Tissue oxygen saturation predicts the development of organ dysfunction during traumatic shock resuscitation

BACKGROUND

Near-infrared spectroscopy (NIRS) can continuously and noninvasively monitor tissue oxygen saturation (StO2) in muscle and may be an indicator of shock severity. Our purpose was to evaluate how well StO2 predicted outcome in high-risk torso trauma patients presenting in shock.

METHODS

The primary outcome in this prospective study was multiple organ dysfunction syndrome (MODS). StO2 data were obtained upon hospital arrival and for 24 hours along with other known predictors of hypoperfusion and clinical outcomes. Clinicians were blinded to StO2 measurements.

RESULTS

Seven Level I trauma centers enrolled 383 patients, 50 of whom developed MODS. Minimum StO2 performed similarly to maximum base deficit (BD) in discrimination of MODS patients. The sensitivity for both measures (StO2 cutoff = 75%; BD cutoff = 6 mEq/L) was 78%, the specificity was 34% to 39%, the positive predictive value was 18% to 20% and the negative predictive value was 88% to 91%. StO2 and BD were also comparable in predicting death.

CONCLUSIONS

NIRS-derived muscle StO2 measurements perform similarly to BD in identifying poor perfusion and predicting the development of MODS or death after severe torso trauma, yet have the additional advantages of being continuous and noninvasive.

Trauma deaths in the first hour: are they all unsalvageable injuries?

BACKGROUND

With the advent of trauma systems, time to definitive care has been decreased. We hypothesized that a subset of patients who are in extremis from the time of prehospital transport to arrival at the trauma center, and who ultimately die early after arrival, may in fact have a potentially salvageable single-organ injury.

METHODS

We reviewed all deaths that occurred in the first hour after hospital admission. Trauma registry, medical records, and autopsy reports for 556 patients were evaluated.

RESULTS

The median time to arrival was 39 minutes, and the median Injury Severity Score was 29. Blunt injuries (53%) were most commonly auto-accident injuries (134 of 285 patients; 47%). Penetrating wounds (42%) were mostly gunshot wounds to the chest (73 of 233 patients; 31%). For patients with initial vital signs, the most common cause of death was isolated brain injury (26 patients; 28%). Possibly survivable injuries (single organ or vessel) occurred in 35 (38%) patients, of which 4 were isolated spleen injuries (4%).

CONCLUSIONS

Some patients with potentially survivable single organ injuries did not have associated head injuries. An aggressive approach is warranted on patients with detectable vital signs on at least one occasion in the field but who arrive at the trauma center in extremis.

A large single-center experience with treatment of patients with crotalid envenomations: outcomes with and evolution of antivenin therapy

BACKGROUND

Antivenin (crotalid) polyvalent (ACP; Antivenin Crotalidae Polyvalent; Wyeth, Melville, NY) is associated with frequent allergic reactions. Allergic reactions are fewer with ovine Fab antivenin (FabAV). This study describes the management of crotalid envenomations in patients treated with FabAV or ACP, and without antivenin.

METHODS

We performed a retrospective chart review of crotalid envenomations over 10 years. Demographic data, hematologic profiles, details of antivenin administration, and in-hospital morbidity and mortality were collected.

RESULTS

There were no mortalities and a single amputation. Fewer fasciotomies were performed in the FabAV (9%) group versus the ACP group (24%). Mean hospital stay was 3.4 days. No allergic reactions were associated with FabAV. Fourteen of 211 reactions were associated with ACP (P < .001). Coagulopathy was frequent.

CONCLUSIONS

FabAV represents an improvement in management of crotalid envenomations because of reduced allergic reactions. Serious morbidity and mortality is rare. Coagulopathy is frequent but bleeding is not. Limb salvage is high. Surgical debridement and ACP are contraindicated when FabAV is available.

Is there an optimal time for laparoscopic cholecystectomy in acute cholecystitis?

BACKGROUND

Laparoscopic cholecystectomy (LC) is safe in acute cholecystitis, but the exact timing remains ill-defined. This study evaluated the effect of timing of LC in patients with acute cholecystitis.

METHODS

Prospective data from the hospital registry were reviewed. All patients admitted with acute cholecystitis from June 1994 to January 2004 were included in the cohort.

RESULTS

Laparoscopic cholecystectomy was attempted in 1,967 patients during the study period; 80% were women, mean patient age was 44 years (range, 20-73 years). Of the 1,967 LC procedures, 1,675 were successful, and 292 were converted to an open procedure (14%). Mean operating time for LC was 1 h 44 min (SD +/- 50 min), versus 3 h 5 min (SD +/- 79 min) when converted to an open procedure. Average postoperative length of stay was 1.89 days (+/- 2.47 days) for the laparoscopic group and 4.3 days (+/- 2.2 days) for the conversion group. No clinically relevant differences regarding conversion rates, operative times, or postoperative length of stay were found between patients who were operated on within 48 h compared to those patients who were operated on post-admission days 3-7.

