearbook of Intensive Care and Emergency Medicine, 2001
ed.,Springer: 331-341

Advances in fluid resuscitation of hemorrhagic shock.

Tremblay LN, Rizoli SB, Brenneman FD.
Sunnybrook & Women's College Health Sciences Centre,
University of Toronto, Ont.

Canadian Journal of Surgery. 2001 Jun;44(3):172-9.

The optimal fluid for resuscitation in hemorrhagic shock would combine the volume expansion and oxygen-carrying capacity of blood without the need for cross-matching or the risk of disease transmission. Although the ideal fluid has yet to be discovered, current options are discussed in this review, including crystalloids, colloids, blood and blood substitutes. The future role of blood substitutes is not yet defined, but the potential advantages in trauma or elective surgery may prove to be enormous.

Irreversible shock is not irreversible: a new model of massive hemorrhage and resuscitation.

Healey MA, Samphire J, Hoyt DB, Liu F, Davis R, Loomis WH.
Department of Surgery, University of Saskatchewan,
Saskatoon, Saskatchewan, Canada.

J Trauma. 2001 May;50(5):826-34.

BACKGROUND: Existing shock models do not address the patient with massive hemorrhage (> 1 blood volume). Such patients often die from irreversible shock. This model simulates the clinical scenario of massive hemorrhage and resuscitation (MHR) to determine if irreversible shock can be reversed.

METHODS: Lewis rats were bled at a rate of 1 estimated blood volume (EBV) per hour for 2 hours with simultaneous infusion of resuscitation mixture (RM) consisting of red blood cells and crystalloid. Blood pressure was maintained at a mean arterial pressure (MAP) of 50 mm Hg during the 2 hours of hemorrhage. Hemorrhage was stopped and resuscitation continued for 1 hour until 6, 8, or 10 x EBV of RM was infused. Control animals were subjected to a traditional fixed pressure hemorrhage to MAP of 50 mm Hg for 2 hours followed by resuscitation to MAP > 90 mm Hg for 1 hour with crystalloid alone. Two-week survival was compared using a chi2 test.

RESULTS: Control animals (n = 13) were hemorrhaged 48% 5% of EBV and had a mortality rate of 23%. MHR animals had severity and duration of hypotension identical to that of controls but were hemorrhaged 214% 8% of EBV. Despite receiving 390 mL/kg of RM and a final hematocrit of 37%, 14 of 15 animals resuscitated with 6 x EBV died from "irreversible" shock (mortality, 93%; p < 0.001 vs. controls). When very large volumes of resuscitation were used, survival rates improved significantly. The 10 x EBV group received 120% of lost red blood cells and 530 mL/kg of crystalloid and had 64% survival at 2 weeks (p < 0.01 vs. 6 x EBV group).

CONCLUSION: This MHR model is much more lethal than a traditional severe hemorrhage model and reproduces the clinical picture of irreversible shock. This irreversible shock can be reversed with very large volumes of resuscitation.

Reviewer’s note:
The control group (rats) was bled down to a blood pressure of 50 mm Hg and maintained there for 2 hours. The other groups had continuing hemorrhage, while fluid infusion was given. After 2 hours, hemorrhage was controlled. The fluid resuscitation was given to the experimental animals, during bleeding and after resuscitation.

No fluids until bleeding stopped : 23% 2-week mortality.
Giving fluids to 6 X EBV : 93% 2-week mortality.
Giving fluids to 10 X EBV : 36% 2-week mortality.

Improved survival with early fluid resuscitation following hemorrhagic shock.

Santibanez-Gallerani AS, Barber AE, Williams SJ, ZhaoB S Y, Shires GT
Department of Surgery, University of Nevada School of Medicine, 2040 W. Charleston Boulevard, Suite 501,
Las Vegas, Nevada 89102, USA.

World Journal of Surgery. 2001 May;25(5):592-7.

Recent studies have questioned the benefits of early fluid resuscitation in hemorrhagic shock. The purpose of the current study is to evaluate the effects of early fluid resuscitation (HSE) (15 minutes), delayed fluid resuscitation (HSD) (60 minutes), and no fluid resuscitation (HSU) on cytokine levels, hepatic resting membrane potential (Em), renal function, and mortality. Eighty male Sprague-Dawley rats (350-450 g) were hemorrhaged 35% of their total blood volume and then received 40, 80, or 100 ml of crystalloid per kilogram as intravenous fluids (IVFs). The implementation of HSE resulted in stabilization of the Em (-29 mV), which was significantly different from that seen with HSD or HSU (-24 and -29 mV, respectively). The timing of resuscitation did not affect the elevation of tumor necrosis factor (TNFalpha) levels. The interleukin-6 (IL-6) levels for the HSE group were 81, 101, and 274 pg/ml for 40, 80, and 100 ml/kg, respectively. In contrast, HSD group IL-6 levels were 440, 566, and 632 pg/ml for 40, 80, and 100 ml/kg (p < 0.0001). IL-6 levels for the HSU group was 427 pg/ml, which was significantly different from that of the HSE group (p < 0.05). Urine output was present in 58% of the HSE rats but only 24% in the HSD rats and 0% of the HSU rats. Mortality was 11% for HSE, 58% for HSD, and 50% for HSU rats.

Despite the recent studies questioning the benefits of early fluid resuscitation, these data show marked improvement in hepatic stability, the presence of urine output, decreased IL-6 levels, and significantly lower mortality when IVFs were given early after hemorrhagic shock. Furthermore, excessive fluid resuscitation (100 ml/kg) resulted in an increased inflammatory cytokine level and mortality and may account for the controversy.

Fluid resuscitation for the trauma patient.

Nolan J.

Resuscitation 2001 Jan;48(1):57-69.

