Christine S. Cocanour

Both primary and secondary abdominal compartment syndrome can be predicted early and are harbingers of multiple organ failure

BACKGROUND Primary abdominal compartment syndrome (ACS) is a known complication of damage control. Recently secondary ACS has been reported in patients without abdominal injury who require aggressive resuscitation. The purpose of this study was to compare the epidemiology of primary and secondary ACS and develop early prediction models in a high-risk cohort who were treated in a similar fashion. METHODS Major torso trauma patients underwent standardized resuscitation and had prospective data collected including occurrence of ACS, demographics, ISS, urinary bladder pressure, gastric tonometry (GAP(CO2) = gastric regional CO(2) minus end tidal CO(2)), laboratory, respiratory, and hemodynamic data. With primary and secondary ACS as endpoints, variables were tested by uni- and multivariate logistic analysis (MLA). RESULTS From 188 study patients during the 44-month period, 26 (14%) developed ACS-11 (6%) were primary ACS and 15 (8%) secondary ACS. Primary and secondary ACS had similar demographics, shock, and injury severity. Significant univariate differences included: time to decompression from ICU admit (600 +/- 112 vs. 360 +/- 48 min), Emergency Department (ED) crystalloid (4 +/- 1 vs. 7 +/- 1 L), preICU crystalloid (8 +/- 1 vs. 12 +/- 1L), ED blood administration (2 +/- 1 vs. 6 +/- 1 U), GAP(CO2) (24 +/- 3 vs. 36 +/- 3 mmHg), requiring pelvic embolization (9 vs. 47%), and emergency operation (82% vs. 40%). Early predictors identified by MLA of primary ACS included hemoglobin concentration, GAP(CO2), temperature, and base deficit; and for secondary ACS they included crystalloid, urinary output, and GAP(CO2). The areas under the receiver-operator characteristic curves calculated upon ICU admission are primary= 0.977 and secondary= 0.983. Primary and secondary ACS patients had similar poor outcomes compared with nonACS patients including ventilator days (primary= 13 +/- 3 vs. secondary= 14 +/- 3 vs. nonACS = 8 +/- 2), multiple organ failure (55% vs. 53% vs. 12%), and mortality (64% vs. 53% vs. 17%). CONCLUSION Primary and secondary ACS have similar demographics, injury severity, time to decompression from hospital admit, and bad outcome. 2 degrees ACS is an earlier ICU event preceded by more crystalloid administration. With appropriate monitoring both could be accurately predicted upon ICU admission.

Vacuum-assisted wound closure provides early fascial reapproximation in trauma patients with open abdomens

BACKGROUND Damage control and decompressive laparotomies salvage severely injured patients who would have previously died. Unfortunately, many of these patients develop open abdomens. A variety of management strategies exist. The end result in many cases, however, is a large ventral hernia that requires a complex repair 6 to 12 months after discharge. We instituted vacuum-assisted wound closure (VAWC) to achieve early fascial closure and eliminate the need for delayed procedures. METHODS For 12 months ending June 2000, 14 of 698 trauma intensive care unit admissions developed open abdomens and were managed with VAWC dressing. This was changed every 48 hours in the operating room with serial fascial approximation until complete closure. RESULTS Fascial closure was achieved in 13 patients (92%) in 9.9 +/- 1.9 days, and 2.8 +/- 0.6 VAWC dressing changes were performed. There were 2 wound infections, no eviscerations, and no enteric fistulas. CONCLUSIONS Use of VAWC can safely achieve early fascial closure in more than 90% of trauma patients with open abdomens.

Secondary abdominal compartment syndrome is an elusive early complication of traumatic shock resuscitation.

BACKGROUND The term secondary abdominal compartment syndrome (ACS) has been applied to describe trauma patients who develop ACS but do not have abdominal injuries. The purpose of this study was to describe major trauma victims who developed secondary ACS during standardized shock resuscitation. METHODS Our prospective database for standardized shock resuscitation was reviewed to obtain before and after abdominal decompression shock related data for secondary ACS patients. Focused chart review was done to confirm time-related outcomes. RESULTS Over the 30 months period ending May 2001, 11 (9%) of 128 standardized shock resuscitation patients developed secondary ACS. All presented in severe shock (systolic blood pressure 85 +/- 5 mm Hg, base deficit 8.6 +/- 1.6 mEq/L), with severe injuries (injury severity score 28 +/- 3) and required aggressive shock resuscitation (26 +/- 2 units of blood, 38 +/- 3 L crystalloid within 24 hours). All cases of secondary ACS were recognized and decompressed within 24 hours of hospital admission. After decompression, the bladder pressure and the systemic vascular resistance decreased, while the mean arterial pressure, cardiac index, and static lung compliance increased. The mortality rate was 54%. Those who died failed to respond to decompression with increased cardiac index and did not maintain decreased bladder pressure. CONCLUSIONS Secondary ACS is an early but, if appropriately monitored, recognizable complication in patients with major nonabdominal trauma who require aggressive resuscitation.