CONCLUSIONS

The timing of laparoscopic cholecystectomy in patients with acute cholecystitis has no clinically relevant effect on conversion rates, operative times, or length of stay.

Transparent and open discussion of errors does not increase malpractice risk in trauma patients

OBJECTIVE

We set out to determine if there is an increased medical malpractice lawsuit rate when trauma patient cases are presented at an open, multidisciplinary morbidity and mortality conference (M&M).

INTRODUCTION

Patient safety proponents emphasize the importance of transparency with respect to medical errors. In contrast, the tort system focuses on blame and punishment, which encourages secrecy. Our question: Can the goals of the patient safety movement be met without placing care providers and healthcare institutions at unacceptably high malpractice risk?

METHODS

The trauma registry, a risk management database, along with the written minutes of the trauma morbidity and mortality conference (M&M) were used to determine the number and incidence of malpractice suits filed following full discussion at an open M&M conference at an academic level I trauma center.

RESULTS

A total of 20,749 trauma patients were admitted. A total of 412 patients were discussed at M&M conference and a total of seven lawsuits were filed. Six of the patients were not discussed at M&M prior to the lawsuit being filed. One patient was discussed at M&M prior to the lawsuit being filed. The incidence of lawsuit was calculated in three groups: all trauma patients, all trauma patients with complications, and all patients presented at trauma M&M conference. The ratio of lawsuits filed to patients admitted and incidence in the three groups is as follows: All Patients, 7 lawsuits/20,479 patients (4.25 lawsuits/100,000 patients/year); M&M Presentation, 1 lawsuit/421 patients (29.6 lawsuits/100,000 patients/year); All Trauma Complications, 7 lawsuits/6,225 patients (14 lawsuits/100,000 patients/year). Patients with a complication were more likely to sue (P < 0.01); otherwise, there were no statistical differences between groups.

CONCLUSIONS

A transparent discussion of errors, complications, and deaths does not appear to lead to an increased risk of lawsuit.

Senior Medical Student “Boot Camp”: Can Result in Increased Self-Confidence Before Starting Surgery Internships

OBJECTIVE

Surgical residents often begin the internship without prerequisite skills necessary for appropriate patient care. The purpose of this study was to develop a surgical internship readiness elective or senior medical student (SMS) "Boot Camp" for fourth-year medical students to prepare them for the rigors of surgery internship.

DESIGN

Sixteen fourth-year medical students completed a series of clinical and didactic sessions over a 4-week elective. Students evaluated the effectiveness of the elective with a pre- and post-survey that focused on confidence levels in 4 areas: anatomic dissection, administrative skills, technical skills, and patient management. Students also participated in a focus group session that identified strengths and weaknesses of the elective. Students were also assessed on performance by anesthesiology faculty in the mock patient code and by nursing faculty in mock nursing page sessions.

RESULTS

Upon completion of the elective, students rated themselves as more confident in all 57 categories on the survey. During the focus group session, students identified several strengths of the elective and offered recommendations for improvements in the elective.

CONCLUSION

The SMS "Boot Camp" gave fourth-year medical students confidence and an opportunity to develop necessary prerequisite skills to begin the surgery internship.

Novel computed tomography scan scoring system predicts the need for intervention after splenic injury

BACKGROUND

The purpose of this study was to develop a computed tomography (CT) scan screening test to predict the need for intervention in patients with splenic injury.

METHODS

CT scans of 20 patients with blunt injury to the spleen were reviewed to identify findings that correlated with the need for intervention (surgery or embolization). A screening test was created and then validated in CT scans from 56 consecutive patients.

RESULTS

Three findings correlated with the need for intervention: 1) devascularization or laceration involving 50% or more of the splenic parenchyma, 2) contrast blush greater than one centimeter in diameter (from active extravasation of intravenous contrast material or pseudoaneurysm formation), and 3) a large hemoperitoneum. The sensitivity of the screening test was 100%, specificity was 88%, and overall accuracy was 93%.

CONCLUSIONS

These CT scan grading criteria appears to reliably predict the need for invasive management in patients with blunt injury to the spleen.

The effect of antipyretic therapy upon outcomes in critically ill patients: a randomized, prospective study

BACKGROUND

Despite the large body of evidence suggesting a beneficial role of fever in the host response, antipyretic therapy is commonly employed for febrile critically ill patients. Our objective was to evaluate the impact of antipyretic therapy strategies on the outcomes of critically ill patients.