Attempts at prehospital fluid replacement should not delay the patient's transfer to hospital. Before bleeding has been stopped, a strategy of controlled fluid resuscitation should be adopted. Thus, the risk of organ ischaemia is balanced against the possibility of provoking more bleeding with fluids. Once haemorrhage is controlled, normovolaemia should be restored and fluid resuscitation targeted against conventional endpoints, the base deficit, and plasma lactate. Initially, the precise fluid used is probably not important, as long as an appropriate volume is given; anaemia is much better tolerated than hypovolaemia. Colloids vary substantially in their pharmacology and pharmacokinetics and the experimental findings from one cannot be extrapolated reliably to another. We still lack reliable data to prove that any of the colloids reduce mortality in trauma patients. In the presence of SIRS, hydroxyethyl starch may reduce capillary leak. Hypertonic saline solutions may have some benefit in patients with head injuries although this has yet to be proven beyond doubt. It is likely that one or more of the haemoglobin-based oxygen carriers currently under development will prove to be valuable in the treatment of the trauma patient.

Permissive Hypotension

Riley B

in Recent Advances in Anaesthesia and Analgesia 21.
ed. Adams AP & Cashman JN. Publ. Churchill Livingstone London 2000.

A randomised controlled trial of prehospital intravenous fluid replacement therapy in serious trauma.

Turner J, Nicholl J, Webber L, Cox H, Dixon S, Yates D.

Health Technology Assessment 2000 Nov;4(31):1-57.

Summary points: The initiation by paramedics of intravenous fluid replacement in injured patients at the accident scene is becoming a routine procedure although there is uncertainty surrounding this practice. This pragmatic randomised study involving 1309 patients compared the effects of two different fluid protocols: A: intravenous fluids administered at the incident scene; and B: fluids withheld until arrival at hospital. No significant differences in outcome were found between the two protocol groups; but protocol compliance was poor – 31% of group A and 20% of group B received prehospital fluids. This study does not support the idea that protocols recommending fluid administration do harm. But it is possible that either giving fluids early does no harm, or that the specific protocols used make little difference. In the absence of clear evidence, the authors suggest that Ambulance services should concentrate on avoiding unnecessary delays and speeding up transfer to definitive care in hospital rather than concentrate on their fluids protocols.

Permissive hypotension

U. Kreimeier, S. Prueckner, K. Peter,
Department of Anaesthesiology, Klinikum Grosshadern,
Ludwig-Maximilian University, Munich (D)

SchweizMedWochenschr [Swiss Medical Weekly] 2000 Oct 21;130: 1516-24

In trauma patients restoration of intravascular volume in an attempt to achieve normal systemic pressure faces the risk of increasing blood loss and thereby potentially affecting mortality. Due to the lack of controlled clinical trials in this field, the growing evidence that hypotensive resuscitation results in improved long-term survival mainly stems from experimental studies in animals. The main differences between concepts for the reduction of blood loss in systemic hypotension are between "deliberate hypotension" (synonym "controlled hypotension", used intraoperatively), "delayed resuscitation" (where the hypotensive period is intentionally prolonged until operative intervention) and "permissive hypotension" (where restrictive fluid therapy increases systemic pressure without reaching normotension). In this review the concept of "permissive hypotension" is delineated on the basis of macro- and microcirculatory changes secondary to hypovolaemia and low driving pressure, and the potential indications and limitations are discussed.

Timing and volume of fluid administration for patients with bleeding following trauma.

Kwan I, Bunn F, Roberts I,
WHO Pre-Hospital Trauma Care Steering Committee.
Department of Paediatric Epidemiology and Biostatistics,
Institute of Child Health, 30 Guilford Street, London, UK, WC1N 1EH.

Cochrane Database of Systematic Reviews. Last updated 2000 Sep 25.
Repeated in the Cochrane Library, Issue 3, 2002:

BACKGROUND: Treatment of haemorrhagic shock involves maintaining blood pressure and tissue perfusion until bleeding is controlled. Different resuscitation strategies have been used to maintain the blood pressure in trauma patients until bleeding is controlled. However, while maintaining blood pressure may prevent shock, it may worsen bleeding.

OBJECTIVES: To assess the effects of early versus delayed, and larger versus smaller volume of fluid administration in trauma patients with bleeding.

SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register, the specialised register of the Injuries Group, MEDLINE, EMBASE, the National Research Register and the Science Citation Index. We checked reference lists of identified articles and contacted authors and experts in the field.

SELECTION CRITERIA: Randomised trials of the timing and volume of intravenous fluid administration in trauma patients with bleeding. Trials in which different types of intravenous fluid were compared were excluded.

DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed trial quality.

MAIN RESULTS: We did not combine the results quantitatively because the interventions and patient populations were so diverse. Early versus delayed fluid administration: Three trials reported mortality and two coagulation data. In the first trial (n=598) relative risk (RR) for death with early fluid administration was 1.26 (95% confidence interval of 1.00-1.58). The weighted mean differences (WMD) for prothrombin time and partial thromboplastin time were 2.7 (95% CI 0.9-4.5) and 4.3 (95% CI 1.74-6.9) seconds respectively. In the second trial (n=50) RR for death with early blood transfusion was 5.4 (95% CI 0.3-107.1). The WMD for partial thromboplastin time was 7.0 (95% CI 6.0-8.0) seconds. In the third trial (n=1309) RR for death with early fluid administration was 1.06 (95% CI 0.77-1.47). Larger versus smaller volume of fluid administration: Three trials reported mortality and one coagulation data. In the first trial (n=36) RR for death with a larger volume of fluid resuscitation was 0.80 (95% CI 0.28-22.29). Prothrombin time and Partial thromboplastin time were 14.8 and 47.3 seconds in those who received a larger volume of fluid as compared to 13.9 and 35.1 seconds in the comparison group. In the second trial (n=99) RR for death with a high (100 mm Hg) compared to low (70 mm Hg) systolic blood pressure resuscitation target was 1.02 (95% CI 0.27-3.85). In the third trial (n=25) there were no deaths.

