William J. Flynn

Prospective evaluation of epidural versus intrapleural catheters for analgesia in chest wall trauma.

Severe blunt chest trauma can produce multiple rib fractures, flail segments, and pulmonary contusions. All of these injuries produce pain and diminished pulmonary function. The effectiveness of intrapleural and epidural administration of bupivacaine was prospectively evaluated in 19 patients with severe chest trauma. Pain relief and pulmonary function were evaluated for 72 hours after catheter placement. Epidural administration of bupivacaine significantly reduced pain at rest and with motion compared with the intrapleural route (p < 0.05). Parenteral narcotic use was also significantly less in the epidural group (p < 0.05). Negative inspiratory pressure and tidal volume were significantly increased with epidural anesthesia (p < 0.05). Vital capacity, FIO2, minute ventilation, and respiratory rate were not affected. Mild hypotension was a common complication with epidural catheters. We conclude that continuous epidural analgesia is superior to intrapleural block and significantly improves tidal volume and negative inspiratory pressure.

Pentoxifylline but not saralasin restores hepatic blood flow after resuscitation from hemorrhagic shock

After determining that hepatic blood flow remains impaired after resuscitation from hemorrhagic shock, we used the angiotensin II receptor antagonist saralasin and pentoxifylline to investigate their respective effects on hepatic blood flow responses after resuscitation from hemorrhagic shock. Rats were bled to 50% of baseline blood pressure for 60 min and resuscitated with shed blood and an equal volume of lactated Ringers solution. Saralasin [10 micrograms/kg per min (n = 6)], pentoxifylline [25 mg/kg bolus and 12.5 mg/kg per hr (n = 7)], or saline (n = 11) were started with the onset of resuscitation. Total hepatic blood flow measured by ultrasonic transit time flow meter, effective nutrient hepatic blood flow measured by galactose clearance, mean arterial pressure, and cardiac output were recorded at 15-min intervals for 2 hr after resuscitation. Hemorrhage decreased cardiac output 57% below baseline and decreased total hepatic blood flow 64% below baseline. Resuscitation restored cardiac output to baseline levels in all three groups. Despite restoration of cardiac output, total hepatic and effective hepatic blood flow remained significantly below baseline in the saline control and saralasin groups but was restored to baseline levels in the pentoxifylline group. These data indicate that angiotensin II does not contribute significantly to the hepatic blood flow impairment after resuscitation from hemorrhagic shock. Improvement in flow with pentoxifylline implies that hemorrhage and resuscitation impair hepatic microvascular hemorrheology and that addition of pentoxifylline to standard resuscitation corrects the impairment.

Is colostomy always necessary in the treatment of open pelvic fractures

BACKGROUND Wound management in open pelvic fractures has used fecal diversion, debridement, and closure by secondary intention to prevent pelvic sepsis. Colostomy care and takedown adds to the morbidity and resource utilization of this approach. We reviewed our experience to determine if a selective approach to fecal diversion based on wound location was possible. METHODS Retrospective analysis of patients admitted to a Level I trauma center during an 8-year period. Fractures were classified as open if the fracture was in continuity with the wound. Wounds were classified as perineal if they involved the rectum, ischiorectal fossa, or genitalia, and as nonperineal if they involved the pubis anteriorly, iliac crest, or anterior thigh. Pelvic sepsis was defined as cellulitis, fasciitis, or infection of a pelvic hematoma. Diversion consisted of loop or end colostomy. RESULTS Eighteen patients with open fractures were identified. Four died from closed head injury and blood loss. The remaining 14 were treated as follows. Five patients with perineal wounds had diversion of their fecal stream. Their Injury Severity Score was 34 +/- 8.3 and their Revised Trauma Score was 7.69 +/- 0.15. No patient developed pelvic sepsis. Nine patients with nonperineal wounds did not undergo diversion. Their Injury Severity Score was 28.6 +/- 5.3 and their Revised Trauma Score was 7.36 +/- 0.45. No patients developed pelvic sepsis in the nondiverted group. CONCLUSION No patients with anterior wounds and an intact fecal stream developed pelvic sepsis. Colostomy may not be necessary in all patients with open pelvic fracture. Protocols using fecal diversion based on wound location appear to be safe and may decrease resource utilization and subsequent morbidity related to colostomy closure.

