Proceedings of resources for optimal care of acute care and emergency surgery consensus summit Donegal Ireland

BACKGROUND

Opportunities to improve emergency surgery outcomes exist through guided better practice and reduced variability. Few attempts have been made to define optimal care in emergency surgery, and few clinically derived key performance indicators (KPIs) have been published. A summit was therefore convened to look at resources for optimal care of emergency surgery. The aim of the Donegal Summit was to set a platform in place to develop guidelines and KPIs in emergency surgery.

METHODS

The project had multidisciplinary global involvement in producing consensus statements regarding emergency surgery care in key areas, and to assess feasibility of producing KPIs that could be used to monitor process and outcome of care in the future.

RESULTS

Forty-four key opinion leaders in emergency surgery, across 7 disciplines from 17 countries, composed evidence-based position papers on 14 key areas of emergency surgery and 112 KPIs in 20 acute conditions or emergency systems.

CONCLUSIONS

The summit was successful in achieving position papers and KPIs in emergency surgery. While position papers were limited by non-graded evidence and non-validated KPIs, the process set a foundation for the future advancement of emergency surgery.

Multiinstitutional experience with the management of superior mesenteric artery injuries

BACKGROUND

Superior mesenteric artery (SMA) injuries are rare and often lethal injuries incurring very high morbidity and mortality. The purposes of this study are to review a multiinstitutional experience with these injuries; to analyze Fullen's classification based on anatomic zone and ischemia grade for its predictive value; to correlate the American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS) for abdominal vascular injury with mortality; and to identify independent risk factors predictive of mortality, describing current trends for the management of this injury in America.

DESIGN

We performed a retrospective multiinstitutional study of patients sustaining SMA injuries involving 34 trauma centers in the US over 10 years. Outcomes variables, both continuous and dichotomous, were analyzed initially with univariate methods. For the subsequent multivariate analysis, stepwise logistic regression was used to identify a set of risk factors significantly associated with mortality.

RESULTS

There were 250 patients enrolled, with a mean Revised Trauma Score (RTS) of 6.44 and a mean Injury Severity Score (ISS) of 25. Surgical management consisted of ligation in 175 of 244 patients (72%), primary [corrected] repair in 53 of 244 patients (22%), autogenous grafts were used in 10 of 244 (4%), and prosthetic grafts of PTFE in 6 of 244 patients (2%). Overall mortality was 97 of 250 patients (39%). Mortality versus Fullen's zones: zone I, 39 of 51 (76.5%); zone II, 15 of 34 (44.1%); zone III, 11 of 40 (27.5%); and zone IV, 25 of 108 (23.1%). Mortality versus Fullen's ischemia grade: grade 1, 22 of 34 (64.7%). Mortality versus AAST-OIS for abdominal vascular injury: grade I, 9 of 55 (16.4%); grade II, 13 of 51 (25.5%); grade III, 8 of 20 (40%); grade IV, 37 of 69 (53.6%); and grade V, 17 of 19 (89.5%). Logistic regression analysis identified as independent risk factors for mortality the following: transfusion of greater than 10 units of packed RBCs, intraoperative acidosis, dysrhythmias, injury to Fullen's zone I or II, and multisystem organ failure.

CONCLUSION

SMA injuries are highly lethal. Fullen's anatomic zones, ischemia grade, and AAST-OIS abdominal vascular injuries correlate well with mortality. Injuries to Fullen's zones I and II, Fullen's maximal ischemia grade, and AAST-OIS injury grades IV and V, high-intraoperative transfusion requirements, and presence of acidosis and disrhythmias are significant predictors of mortality. All of these predictive factors for mortality must be taken into account in the surgical management of these injuries.

Complete recovery after normothermic hemorrhagic shock and profound hypothermic circulatory arrest of 60 minutes in dogs

OBJECTIVE

We hypothesize that during severe normothermic hemorrhagic shock (HS), induction of profound hypothermic circulatory arrest (PHCA) of 60 minutes to allow repair of otherwise lethal injuries in a bloodless field, can be survived without brain damage. In previous dog studies, normothermic HS with mean arterial pressure (MAP) of 40 mm Hg for 30 minutes, followed by PHCA of 2 hours at brain (tympanic membrane) temperature of 5 to 10 degrees C and core temperature of 10 degrees C, induced and reversed with cardiopulmonary bypass, resulted in survival with mild histopathologic brain damage. This study was designed to determine the severity of HS that can safely allow 1 hour of PHCA. In pilot studies with HS at MAP 30 mm Hg for 90 minutes with or without subsequent PHCA of 60 minutes there were no survivors.

METHODS

In the definitive study, outcomes in four groups of five dogs each were compared: group I, HS at MAP 30 mm Hg for 60 minutes and normothermic fluid resuscitation; group II, HS at MAP 30 mm Hg for 60 minutes, PHCA for 60 minutes, and resuscitation; group III, HS at MAP 40 mm Hg for 60 minutes and normothermic fluid resuscitation; and group IV, HS at MAP 40 mm Hg for 60 minutes, PHCA for 60 minutes, and resuscitation. Controlled ventilation was maintained for at least 20 hours and intensive care for 72 hours.

