Jon M. Burch

THE ABDOMINAL COMPARTMENT SYNDROME

1. ACS is caused by an acute increase in intra-abdominal pressure, usually as a result of intra-abdominal hemorrhage. 2. The most common and significant complications are respiratory and renal failure. 3. Abdominal decompression promptly reverses the complications of ACS. 4. Failure to recognize and treat ACS is inevitably fatal.

Abbreviated laparotomy and planned reoperation for critically injured patients.

The triad of hypothermia, acidosis, and coagulopathy in critically injured patients is a vicious cycle that, if uninterrupted, is rapidly fatal. During the past 7.5 years, 200 patients were treated with unorthodox techniques to abruptly terminate the laparotomy and break the cycle. One hundred seventy patients (85%) suffered penetrating injuries and 30 (15%) were victims of blunt trauma. The mean Revised Trauma Score, Injury Severity Score, and Trauma Index Severity Score age combination index predicted survival were 5.06%, 33.2%, and 57%, respectively. Resuscitative thoracotomies were performed in 60 (30%) patients. After major sources of hemorrhage were controlled, the following clinical and laboratory mean values were observed: red cell transfusions--22 units, core temperature--32.1 C, and pH--7.09. Techniques to abbreviate the operation included the ligation of enteric injuries in 34 patients, retained vascular clamps in 13, temporary intravascular shunts in four, packing of diffusely bleeding surfaces in 171, and the use of multiple towel clips to close only the skin of the abdominal wall in 178. Patients then were transported to the surgical intensive care unit for vigorous correction of metabolic derangements and coagulopathies. Ninety-eight patients (49%) survived to undergo planned reoperation (mean delay 48.1 hours), and 66 of 98 (67%) survived to leave the hospital. With the exception of intravascular shunts, there were survivors who were treated by each of the unorthodox techniques. Of 102 patients who died before reoperation 68 (67%) did so within 2 hours of the initial procedure. Logistic regression showed that red cell transfusion rate and pH may be helpful in determining when to consider abbreviated laparotomy. The authors conclude that patients with hypothermia, acidosis, and coagulopathy are at high risk for imminent death, and that prompt termination of laparotomy with the use of the above techniques is a rational approach to an apparently hopeless situation.

Postinjury multiple organ failure: a bimodal phenomenon

To better define the epidemiology of postinjury multiple organ failure (MOF), we prospectively evaluated 457 high-risk trauma patients who survived more than 48 hours. Overall, 70 (15%) developed MOF. In 27 (39%) patients, the occurrence was early, while in 43 (61%) patients the presentation was delayed. At presentation, early MOF had more cardiac dysfunction, while late MOF had greater hepatic failure. Indices of shock were more critical risk factors for early MOF, while advanced age was more important for late MOF. While early and late MOF had a similar high incidence of major infections, these appeared to be more important in precipitating late MOF. Finally, while mortality is similar, early MOF patients appear to succumb faster. In conclusion, postinjury MOF remains a significant challenge and appears to present in at least two patterns (i.e., early versus late). Better understanding of the relative roles of the dysfunctional inflammation and infections in early MOF versus late MOF may facilitate the development of new strategies for the prevention and treatment of morbid syndrome.

Prospective characterization and selective management of the abdominal compartment syndrome

BACKGROUND The abdominal compartment syndrome (ACS) is now recognized as a frequent confounder of surgical critical care following major trauma; however, few prospective data exist concerning its characterization, evolution, and response to decompression. METHODS Acutely injured patients with an injury severity scale (ISS) score >15 requiring emergent laparotomy and intensive care unit (ICU) admission were prospectively evaluated for the development of ACS. The syndrome was defined as an intra-abdominal pressure (IAP) >20 mm Hg complicated by one of the following: peak airway pressure (PAP) >40 cm H2O, oxygen delivery index (DO2I) <600 mL O2/min/m2, or urine output (UO) <0.5 mL/kg/hr. Physiologic response to decompression was similarly documented prospectively. RESULTS Over a 14-month period ending December 1995, 21 (14%) of 145 patients (ISS >15) requiring laparotomy and admitted to our surgical ICU developed ACS; mean age was 39 +/- 9 years; injury mechanism was blunt in 60%; ISS 26 +/- 6. At initial laparotomy, 67% underwent abdominal packing (57% for major liver injuries). Mean IAP was 27 +/- 2.3 mm Hg, and time from laparotomy to decompression was 27 +/- 4 hours; 24% were planned whereas the remaining were prompted by deteriorating organ function as defined above (cardiopulmonary in 43%; renal in 19%; both renal and cardiopulmonary in 14%). Following decompression, there was an increase in cardiac index, oxygen delivery, urine output, and static compliance while there was a decrease in pulmonary capillary wedge pressure, systemic vascular resistance, and peak airway pressure. CONCLUSIONS The abdominal compartment syndrome occurs in a significant number of severely injured patients, and it develops quickly (27 +/- 4 hours). Cardiopulmonary deterioration is the most frequent reason prompting decompression. Timely decompression of the ACS results in improvements in cardiopulmonary and renal function. These data support the use of the proposed ACS grading system for selective management of the syndrome.

