When Is It Safe to Discharge Asymptomatic Patients With Abdominal Stab Wounds?

BACKGROUND

This study sought to determine the time from hospital presentation to surgical intervention for hemodynamically stable patients with abdominal stab wounds. The objective was to identify the optimal time for observation of these asymptomatic patients before safe hospital discharge.

METHODS

The authors reviewed a prospectively collected trauma database at their level 1 trauma center. The time from admission to surgery was noted in their patient population. All stab wound patients who underwent either peritoneal lavage or immediate surgery were excluded from the study.

RESULTS

During a 7-year period, 650 asymptomatic patients with abdominal stab wounds were admitted for serial examination. The study showed that 567 of these patients had no abdominal surgical intervention, whereas 68 underwent abdominal surgery (15 left the center against medical advice). No patients were identified as requiring surgery more than 12 hours after presentation.

CONCLUSION

It appears that asymptomatic patients with abdominal stab wounds may be discharged from the hospital after 12 hours of observation with little likelihood of missed injury.

Splanchnic Hypoperfusion-Directed Therapies in Trauma: A Prospective, Randomized Trial

Splanchnic hypoperfusion as reflected by gastric intramucosal acidosis has been recognized as an important determinant of outcome in shock. A comprehensive splanchnic hypoperfusion-ischemia reperfusion (IRP) protocol was evaluated against conventional shock management protocols in critical trauma patients. The study was a prospective randomized trial comparing three therapeutic approaches to hypoperfusion after severe trauma in 151 trauma patients admitted to the intensive care unit. Group 1 patients received hemodynamic support based on conventional indicators of hypoperfusion. In group 2, resuscitation was further guided by gastric tonometry-derived estimates of splanchnic hypoperfusion and included more invasive hemodynamic monitoring and additional administration of colloid or crystalloid solutions, or inotropic support. Group 3 patients additionally received therapies specifically aimed at optimizing splanchnic perfusion and minimizing oxidant-mediated damage from reperfusion. The three groups were similar based on age, Injury Severity Score, and Acute Physiology and Chronic Health Evaluation II Scores. There were no statistically significant differences in mortality rates, organ dysfunction, ventilator days, or length of stay between any of the interventions. Techniques of optimization of splanchnic perfusion and minimization of oxidant-mediated reperfusion injury evaluated in this study were not advantageous relative to standard resuscitation measures guided by conventional or tonometric measures of hypoperfusion in the therapy of occult and clinical shock in trauma patients.

Secondary ultrasound examination increases the sensitivity of the FAST exam in blunt trauma

INTRODUCTION

Approximately one third of stable patients with significant intra-abdominal injury do not have significant intraperitoneal blood evident on admission. We hypothesized that a delayed, repeat ultrasound study (Secondary Ultrasound--SUS) will reveal additional intra-abdominal injuries and hemoperitoneum.

METHODS

We performed a prospective observational study of trauma patients at our Level I trauma center from April 2003 to December 2003. Patients underwent an initial ultrasound (US), followed by a SUS examination within 24 hours of admission. Patients not eligible for a SUS because of early discharge, operative intervention or death were excluded. All US and SUS exams were performed and evaluated by surgical/emergency medicine house staff or surgical attendings.

RESULTS

Five hundred forty-seven patients had both an initial US and a SUS examination. The sensitivity of the initial US in this patient population was 31.1% and increased to 72.1% on SUS (p < 0.001) for intra-abdominal injury or intra-abdominal fluid. The specificity for the initial US was 99.8% and 99.8% for SUS. The negative predictive value was 92.0% for the initial US and increased to 96.6% for SUS (p = 0.002). The accuracy of the initial ultrasound was 92.1% and increased to 96.7% on the SUS (p < 0.002). No patient with a negative SUS after 4 hours developed clinically significant hemoperitoneum.

CONCLUSION

A secondary ultrasound of the abdomen significantly increases the sensitivity of ultrasound to detect intra-abdominal injury.