Brain injury causes loss of cardiovascular response to hemorrhagic shock.

The combined cardiovascular effects of hemorrhagic shock and mechanical brain injury were modeled in five groups of pigs. Standard and hypertonic saline resuscitation of hypotension were evaluated. Changes in mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), intracranial pressure (ICP), and brain water were measured. Brain injury (BI) was produced with a fluid percussion device that generated an extradural pressure of 3.5 x 10(5) N/m2 for 400 msec. Shock was caused by bleeding to a MAP of 60 mm Hg for 60 minutes and then resuscitated with shed blood only or shed blood plus 0.9% or 1.8% saline. Brain-injured only and shocked-only pigs served as controls. We found that brain injury alone caused refractory hypotension. Less shed blood was required to produce shock in brain injured animals (p < .05). Shock accompanied by brain injury was not reversed with crystalloid solutions. Volumes of saline required to restore blood pressure were large (> 6 L in 3 hours). 1.8% saline produced less rise in ICP than 0.9% saline but was less effective in restoring blood pressure. Brain edema was not decreased with 1.8% saline. Brain injury altered vascular compensation to hemorrhage and made accepted resuscitative measures ineffective.

Xanthine oxidase inhibition after resuscitated hemorrhagic shock restores mesenteric blood flow without vasodilation.

To determine the contribution of xanthine oxidase-mediated reperfusion injury to the blood flow deficits seen in the intestinal microcirculation after resuscitated hemorrhagic shock, rats were prepared for intravital microscopic study then bled to 50% of baseline blood pressure for 60 min. Treatment animals received a 50 mg/kg bolus and a 25 mg/kg/h infusion of the xanthine oxidase inhibitor allopurinol after shock but before standard resuscitation with shed blood and an equal volume of Ringers lactate. A similarly resuscitated group served as control. Blood flow and vessel diameters were measured in the neurovascularly intact terminal ileum using intravital microscopy and doppler velocimetry. Resuscitation restored cardiac output and blood pressure in both groups. Blood flow in first order arterioles 120 min postresuscitation was 41 % of baseline in the standard resuscitation group and 77% of baseline in the allopurinol-treated group. A1 arteriolar diameter was not significantly different between the two groups, being 73 and 82% of baseline, respectively. These data suggest that xanthine oxidase-mediated ischemia-reperfusion injury contributes to blood flow deficits in the small intestinal microcirculation after resuscitated hemorrhagic shock and that the improvement in blood flow seen with allopurinol is not due to vasodilation within the microvasculature.

Development of a longitudinal study of complications and functional outcomes after traumatic brain injury

Primary objective : To create a longitudinal database of patients with moderate and severe traumatic brain injury. Research design : A prospective study design was used to collect data pertaining to demographics, acute and post-acute management, complications, resource utilization and functional outcomes. Methods and procedures : Data were collected on 233 patients with a Glasgow Coma Score of 12 or less, admitted to a Level 1 Trauma Centre within 24 hours of injury and continued through post-hospitalization follow-up. Main outcomes and results : The mean age was 37.7 years, 70% were males, 54% were motor vehicle related accidents, and 21% died. Of the 185 survivors, 23% were discharged directly home from acute hospital care and 74% required inpatient rehabilitation. At hospital discharge, 76% had Rancho Los Amigos Scores of VII or higher; 81% had no or only mild verbal communication deficits and 79% were able to ambulate. Conclusions : The study indicates that while it is difficult to predict functional outcomes for individual survivors of TBI in the early stages of acute care, they are often better than suspected at the time of injury.