CONCLUSIONS: We found no evidence from randomised controlled trials to support early or larger volume of intravenous fluid administration in uncontrolled haemorrhage. There is continuing uncertainty about the best fluid administration strategy in bleeding trauma patients. Further randomised controlled trials are needed to establish the most effective fluid resuscitation strategy.

The role of intravenous therapy in the pre-hospital trauma setting

Brown D.

Literature Review, 2000

Reviewer’s comments:
Briefly covers types of shock. Dscusses recent trends to restrict fluids until hemorrhage is controlled.
A good introduction to the science of fluid therapy for shock.

Fluid resuscitation in the initial management of post-traumatic shock: the concept of permissive hypotension.

Brett AS.

Clinical Intensive Care 2000 June;11(3):121-6.

Haemorrhage is one of the major causes of death with the first hours after trauma. The control of haemorrhage has been recognized as the single most important intervention in the management of the bleeding patient; a fact that was emphasized by WB Cannon in his seminal description of the management of missile victims on the Western Front. Cannon also identified the early correction of hypothermia, careful transportation, opiate analgesia, splintage, and appropriate dressings as measures, which might influence the evolution of shock in the first hours after wounding. Such measures remain essential features of trauma resuscitation in the 21st century. Of critical relevance to the subject of this review, Cannon warned that the infusion of salt solutions to elevate the blood pressure before a surgeon was in a position to control bleeding might accelerate haemorrhage. The aim of this narrative review is to present evidence from animal models and clinical studies, so that clinicians and other healthcare workers can make rational decisions regarding the goals for fluid resuscitation in the initial phase of the resuscitation of the bleeding trauma patient.

The effect of vigorous fluid resuscitation in uncontrolled hemorrhagic shock after massive splenic injury.

Solomonov E, Hirsh M, Yahiya A, Krausz MM.
Department of Surgery A, Rambam Medical Center, Haifa, Israel.

Critical Care Medicine. 2000 Mar;28(3):749-54.

Editorial:
Regardless of origin, uncontrolled hemorrhage is uncontrolled hemorrhage
Tisherman SA.
Critical Care Medicine. 2000 Mar;28(3):892-4

OBJECTIVE: Using a standardized massive splenic injury model of uncontrolled hemorrhagic shock, we studied the effect of vigorous fluid resuscitation on the hemodynamic response and survival time in rats. DESIGN: Randomized, controlled study. Duration of follow-up was 4 hrs.

SETTING: University research laboratory.

SUBJECTS: Adult male Sprague-Dawley rats, weighing 240-430 g.

INTERVENTIONS: Standardized massive splenic injury was induced by two transverse incisions in the rat's spleen. The animals were randomized into four groups: group 1 (n = 8) underwent sham operation; in group 2 (n = 15), massive splenic injury was untreated; in group 3 (n = 15), massive splenic injury was treated with 41.5 mL/kg 0.9% sodium chloride (large-volume normal saline); and in group 4 (n = 15), massive splenic injury was treated with 5 mL/kg 7.5% sodium chloride (hypertonic saline).

MEASUREMENTS AND MAIN RESULTS: The hemodynamic and metabolic variables in the sham-operated group 1 were stable throughout the experiment. Mean arterial pressure in group 2 decreased from 86.5 +/- 4.0 to 50.3 +/- 6.3 mm Hg (p < .001) in the first 15 mins after massive splenic injury. Mean survival time in group 2 was 127.5 +/- 17.0 mins; total blood loss was 33.8% +/-2.6% of blood volume; and the mortality rate at 1 hr was 13.3%. Bolus infusion of large-volume normal saline after 15 mins resulted in an early increase in mean arterial pressure from 48.6 +/-7.4 to 83.3 +/- 7.2 mm Hg (p < .01); it then rapidly decreased to 24.6 +/- 8.6 mm Hg (p < .001) after 60 mins. The mean survival time (95.3 +/- 16.4 mins) was significantly lower than in group 2 (p < .01); total blood loss (48.0% +/- 4.3%) was significantly higher than in group 2 (p < .01); and mortality rate in the first hour was 33.3% (p < .05). Bolus infusion of hypertonic saline also decreased survival time to 93.3 +/- 20.3 mins (p < .01), but total blood loss was 35.2% +/- 3.0%, which was not significantly different from the blood loss in group 2. The mortality rate in the first hour (60.0%) was significantly higher than in group 2 (p < .005).

CONCLUSIONS: Vigorous infusion of normal saline after massive splenic injury resulted in a significant increase in intra-abdominal bleeding and decreased survival time. The hemodynamic response to crystalloid infusion in blunt abdominal trauma is primarily dependent on the severity of injury and the rate of blood loss.

Crystalloid or colloid resuscitation of uncontrolled hemorrhagic shock after moderate splenic injury.

Krausz MM, Bashenko Y, Hirsh M.
Department of Surgery A, Rambam Medical Center, Haifa, Israel.

Shock. 2000 Mar;13(3):230-5.

Using a standardized moderate splenic injury (MSI) model of uncontrolled hemorrhagic shock, we studied the effect of vigorous crystalloid or colloid fluid resuscitation on the hemodynamic response and survival time in rats. The animals were randomized into 6 groups: group 1 (n = 8) sham-operated, group 2 (n = 10) MSI untreated, group 3 (n = 10) MSI treated with 41.5 mL/kg Ringer's lactate (large-volume Ringer's lactate [LVRL]), group 4 (n = 10) MSI treated with 5 mL/kg 7.5% NaCl (hypertonic saline [HTS]), group 5 (n = 10) MSI treated with 7.5 mL/kg hydroxyethyl starch (HES-7.5), group 6 (n = 10) MSI treated with 15 mL/kg hydroxyethyl starch (HES-15). After MSI, mean arterial pressure (MAP) in group 2 decreased from 105.0+/-5.6 to 64.0+/-12.7 mmHg (P < 0.001) after 60 min. Mean survival time was 157.4+/-28.9 min, and total blood loss was 24.0+/-5.4% of blood volume. LVRL infusion resulted in an early rise in MAP from 75.2+/-8.7 to 96.7+/-9.0 mmHg (P < 0.01), which then rapidly dropped to 43.0+/-9.7 mmHg (P < 0.001) after 60 min. The mean survival time was 140.7+/-22.3 min, and total blood loss was 41.4+/-4.8% (P < 0.05). Total blood loss following HTS infusion was 24.7+/-3.7%, and mean survival time was 177.5+/-18.9 min. HES-7.5 infusion was followed by bleeding of 25.6+/-5.1%, and mean survival time was 181+/-16.1. HES-15 infusion resulted in an increase in blood loss to 48.2+/-7.3% (P < 0.05), and mean survival time of 133.0+/-27.7 min.