METHODS

Patients admitted to the Trauma Intensive Care Unit over a nine-month period were eligible for inclusion, except those with traumatic brain injury. Patients were randomized on day three of the ICU stay into aggressive or permissive groups. The aggressive group received acetaminophen 650 mg every 6 h for temperature of >38.5 degrees C and a cooling blanket was added for temperature of >39.5 degrees C. The permissive group received no treatment for temperature of >38.5 degrees C, but instead had treatment initiated at temperature of >40 degrees C, at which time acetaminophen and cooling blankets were used until temperature was <40 degrees C. Patient demographics, daily temperatures, systemic inflammatory response syndrome (SIRS) scores, multiple organ dysfunction syndrome (MODS) scores, and infections and complications were recorded.

RESULTS

Between December, 2002 and September, 2003, 572 patients were screened, of whom 82 met criteria for enrollment. Forty-four patients were randomized to the aggressive group and 38 patients were randomized to the permissive group for a total of 961 and 751 ICU days, respectively. There were 131 infections in the aggressive group and 85 infections in the permissive group (4 +/- 6 vs. 3 +/- 2 infections per patient, p = 0.26). There were seven deaths in the aggressive group and only one death in the permissive group (p = 0.06, Fisher Exact Test). The study was stopped after the first interim analysis due to the mortality difference, related to the issues of waiver of consent and the mandate for minimal risk.

CONCLUSIONS

Aggressively treating fever in critically ill patients may lead to a higher mortality rate.

Effects of arginine vasopressin during resuscitation from hemorrhagic hypotension after traumatic brain injury

OBJECTIVE

Two series of experiments were designed to evaluate whether early arginine vasopressin improves acute outcome following resuscitation from traumatic brain injury and severe hemorrhagic hypotension.

DESIGN

Prospective randomized, blinded animal study.

SETTING

University laboratory.

SUBJECTS

Thirty-three swine.

INTERVENTIONS

In series 1 (n = 19), after traumatic brain injury with hemorrhage and 12 mins of shock (mean arterial pressure approximately 20 mm Hg), survivors (n = 16) were initially resuscitated with 10 mL/kg crystalloid. After 30 mins, crystalloid and blood with either 0.1 unit x kg(-1) x hr(-1) arginine vasopressin or placebo was titrated to a mean arterial pressure target >or=60 mm Hg. After 90 mins, all received mannitol and the target was cerebral perfusion pressure >or=60 mm Hg. To test cerebrovascular function, 7.5% inhaled CO2 was administered periodically. In series 2 (n = 14), the identical protocol was followed except the shock period was 20 mins and survivors (n = 10) received a bolus of either arginine vasopressin (0.2 units/kg) or placebo during the initial fluid resuscitation.

MEASUREMENTS AND MAIN RESULTS

In series 1, by 300 mins after traumatic brain injury with arginine vasopressin (n = 8) vs. placebo (n = 8), the fluid and transfusion requirements were reduced (both p < .01), intracranial pressure was improved (11 +/- 1 vs. 23 +/- 2 mmHg; p < .0001), and the CO2-evoked intracranial pressure elevation was reduced (7 +/- 2 vs. 26 +/- 3 mm Hg, p < .001), suggesting improved compliance. In series 2, with arginine vasopressin vs. placebo, cerebral perfusion pressure was more rapidly corrected (p < .05). With arginine vasopressin, five of five animals survived 300 mins, whereas three of five placebo animals died. The survival time with placebo was 54 +/- 4 mins (p < .05 vs. arginine vasopressin).

CONCLUSIONS

Early supplemental arginine vasopressin rapidly corrected cerebral perfusion pressure, improved cerebrovascular compliance, and prevented circulatory collapse during fluid resuscitation of hemorrhagic shock after traumatic brain injury.

Systemic coagulation changes caused by pulmonary artery catheters: laboratory findings and clinical correlation

BACKGROUND

A higher rate of pulmonary embolism has been associated with pulmonary artery (PA) catheters; however, no mechanism has been described. Conventional tests of coagulation reveal no changes related to PA catheterization. The purpose of this study was to determine whether PA catheterization resulted in a hypercoagulable state detectable by thrombelastography (TEG).

METHODS

ANIMAL

Healthy, anesthetized, swine (n = 19) underwent PA catheterization. Samples were drawn from 7F femoral arterial catheters before and two hours after PA catheterization, at 5 mL/min, and analyzed (native whole blood, n = 15, kaolin activated blood, n = 4) by TEG (Hemoscope, Niles, IL) at precisely two minutes. Human: An IRB-approved prospective, observational trial was conducted in critically ill patients (n = 19). Samples were drawn from 22-gauge radial artery catheters, before and three hours after PA catheterization. Kaolin-activated TEG samples were analyzed at precisely five minutes. Data are mean +/- SE; Groups were compared with analysis of variance and significance was assessed at the 95% confidence interval.