RESULTS

In groups I and II, two of five dogs in each group survived to 72 hours. In groups III and IV, all ten dogs survived. All survivors were functionally normal, with neurologic deficit scores (0% = normal, 100% = brain dead) of < 10%. Light microscopic scoring of 18 brain regions revealed no ischemic changes. All nonsurvivors had a severe metabolic acidemia after HS and developed multiple organ failure, including pulmonary edema, pneumonia, and intestinal necrosis.

CONCLUSIONS

The critical level of hypotension during 60 minutes normothermic HS that is compatible with survival in dogs is a MAP of between 30 and 40 mm Hg. After otherwise survivable severe normothermic HS of 60 minutes, PHCA of 60 minutes does not add brain damage or mortality, and may allow survival from injuries that would otherwise be irreparable.

Pain perception and serum beta-endorphin in trauma patients

Acute traumatic injury engenders the production of beta-endorphin (BE) and other endogenous opioids. Elevated BE concentration putatively correlates with pain perception in trauma patients. The authors examined traumatic injury severity, pain perception, and BE concentration in patients admitted to an urban trauma center. Brief rating instruments for pain and unpleasantness were administered, and blood was drawn for BE analysis in 48 trauma admissions and 33 age-, gender-, and race-matched control subjects for comparison. The authors found no correlation between severity of pain perception and BE, but a significant correlation was found between BE and patient body weight (P < 0.05), physician pain rating (P < 0.01), and Injury Severity Score (P < 0.001). The results suggest that past findings associating trauma pain perception and BE concentration are spurious.

Uncontrolled hemorrhagic shock outcome model in rats

During uncontrolled hemorrhagic shock (UHS) in acute animals models, attempts to achieve normotension with i.v. fluid resuscitation (FR) caused further bleeding and higher acute mortality. In the absence of a published clinically realistic long-term animal outcome study of UHS, we developed such a model in rats. In the preliminary study, phase I of the model involved 60 min of simulated 'pre-hospital' UHS by tail amputation and different FR regimens. Phase II involved 120 min of simulated 'hospital' treatment with hemostasis and all-out FR, including blood infusion. Phase III involved observing recovery and survival to 72 h (3 days). Rats were maintained under very light N2O-O2-halothane anesthesia and spontaneous breathing via mask during phases I and II and were awake during phase III. Tail amputation-induced UHS alone, studied in 4 groups of 10 rats each, resulted in unpredictable spontaneous hemostasis and great variability in shed blood volume, severity of shock, and mortality. The final model, which achieved consistent blood loss and outcome, included an initial volume-controlled hemorrhage of 3 ml/100 g over 15 min and untreated HS for another 15 min, followed by tail amputation for UHS over another 60 min. This phase I of 90 min was followed by phase II of 60 min. In group 1, without FR in phases I and II, all 10 rats died by 12 h. In group 2, without FR in phase I and hemostasis plus all-out FR with lactated Ringer's solution and blood to hematocrit (Hct) 30% in phase II, 5 of 10 rats died at the end of phase I and 9 of 10 died at the end of phase III. This final volume-initiated UHS model may be suitable for comparing different pre-hospital treatment modalities in terms of outcome.

Use of oral contrast material in abdominal trauma CT scans: is it dangerous?

OBJECTIVE

To determine the potential risks of the use of oral contrast medium for bowel opacification in abdominal trauma computed tomography (CT) scanning.

DESIGN

A retrospective chart review.

MATERIALS AND METHODS

506 consecutive patients who had CT evaluation of acute blunt abdominal trauma. All had both intervenous and "oral" administration of iodinated contrast material. Alert cooperative patients drank 450 ml of a 2.5% solution of Gastroview, while obtunded or uncooperative patients had the same volume and concentration of medium administered through a nasogastric tube, following endotracheal intubation.

RESULTS

No patients had aspiration of the contrast medium or gastric contents attributable to performance of the CT scan, except for one patient who had inadvertent installation of contrast through a tube that had been placed into the right main bronchus rather than the stomach.

CONCLUSIONS

Bowel opacification is important for optimal CT evaluation of abdominal trauma and can be used with confidence. Attention to proper preparation and administration of the contrast material and, more importantly, control of the patient's airway by appropriate tracheal intubation are essential to assure the safety of the procedure.