Large-volume Ringer's lactate (LVRL) or hydroxyethyl starch (HES-15) infusion in uncontrolled hemorrhagic shock after moderate splenic injury resulted in a significant increase in intra-abdominal bleeding, but survival time remained unchanged compared with untreated, small-volume HTS-, or HES-7.5-treated animals. The hemodynamic response to large-volume crystalloid or colloid infusion was similar to moderate large-vessel injury.

Early changes in Oxygenation and Chest Wall Compliance associated with Large Volume Shock Resuscitation

Marvin RG, McKinley BA, Cocanour CS, Moore FA,
University of Texas-Houston Medical School, Houston, TX

Poster, AAST 2000

Conclusion: Patients who sustain major trauma and are resuscitated with large volumes of isotonic crystalloid solution have significant decreases in oxygenation and pulmonary compliance. However, both parameters start to improve within 48 hours. Sustained respiratory failure due only to the volume of fluid administered is unlikely.

Effects of traditional versus delayed resuscitation on serum lactate and base deficit.

Baron BJ, Sinert RH, Sinha AK, Buckley MC, Shaftan GW, Scalea TM.
Department of Emergency Medicine, SUNY Health Science Center at Brooklyn,
New York, NY 11203, USA.

Resuscitation. 1999 Dec;43(1):39-46.

OBJECTIVE: To test the hypothesis that delayed resuscitation of hemorrhagic shock produces a less severe shock insult than traditional resuscitation, characterized by repeated episodes of alternating hypotension and normotension.

METHODS: Female pigs were divided into three groups. Sham operated controls (C) (n = 4), sustained hypotension (SS) (n = 6), and hypotension with multiple cycles of shock and resuscitation (SR) (n = 6). SS and SR animals were bled to a mean arterial pressure (MAP) of 50 mmHg. SS animals were maintained at an MAP of 50 mmHg for 65 min and then resuscitated to baseline blood pressure with normal saline and shed blood. SR animals were initially bled and maintained at an MAP of 50 mmHg for 35 min, resuscitated to baseline BP, and subsequently bled and resuscitated twice more. The total period of shock was the same in both SS and SR.

RESULTS: Following hemorrhage, there was a significant increase in lactate and base deficit in SS as compared to C and SR.

CONCLUSION: Delayed resuscitation produces a more profound shock insult than traditional resuscitation.

Fluid replacement.

Nolan J.

British Medical Bulletin. 1999 Dec;55(4):821-43

Appropriate fluid replacement is an essential component of trauma patient resuscitation. Once haemorrhage is controlled, the restoration of normovolaemia is a priority. In the presence of uncontrolled haemorrhage, aggressive fluid resuscitation may be harmful. The crystalloid-colloid debate continues, but existing clinical practice is more likely to reflect local biases and dogma rather than evidence-based medicine. Colloids vary substantially in their pharmacology and pharmacokinetics and the experimental findings based on one colloid cannot be extrapolated reliably to another. In the initial stages of trauma patient resuscitation, the precise fluid used is probably not important, as long as an appropriate volume is given. Later, when the microcirculation is relatively leaky, there may be some advantages to colloids such as hydroxyethyl starch. Hypertonic saline solutions may have some benefit in patients with head injuries. A number of haemoglobin solutions are under development but one of the most promising of these solutions will eventually become routine therapy for trauma patient resuscitation. In the mean time, contrary to traditional teaching, recent data suggest that a restrictive strategy of red cell transfusion may improve outcome in some critically ill patients.

Limited resuscitation with hypertonic saline, hypertonic sodium acetate, and lactated Ringer's solutions in a model of uncontrolled hemorrhage from a vascular injury.

Doucet JJ, Hall RI.
Department of Surgery, Dalhousie University, Queen Elizabeth II Health Sciences Centre,
Halifax, Nova Scotia, Canada.

J Trauma. 1999 Nov;47(5):956-63.

BACKGROUND: Hypertonic sodium acetate-dextran solution (HAD) causes vasodilatation and buffers metabolic acidosis. In controlled hemorrhage models, HAD in small volumes increases cardiac output without increasing blood pressure, thus creating a "high flow-low pressure" state. The objective of this study was to determine whether limited resuscitation of uncontrolled hemorrhage with HAD solution improves gut perfusion as measured by intestinal mucosal tonometry.

METHODS: Three groups of 10 swine were bled 25 mL/kg by means of a femoral artery catheter to produce a mean blood pressure of 30 mm Hg. A 4-mm abdominal aortic laceration was then produced by pulling out a preimplanted wire loop. Groups were then randomly assigned to be resuscitated with either lactated Ringer's solution, a hypertonic saline-dextran solution or HAD solution sufficient to maintain a mean blood pressure of 45 mm Hg for 5 hours or until death. Outcomes were measured by survival, intraperitoneal blood loss, hemodynamic monitoring, and ileal mucosal tonometry.

RESULTS: HAD infusions caused transient worsening of hypotension and were associated with increased mortality (p = 0.038). Blood loss and volumes required for resuscitation were significantly increased in the lactated Ringer's solution group. HAD showed significant buffering effect against metabolic acidosis in arterial blood only, but intestinal ileal mucosal tonometry was not different among the groups.

