Resuscitation beyond the abdominal compartment syndrome.

PURPOSE OF REVIEW: In the 1980s, we witnessed tremendous advances in trauma care including trauma system development, advanced trauma life support, damage control surgery and ICU resuscitation. As a result, patients who used to bleed to death in the operating room survived. However, many went on to develop multiple organ failure (MOF) and in the mid-1990s, an epidemic of abdominal compartment syndrome (ACS) that emerged in these MOF survivors stimulated fundamental changes in early management of patients arriving in shock with severe bleeding. RECENT FINDINGS: In the early 2000s, a massive transfusion protocol (emphasizing aggressive use of fresh frozen plasma) coupled with hypotensive resuscitation and rapid hemorrhage control were implemented and refined at a busy level I trauma center in Houston, Texas, USA. These changes were associated with a 50% reduction in mortality in massive transfusion patients, and ACS virtually disappeared. SUMMARY: ACS is a modifiable link in the MOF cascade to death after severe shock. However, as ACS disappears, MOF is still occurring. Although fewer patients are dying of MOF, it remains the leading cause of prolonged ICU stays and long-term disability. This experience underscores the importance of ongoing epidemiologic characterization of postinjury MOF.

Performance of a computerized protocol for trauma shock resuscitation.

BACKGROUND: A computerized protocol was developed and used to standardize bedside clinician decision making for resuscitation of shock due to severe trauma during the first day in the intensive care unit (ICU) at a metropolitan Level I trauma center. We report overall performance of a computerized protocol for resuscitation of shock due to severe trauma, incorporating two options for resuscitation monitoring and intervention intensity, according to: (1) duration of use and (2) acceptance of computerized protocol-generated instructions. METHODS: A computerized protocol operated by clinicians, using a personal computer (PC) at the bedside, was used to guide clinical decision making for resuscitation of patients meeting specific injury and shock criteria. The protocol generated instructions that could be accepted or declined. Clinician acceptance of the protocol instructions was stored by the PC software in a database for each patient. A rule-based, data-driven protocol was developed using literature evidence, expert opinion, and ongoing protocol performance analysis. Logic-flow diagrams were used to facilitate communication among multidisciplinary protocol development team members. The protocol was computerized using standard programming methods and implemented using cart-mounted PCs with a touch screen and keyboard interfaces. Protocol progression began with patient demographic data and criteria entry, confirmation of hemodynamic monitor instrumentation, request for specific hemodynamic performance data, and instructions for specific interventions (or no intervention). Use and performance of the computerized protocol was recorded in a protocol execution database. The protocol was continuously maintained with new literature evidence and database performance analysis findings. Initially implemented in 2000, the computerized protocol was refined in 2004 with two options for resuscitation intensity: pulmonary artery catheter- and central venous pressure-directed resuscitation. RESULTS: Over 2 years ending at August 2006, a total of 193 trauma patients (mean Injury Severity Score was 27, survival rate 89%) were resuscitated using the computerized protocol. Protocol duration was 4400 hours or 22.7 +/- 0.4 hours per patient. The computerized protocol generated 3724 instructions (19 +/- 1 per patient) that required a bedside clinician response. In all, 94% of these instructions were accepted by the bedside clinician users. CONCLUSIONS: A computerized protocol to guide decision making for trauma shock resuscitation in a Level 1 trauma center surgical ICU was developed and used as standard of care. During 2 years ending at August 2006, 94% of computer-generated instructions for specific interventions or measurements of hemodynamic performance were accepted by bedside clinicians, indicating appropriate, useful design and reliance on the computerized protocol system.

Increased plasma and platelet to red blood cell ratios improves outcome in 466 massively transfused civilian trauma patients.

OBJECTIVE: To determine the effect of blood component ratios in massive transfusion (MT), we hypothesized that increased use of plasma and platelet to red blood cell (RBC) ratios would result in decreased early hemorrhagic death and this benefit would be sustained over the ensuing hospitalization. SUMMARY BACKGROUND DATA: Civilian guidelines for massive transfusion (MT > or =10 units of RBC in 24 hours) have typically recommend a 1:3 ratio of plasma:RBC, whereas optimal platelet:RBC ratios are unknown. Conversely, military data shows that a plasma:RBC ratio approaching 1:1 improves long term outcomes in MT combat casualties. There is little consensus on optimal platelet transfusions in either civilian or military practice. At present, the optimal combinations of plasma, platelet, and RBCs for MT in civilian patients is unclear. METHODS: Records of 467 MT trauma patients transported from the scene to 16 level 1 trauma centers between July 2005 and June 2006 were reviewed. One patient who died within 30 minutes of admission was excluded. Based on high and low plasma and platelet to RBC ratios, 4 groups were analyzed. RESULTS: Among 466 MT patients, survival varied by center from 41% to 74%. Mean injury severity score varied by center from 22 to 40; the average of the center means was 33. The plasma:RBC ratio ranged from 0 to 2.89 (mean +/- SD: 0.56 +/- 0.35) and the platelets:RBC ratio ranged from 0 to 2.5 (0.55 +/- 0.50). Plasma and platelet to RBC ratios and injury severity score were predictors of death at 6 hours, 24 hours, and 30 days in multivariate logistic models. Thirty-day survival was increased in patients with high plasma:RBC ratio (> or =1:2) relative to those with low plasma:RBC ratio (<1:2) (low: 40.4% vs. high: 59.6%, P < 0.01). Similarly, 30-day survival was increased in patients with high platelet:RBC ratio (> or =1:2) relative to those with low platelet:RBC ratio (<1:2) (low: 40.1% vs. high: 59.9%, P < 0.01). The combination of high plasma and high platelet to RBC ratios were associated with decreased truncal hemorrhage, increased 6-hour, 24-hour, and 30-day survival, and increased intensive care unit, ventilator, and hospital-free days (P < 0.05), with no change in multiple organ failure deaths. Statistical modeling indicated that a clinical guideline with mean plasma:RBC ratio equal to 1:1 would encompass 98% of patients within the optimal 1:2 ratio. CONCLUSIONS: Current transfusion practices and survival rates of MT patients vary widely among trauma centers. Conventional MT guidelines may underestimate the optimal plasma and platelet to RBC ratios. Survival in civilian MT patients is associated with increased plasma and platelet ratios. Massive transfusion practice guidelines should aim for a 1:1:1 ratio of plasma:platelets:RBCs.