Tissue hemoglobin O2 saturation during resuscitation of traumatic shock monitored using near infrared spectrometry.

BACKGROUND Near infrared (NIR) spectrometry offers a noninvasive monitor of tissue hemoglobin O2 saturation and has been developed to report a quantitative clinical variable, StO2 [= HbO2/(HbO2 + Hb)]. In this study, a prototype NIR oximeter was used to investigate the hypothesis that changes in systemic O2 delivery index (D(O2)I) would be reflected by changes in StO2 in skeletal muscle, subcutaneous tissue, or both, as reperfusion occurs during shock resuscitation. StO2 was also compared with other indices of severity of shock or adequacy of resuscitation, including arterial base deficit, lactate, gastric mucosal P(CO2) (PgCO2), and mixed venous hemoglobin O2 saturation (S(VO2)). METHODS Skeletal muscle and subcutaneous tissue StO2 were monitored simultaneously in eight severely injured trauma patients (88% blunt mechanism; age, 42 +/- 6 years; Injury Severity Score, 27 +/- 3) during standardized shock resuscitation in the intensive care unit with the primary goal of D(O2)I > or = 600 mL O2/min/m2 for 24 hours, and for an additional 12 hours during transition from resuscitation to standard intensive care unit care. RESULTS Skeletal muscle StO2 increased significantly from 15 +/- 2% (mean +/- SEM) at the start of resuscitation to 49 +/- 14% at 24 hours, and to approximately 55% from 25 to 36 hours. Subcutaneous tissue StO2 approximately 82% and was significantly greater than skeletal muscle StO2 throughout. D(O2)I increased significantly from 372 +/- 54 to 718 +/- 47 mL O2/min/m2 during resuscitation. Over 36 hours, mean D(O2)I and skeletal muscle StO2 were highly correlated (r = 0.95). Neither D(O2)I-PgCO2 nor D(O2)I-S(VO2) were significantly correlated; neither S(VO2) nor subcutaneous tissue StO2 changed significantly. CONCLUSION Hemoglobin O2 saturation was monitored noninvasively and simultaneously in skeletal muscle and subcutaneous tissues as StO2 (%) by using a prototype NIR oximeter. Skeletal muscle StO2 tracked systemic O2 delivery during and after resuscitation. As a rapidly deployable, noninvasive monitor of peripheral tissue oxygenation and O2 delivery, skeletal muscle StO2 obtained using NIR spectrometry would be useful to guide resuscitation in the intensive care unit, to monitor resuscitation status in the operating room, and, potentially, in combination with indicators such as base deficit and lactate, to detect shock during initial assessment of the severe trauma patient in the emergency department.

Vacuum-assisted wound closure achieves early fascial closure of open abdomens after severe trauma.

BACKGROUND This study reviews the efficacy of vacuum-assisted wound closure (VAWC) to obtain primary fascial closure of open abdomens after severe trauma. METHODS The study population included shock resuscitation patients who had open abdomens treated with VAWC. The VAWC dressing was changed at 2- to 3-day intervals and downsized as fascial closure was completed with interrupted suture. The Trauma Research Database and the medical records were reviewed for pertinent data. RESULTS Over 26 months, 35 patients with open abdomens were managed by VAWC. Six died early, leaving 29 patients who were discharged. Of these, 25 (86%) were successfully closed using VAWC at a mean of 7 +/- 1 days (range, 3-18 days). Of the four patients that failed VAWC, two developed fistulas. No patients developed evisceration, intra-abdominal abscess, or wound infection. CONCLUSION VAWC achieved early fascial closure in a high percentage of open abdomens, with an acceptable rate of complications.