CONCLUSION: HAD did not improve gut perfusion despite buffering the systemic acidosis of shock and caused increased mortality. Limited resuscitation with any of these solutions is associated with significant mucosal acidosis.

Treatments to support blood pressure increases bleeding and/or decreases survival in a rat model of closed head trauma combined with uncontrolled hemorrhage.

Talmor D, Merkind V, Artru AA, Shapiro O, Geva D, Roytblat L, Shapira Y.
Division of Anesthesiology, Ben-Gurion University of the Negev, Faculty of Health Sciences,
Soroka Medical Center, Beer Sheva, Israel.

Anesth Analg. 1999 Oct;89(4):950-6.

Hemorrhagic hypotension may aggravate the detrimental effects of head trauma on neurologic outcome. Our study examined whether using phenylephrine or large volumes of saline IV to increase mean arterial blood pressure (MAP) to 70, 80, or 90 mm Hg during the combination of head trauma and uncontrolled hemorrhage would improve neurologic outcome. Rats were assigned to one of 17 groups. In Groups 1-5, the variables were head trauma (yes/no), hemorrhage (yes/no), 0 or 3 mL saline per milliliter of blood lost, and no target MAP. In Groups 6-11, hemorrhage was or was not combined with head trauma, and large volumes of saline were given IV to achieve target MAPs of 70, 80, or 90 mm Hg. Groups 12-17 were similar to Groups 6-11 except that phenylephrine was used rather than saline to achieve target MAPs. Saline increased blood loss at 2 h to approximately 16 and 25 mL at a MAP of 80 and 90 mm Hg respectively, increased (worsened) the neurodeficit score but not cerebral edema at 24 h, and decreased survival rate at 2 and 24 h. Because phenylephrine was fatal for 62 of 63 rats, group mean values for blood loss, neurodeficit score, and brain tissue specific gravity could not be calculated. We conclude that supporting MAP with either phenylephrine or large volumes of saline worsened the neurodeficit score and/or survival and did not affect cerebral edema formation in our rat model of head trauma combined with hemorrhage.

IMPLICATIONS: The results of this study indicate that maintaining mean arterial blood pressure at 70, 80, or 90 mm Hg with either phenylephrine or large volumes of saline worsened the neurodeficit score and/or survival and did not affect cerebral edema formation in our rat model of head trauma combined with hemorrhage.

Aggravated uncontrolled hemorrhage induced by intravenous fluid administration
Article in Swedish

Riddez L, Hahn R.
Kirurgkliniken, Stockholm.

Lakartidningen. 1999 Sep 15;96(37):3893-4.

A model of uncontrolled haemorrhage where a 0.5 mm laceration is made in the porcine abdominal aorta has shown outcome to be impaired by conventional fluid therapy given to restore blood volume. Findings in recent studies where the difference in blood flow rates, proximal vs. distal to the site of vascular lesion, was used as a measure of bleeding suggest the adverse effect of fluid therapy to be strongly associated with re-bleeding after primary haemostasis has occurred. Optimal survival is dependent on a fluid infusion rate ensuring balance between the risk of re-bleeding and the beneficial effects of fluid therapy on oxygen consumption.

Logistics of parental fluids in battlefield resuscitation

Peace FJ; Lyons WS.
Division of Surgery, Walter Reed Army Institute of Research,
Washington, DC 20307 USA

Military Medicine, 1999 Sept; 164(9):653-5.

The paper discusses the substantial reduction in weight and volume of the fluids of resuscitation that is possible and desirable on the basis of sound physiology and the vast experience of the U.S. Army in four major wars in this century. We note the major shift in emphasis from massive colloid and whole blood in World War II and Korea to massive crystalloid and packed cells in Vietnam and the serious complications with which this was associated. These complications were edematous in nature and best known as the Da Nang lung, or adult respiratory distress syndrome, multiorgan dysfunction syndrome, and systemic inflammatory response syndrome. The advantage of colloid in reducing the weight and volume of resuscitation fluids in forward areas by 60% to 90%, as well as in avoiding the edematous complications of crystalloids, are emphasized.

Prehospital Fluid Administration for Thoracic Trauma

Hyde AJ, Graham TR,

Pre-Hospital Immediate Care, 1999 June ;3:99-101

Fluid administration is an established component of resuscitation in cases of trauma. Often this occurs as part of a set protocol, and little thought is given to the pathophysiology of the underlying injury. This approach is often beneficial, particularly in hypovolaemic patients, and in the majority of cases will be harmless. Unfortunately, there are certain instances, particularly with thoracic trauma, when such an indiscriminate policy can be detrimental and even fatal. This has recently brought into question the whole issue of fluid resuscitation, and the concept of “hypotensive resuscitation has been introduced. This relies on fluid resuscitation only to the point of critical organ perfusion, and not beyond. Unless specifically indicated, fluids may be withheld until assessment in the emergency room. This policy not only prevents the potential for disastrous consequences of over transfusion, but reduces time spent at scene, and therefore expedites transfer.

Initial Resuscitation.

Mattox KL, Brundage SI, Hirshberg A.

New Horiz 1999 Spring;7(1): 4-9.

Initial resuscitation volume in uncontrolled hemorrhage: effects on organ function.

Haizlip TM Jr, Poole GV, Falzon AL.
Department of Surgery, University of Mississippi Medical Center,
Jackson 39216, USA.

American Surgeon 1999 Mar;65(3):215-7.