Predictors of mortality in trauma patients

The purpose of this study was to ascertain risk factors for death from trauma. The large cohort allows for simultaneous evaluation of known mortality risk factors along with controlling for factors to assess the influence of each independently. Individually, base deficit, temperature, hypotension, age, and injury severity have been shown to be associated with an increased risk of death. However, in the English literature, there is no data on the independent predictive power and interaction of these risk factors. A review of trauma registry parameters from 1995 to 2000 was used. Demographics, injury severity, physiological and hematological parameters, and time data were evaluated in a univariate analysis. Variables significantly associated with mortality were entered into a stepwise backward multiple logistic regression. There were 1276 deaths (8.9%) with 25 per cent of the deaths within 3 hours. The top four predictors of mortality in this group were partial thromboplastin time (OR 3.37, 95% CI: 2.51-4.52), positive head computed tomography result (OR, 2.47; 95% CI, 1.95-3.04), initial hemoglobin (OR, 1.69; 95% CI, 1.23-2.31), base deficit (OR, 1.62; 95% CI, 1.29-2.04), and trauma resuscitation bay systolic blood pressure (OR, 1.45; 95% CI, 1.11-1.88). We conclude that prognostic indicators of all-cause mortality after trauma, which remain independent in the presence of all other factors and are potentially treatable, included low hemoglobin, elevated prothrombin and partial thromboplastin time, low scene and trauma bay systolic pressure, and elevated base deficit. The independent indicators of mortality, which are untreatable, included head injury, increasing age, and Injury Severity Score.

Predictors of Mortality in Trauma Patients

The purpose of this study was to ascertain risk factors for death from trauma. The large cohort allows for simultaneous evaluation of known mortality risk factors along with controlling for factors to assess the influence of each independently. Individually, base deficit, temperature, hypotension, age, and injury severity have been shown to be associated with an increased risk of death. However, in the English literature, there is no data on the independent predictive power and interaction of these risk factors. A review of trauma registry parameters from 1995 to 2000 was used. Demographics, injury severity, physiological and hematological parameters, and time data were evaluated in a univariate analysis. Variables significantly associated with mortality were entered into a stepwise backward multiple logistic regression. There were 1276 deaths (8.9%) with 25 per cent of the deaths within 3 hours. The top four predictors of mortality in this group were partial thromboplastin time (OR 3.37, 95% CI: 2.51–4.52), positive head computed tomography result (OR, 2.47; 95% CI, 1.95–3.04), initial hemoglobin (OR, 1.69; 95% CI, 1.23–2.31), base deficit (OR, 1.62; 95% CI, 1.29–2.04), and trauma resuscitation bay systolic blood pressure (OR, 1.45; 95% CI, 1.11–1.88). We conclude that prognostic indicators of all-cause mortality after trauma, which remain independent in the presence of all other factors and are potentially treatable, included low hemoglobin, elevated prothrombin and partial thromboplastin time, low scene and trauma bay systolic pressure, and elevated base deficit. The independent indicators of mortality, which are untreatable, included head injury, increasing age, and Injury Severity Score.

Building a Better Fluid for Emergency Resuscitation of Traumatic Brain Injury

Hextend (HEX) is a colloid solution that is FDA-approved for volume expansion during surgery. ATL-146e is a novel adenosine A2A receptor agonist that has anti-inflammatory, neuroprotective, and coronary vasodilator properties. Three series of experiments were designed to evaluate the therapeutic potential of HEX+/-ATL-146e for emergency resuscitation from traumatic brain injury (TBI) + hemorrhagic hypotension.