Effects of poloxamer 188 on human PMN cells.

BACKGROUND: Poloxamer 188 (P188), a nonionic block copolymer chemical surfactant known to have cytoprotective, rheologic, anti-inflammatory, and anti-thrombotic activity, has shown promise in the management of selected trauma patients. We studied human PMN oxidative burst and adhesion molecule expression when exposed to P188. METHODS: After RBC lysis of whole blood samples, white blood cell components were primed with phosphotidylcholine, primed and activated with fMLP, primed and activated with PMA, or left unstimulated. Each group was treated with vehicle or P188 (0.005-15 mg/ml concentrations). Flow cytometry quantified: (1) PMN superoxide anion production and (2) PMN marker expression of CD11b and L-selectin. RESULTS: Among non-PMA activated PMNs, P188 increased superoxide anion production. PMA-activated PMNs decreased superoxide anion production, proportional to P188 dose. Among fMLP-activated PMNs, the highest P188 dose increased the expression of CD11b. Among PMA-activated PMNs, decreased CD11b expression was seen for the mid-range doses. CONCLUSIONS: PMNs altered their oxidative burst and marker expression after exposure to P188. When used at lower doses, P188 may increase the oxidative burst response and, when used at very high doses, increase CD11b expression. However, if PMNs are in a maximally activated state, a higher dose of P188 may decrease the oxidative burst response and decrease CD11b expression.

Acute lower extremity compartment syndrome (ALECS) screening protocol in critically ill trauma patients.

BACKGROUND: Acute lower extremity compartment syndrome (ALECS) is a devastating complication that often presents silently in critically injured patients; therefore, we developed a protocol to screen high-risk patients. METHODS: This prospective observational study included all Shock Trauma intensive care unit patients who met specific high-risk criteria including pulmonary artery catheter-directed shock resuscitation, open or closed tibial shaft fracture, major vascular injury below the aortic bifurcation, abdominal compartment syndrome, or pelvic or lower extremity crush injury. Patients were screened at admission and every 4 hours thereafter for the first 48 hours of admission. Screening included physical examination (PE) and anterior or deep posterior calf compartment pressure measurements when PE was suspicious or unreliable. A positive screening, defined as a DeltaP <30 mm Hg (where DeltaP is the difference between the diastolic blood pressure and the compartment pressure), mandated a four-compartment fasciotomy. RESULTS: During a 6-month period, the incidence of ALECS in screened patients was surprisingly high at 20% (9 patients). With diligent screening, it was diagnosed early in the patient's Shock Trauma intensive care unit course. These were patients with severe injuries with an Injury Severity Score of 32.0 +/- 12.5 who exhibited significant volume depletion, with a base deficit of 12.9 +/- 5.9 mEq/L and a lactate level of 13.0 +/- 5.2 mmol/L, requiring large volume resuscitation. Although aggressive fasciotomy resulted in no limb loss, ALECS was associated with an exceedingly high mortality rate at 67%. CONCLUSIONS: ALECS is an important clinical entity in critically injured patients with trauma associated with significant mortality. Aggressive screening may provide some diagnostic insight to those at risk.

A multidisciplinary clinical pathway decreases rib fracture-associated infectious morbidity and mortality in high-risk trauma patients.

BACKGROUND: We initiated a multidisciplinary clinical pathway targeting patients greater than 45 years of age with more than 4 rib fractures. The purpose of the current study was to evaluate the effect of this pathway on infectious morbidity and mortality. METHODS: This was a prospective cohort study. Data evaluated included patient demographics, injury characteristics, pain management details, lengths of stay, morbidity, and mortality. Univariate and multivariate analyses were performed using a significance level of P < .05. RESULTS: When adjusting for age, injury severity score, and number of rib fractures, the clinical pathway was associated with decreased intensive care unit length of stay by 2.4 days (95% confidence interval [CI] -4.3, -0.52 days, P = .01) hospital length of stay by 3.7 days (95% CI -7.1, -0.42 days, P = .02), pneumonias (odds ratio [OR] 0.12, 95% CI 0.04 to 0.34, P < .001), and mortality (OR 0.37, 95% CI 0.13 to 1.03, P = .06). CONCLUSIONS: Implementation of a rib fracture multidisciplinary clinical pathway decreased mechanical ventilator-dependent days, lengths of stay, infectious morbidity, and mortality.