RESULTS

In both animals and patients, PA catheterization truncated R times (time to initial fibrin formation). In swine, the R times were 17.6 +/- 1.3 minutes (native) and 3.8 +/- 0.4 (kaolin) before PA catheterization, and decreased to 6.3 +/- 1.0 minutes (p = 0.002) and 1.9 +/- 0.5 minutes (p = 0.010) afterward. There were no changes in pH or temperature during the experiment. In patients, 4 of 19 were excluded for protocol violations. The R time was 6.3 +/- 1.0 minutes (kaolin) before and 3.0 +/- 0.3 minutes after catheterization (p = 0.003). No changes were observed in conventional coagulation parameters, temperature or pH.

CONCLUSION

In healthy swine, and critically ill patients, PA catheters may enhance thrombin formation and fibrin polymerization, indicating a systemic hypercoagulable state. This may explain why PA catheters are associated with an increased risk of pulmonary emboli.

A clinically relevant liver injury grading system by CT, preliminary report

Current computed tomography (CT) grading scales are anatomic and do not reliably identify those liver injuries requiring intervention (surgery or angioembolization). We propose a clinically relevant CT grading system that could predict need for intervention. CT scans of 11 patients with hepatic injury were reviewed to establish criteria that correspond with intervention. Five features were identified that were associated with intervention: laceration in greater than or equal to three segments, laceration extending into the hilum, hemoperitoneum, active extravasation, and sentinel clot. Radiologists then evaluated the predictability of these criteria by analyzing 24 CT scans. Inter-observer agreement of the American Association for the Surgery of Trauma (AAST) grading system was compared to this new system. In the analysis of 24 CT scans, active extravasation and sentinel clot demonstrated the highest specificity for intervention. This new grading system had superior inter-observer agreement (k=0.56) as compared to the AAST grading system (k=0.47). Active extravasation and the presence of sentinel clot should form the foundation of a new liver grading system.

Five percent albumin for adult burn shock resuscitation: lack of effect on daily multiple organ dysfunction score

BACKGROUND

The effect of 5 percent human albumin on multiple organ dysfunction was investigated during the first 14 days of treatment to determine whether albumin resuscitation might benefit adult burn patients.

STUDY DESIGN AND METHODS

Multicenter unblinded controlled trial with stratified block (two patients per block) randomization by center and mortality prediction at enrollment (high-risk stratum [predicted mortality, 50%-90%] and low-risk stratum [predicted mortality, <50%]). The primary outcome was the worst multiple organ dysfunction score (MODS), excluding the cardiovascular component, to Day 14. Eligible adults (>15 years) suffering from thermal injury not more than 12 hours before enrollment received fluid resuscitation with Ringer's lactate (n=23) or 5 percent human albumin plus Ringer's lactate (n=19) by protocol to achieve recommended (American Burn Association) resuscitation endpoints.

RESULTS

Forty-two patients were randomly assigned. There were no significant differences (median [95% confidence intervals]) in age (36 [24-45] vs. 31 [25-39] years), burn size (39 [32-53] vs. 32 [26-34] total body surface area percentage), inhalation injury (n=12/19 vs. n=11/23), or baseline MODS (3 [1-5] vs. 1.5 [0-2]) between the treatment and control groups. In an intention-to-treat analysis, there was no significant difference between the treatment and control group in the lowest MODS from Day 0 to Day 14 (analysis of covariance, p=0.73).

CONCLUSION

Treatment with 5 percent albumin from Day 0 to Day 14 does not decrease the burden of MODS in adult burn patients.

Resuscitation with Pressors after Traumatic Brain Injury

BACKGROUND

The purpose of the study was to compare initial resuscitation with arginine vasopressin (AVP), phenylephrine (PE), or isotonic crystalloid fluid alone after traumatic brain injury and vasodilatory shock.

STUDY DESIGN

Anesthetized, ventilated swine (n = 39, 30 +/- 2 kg) underwent fluid percussion traumatic brain injury followed by hemorrhage (30 +/- 2mL/kg) to a mean arterial pressure < 30mmHg, then were randomized to 1 of 5 groups to maintain mean arterial pressure > 60mmHg for 30 to 60minutes, then cerebral perfusion pressure > 60mmHg for 60 to 300minutes, either unlimited crystalloid fluid only (n = 9), arginine vasopressin + fluid (n = 9), phenylephrine + fluid (n = 9), arginine vasopressin only (n = 5), or phenylephrine only (n = 5). Heterologous transfusions were administered if hematocrit was < 13, and mannitol was administered if intracranial pressure was > 20 mmHg. Cerebrovascular reactivity was evaluated with serial CO(2) challenges.