Prehospital hypertonic saline/dextran infusion for post-traumatic hypotension. The U.S.A. Multicenter Trial.

The safety and efficacy of 7.5% sodium chloride in 6% dextran 70 (HSD) in posttraumatic hypotension was evaluated in Houston, Denver, and Milwaukee. Multicentered, blinded, prospective randomized studies were developed comparing 250 mL of HSD versus 250 mL of normal crystalloid solution administered before routine prehospital and emergency center resuscitation. During a 13-month period, 422 patients were enrolled, 211 of whom subsequently underwent operative procedures. Three hundred fifty-nine patients met criteria for efficacy analysis, 51% of whom were in the HSD group. Seventy-two per cent of all patients were victims of penetrating trauma. The mean injury severity score (19), Trauma Score plus Injury Severity Score (TRISS) probability of survival, revised trauma scores (5.9), age, ambulance times, preinfusion blood pressure, and etiology distribution were identical between groups. The total amount of fluid administered, white blood cell count, arterial blood gases, potassium, or bicarbonate also were identical between groups. The HSD group had an improved blood pressure (p = 0.024). Hematocrit, sodium chloride, and osmolality levels were significantly elevated in the Emergency Center. Although no difference in overall survival was demonstrated, the HSD group requiring surgery did have a better survival (p = 0.02), with some variance among centers. The HSD group had fewer complications that the standard treatment group (7 versus 24). A greater incidence of adult respiratory distress syndrome, renal failure, and coagulopathy occurred in the standard treatment group. No anaphylactoid nor Dextran-related coagulopathies occurred in the HSD group. Although this trial demonstrated trends supportive of HSD in hypotensive hemorrhagic shock patients requiring surgery, a larger sample size will be required to establish which subgroups of trauma patients might maximally benefit from the prehospital use of a small volume of hyperosmolar solution. This study demonstrates the safety of administering 250 mL 7.5% HDS to this group of patients.

Blunt carotid arterial injuries : implications of a new grading scale

BACKGROUND Blunt carotid arterial injuries (BCI) have the potential for devastating outcomes. A paucity of literature and the absence of a formal BCI grading scale have been major impediments to the formulation of sound practice guidelines. We reviewed our experience with 109 BCI and developed a grading scale with prognostic and therapeutic implications. METHODS Patients admitted to a Level I trauma center were evaluated with cerebral arteriography if they exhibited signs or symptoms of BCI or met criteria for screening. Patients with BCI were treated with heparin unless they had contraindications, and follow-up arteriography was performed at 7 to 10 days. Endovascular stents were deployed selectively. A prospective database was used to track the patients. RESULTS A total of 76 patients were diagnosed with 109 BCI. Two-thirds of mild intimal injuries (grade I) healed, regardless of therapy. Dissections or hematomas with luminal stenosis (grade II) progressed, despite heparin therapy in 70% of cases. Only 8% of pseudoaneurysms (grade III) healed with heparin, but 89% resolved after endovascular stent placement. Occlusions (grade IV) did not recanalize in the early postinjury period. Grade V injuries (transections) were lethal and refractory to intervention. Stroke risk increased with injury grade. Severe head injuries (Glasgow Coma Scale score < or =6) were found in 46% of patients and confounded evaluation of neurologic outcomes. CONCLUSION This BCI grading scale has prognostic and therapeutic implications. Nonoperative treatment options for grade I BCI should be evaluated in prospective, randomized trials. Accessible grade II, III, IV, and V lesions should be surgically repaired. Inaccessible grade II, III, and IV injuries should be treated with systemic anticoagulation. Endovascular techniques may be the only recourse in high grade V injuries and warrant controlled evaluation in the treatment of grade III BCI.