Conventional resuscitation of hypovolemia due to hemorrhage has consisted of aggressive fluid administration. Recent studies have suggested that surgical control of bleeding before fluid resuscitation might improve early survival. The effects of limited resuscitation on organ function have not been assessed in these studies. We developed a model of moderate intraperitoneal hemorrhage designed to evaluate long-term end-organ function after various resuscitation protocols. Male Sprague-Dawley rats underwent ketamine anesthesia, followed by placement of femoral artery and vein lines. Intraperitoneal hemorrhage was induced by division of distal branches of the ileocolic artery and vein. After 5 minutes of bleeding, the animals were randomized to one of three resuscitation groups: Group 1 received no fluid resuscitation before surgical control of the hemorrhage; Group 2 received 0.5 mL of lactated Ringer's solution (LR) every 5 minutes for a mean arterial pressure (MAP) of less than 80 mm Hg; Group 3 received 2.0 mL of LR every 5 minutes for a MAP of less than 80 mm Hg. In all three groups, after 20 minutes, the bleeding was surgically controlled. All rats were then resuscitated with LR to a MAP of 80 mm Hg. The intravascular lines were removed, and the rats were allowed to recover from anesthesia and were returned to animal holding. On the 7th day, survivors were sacrificed, and their blood was assayed for hematocrit and serum levels of bilirubin, alanine aminotransferase, urea nitrogen, and creatinine. Kidneys, lungs, and liver were harvested for microscopic examination. Survival was lower in Group 2 than in the other groups (90%, 60%, and 100%, respectively; P = 0.04), but all deaths occurred within 3 hours of hemorrhage and were due to either hypovolemia or anesthetic complications. No histologic abnormalities were identified in the livers of the animals that survived, but pulmonary atelectasis and mild-to-moderate renal tubular necrosis were identified uniformly. No histologic differences could be discerned between the groups. Hematocrit and indices of liver and renal function were similar in all groups, and no animal developed organ dysfunction. In this model of moderate uncontrolled intraperitoneal hemorrhage, the volume of fluid resuscitation, or the absence of resuscitation, had an inconsistent effect of 7-day survival and did not influence function or histologic appearance of the liver, lungs, or kidneys 7 days after hemorrhage.

Limited volume resuscitation in penetrating thoracoabdominal trauma.

de Guzman E. Shankar MN. Mattox KL.
Trauma Services, Ben Taub General Hospital,
Houston, TX 77030, USA.

AACN Clinical Issues. 1999 Feb;10(1):61-8,.

Trauma is the leading cause of death in young adults. Development of trauma centers in urban settings including emergency medical services has contributed greatly to the improved quality of trauma patient care. Based on animal experiments performed 3 decades ago, the traditional management of hypovolemic hemorrhagic shock includes adequate circulatory volume with aggressive initial infusion of crystalloid solution. However, in several recent animal studies, investigators have found that aggressive treatment with fluids before control of bleeding results in a higher mortality rate, especially if blood pressure is elevated. This notion has been supported by findings in a recent prospective, randomized study involving patients with penetrating injuries to the torso. This article discusses briefly the pathophysiology of shock and hemostasis and the current literature on fluid resuscitation, with emphasis on limited volume resuscitation in patients with penetrating thoracoabdominal injuries.

Controlled resuscitation for uncontrolled hemorrhagic shock

Burris D; Rhee P; Kaufmann C; Pikoulis E; Austin B; Eror A; DeBraux S; Guzzi L; Leppaniemi A.
Department of Surgery, Uniformed Services University of the Health Sciences,
Bethesda, Maryland 20814-4799 USA.

J Trauma, 1999 Feb;46(2):216-23

OBJECTIVE: To test the hypothesis that controlled resuscitation can lead to improved survival in otherwise fatal uncontrolled hemorrhage.

METHODS: Uncontrolled hemorrhage was induced in 86 rats with a 25-gauge needle puncture to the infrarenal aorta. Resuscitation 5 minutes after injury was continued for 2 hours with lactated Ringer's solution (LR), 7.3% hypertonic saline in 6% hetastarch (HH), or no fluid (NF). Fluids infused at 2 mL x kg(-1) x min(-1) were turned on or off to maintain a mean arterial pressure (MAP) of 40, 80, or 100 mm Hg in six groups: NF, LR 40, LR 80, LR 100, HH 40, and HH 80. Blood loss was measured before and after 1 hour of resuscitation.

RESULTS: Survival was improved with fluids. Preresuscitation blood loss was similar in all groups. NF rats did not survive 4 hours. After 72 hours, LR 80 rats (80%) and HH 40 rats (67%) showed improved survival over NF rats (0%) (p < 0.05). Rebleeding increased with MAP. Attempts to restore normal MAP (LR 100) led to increased blood loss and mortality.

CONCLUSION: Controlled resuscitation leads to increased survival compared with no fluids or standard resuscitation. Fluid type affects results. Controlled fluid use should be considered when surgical care is not readily available

The effects of varying fluid volume and rate of resuscitation during uncontrolled hemorrhage.

Soucy DM, Rudé M, Hsia WC, Hagedorn FN, Illner H, Shires GT.
Department of Surgery, Texas Tech University Health Sciences Center,
Lubbock 79430, USA

J Trauma, 1999 Feb;46(2):209-15.

BACKGROUND: The role of rate and volume of infusion in survival from experimental uncontrolled hemorrhage was evaluated.

METHODS: Hemorrhage was initiated using tail resection in 43 female rats assigned to the following five groups: nonresuscitated; resuscitated with moderate volume, slower rate; resuscitated with moderate volume, faster rate; resuscitated with high volume, slower rate; and resuscitated with high volume, faster rate.

RESULTS: A trend toward improved survival was noted with faster rate of infusion (60 vs. 33.3% survival rate with moderate volume and 28.6 vs. 12.5% with high volume, compared with 16.7% in the nonresuscitated animals).

CONCLUSION: Rapid infusion of moderate volume of isotonic saline improved survival in uncontrolled hemorrhage. Extreme volumes, infused rapidly, also resulted in higher survival rates compared with those observed in nonresuscitated rats

Reviewer’s note:
This is evidence against ‘permissive hypotension’ for uncontrolled bleeding. This group published other studies that similarly show decreased mortality with fluid infusion (Surgery, 1998 and Annals of Surgery, 1995 – both in this list).

Early isotonic saline resuscitation from uncontrolled hemorrhage in rats.