RESULTS

In all groups, physiologic variables were similar at baseline and at the end of shock. On resuscitation, all achieved mean arterial pressure and cerebral perfusion pressure goals. Brain tissue PO(2)s were similar. With fluid only, more blood and mannitol were required, intracranial pressure and peak inspiratory pressure were higher, and cerebrovascular reactivity was decreased (all p < 0.05 versus pressor + fluid). With either pressor + fluid, cardiac output, heart rate, lactate, and mixed venous O(2) saturation were similar to fluid only, but total fluid requirements and urine output were both reduced (p < 0.05). With either pressor only, intracranial pressure remained low, but mixed venous O(2) saturation, cardiac output, and urine output were decreased (all p < 0.05 versus other groups).

CONCLUSIONS

To correct vasodilatory shock after traumatic brain injury, a resuscitation strategy that combined either phenylephrine or arginine vasopressin plus crystalloid was superior to either fluid alone or pressor alone.

Recent trends in the management of combined pancreatoduodenal injuries

In an effort to better characterize the natural history of pancreatoduodenal injuries, we present a review of clinical experiences in the treatment of combined traumatic pancreatoduodenal injuries, focusing on patients in extremis. Records of patients with abdominal trauma admitted to a level 1 trauma center from 1997 to 2001 were reviewed. Of 240 patients who sustained a pancreatic or duodenal injury, 33 had combined pancreatoduodenal injuries. Eighty-two per cent of the patients (27/33) in this series had penetrating injuries, 72 per cent (24) sustained gunshot wounds (GSW). Thirty-one patients were male, and the mean age was 33 years (range, 7-74). These patients presented with an average Injury Severity Score (ISS) of 22 +/- 12 and an average Glasgow Coma Score of 14 +/- 2. Overall length of stay was 39 +/- 59 days (range, 0-351 days). These 33 patients underwent a total of 57 laparotomies with an average of 1.7 operations per patient (range, 1 to 5 operations). Eighty-four per cent of the patients had an associated gastrointestinal injury and 45 per cent had a major vascular injury. Thirteen of the 33 (39%) patients presented in extremis, all 13 underwent an abbreviated laparotomy. The complication rate was 36 per cent, including fistula, abscess, pancreatitis, and organ dysfunction. There were 6 hospital deaths for a mortality rate of 18 per cent. Pancreatoduodenal injuries are associated with a variety of other serious injuries, which add to the overall complexity of these patients. Abbreviated laparotomy may be helpful when managing combined pancreatoduodenal injuries in patients who are in extremis.

Early Vasopressin Improves Short-Term Survival after Pulmonary Contusion

Arginine vasopressin (AVP) is a promising treatment for several types of irreversible shock, but its therapeutic potential has not been examined after severe chest trauma. Two series of experiments were performed to fill this gap.

METHODS

Series 1: anesthetized, mechanically-ventilated pigs (n = 20, 29 +/- 1 kg) received a blast to the chest, followed by a "controlled" arterial hemorrhage to a mean arterial pressure (MAP) <30 mm Hg. At 20 minutes, a 10 mL/kg normal saline (NS) bolus was followed by either 0.1 U/kg AVP bolus or NS, in randomized, blinded fashion. From 30-300 minutes, either AVP (0.4 U/kg/hr plus NS) or NS alone was infused as needed to MAP>70 mm Hg. Series 2: Swine (n = 15) received the chest injury followed by partial left hepatectomy to produce "uncontrolled" hemorrhage. Resuscitation was the same as in series 1.

RESULTS

The blast created bilateral parenchymal contusions (R > L), hemo/pneumothorax and progressive cardiopulmonary distress. In Series 1, there were 3/20 deaths before randomization, 0/8 deaths after resuscitation with AVP versus 4/9 deaths with NS (p = 0.029). In surviving animals, with AVP versus NS, fluid requirements and peak airway pressures were lower while P/F was higher (all p < 0.05). In Series 2, with uncontrolled hemorrhage, there were 5/15 deaths before randomization. Upon resuscitation with AVP versus NS, survival time and blood loss were both improved, but the differences did not reach statistical significance.

CONCLUSIONS

After severe chest trauma with controlled hemorrhage, early AVP decreased mortality, reduced fluid requirements and improved pulmonary function. With uncontrolled hemorrhage, early AVP did not increase the risk for bleeding.