Nonocclusive bowel necrosis occurring in critically ill trauma patients receiving enteral nutrition manifests no reliable clinical signs for early detection

BACKGROUND Nonocclusive bowel necrosis (NOBN) has been associated with early enteral nutrition (EN). The purpose of this study was to determine the incidence of this complication in our trauma intensive care unit population and to define a typical patient profile vulnerable to NOBN. METHODS Thirteen cases of NOBN were identified among 4,311 patients (0.3%) over a 64-month period ending October 1998. Their charts were analyzed for a variety of clinical data, including prospective EN tolerance data in 4. RESULTS Twelve (92%) patients were enterally fed prior to diagnosis for 10 +/- 8 days (range 3 to 21). Tachycardia (n = 12, 92%); fever/hypothermia, (n = 12, 92%), and an abnormal white blood cell count (n = 11, 85%) were consistently present. Abdominal distention was common but tended to be a late sign (n = 12). Seven (56%) survived. In 4 patients with tolerance data, 3 reached the goal rate of feeds prior to diagnosis. Two became distended at >12 hours from diagnosis. Gastric tonometry demonstrated a decreased NgpHi (<7.30) after starting EN in all 3 in whom it was monitored. CONCLUSIONS NOBN developed in 0.3% of our trauma patients. Onset occurs in the second week in high-acuity patients who have had a period of EN tolerance. Clinical findings resemble bacterial sepsis with tachycardia, fever, and leukocytosis. Gastrointestinal specific signs are not consistent or occur late. Thus, we could not identify an early, useful clinical indicator. Gastric carbon dioxide tonometry may detect a vulnerable subgroup of patients.

Mucormycosis in trauma patients.

Cutaneous mucormycosis is a rare but often fatal infection in trauma patients. We retrospectively reviewed a 9-year experience with mucormycosis among injured patients. Eleven patients had biopsy- or culture-proven mucormycosis. Nine patients were victims of blunt trauma, two patients had burns measuring greater than 50% TBSA. No patient was at increased risk because of underlying disease or immunosuppression prior to injury. All 11 patients had open wounds on admission. Four patients died of mucormycosis. All nonsurvivors had phycomycotic gangrenous cellulitis of the head, the trunk, or both. In contrast, survivors had involvement of only the extremities. Because of underlying disease, contaminating wounds, antibiotic use, or immunocompromise secondary to shock and sepsis, trauma patients are at risk of developing mucormycosis. To successfully treat mucormycosis, diagnosis must be prompt and accompanied by aggressive debridement and parenteral administration of amphotericin B.

Age should not be a consideration for nonoperative management of blunt splenic injury.

BACKGROUND Operative management of blunt splenic injury is recommended for adults > or = 55 years. Because this is not our practice, we did a retrospective review to compare outcomes of patients > or = 55 years old versus patients < 55 years old. METHODS During a 5-year period ending in July of 1998, 461 patients (3%) admitted to our Level I trauma center had a blunt splenic injury. Eighty-six patients (19%) died within 24 hours of massive injuries, leaving 375 patients for evaluation. Data were obtained from our trauma registry and medical records. RESULTS A total of 29 patients (8%) were > or = 55 years old (mean age, 67 +/- 2 years; mean injury severity score [ISS] 25 +/- 2). Of these, 18 patients (62%) underwent nonoperative management (NOM). A total of 346 patients (92%) were < 55 years old (mean age, 28 +/- 0.6; mean ISS, 20 +/- 1). Of these, 198 patients (57%) underwent NOM. The failure rate was not different between the two age groups (17% vs. 14%). However, the ISS and mortality rate were significantly higher in the older age group that failed (ISS, 29.3 +/- 2.6 vs. 19.5 +/- 2.1; mortality: 67% vs. 4%). None of the deaths could be attributed to splenic injury. CONCLUSION Adults > or = 55 years old with blunt splenic injury are successfully treated by NOM. Although older adults had significantly greater injuries, they had similar failure rates of NOM when compared with younger adults. Older adults had significantly higher mortality, but this was not a result of their splenic injury. Therefore, age should not be a criteria for NOM of blunt splenic injury.