METHODS

In the first two studies in vivo, anesthetized, ventilated pigs (30-45 kg) received a fluid percussion TBI, 45% arterial hemorrhage, and 30 minutes shock period. In Series 1, resuscitation consisted of unlimited crystalloid (n = 8) or HEX (n = 8) to correct systolic arterial pressure >100 mm Hg and heart rate <100 bpm for the first 60 minutes ("emergency phase"), and then maintain cerebral perfusion pressure (CPP) > 70 mm Hg for 60-240 minutes. In Series 2 (n = 31), resuscitation consisted of a 1 L bolus of HEX + ATL-146e (10 ng/kg/min, n = 10) or HEX +placebo (n = 10) followed by crystalloid to the same endpoints. In Series 3 in vivo, the hemodynamic response evoked by 0, 10, 50, or 100 ng/kg/min ATL-146e was measured before or 60 minutes after HEX resuscitation from 45% hemorrhage.

RESULTS

Following TBI+hemorrhage, there were 4/22 deaths in series 1 and 11/31 deaths in series 2. In those alive at 30 minutes, mean arterial pressure, cardiac index, mixed venous O2 saturation, and cerebral venous O2 saturation were all reduced by 40-60%, while heart rate and lactate were increased 2-5 fold. With no resuscitation (n = 2), there was minimal hemodynamic compensation and progressive acidosis. Upon resuscitation, these values corrected but intracranial pressure progressively rose from <5 mm Hg to 15-20 mm Hg. Series 1: With HEX (n = 8) versus crystalloid (n = 8), CPP was less labile, acid/base was maintained, and the fluid requirement was reduced by 60% (all p < 0.05) Series 2: With ATL-146e (n = 10) versus placebo (n = 10), stroke volume and cardiac output were improved by 40-60%, and the fluid requirement was reduced by 30% (all p < 0.05). Series 3: ATL-146e caused a dose-related increase (p < 0.05) in stroke volume after, but not before, hemorrhage. The effects on pre-load, afterload, and heart rate were similar before and after hemorrhage.

CONCLUSIONS

HEX alone is a safe and efficacious low volume alternative to initial crystalloid resuscitation after TBI. An adenosine A2A agonist combined with 1 L of HEX safely and effectively counteracted a decrease in cardiac performance noted after TBI+hemorrhage without causing hypotension or bradycardia.

Changes in intracranial pressure, coagulation, and neurologic outcome after resuscitation from experimental traumatic brain injury with hetastarch

BACKGROUND

In a model of traumatic brain injury (TBI), 2 protocols compared changes in intracranial pressure (ICP), coagulation, and neurologic outcome after intravenous fluid (IVF) resuscitation with either Hextend (HEX, 6% hetastarch in lactated electrolyte injection) or standard of care, crystalloid plus mannitol (MAN).

METHODS

In the nonsurvivor protocol, swine (n = 28) received a fluid percussion TBI and hemorrhage (27 +/- 3 mL/kg). At 30 minutes, resuscitation began with lactated Ringer's (LR) or HEX. After 60 minutes, MAN (1 g/kg) or placebo was given plus supplemental IVF to maintain cerebral perfusion pressure (CPP) > or = 70 mm Hg for 240 minutes. Swine in the survivor group (n = 15) also underwent TBI and hemorrhage, and resuscitation with HEX was compared to that of normal saline (NS)+MAN. Neurologic outcome and coagulation were evaluated for 72 hours.

RESULTS

In the nonsurvivor protocol, HEX, LR+MAN, and HEX+MAN attenuated the time-related rise of ICP and prevented ICP >20 mm Hg versus LR alone (P < .05). HEX alone maintained CPP (relative to baseline) and decreased total IVF by 50% versus LR +/- MAN (P < .05). MAN had no additive effect with HEX. Coagulation, measured by thromboelastograph reaction time (R), was 11 +/- 1 and 9 +/- 1 minutes at baseline and after TBI (before randomization). At 240 minutes after HEX or LR+MAN, R was 6 +/- 1 or 7 +/- 2 minutes, which indicates a hypercoagulable state, but there was no difference between treatments. In the survivor protocol, ICP and CPP were similar with NS+MAN versus HEX, but IVF requirement was 161 +/- 20 versus 28 +/- 3 mL/kg (P < .05). Motor scores were higher on days 2 and 3 with HEX (P < .05). At 72 hours, R was 28 +/- 14 versus 26 +/- 6 minutes with NS+MAN versus HEX, which indicates a hypocoagulable state, but there was no difference between treatments.