Recent Trends in the Management of Combined Pancreatoduodenal Injuries

In an effort to better characterize the natural history of pancreatoduodenal injuries, we present a review of clinical experiences in the treatment of combined traumatic pancreatoduodenal injuries, focusing on patients in extremis. Records of patients with abdominal trauma admitted to a level 1 trauma center from 1997 to 2001 were reviewed. Of 240 patients who sustained a pancreatic or duodenal injury, 33 had combined pancreatoduodenal injuries. Eighty-two per cent of the patients (27/33) in this series had penetrating injuries, 72 per cent (24) sustained gunshot wounds (GSW). Thirty-one patients were male, and the mean age was 33 years (range, 7–74). These patients presented with an average Injury Severity Score (ISS) of 22 ± 12 and an average Glasgow Coma Score of 14 ± 2. Overall length of stay was 39 ± 59 days (range, 0–351 days). These 33 patients underwent a total of 57 laparotomies with an average of 1.7 operations per patient (range, 1 to 5 operations). Eighty-four per cent of the patients had an associated gastrointestinal injury and 45 per cent had a major vascular injury. Thirteen of the 33 (39%) patients presented in extremis, all 13 underwent an abbreviated laparotomy. The complication rate was 36 per cent, including fistula, abscess, pancreatitis, and organ dysfunction. There were 6 hospital deaths for a mortality rate of 18 per cent. Pancreatoduodenal injuries are associated with a variety of other serious injuries, which add to the overall complexity of these patients. Abbreviated laparotomy may be helpful when managing combined pancreatoduodenal injuries in patients who are in extremis.

Resuscitation with a hemoglobin-based oxygen carrier after traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) remains an exclusionary criterion in nearly every clinical trial involving hemoglobin-based oxygen carriers (HBOCs) for traumatic hemorrhage. Furthermore, most HBOCs are vasoactive, and use of pressors in the setting of hemorrhagic shock is generally contraindicated. The purpose of this investigation was to test the hypothesis that low-volume resuscitation with a vasoactive HBOC (hemoglobin glutamer-200 [bovine], HBOC-301; Oxyglobin, BioPure, Inc., Cambridge, MA) would improve outcomes after severe TBI and hemorrhagic shock.

METHODS

In Part 1, anesthetized swine received TBI and hemorrhage (30 +/- 2 mL/kg, n = 15). After 30 minutes, lactated Ringer's (LR) solution (n = 5), HBOC (n = 5), or 10 mL/kg of LR + HBOC (n = 5) was titrated to restore systolic blood pressure to > or = 100 mm Hg and heart rate (HR) to < or = 100 beats/min. After 60 minutes, fluid was given to maintain mean arterial pressure (MAP) at > or = 70 mm Hg and heterologous whole blood (red blood cells [RBCs], 10 mL/kg) was transfused for hemoglobin at < or = 5 g/dL. After 90 minutes, mannitol (MAN, 1 g/kg) was given for intracranial pressure > or = 20 mm Hg, LR solution was given to maintain cerebral perfusion pressure at > or = 70 mm Hg, and RBCs were given for hemoglobin of < or = 5 g/dL. In Part 2, after similar TBI and resuscitation with either LR + MAN + RBCs (n = 3) or HBOC alone (n = 3), animals underwent attempted weaning, extubation, and monitoring for 72 hours.

RESULTS

In Part 1, relative to resuscitation with LR + MAN + RBCs, LR + HBOC attenuated intracranial pressure (12 +/- 1 mm Hg vs. 33 +/- 6 mm Hg), improved cerebral perfusion pressure in the initial 4 hours (89 +/- 6 mm Hg vs. 60 +/- 3 mm Hg), and improved brain tissue PO2 (34.2 +/- 3.6 mm Hg vs. 16.1 +/- 1.6 mm Hg; all p < 0.05). Cerebrovascular reactivity and intracranial compliance were improved with LR + HBOC (p < 0.05) and fluid requirements were reduced (30 +/- 12 vs. 280 +/- 40 mL/kg; p < 0.05). Lactate and base excess corrected faster with LR + HBOC despite a 40% reduction in cardiac index. With HBOC alone and LR + HBOC, MAP and HR rapidly corrected and remained normal during observation; however, with HBOC alone, lactate clearance was slower and systemic oxygen extraction was transiently increased. In Part 2, resuscitation with HBOC alone allowed all animals to wean and extubate, whereas none in the LR + MAN + RBCs group was able to wean and extubate. At 72 hours, no HBOC animal had detectable neurologic deficits and all had normal hemodynamics.