Greene SP, Soucy DM, Song WC, Barber AE, Hagedorn FN, Illner HP, Shires GT.
Department of Emergency Medicine, Texas Tech University Health Sciences Center,
El Paso, USA.

Surgery. 1998 Sep;124(3):568-74

BACKGROUND: Attempts to modify traditional fluid resuscitation have been based on animal models that evaluate several variables including anesthesia. This study presents the effects of early saline resuscitation from severe uncontrolled hemorrhage unanesthetized rats.

METHODS: Sixty-three female Sprague-Dawley rats were equally divided into three groups: group A, nonresuscitated; and groups B and C, resuscitated with isotonic saline (40 and 80 mL/kg, respectively). Hemodynamics, blood loss, survival time, and mortality were recorded for 360 minutes after the hemorrhage, which was initiated by 75% resection of the tail.

RESULTS: In group C, 80 mL/kg of saline significantly lowered mortality (24% vs 76% and 71% for groups A and B, respectively) with concomitant increases in mean survival time (241 +/- 103 min vs 146 +/- 108 and 175 +/- 92 min for groups A and B, respectively). There were no statistically significant differences in blood loss, hematocrit, or hemodynamic parameters among the groups.

CONCLUSIONS: Early and adequate isotonic saline resuscitation of unanesthetized rats improved outcome despite continuing hemorrhage. The significantly lower mortality rate and increased survival time were not a result of transiently improved arterial pressure and did not correlate with blood loss. No significant bleeding increases were noted in the resuscitated groups.

Reviewer’s Note:
Like other studies by this group, this demonstrates improve survival with fluid infusion, in a rat experiment of uncontrolled bleeding. Their findings are opposite to those found by other researchers.

Delayed fluid resuscitation of head injury and uncontrolled hemorrhagic shock.

Bourguignon PR, Shackford SR, Shiffer C, Nichols P, Nees AV.
Department of Surgery, University of Vermont College of Medicine,
Burlington 05401, USA.

Archives of Surgery. 1998 Apr;133(4):390-8.

OBJECTIVE: To evaluate the effects of delayed vs early fluid resuscitation on cerebral hemodynamics after severe head injury and uncontrolled hemorrhagic shock.

DESIGN: Prospective, randomized, controlled experimental trial.

SETTING: Surgical research laboratory.

PARTICIPANTS: Immature swine (N=16) weighing 40 to 50 kg.

INTERVENTIONS: Twelve swine were subjected to cryogenic brain lesion and hemorrhage to maintain a mean arterial pressure (MAP) of 50 mm Hg. Animals were randomized to receive 1 L of Ringer lactate solution in 20 minutes, starting 20 minutes after injury and hemorrhage, followed by 1 L of Ringer lactate solution in 30 minutes (ER group) (n=6), or no fluid resuscitation (DR group) (n=6). The 4 control animals underwent instrumentation only. The study ended 70 minutes after head injury and hemorrhage.

MAIN OUTCOME MEASUREMENTS: Measurements of MAP, bilateral regional cerebral blood flow, serum hemoglobin level, systemic and regional cerebral oxygen delivery, and intracranial pressure performed at baseline and 20 (phase 1), 50 (phase 2), and 70 minutes (phase 3) after head injury and hemorrhage. Lesion size (percentage of ipsilateral cortex) was measured post mortem.

RESULTS: All animals survived the experimental period. Systemic cerebral oxygen delivery in the DR group was significantly lower at phase 3 compared with that of the ER group (31.5% vs 53.1% at baseline) (P=.03). However, bilateral regional cerebral oxygen delivery was significantly greater in the DR group at phase 3 compared with that of the ER group (71.5% vs 47.0% at baseline in the injured side; 72.9% vs 48.4% at baseline in the noninjured side) (P=.02). Bilateral cerebral blood flow was similar in all groups at all times. The ER group showed a trend toward a greater intracranial pressure elevation (6.8 vs -0.25) (P=.07) and lesion size (37.0% vs 28.6%) (P=.07). Hemoglobin level became significantly lower in the ER group at phase 2 (7.0 vs 10.7) (P=.03) and remained lower at phase 3 (6.9 vs 11.7) (P=.01).

CONCLUSIONS: Early fluid resuscitation with Ringer lactate solution following head injury and uncontrolled hemorrhagic shock worsens cerebral hemodynamics. Cerebral pressure autoregulation is sufficiently intact following head injury to maintain regional cerebral oxygen delivery without asanguineous fluid resuscitation.

Reviewer’s note:
They found that routine aggressive resuscitation (with Ringer's Lactate) in uncontrolled hemorrhage with severe head injury worsens cerebral hemodynamic parameter. Such fluid administration and could possibly contribute to secondary brain injury.

Resuscitation after uncontrolled venous hemorrhage: Does increased resuscitation volume improve regional perfusion?

Smail N, Wang P, Cioffi WG, Bland KI, Chaudry IH.
Center for Surgical Research and Department of Surgery,
Brown University School of Medicine and Rhode Island Hospital, Providence 02903, USA.

J Trauma. 1998 Apr;44(4):701-8.

BACKGROUND: Recent studies have questioned the use of aggressive fluid resuscitation after uncontrolled arterial hemorrhage until the bleeding is controlled. However, it remains unknown whether resuscitation after hemorrhage from a venous origin (usually nonaccessible to surgical intervention) has any beneficial or deleterious effects on regional perfusion. The aim of this study, therefore, was to determine whether increased volume of fluid resuscitation after uncontrolled venous hemorrhage improves hemodynamic profile and regional perfusion in various tissues.

MATERIALS AND METHODS: After methoxyflurane anesthesia and midline laparotomy, both lumbar veins in the rat were severed, which resulted in lowering the mean arterial blood pressure to approximately 40 mm Hg. This pressure was maintained for 45 minutes by allowing further bleeding from the lumbar veins. The abdominal incision was then closed in layers and the animals received either 0, 10, or 30 mL of lactated Ringer's solution intravenously over a period of 60 minutes. Cardiac output and regional blood flow were determined by radioactive microspheres immediately or at 1.5 hours after the completion of resuscitation.