CONCLUSIONS

Hextend as the sole resuscitation fluid after severe TBI reduces fluid requirement, obviates the need for mannitol, improves neurologic outcome, and has no adverse effect on the coagulation profile relative to the crystalloid plus mannitol standard of care.

Noninvasive muscle oxygenation to guide fluid resuscitation after traumatic shock

BACKGROUND

Three different protocols tested the hypothesis that hind limb muscle tissue O(2) saturation (StO(2)), measured noninvasively with near-infrared spectroscopy (NIRS), is as reliable as invasive systemic oxygenation indices to guide fluid resuscitation.

METHODS

In series 1, swine (n=30) were hemorrhaged, then received either no fluid, a fixed volume of colloid (15 mL/kg), or shed blood plus lactated Ringer's (LR) titrated to MAP >60 mm Hg. In series 2, swine (n=16) received a penetrating femur injury, a 47% to 55% hemorrhage to determine a median lethal dose (LD(50)) then shed blood plus LR titrated to MAP >60 mm Hg. In series 3, swine (n=5) received the femur injury plus LD(50) hemorrhage, and were resuscitated with LR titrated to StO(2) >50%.

RESULTS

In series 1, StO(2) tracked mixed venous O(2) saturation (SvO(2)), but discriminated between 3 survivor groups better than SvO(2), arterial lactate, or arterial base excess. In series 2, StO(2) tracked SvO(2) but discriminated between 2 survivor groups better than SvO(2), arterial lactate, or arterial base excess. In series 3, animals survived to extubation when resuscitated to an StO(2) target.

CONCLUSIONS

Noninvasive muscle StO(2) determined by NIRS was more reliable than invasive oxygenation variables as an index of shock. Because muscle StO(2) can be easily monitored in emergency situations, it may represent an improved method to gauge the severity of shock or the adequacy of fluid resuscitation after trauma.

Therapeutic potential of exogenous ubiquitin during resuscitation from severe trauma

BACKGROUND

Recent studies suggest that extracellular ubiquitin could have a physiologic role in immunodepression in sepsis and trauma. The therapeutic potential of exogenous ubiquitin after trauma has not been examined. To fill this gap, we designed a series of experiments in a clinically relevant trauma model.

METHODS

Forty minutes after femur fractures and hemorrhage, swine received 1.3 mg of ubiquitin per kilogram or bovine serum albumin intravenously followed by fluid resuscitation to maintain systemic hemodynamics. Leukocyte function and the immunomodulatory capacity of serum were assessed measuring endotoxin-evoked tumor necrosis factor-alpha (TNF alpha) production ex vivo. TNF alpha and ubiquitin were quantified with enzyme-linked immunosorbent assay.

RESULTS

Intravenous ubiquitin had no significant hemodynamic effect in normal animals. After injury, ubiquitin significantly reduced fluid requirements by at least 60% (p < 0.05). The injury was associated with transient immunodepression, as reflected by reduced endotoxin-evoked TNF alpha production by 40% to 50%. With ubiquitin, this response remained depressed for 100 to 160 minutes (p < 0.05), but fully recovered to baseline with albumin.

CONCLUSION

Ubiquitin is apparently safe and effective for reducing fluid requirements as a measure of diffuse capillary leak. This immunomodulatory property suggests a new therapeutic approach after injury in particular, and for infectious and noninfectious inflammation in general.