CONCLUSION

The use of HBOC-301 supplemented by a crystalloid bolus was clearly superior to the standard of care (LR + MAN + RBCs) after TBI. This may represent a new indication for HBOCs. Use of HBOC eliminated the need for RBC transfusions and mannitol. The inherent vasopressor effect of HBOCs, especially when used alone, may misguide initial resuscitation, leading to transient poor global tissue perfusion despite restoration of MAP and HR. This suggests that MAP and HR are inadequate endpoints with HBOC resuscitation. HBOC use alone after TBI permitted early extubation and excellent 72-hour outcomes.

Magnetic resonance cholangiopancreatography accurately detects common bile duct stones in resolving gallstone pancreatitis

BACKGROUND

There is controversy about the optimal method to detect common bile duct (CBD) stones in patients with mild resolving gallstone pancreatitis. The aim of this study was to evaluate magnetic resonance cholangiopancreatography (MRCP) in detecting choledocholithiasis in this group of patients.

STUDY DESIGN

A prospective randomized trial was conducted. Patients randomized to group 1 (n = 34) underwent laparoscopic cholecystectomy (LC) and intraoperative cholangiography (IOC). Those randomized to group 2 (n = 29) had preoperative MRCP, of these, patients with negative MRCP underwent LC and IOC, patients with positive MRCP had preoperative ERCP followed by LC.

RESULTS

Sixty-three patients were randomized (34 to group 1 and 29 to group 2). CBD stones were found in 5 patients in group 1. CBD exploration was performed in 2 patients, preoperative ERCP in 1, and postoperative ERCP in the other 2. MRCP showed CBD stones in 4 patients in group 2. There were two false-positive MRCPs. Four patients with a negative MRCP did not have IOC or ERCP, the remaining 21 patients with a negative MRCP had a negative IOC. The MRCP sensitivity was 100% (95% CI, 16-100%), specificity 91% (95% CI, 72-99%), positive predictive value 50% (95% CI, 7-93%), negative predictive value 100% (95% CI, 84-100%), and accuracy 92% (95% CI, 74-99%).

CONCLUSIONS

Patients with resolving gallstone pancreatitis and a negative MRCP do not need preoperative ERCP or IOC. Only patients with a positive MRCP will require preoperative ERCP.

How Long Should You Wait for a Chest Radiograph after Placing a Chest Tube on Water Seal? A Prospective Study

OBJECTIVE

The purpose of this study was to determine the optimal time interval for identifying a pneumothorax (PTX) on chest radiograph (CXR) after placing a chest tube on water seal.

METHODS

One hundred nineteen chest tubes were placed on water seal according to a prospective, observational study protocol. After water seal, both an early (3.1 +/- 2.1 hours) and a late (17.6 +/- 8.0 hours) CXR was obtained.

RESULTS

Thirty-one patients had a PTX on follow-up CXRs. There were 22 early and 9 late PTXs identified. Three patients in the early group had a clinically significant PTX or an increase in the size of PTX on follow-up CXR. None of the patients in the late group had a clinically significant PTX (any worsening of their PTX) or required further intervention.

CONCLUSION

A normal chest radiograph obtained 3 hours after placing a chest tube on water seal effectively excludes development of a clinically significant pneumothorax.

Trauma surgery malpractice risk: perception versus reality

OBJECTIVE

We set out to compare the malpractice lawsuit risk and incidence in trauma surgery, emergency surgery, and elective surgery at a single academic medical center.

SUMMARY AND BACKGROUND DATA

The perceived increased malpractice risk attributed to trauma patients discourages participation in trauma call panels and may influence career choice of surgeons. When questioned, surgeons cite malpractice risk as a rationale for not providing trauma care. Little data substantiate or refute the perceived high trauma malpractice risk. We hypothesized that the malpractice risk was equivalent between an elective surgical practice and a trauma/emergency practice.

METHODS

Three prospectively maintained institutional databases were used to calculate and characterize malpractice incidence and risk: a surgical operation database, a trauma registry, and a risk management/malpractice database. Risk groups were divided into elective general surgery (ELECTIVE), urgent/emergent, nontrauma general surgery (URGENT), and trauma surgery (TRAUMA). Malpractice claims incidence was calculated by dividing the total number of filed lawsuits by the total number of operative procedures over a 12-year period.

RESULTS

Over the study period, 62,350 operations were performed. A total of 21 lawsuits were served. Seven were dismissed. Three were granted summary judgments to the defendants. Ten were settled with payments to the plaintiffs. One went to trial and resulted in a jury verdict in favor of the defendants. Total paid liability was 4.7 million dollars(391,667 dollars/year). Total legal defense costs were 1.3 million dollars(108,333 dollars/year). The ratio of lawsuits filed/operations performed and incidence in the 3 groups is as follows: ELECTIVE 14/39,080 (3.0 lawsuits/100,000 procedures/year), URGENT 5/17,958, (2.3 lawsuits/100,000 procedures/year), and TRAUMA 2/5312 (3.1/100,000 procedures/year). During the study period, there were an estimated 49,435 trauma patients evaluated. The incidence of malpractice lawsuits using this denominator is 0.34 lawsuits/100,000 patients/year.