RESULTS: Fluid resuscitation with 10 or 30 mL lactated Ringer's solution increased mean arterial blood pressure and cardiac output immediately after resuscitation compared with the nonresuscitated animals. At both time points, regional perfusion in the heart, kidney and intestines remained significantly decreased compared with the sham values, irrespective of the volume of fluid resuscitation. Moreover, no further improvements in hemodynamics or regional perfusion occurred when volume resuscitation was increased from 10 mL to 30 mL. Total hepatic blood flow, however, increased with 10 mL lactated Ringer's solution compared with the other hemorrhage groups and the increase was evident even at 1.5 hours after resuscitation.

CONCLUSIONS: Fluid resuscitation after uncontrolled venous bleeding transiently increased cardiac output and mean arterial blood pressure compared with nonresuscitated animals. Moderate fluid administration, i.e., 10 mL, however, did increase total hepatic blood flow. In contrast, increasing the resuscitation volume to 30 mL did not improve hemodynamic parameters or regional perfusion. Thus moderate instead of no resuscitation or larger volume of resuscitation is recommended in an uncontrolled model of venous hemorrhage.

Central and regional hemodynamics during crystalloid fluid therapy after uncontrolled intra-abdominal bleeding.

Riddez L, Johnson L, Hahn RG.

J Trauma 1998 Mar;44:433-439

OBJECTIVE: To study the effect of graded crystalloid fluid resuscitation on central hemodynamics and outcome after intra-abdominal hemorrhage.

METHODS: Ten minutes after a 5-mm long laceration was produced in the infrarenal aorta, 32 pigs were randomized to receive either no fluid or Ringer's solution in the proportion 1:1, 2:1, or 3:1 to the expected amount of blood lost per hour (26 mL kg[-1]) over 2 hours. The hemodynamics were studied using arterial and pulmonary artery catheters and four blood flow probes placed over major blood vessels.

RESULTS: During the first 40 minutes after the injury, the respective blood flow rates in the distal aorta were 39% (no fluid), 41% (1:1), 56% (2:1), and 56% (3:1) of the baseline flow. Fluid resuscitation increased cardiac output but had no effect on arterial pressure, oxygen consumption, pH, or base excess. Rebleeding occurred only with the 2:1 and 3:1 fluid programs. Survival was highest with the 1:1 and 2:1 programs.

CONCLUSIONS: Crystalloid fluid therapy improved the hemodynamic status but increased the risk of rebleeding. Therefore, a moderate fluid program offered the best chance of survival Reviewer’s note: The authors wanted to test the "low fluid hypothesis" of transport. Limited volume resuscitation was more likely to result in survival than fluid therapy at the standard 3 litres given:1litre of lost blood ratio. (Then) standard resuscitation caused a higher bleeding rate.

Hypothermia from realistic fluid resuscitation in a model of hemorrhagic shock.

Silbergleit R, Satz W, Lee DC, McNamara RM.
Department of Emergency Medicine, George Washington University,
Washington, DC, USA.

Annals of Emergency Medicine 1998 Mar;31(3):339-43.

STUDY OBJECTIVE: To correlate changes in core body temperature with changes in mean arterial pressure (MAP) and cardiac output (CO) and with the administration of room-temperature intravenous fluids in a clinically relevant large-animal model of uncontrolled hemorrhage.

METHODS: Ten swine were subjected to uncontrolled hemorrhage through a flow-monitored shunt placed between the femoral artery and the peritoneal cavity. Animals were randomly assigned to a treatment or a control group. The control group (n=5) received no intravenous fluids. The treatment group (n=5) received 80 mL/kg (3:1 crystalloid/blood loss) ambient-temperature lactated Ringer's solution over a 10-minute resuscitation phase initiated 10 minutes after injury. CO and core body temperature, measured with the use of a pulmonary artery catheter, and MAP were the primary outcomes. We analyzed differences between groups with the use of repeated-measures ANOVA. Change of temperature was analyzed against the change in CO, and against fluid infusion for each interval, by means of regression analysis.

RESULTS: The unresuscitated control animals had no change in core temperature despite profound hemorrhagic shock and hypotension. The animals treated with fluids had a mean 2.6 degrees C decrease in core temperature during fluid resuscitation (95% confidence interval [CI], 1.8 to 3.5). A 1.5 degrees C decrease in core temperature (95% CI, .1 to 2.0) persisted at the end of 60 minutes (40 minutes after fluid resuscitation was discontinued). Core temperatures in control animals were 2.8 degrees C lower than those in treated animals after fluid resuscitation (95% CI, .8 to 4.8). Decreases in core temperature correlated with fluid infusion (beta=-35.2 mL/kg x degrees C, R2=.75) and increases in CO (beta=-1.46 L/min x degrees C, R2=.69).

CONCLUSION: Ambient-temperature crystalloid resuscitation in a clinically relevant large-animal model of hemorrhagic shock causes small decreases in core body temperature. Resuscitation rather than shock is the main cause of decreased body temperature in this model.

Reappraising the prehospital care of the patient with major trauma.

Pepe PE, Eckstein M.
Department of Emergency Medicine, Allegheny University of the Health Sciences,
Pittsburgh, Pennsylvania, USA.

Emerg Med Clin North Am. 1998 Feb;16(1):1-15.

Recent research efforts have demonstrated that many long-standing practices for the prehospital resuscitation of trauma patients may be inappropriate, particularly in certain circumstances. Traditional practices, such as application of antishock garments and IV fluid administration, may even be detrimental in certain patients with uncontrolled bleeding. Endotracheal intubation, although potentially capable of prolonging a patient's ability to tolerate circulatory arrest, may be harmful if overzealous ventilation further compromises cardiac output in such