Alternatives to blood in the 21st century

Persons who suffer traumatic injury are likely to be transfused with considerable amounts of blood during initial resuscitation efforts. Oxygen-carrying solutions are currently in clinical testing as substitutes for red blood cells. Although these agents may eliminate many concerns associated with blood administration (short shelf life, infectious and immunologic risks, the need to type and cross-match), early cell-free hemoglobin solutions demonstrated nephrotoxicity and were associated with pulmonary and systemic hypertension, among other adverse events. Newer polymerized hemoglobin solutions show acceptable safety profiles in the surgical setting and studies are being designed, some with funding from the US Department of Defense, to evaluate their efficacy in hemorrhaging trauma victims.

Pediatric pedestrian trauma study: a pilot project

OBJECTIVE

To evaluate the implementation of the WalkSafe Program, a school based educational injury prevention program for children grades Kindergarten through 5.

METHODS

A randomized comparative design was used for this study. The study was conducted in two high-risk urban school districts, which were chosen based on the geographic areas with the highest pedestrian injury and fatality rates. Four elementary schools (two in each district) were identified as potential study sites. Two intervention schools, one in each school district, were randomly chosen to receive the WalkSafe program; the other two schools served as controls, and received no intervention. The data was collected within the classroom setting for both the intervention and control schools. All elementary school children were administered the same pedestrian safety questionnaire as a pre-test, post-test and at three months following the intervention.

RESULTS

A total of 2300 children participated in the WalkSafe program. The intervention (I) schools showed significant improvement in post-test scores then the control (C) schools (p = 0.012), and the (I) schools were able to maintain their test scores as reflected in a three-month follow-up evaluation (p = 0.47). Grades 3-5 of the (I) schools showed significant improvement in their test scores over grades K-2 (p < 0.0001).

CONCLUSION

The WalkSafe program was shown to improve the pedestrian safety knowledge of elementary school children. Future research will include implementing the WalkSafe program at each elementary school within a single high-risk district.

Effects of exogenous ubiquitin in lethal endotoxemia

BACKGROUND

Recent data indicated a potential role for extracellular ubiquitin in hematopoiesis and inflammation. The biological significance and therapeutic potential of these findings in vivo are unknown. Based on its in vitro abilities to inhibit endotoxin-stimulated tumor necrosis factor alpha (TNFalpha) production, we hypothesized that exogenous ubiquitin has salutary effects on sequelae caused by endotoxin in vivo.

METHODS

Anesthetized and mechanically ventilated swine were infused with endotoxin for 3 hours. Ubiquitin was administered intravenously either 15 minutes before or 45 minutes after the endotoxin infusion was started. Albumin was administered to a control group. An additional control group received only ubiquitin. Ex vivo endotoxin evoked TNFalpha production was measured using a whole blood assay. Ubiquitin and TNFalpha concentrations were determined by enzyme-linked immunosorbent assay.

RESULTS

Ubiquitin reduced mortality (P <.05), prevented development of pulmonary failure (P <.05), reduced fluid requirements (P <.05), and diminished erythema and edema formation. Ubiquitin pretreatment was more effective than treatment 45 minutes after an endotoxin infusion was started. In vivo ubiquitin administration alone inhibited ex vivo endotoxin-evoked TNFalpha secretion, but had no effect on TNFalpha serum levels after endotoxin infusion.

CONCLUSION

In vivo ubiquitin administration has salutary actions during lethal endotoxemia and inhibits ex vivo whole blood TNFalpha production upon endotoxin stimulation. The clinical appearance after ubiquitin treatment in endotoxemia indicates the endothelium as another potential target cell population for interactions with ubiquitin. A novel therapeutic approach to a broad variety of diseases, in which endotoxin triggers immune activation, is suggested.

The epidemic of pediatric traffic injuries in South Florida: a review of the problem and initial results of a prospective surveillance strategy

This study identified specific regional risk factors for the high rate of pediatric pedestrian trauma in Florida. Of the 29 cases studied prospectively, 3 (10%) occurred near ice cream trucks and 13 (45%) involved "dart-outs"; mean hospital charges were 24,478 +/- 43,939 US dollars. Recommendations included an engineering change for a dangerous intersection, and a population-based recommendation was to equip ice cream trucks with extending stop signs.