CONCLUSIONS

These data demonstrate no increased risk of lawsuit when caring for trauma patients, and the actual risk of a malpractice lawsuit was low.

Can near-infrared spectroscopy identify the severity of shock in trauma patients?

BACKGROUND

Our recent experimental study showed that peripheral muscle tissue oxygen saturation (StO2), determined noninvasively by near-infrared spectroscopy (NIRS), was more reliable than systemic hemodynamics or invasive oxygenation variables as an index of traumatic shock. The purpose of this study was to establish the normal range of thenar muscle StO2 in humans and the relationship between shock state and StO2 in trauma patients.

METHODS

This was a prospective, nonrandomized, observational, descriptive study in normal human volunteers (n = 707) and patients admitted to the resuscitation area of our Level I trauma center (n = 150). To establish a normal StO2 range, an NIRS probe was applied to the thenar eminence of volunteers (normals). Subsequently, in a group of trauma patients, an NIRS probe was applied to the thenar eminence and data were collected and stored for offline analysis. StO2 monitoring was performed continuously and noninvasively, and values were recorded at 2-minute intervals. Five moribund trauma patients were excluded. Members of our trauma faculty, blinded to StO2 values, classified each patient into one of four groups (no shock, mild shock, moderate shock, and severe shock) using conventional physiologic parameters.

RESULTS

Mean +/- SD thenar StO2 values for each group were as follows: normals, 87 +/- 6% (n = 707); no shock, 83 +/- 10% (n = 85); mild shock, 83 +/- 10% (n = 19); moderate shock, 80 +/- 12% (n = 14); and severe shock, 45 +/- 26% (n = 14). The thenar StO2 values clearly discriminated the normals or no shock patients and the patients with severe shock (p < 0.05).

CONCLUSION

Decreased thenar muscle tissue oxygen saturation reflects the presence of severe hypoperfusion and near-infrared spectroscopy may be a novel method for rapidly and noninvasively assessing changes in tissue dysoxia.

Spine Injuries Are Common Among Asymptomatic Patients After Gunshot Wounds

BACKGROUND

Spine injuries after gunshot wounds are thought to be rare among asymptomatic patients. The occurrence of spine injuries among asymptomatic patients with gunshot wounds was studied to determine the necessity for mandatory spine immobilization and radiographic imaging.

METHODS

In this retrospective cohort study, initial physical examination, radiographic findings, and final diagnosis and treatment were reviewed. Patients were included if they were admitted to the authors' level 1 trauma center with gunshot wounds to the head, neck, or trunk during a 10-year period. Spine injuries were considered "significant" if the injury was associated with spinal cord injury or required spine-related surgical procedures or prolonged spine immobilization. Spine injuries were defined as "unsuspected" if there were no neurologic findings at admission.

RESULTS

During the study period, 2,450 patients who survived more than 24 hours were admitted with gunshot wounds to the trunk, neck, or head. Of these patients, 244 (approximately 10%) had spine injuries, and 228 of them had complete records. Two thirds of the spine injuries were found to be significant, requiring surgery or prolonged immobilization, and 13% were unsuspected.

CONCLUSIONS

Spine injuries without neurologic signs are not uncommon among patients with gunshot wounds. Complete radiographic spine imaging is therefore recommended to ensure that spine injuries are not missed in this population.

Modified rapid deployment hemostat bandage terminates bleeding in coagulopathic patients with severe visceral injuries

BACKGROUND

We recently reported that a new dressing, the Modified Rapid Deployment Hemostat (MRDH) controlled bleeding in hypothermic coagulopathic swine after traumatic liver avulsion. The purpose of this study was to evaluate the MRDH in coagulopathic trauma patients undergoing abbreviated laparotomy.

METHODS

A prospective, observational clinical trial of the MRDH dressing was performed at our Level One Trauma Center in patients with high-grade visceral injuries with coagulopathy who failed conventional therapy and required packing. Attending surgeons graded the injury and the adequacy of hemostasis following application of the dressing. Patients were followed until discharge or death.

RESULTS

Ten patients were enrolled: nine severe hepatic injuries, and one major abdominal vascular injury. All patients were hypothermic, acidotic, and clinically coagulopathic. Intraoperative hemostasis was immediately obtained after MRDH placement in all cases except one. There was one death.

CONCLUSION

The Modified Rapid Deployment Hemostat terminates bleeding from severe visceral injuries in coagulopathic patients undergoing abbreviated laparotomy.