Operative treatment of truncal vascular injuries in children and adolescents

BACKGROUND/PURPOSE Pediatric truncal vascular injuries are rare, but the reported mortality rate is high (35% to 55%), and similar to that in adults (50% to 65%). This report examines the demographics, mechanisms of injury, associated trauma, and results of treatment of pediatric patients with noniatrogenic truncal vascular injuries. METHODS A retrospective review (1986 to 1996) of a pediatric (< or = 17 years old) trauma registry database was undertaken. Truncal vascular injuries included thoracic, abdominal, and neck wounds. RESULTS Fifty-four truncal vascular injuries (28 abdominal, 15 thoracic, and 11 neck injuries) occurred in 37 patients (mean age, 14+/-3 years; range, 5 to 17 years); injury mechanism was penetrating in 65%. Concomitant injuries occurred with 100% of abdominal vascular injuries and multiple vascular injuries occurred in 47%. Except for aortic and one SMA injury requiring interposition grafts, these wounds were repaired primarily or by lateral venorrhaphy. Nonvascular complications occurred more frequently in patients with abdominal injuries who were hemodynamically unstable (systolic blood pressure [BPS] <90) on presentation (19 major complications in 11 patients versus one major complication in five patients). Thoracic injuries were primarily blunt rupture or penetrating injury to the thoracic aorta (nine patients). Thoracic aortic injuries were treated without bypass, using interposition grafts. In patients with thoracic aortic injuries, there were no instances of paraplegia related to spinal ischemia (clamp times, 24+/-4 min); paraplegia occurred in two patients with direct cord and aortic injuries. Concomitant injuries occurred with 83% of thoracic injuries and multiple vascular injuries occurred in 25%. All patients with thoracic vascular injuries presenting with BPS of less than 90 died (four patients), and all with BPS 90 or over survived (eight patients). There were 11 neck wounds in 9 patients requiring intervention, and 8 were penetrating. Overall survival was 81%; survival from abdominal vascular injuries was 94%, thoracic injuries 66%, and neck injuries 78%. CONCLUSIONS Survival and subsequent complications are related primarily to hemodynamic status at the time of presentation, and not to body cavity or vessel injured. Primary anastomosis or repair is applicable to most nonaortic wounds. The mortality rate in pediatric abdominal vascular injuries may be lower than previously reported.

Are scene flights for penetrating trauma justified

OBJECTIVE To evaluate the medical efficacy of helicopter scene flights for patients with noncranial penetrating injuries. DESIGN A retrospective review of 122 consecutive victims of noncranial penetrating injuries evacuated by helicopter from the scene of injury to a level I trauma center. There were no medical criteria for accepting or rejecting a request for a scene flight by any public safety agency or emergency medical service (EMS). Flights were dispatched if the weather permitted and if a helicopter was available. RESULTS The majority of patients were critically wounded. Their average Revised Trauma Score was 10.6, and 15.6% of the patients died (19 of 122), including all 11 patients who required prehospital cardiopulmonary resuscitation. Helicopter transport from the scene did not hasten trauma center arrival for any of the 122 patients. Ninety-two of the first-responder EMS units (75.4%) were advanced life support units (ALS) with crews of paramedics. The remaining 30 (24.6%) first-responder EMS units were basic life support units (BLS) with crews of emergency medical technicians (EMTs). Six of 122 patients (4.9%) required medical interventions by the medical flight crews beyond the capabilities of the ground EMS personnel. Only 3 of the 92 patients (3.3%) treated by first-responding paramedics received medical interventions by the medical flight crews beyond those authorized for paramedics (one cricothyroidotomy and two needle thoracenteses). Two of the 30 patients (6.7%) treated by first-responding EMTs received medical interventions by the medical flight crews not authorized for the EMTs. The on-scene paramedics performed endotracheal intubation on 10 patients. However, because of subsequent clinical deterioration, the medical flight crews performed endotracheal intubations on nine additional patients. In addition, two patients intubated by the first-responding paramedics required reintubation by the medical flight crews. CONCLUSIONS Scene flights in this metropolitan area for patients who suffered noncranial penetrating injuries demonstrated that these flights were not medically efficacious. This conclusion rests on the findings that arrival at a trauma center was not hastened by scene flights and that only 4.9% of patients required prehospital care by the medical flight crew beyond the capabilities of the first-responding EMS personnel (2.5 and 6.7% for ALS and BLS responders, respectively). Based on this experience, we believe that in metropolitan areas, scene flights for victims of noncranial penetrating injuries should be restricted to critically injured patients likely to require prehospital care by the medical flight crew that is beyond the capabilities of the first responders or when the scene flight is likely to significantly hasten the arrival of the injured patient to an appropriate trauma center.