Blood substitutes

PURPOSE OF REVIEW

Risk of disease transmission and limitations in the ability to transfuse in the prehospital or combat setting have stimulated research in the field of oxygen therapeutics. Several products have completed safety trials and are presently undergoing investigation for their efficacy. In the near future, the clinician will likely employ these products in the management of a variety of patient populations. Though similar in their oxygen carrying capacity, each agent possesses distinct physiologic effects. Understanding of the benefits and shortcomings of the various compounds is essential in order to optimally utilize them in various clinical settings. This review provides an overview of recent developments in the field of oxygen therapeutics and highlights results of clinical trials.

RECENT FINDINGS

Modified hemoglobin solutions of human or bovine origin and perfluorochemical-based emulsions are in advanced stages of clinical testing. Bovine hemoglobin-based solutions have been associated with vascular reactivity, methemoglobin formation and development of antibodies. Larger safety trials are necessary before they can find widespread use. Polymerized human hemoglobin solutions have a favorable safety profile in early trials and have been effective as a resuscitation fluid in circumstances when red cells may be unavailable. Unfortunately, outdated human blood, the substrate for this product, is itself in short supply. Perfluorocarbons similarly reduce the need for allogeneic transfusion, but the need for high-inspired oxygen levels currently limits use. Recombinant, polymer-encapsulated and additional forms of chemically modified hemoglobins are being developed and are undergoing testing in animal models

SUMMARY

Oxygen carriers offer a viable alternative to allogeneic transfusion. All oxygen therapeutic agents are not clinically equivalent. Optimal utilization requires a thorough understanding of the therapeutic potentials and adverse effects of the solution being considered for use.

Transfusion in surgery and trauma

The role of transfusion in surgery and trauma continues to evolve with our greater understanding of the true indications for and effects of transfusion. The potential adverse immune consequences and end-organ effects of blood transfusion must be weighed against the need for replacement of blood volume and oxygen-carrying capacity. The techniques to conserve blood and avoid transfusion play an important role in caring for the bleeding surgical patient. The future holds great promise for the possibility of redefining the art of blood transfusion and perhaps one day replacing it entirely.

Inter- and intrarater reliability in computed axial tomographic grading of splenic injury: why so many grading scales?

OBJECTIVE

After splenic trauma, critical decisions regarding operative intervention are often made with the aid of computed axial tomographic (CT) scan findings. No CT scan-based grading scale has been demonstrated to predict accurately which patients require operative or radiologic intervention for their splenic injuries. We hypothesized that use of the most common grading scale, the American Association for the Surgery of Trauma scale, would be associated with low intra- and interreliability scores. We assessed the ability of experienced trauma radiologists to differentiate grade III from grade IV splenic injuries.

METHODS

The films of patients who had undergone abdominal CT scanning before splenectomy for grade III or IV injuries were serially evaluated by four trauma radiology faculty weekly for 3 weeks. We assessed intra- and interrater reliability for grading and for presence of contrast blush.

RESULTS

Intrarater reproducibility yielded a weighted kappa score of 0.15 to 0.77. Interrater reliability weighted kappa scores ranged from 0 to 0.84, with a mean value of 0.23.

CONCLUSION

CT imaging is not reliable for identifying grades III and IV splenic injury, as experienced radiologists often underestimate the magnitude of injury. Interrater reliability is poor. Factors other than the CT grade of splenic injury should determine whether patients require operative or angiographic therapy.

Outcome of motorcycle riders at one year post-injury

OBJECTIVE

There is little information about the long-term effects of injury on victims of motorcycle crashes. Following the repeal of the mandatory helmet law in Florida, we studied the impact of crashes on riders and their outcomes one year post-injury.