The first randomized trial of human polymerized hemoglobin as a blood substitute in acute trauma and emergent surgery

BACKGROUND Human polymerized hemoglobin (PolyHeme) is a universally compatible, disease-free, oxygen-carrying resuscitative fluid. This is the first prospective, randomized trial to compare directly the therapeutic benefit of PolyHeme with that of allogeneic red blood cells (RBCs) in the treatment of acute blood loss. STUDY DESIGN Forty-four trauma patients (33 male, 11 female) aged 19-75 years with an average Injury Severity Score (ISS) score of 21+/-10 were randomized to receive red cells (n = 23) or up to 6 U (300 g) of PolyHeme (n = 21) as their initial blood replacement after trauma and during emergent operations. RESULTS There were no serious or unexpected adverse events related to PolyHeme. The PolyHeme infusion of 4.4+/-2.0 units (mean +/- SD) resulted in a plasma [Hb] of 3.9+/-1.3 g/dL, which accounted for 40% of the total circulating [Hb]. There was no difference in total [Hb] between the groups before infusion (10.4+/-2.3 g/dL control vs. 9.4+/-1.9 g/dL experimental). At end-infusion the experimental RBC [Hb] fell to 5.8+/-2.8 g/dL vs. 10.6+/-1.8 g/dL (p < 0.05) in the control, although the total [Hb] was not different between the groups or from pre-infusion. The total number of allogeneic red cell transfusions for the control and experimental groups was 10.4+/-4.2 units vs. 6.8+/-3.9 units (p < 0.05) through day 1, and 11.3+/-4.1 units vs. 7.8 +/-4.2 units (p = 0.06) through day 3. CONCLUSIONS PolyHeme is safe in acute blood loss, maintains total [Hb] in lieu of red cells despite the marked fall in RBC [Hb], and reduces the use of allogeneic blood. PolyHeme appears to be a clinically useful blood substitute.

The devastating potential of blunt vertebral arterial injuries.

OBJECTIVE To formulate management guidelines for blunt vertebral arterial injury (BVI). SUMMARY BACKGROUND DATA Compared with carotid arterial injuries, BVIs have been considered innocuous. Although screening for BVI has been advocated, particularly in patients with cervical spine injuries, the appropriate therapy of lesions is controversial. METHODS In 1996 an aggressive arteriographic screening protocol for blunt cerebrovascular injuries was initiated. A prospective database of all screened patients has been maintained. Analysis of injury mechanisms and patterns, BVI grades, treatment, and outcomes was performed. RESULTS Thirty-eight patients (0.53% of blunt trauma admissions) were diagnosed with 47 BVIs during a 3.5-year period. Motor vehicle crash was the most common mechanism, and associated injuries were common. Cervical spine injuries were present in 71% of patients, but there was no predilection for cervical vertebral level or fracture pattern. The incidence of posterior circulation stroke was 24%, and the BVI-attributable death rate was 8%. Stroke incidence and neurologic outcome were independent of BVI injury grade. In patients treated with systemic heparin, fewer overall had a poor neurologic outcome, and fewer had a poor outcome after stroke. Trends associated with heparin therapy included fewer injuries progressing to a higher injury grade, fewer patients in whom stroke developed, and fewer patients deteriorating neurologically from diagnosis to discharge. CONCLUSIONS Blunt vertebral arterial injuries are more common than previously reported. Screening patients based on injury mechanisms and patterns will diagnose asymptomatic injuries, allowing the institution of therapy before stroke. Systemic anticoagulation appears to be effective therapy: it is associated with improved neurologic outcome in patients with and without stroke, and it appears to prevent progression to a higher injury grade, stroke, and deterioration in neurologic status.

The unrecognized epidemic of blunt carotid arterial injuries: early diagnosis improves neurologic outcome.