Early predictors of prolonged mechanical ventilation in major torso trauma patients who require resuscitation.

BACKGROUND: The study purpose was to identify early predictors of prolonged mechanical ventilation in major torso trauma patients. METHODS: This was a retrospective review of torso trauma patients who met specific criteria for shock resuscitation and required 48 hours of mechanical ventilation. Independent variables evaluated included patient demographics, injury characteristics, and initial 24-hour resuscitation parameters. Univariate and multivariate logistic regression analyses were performed using a significance level of P <.05. RESULTS: Over 59 months, 224 patients met study criteria. Age was 34 years (range 25 to 69), 68% were male, 78% sustained blunt trauma, and injury severity score was 27 (range 18 to 38). Thirty-three percent required prolonged mechanical ventilation. In the analysis, predictors of prolonged mechanical ventilation included total fluid resuscitation, facial trauma, age, positive end-expiratory pressure > or =10 mm Hg on admission, arterial partial pressure of oxygen divided by the fraction of inspired oxygen ratio less than 300 at 24 hours, and chest abbreviated injury scale score. CONCLUSIONS: The need for prolonged mechanical ventilation can be accurately predicted and these predictors may assist clinicians in resource allocation and patient management decisions.

Ketamine attenuates liver injury attributed to endotoxemia: role of cyclooxygenase-2.

BACKGROUND: Endotoxic shock can cause end-organ dysfunction and liver injury. Critically ill patients frequently require surgical intervention under general anesthesia for source control. However, the effects of anesthetics on organ function during sepsis and their influence on inflammatory mediators such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) remain to be fully elucidated. Because ketamine anesthesia has anti-inflammatory effects in some tissues, we hypothesized that it would attenuate lipopolysaccharide (LPS)-induced liver injury. METHODS: Adult rats were given no anesthesia (saline), continuous isoflurane inhalation, or intraperitoneal (i.p.) injection of ketamine 70 mg/kg. One hour later, the rats received saline or LPS (20 mg/kg i.p.) for 5 hours. The rats were killed, and serum hepatocellular enzymes, liver COX-2, iNOS protein (Western immunoblot), and nuclear factor kappa B (NF-kappaB)-binding activity (electrophoretic mobility shift assay) determined. In a separate study, the role of COX-2 in LPS-induced liver injury was examined by pretreating rats with the selective COX-2 inhibitor NS-398 (3 mg/kg, i.p.) and the role of iNOS examined with the use of the selective inhibitor aminoguanidine (45 mg/kg, i.p.) 1 hour before LPS. RESULTS: LPS increased serum aspartate aminotransferase and alanine aminotransferase levels, hepatic iNOS and COX-2 protein, and nuclear factor NF-kappaB. Ketamine, but not isoflurane, attenuated these effects caused by LPS. COX-2 inhibition with NS-398 as well as iNOS inhibition with aminoguanidine diminished LPS-induced changes in aspartate aminotransferase and alanine aminotransferase levels. CONCLUSIONS: These data indicate that anesthetics differ in their effects on liver injury caused by LPS. Ketamine has hepatoprotective effects, while isoflurane does not. Moreover, the protective effects of ketamine are mediated, at least in part, through a reduction in COX-2 and iNOS protein that could be regulated via changes in NF-kappaB-binding activity.

Seroma formation following breast cancer surgery.

A seroma is the most frequent complication of breast cancer surgery, the etiology of which remains obscure. We reviewed our data to determine the factors related to the incidence of seroma formation in our patients. A retrospective analysis of the records of 359 consecutive patients (334 Hispanic; 93%) who underwent primary surgical therapy from January 1, 1996 to December 31, 2000, with either modified radical mastectomy (MRM) or wide local excision (WLE) and axillary lymph node dissection (ALND) was performed. In all cases, removal of the breast was performed using electrocoagulation, and sharp dissection was used in the axilla. One-eighth inch closed suction round drains were used. Early arm motion was encouraged. The seroma rate was compared to the age of the patient, the presence and number of positive axillary lymph nodes, the total number of axillary lymph nodes removed, tumor size, weight of the patient, the use of neoadjuvant chemotherapy, and the type of surgery performed. The overall seroma rate was 15.8%. Seromas occurred in 19.9% of patients undergoing MRM and in 9.2% of patients undergoing breast-conserving surgery (p=0.01). The seroma rate was not influenced by any other tested variables. All seromas were easily managed with aspiration and pressure; this technical maneuver allowed seroma resolution in all patients except one following one to six aspirations. A seroma did not delay initiation of chemotherapy. No patient developed a capsule requiring excision. In our experience, a seroma is a "necessary evil;" it will occur unpredictably in a predictable number of patients.