SUBJECTS

All patients involved in a motorcycle crash over a six-month time period were assessed at one year post-injury. Demographic information, health status, motorcycle and helmet usage, and employability were surveyed.

RESULTS

There were 94 patients evaluated at our center for the first six-month period following the repeal of the helmet law, where 50 (56%) were wearing a helmet at the time of injury. Of the 94, we were able to contact 45 (48%) at one-year follow up. Fourteen (31%) of those contacted were not wearing a helmet at the time of their crash. At one year post-injury, 23 (51%) reported physical deficits, while 39 (86%) were working. Only 12 (27%) were riding a motorcycle again, and 11 (92%) were wearing a helmet.

CONCLUSIONS

Motorcycle riders at one year post-injury continue to experience physical deficits related to their accidents. There is a small percentage of riders that resume riding a motorcycle after injury. Being involved in a motorcycle accident has deterred the injured rider from riding a motorcycle again at one year post-injury.

Open surgical wounds: how does Aquacel compare with wet-to-dry gauze?

OBJECTIVE

To compare the healing rates of a hydrofibre dressing (Aquacel) and normal wet-to-dry gauze in the treatment of open surgical wounds.

METHOD

Fifty patients with open surgical wounds were randomized to receive either saline-moistened gauze or Aquacel. The rate of wound healing was measured as ml/day (deep wounds) or cm2/day (superficial wounds) at each dressing change until an investigator blinded to the patient group diagnosed the wounds as having healed or the patient was withdrawn from the study.

RESULTS

Of the 50 patients, seven were withdrawn from the study after the first evaluation. Of the remaining 43 patients, 21 had been randomly allocated to the gauze group and 22 to the Aquacel group. For deep wounds, a mean change in the wound healing rate of 1.9 +/- 1.3 cm3/day was reported for the gauze group and 2.9 +/- 2.3 cm3/day for the Aquacel group. These results approach statistical significance (p = 0.082). For superficial wounds, the mean change in the healing rate was 1.6 +/- 1.5 cm2/day for the gauze group and 1.9 +/- 2.2 cm2/day for the Aquacel group, but this was not statistically significant.

CONCLUSION

Aquacel appears to be at least as effective as wet-to-dry gauze in the healing of open surgical wounds.

A prospective randomized study of clinical assessment versus computed tomography for the diagnosis of acute appendicitis

BACKGROUND

The objective of this study was to determine if routine use of computed tomography (CT) for the diagnosis of appendicitis is warranted.

METHODS

During a one-year study period, all patients who presented to the surgical service with possible appendicitis were studied. One hundred eighty-two patients with possible appendicitis were randomized to clinical assessment (CA) alone, or clinical evaluation and abdominal/pelvic CT. A true-positive case resulted in a laparotomy that revealed a lesion requiring operation. A true-negative case did not require operation at one-week follow-up evaluation. Hospital length of stay, hospital charges, perforation rates, and times to operation were recorded.

RESULTS

The age and gender distributions were similar in both groups. Accuracy was 90% in the CA group and 92% for CT. Sensitivity was 100% for the CA group and 91% for the CT group. Specificity was 73% for CA and 93% for CT. There were no statistically significant differences in hospital length of stay (CA = 2.4 +/- 3.2 days vs. CT = 2.2 +/- 2.2 days, p = 0.55), hospital charges (CA = 10,728 US dollars +/- 10,608 vs. CT = 10,317 US dollars +/- 7,173, p = 0.73) or perforation rates (CA = 6% vs. CT = 9%, p = 0.4). Time to the operating room was shorter in the CA group, 10.6 +/- 8.4 h vs. CT, 19.0 +/- 19.0 h (p < 0.01).

CONCLUSIONS

Clinical assessment unaided by CT reliably identifies patients who need operation for acute appendicitis, and they undergo surgery sooner. Routine use of abdominal/pelvic CT is not warranted. Further research is needed to identify sub-groups of patients who may benefit from CT. Computed tomography should not be considered the standard of care for the diagnosis of appendicitis.