OBJECTIVE To determine the benefit of screening for blunt carotid arterial injuries (BCI) in patients who are asymptomatic. SUMMARY BACKGROUND DATA Blunt carotid arterial injuries have the potential for devastating complications. Published studies report 23% to 28% mortality rates, with 48% to 58% of survivors having permanent severe neurologic deficits. Most patients have neurologic deficits when the injury is diagnosed. The authors hypothesized that screening patients who are asymptomatic and instituting early therapy would improve neurologic outcome. METHODS The Trauma Registry of the authors Level I Trauma Center identified patients with BCI from 1990 through 1997. Beginning in August 1996, the authors implemented a screening for BCI. Arteriography was used for diagnosis. Patients without specific contraindications were anticoagulated. Endovascular stents were deployed in the setting of pseudoaneurysms. RESULTS Thirty-seven patients with BCI were identified among 15,331 blunt-trauma victims (0.24%). During the screening period, 25 patients were diagnosed with BCI among 2902 admissions (0.86%); 13 (52%) were asymptomatic. Overall, eight patients died, and seven of the survivors had permanent severe neurologic deficits. Excluding those dying of massive brain injury and patients admitted with coma and brain injury, mortality associated with BCI was 15%, with severe neurologic morbidity in 16% of survivors. The patients who were asymptomatic at diagnosis had a better neurologic outcome than those who were symptomatic. Symptomatic patients who were anticoagulated showed a trend toward greater neurologic improvement at the time of discharge than those who were not anticoagulated. CONCLUSIONS Screening allows the identification of asymptomatic BCI and thereby facilitates early systemic anticoagulation, which is associated with improved neurologic outcome. The role of endovascular stents in the treatment of blunt traumatic pseudoaneurysms remains to be defined.

Treatment-related outcomes from blunt cerebrovascular injuries: importance of routine follow-up arteriography.

ObjectiveTo assess the impact of routine follow-up arteriography on the management and outcome of patients with acute blunt cerebrovascular injuries (BCVI). Summary Background DataDuring the past 5 years there has been increasing recognition of BCVI, but the management of these lesions remains controversial. The authors previously proposed a grading system for BCVI, with grade-specific management guidelines. The authors have noted that a significant number of injuries evolve within 7 to 10 days, warranting alterations in therapy. MethodsA prospective database of a regional trauma center’s experience with BCVI has been maintained since 1990. A policy of arteriographic screening for BCVI based on injury mechanism (e.g., cervical hyperextension) and injury patterns (e.g., cervical and facial fractures) was instituted in 1996. A grading system was devised to develop management protocols: I = intimal irregularity; II = dissection/flap/thrombus; III = pseudoaneurysm; IV = occlusion; V = transection. ResultsFrom June 1990 to October 2001, 171 patients (115 male, age 36 ± 1 years) were diagnosed with BCVI. Mean injury severity score was 28 ± 1; associated injuries included brain (57%), spine (44%), chest (43%), and face (34%). Mechanism was motor vehicle crash in 50%, fall in 11%, pedestrian struck in 11%, and other in 29%. One hundred fourteen patients had 157 carotid artery injuries (43 bilateral), and 79 patients had 97 vertebral artery injuries (18 bilateral). The breakdown of injury grades was 137 grade I, 52 grade II, 32 grade III, 25 grade IV, and 8 grade V. One hundred fourteen (73%) carotid and 65 (67%) vertebral arteries were restudied with arteriography 7 to 10 days after the injury. Eight-two percent of grade IV and 93% of grade III injuries were unchanged. However, grade I and II lesions changed frequently. Fifty-seven percent of grade I and 8% of grade II injuries healed, allowing cessation of therapy, whereas 8% of grade I and 43% of grade II lesions progressed to pseudoaneurysm formation, prompting interventional treatment. There was no significant difference in healing or in progression of injuries whether treated with heparin or antiplatelet therapy or untreated. However, heparin may improve the neurologic outcome in patients with ischemic deficits and may prevent stroke in asymptomatic patients. ConclusionsRoutine follow-up arteriography is warranted in patients with grade I and II BCVIs because most of these patients (61% in this series) will require a change in management. A prospective randomized trial will be necessary to identify the optimal treatment of BCVI.