Allopurinol plus standard resuscitation preserves hepatic blood flow and function following hemorrhagic shock

To determine the contribution of ischemia-reperfusion injury (IRI) to the blood flow deficit and hepatocellular dysfunction seen after resuscitation from hemorrhagic shock, the xanthine oxidase inhibitor allopurinol was given to rats as a 50 mg/kg bolus after shock but before resuscitation and continued as a 25 mg/kg/h infusion. Resuscitation with shed blood and lactated Ringers restored cardiac output and blood pressure in both groups. Control animals demonstrated a reduction in total hepatic and effective hepatic blood flow to 59% and 43% of baseline values, respectively. Allopurinol resulted in a return to baseline values of both variables. Allopurinol treatment resulted in a 350% increase in xanthine, a 630% increase in hypoxanthine, and a 70% reduction in uric acid concentrations. These data suggest that IRI contributes to the organ dysfunction and blood flow deficits seen after resuscitated hemorrhagic shock the effect of which can be attenuated by the addition of the xanthine oxidase inhibitor allopurinol to standard resuscitation.

Correlation of computed tomographic signs of hypoperfusion and clinical hypoperfusion in adult blunt trauma patients.

BACKGROUND The computed tomographic signs of hypoperfusion (CTSHs) have been reported in radiology literature as preceding the onset of clinical shock in children, but its correlation with tenuous hemodynamic status in adult blunt trauma patients has not been well studied. We hypothesized that these CT findings represent a clinically hypoperfused state and predict patient outcomes. METHODS We retrospectively reviewed 52 adult blunt trauma patients who presented to our Level I trauma center with an Injury Severity Score (ISS) greater than 15 and a systolic blood pressure less than 90 mm Hg and who underwent torso CT scans during a period of 5.5 years. Patient’s demographics and clinical data were recorded. All CT scans were assessed by our radiologist (J.M.) for 25 CTSHs. RESULTS Seventy-nine percent of the patients studied exhibited CTSH. The mean number of signs identified per patient was 4. Patient with the most common CTSH, that is, free peritoneal fluid, small bowel enhancement, flattened inferior vena cava (IVC), and flattened renal veins, had a significantly higher intensive care unit admission rate than those without (all p < 0.05). Patient with signs of small bowel abnormal enhancement/dilation, flattened IVC/renal vein had worse acidosis (all p < 0.05). A significantly lower admission hemoglobin and an increased need for red blood cell transfusion were found in patient with flattened IVC (p < 0.05), flattened renal vein (p < 0.01), and active contrast extravasation (p < 0.01). Univariate analysis identified small bowel dilatation and splenic injury as factors associated with mortality and laparotomy, respectively. Logistic regression model revealed that splenic injury is a significant independent predictor of laparotomy (odd ratio, 7.50; 95% confidence interval, 1.67–33.71; p < 0.01). CONCLUSION CTSH correlates with clinical hypoperfusion in blunt trauma patients and has important prognostic and therapeutic implications. The presence of CTSH in blunt trauma patients should draw immediate attention and require prompt intervention. Trauma surgeons should be familiar with these signs and include them in the clinical decision-making paradigms to improve outcomes in blunt trauma. LEVEL OF EVIDENCE Diagnostic study, level III.

Revisiting endotracheal self-extubation in the surgical and trauma intensive care unit: Are they all fine?

OBJECTIVES Endotracheal self-extubation (ESE) is a serious health care concern. We designed this study to test our hypothesis that not all patients with ESE are successful in spontaneous breathing and reintubation has negative impact on outcomes. METHODS Data on all 39 patients of ESE in our surgical and trauma intensive care unit (ICU) in 2012 were prospectively collected and retrospectively analyzed. RESULTS There were 42 episodes of ESE in 39 of 939 intubated patients (frequency, 4.0%), with 54% of events requiring reintubation. Pre-ESE positive end-expiratory pressure was higher and Pao2/fraction of inspired oxygen ratio was lower, and the post-ESE respiration rate was higher in the reintubated group. On univariate analysis, weaning and spontaneous breathing trial before ESE were favorable predictors for nonreintubation. Multivariate regression analysis demonstrated that agitation before ESE was an independent predictor of reintubation. The need for reintubation was associated with increased risk of pulmonary infectious complications, ventilator days, the need for tracheostomy, and ICU and hospital LOS. The financial costs for ventilator days and ICU rooms were significantly higher in patients with reintubation. CONCLUSION Not all patients were fine after ESE. We have not decreased the frequency of ESE or improved outcomes if the patients were reintubated. The need for reintubation was not only associated with a high pulmonary complication rate but also prolonged duration on mechanical ventilation and hospital/ICU stay and increased the hospital costs.