Diagnostic peritoneal lavage through an abdominal stab wound

Diagnostic peritoneal lavage (DPL) is one of the most useful tools in the diagnosis of intraperitoneal injuries secondary to stab wounds. The lavage catheter is inserted into the peritoneal cavity through a surgical incision or a blind puncture. Complications related to the catheter insertion were previously reported in both techniques. We describe 2 cases in which the lavage catheter was inserted through the stab wound itself after local wound exploration clearly demonstrated violation of the peritoneum. We suggest that in anterior abdominal stab wounds, the DPL can be safely and effectively performed through the stab wound if penetration to the peritoneum is diagnosed.

Splanchnic Perfusion During Delayed, Hypotensive, or Aggressive Fluid Resuscitation From Uncontrolled Hemorrhage

The purpose of this study was to determine the effect of three different fluid resuscitation strategies on splanchnic perfusion in a clinically relevant model of uncontrolled hemorrhage after liver trauma. Anesthetized swine were instrumented with a gastric near-infrared spectroscopy probe (GStO2), a jejunal tonometer (PrCO2), a portal vein catheter (SpvO2, lactate), and an ultrasonic blood flow probe on the superior mesenteric artery. The liver was lacerated to produce uncontrolled hemorrhage and a shock state characterized by a 40-60% decrease in cardiac output and a decrease in mean arterial pressure (MAP) to 42 +/- 1 mmHg. Animals were randomly assigned to either delayed resuscitation (n = 6); hypotensive resuscitation with lactated Ringer's infusion to MAP = 60 mmHg (n = 6); or aggressive resuscitation with LR to MAP >/= 75 mmHg (n = 6). For the remainder of the protocol, the treatment was identical. The data showed that blood loss (47 +/- 7 and 45 +/- 10 mL/kg) and total fluid requirements (118 +/- 73 and 171 +/- 85 mL/kg) were similar with either hypotensive or aggressive resuscitation. In contrast, with delayed resuscitation, both values were lower (27 +/- 2 mL/kg and 87 +/- 33 mL/kg, both P < 0.05). Despite aggressive resuscitation, SpvO2 and GstO2 were about 10% lower (both P < 0.05 within group) and PrCO2 was about 20 mmHg higher (P < 0.05 within group) than the corresponding values in the other two groups. Thus, delayed resuscitation minimized the blood loss but did not restore tissue oxygenation, whereas aggressive resuscitation was associated with maximal blood loss and splanchnic hypoperfusion. For this reason, it is reasonable to conclude that hypotensive resuscitation might be an effective strategy to maintain splanchnic perfusion after blunt abdominal trauma and uncontrolled hemorrhage.

Randomized clinical trial of intermittent pneumatic compression and low molecular weight heparin in trauma

Background

After trauma, up to 60 per cent of immobilized patients have been reported to develop a silent deep vein thrombosis (DVT). No large, prospective randomized trials have tested the efficacy of intermittent pneumatic compression (IPC) devices in these patients.

Methods

A prospective randomized trial was performed of 442 patients who received thromboprophylaxis using either an IPC device or low molecular weight heparin (LMWH). Duplex imaging was performed on both legs on admission, and was repeated weekly thereafter until discharge, at 30 days or when there was a thrombotic event, whichever occurred first.

Results

There were no significant differences in time spent in intensive care, or the proportion of patients with pelvic fractures, spinal cord or head injuries between the two groups. Six patients (2·7 per cent) developed a DVT in the IPC group and one (0·5 per cent) in the LMWH group (P = 0·122). Pulmonary embolism occurred in one patient in each group. There were 13 minor bleeding episodes (four in the IPC group and nine in the LMWH group) and eight major bleeding episodes (four in each group), none of which required operative intervention.

Conclusion

The low rate of thromboembolic complications and the cost savings suggest that IPC might be used safely and effectively for thromboprophylaxis in trauma patients.