Changing etiology of iliopsoas abscess

Over a 5-year period, iliopsoas abscesses were found in 11 patients. Although the most common underlying condition was Crohn's disease (3 of 11 patients), 5 abscesses resulted from hematogenous spread from a distant site. Each of these five patients was elderly, severely malnourished, or had an underlying chronic disease. Fever was a presenting sign in 8 of 11 patients, whereas all 4 patients who presented with back pain had nontuberculous lumbar osteomyelitis or disk space infections. No patient presented with the classic triad of fever, back pain, and anterior thigh or groin pain. Computed tomographic (CT) scans accurately established the clinical diagnosis in 10 of 11 patients. Two of the patients died. One patient was an intravenous drug abuser, whereas the other patient was being treated with steroids for systemic lupus erythematosus. Elderly patients, diabetics, and patients with chronic disease are susceptible to this kind of occult infection and may present with minimal clinical findings. Aggressive diagnosis using CT scanning and treatment with resection of involved bowel, complete drainage of the abscess, and prolonged antibiotics are required to salvage these patients.

Profound hypothermia (less than 10 degrees C) compared with deep hypothermia (15 degrees C) improves neurologic outcome in dogs after two hours' circulatory arrest induced to enable resuscitative surgery

Deaths from uncontrollable hemorrhage might be prevented by arresting the circulation under protective hypothermia to allow resuscitative surgery to repair these injuries in a bloodless field. We have shown previously that in hemorrhagic shock, circulatory arrest of 60 minutes under deep hypothermia (tympanic membrane temperature, Ttm = 15 degrees C) was the maximum duration of arrest that allowed normal brain recovery. We hypothesize that profound cerebral hypothermia (Ttm less than 10 degrees C) could extend the duration of safe circulatory arrest. In pilot experiments, we found that the cardiopulmonary system did not tolerate arrest at a core (esophageal) temperature (Tes) of less than 10 degrees C. Twenty-two dogs underwent 30-minute hemorrhagic shock (mean arterial pressure 40 mm Hg), rapid cooling by cardiopulmonary bypass (CPB), blood washout to a hematocrit of less than 10%, and circulatory arrest of 2 hours. In deep hypothermia group 1 (n = 10), Ttm was maintained at 15 degrees C during arrest. In profound hypothermia group 2 (n = 12), during cooling with CPB, the head was immersed in ice water, which decreased Ttm to 4 degrees-7 degrees C. The Tes was 10 degrees C in all dogs during arrest. Reperfusion and rewarming were by CPB for 2 hours. Controlled ventilation was to 24 hours, intensive care to 72 hours. In the 20 dogs that followed protocol, best neurologic deficit scores (0% = normal, 100% = brain death) at 24-72 hours were 23% +/- 19% in group 1 and 12% +/- 8% in group 2 (p = 0.15). Overall performance categories and histologic damage scores were significantly better in group 2 (p = 0.04 and p less than 0.001, respectively). We conclude that profound cerebral hypothermia with CPB plus ice water immersion of the head can extend the brain's tolerance of therapeutic circulatory arrest beyond that achieved with deep hypothermia.

Argon beam coagulation is superior to conventional techniques in repair of experimental splenic injury

Present management of splenic trauma focuses on splenic preservation. However, conventional operative techniques for splenic salvage are time consuming and frequently ineffective. The purpose of this study was to assess the efficacy of the argon beam coagulator (ABC) in the management of experimental splenic injury. Ten adult miniature pigs were randomized to treatment with either conventional surgical techniques (topical Surgicel, electrocautery, suture-ligation, digital pressure) or splenic repair with the ABC. Three standard splenic injuries were made in each pig: capsular avulsion, splenic laceration, and hemisplenectomy. The ABC was more effective in treating all three types of splenic injury. The time required to achieve hemostasis and total operative time were significantly less in the group treated with the ABC for all three types of splenic injuries (p less than 0.05, Student's t-test, two sided). Operative blood loss was significantly less in the group treated with ABC for avulsion and hemisplenectomy (p less than 0.05, Student's t-test, two sided). Recurrent bleeding was significantly higher in the group treated with conventional techniques (p less than 0.001, Fisher's exact test, two-sided). We conclude that the argon beam coagulator is more effective than conventional techniques in treating experimental splenic injuries. The ABC provides more rapid and reliable hemostasis. Clinical trials using the ABC for splenic injury are warranted.

Therapeutic deep hypothermic circulatory arrest in dogs: a resuscitation modality for hemorrhagic shock with 'irreparable' injury

Early deaths from trauma are often caused by exsanguinating hemorrhage from injuries that appear "irreparable." We explored the limits of deep hypothermic circulatory arrest induced during hemorrhagic shock to enable repair of these injuries in a bloodless field. In 15 dogs, after 30 minutes of hemorrhagic shock (mean arterial pressure, 40 mm Hg), cardiopulmonary bypass (CPB) was used to cool to 15 degrees C in 13-37 minutes. After circulatory arrest of 60 (Group 1), 90 (Group 2), or 120 (Group 3) minutes, reperfusion and rewarming were accomplished by CPB. All dogs survived greater than 72 hours. Best neurologic deficit scores (ND) (0% = normal, 100% = brain death) were 0 +/- 0% (normal) in Group 1, 10 +/- 8% (mild disability) in Group 2, and 27 +/- 24% in Group 3. Outcome in Group 3 dogs ranged from near-normal to comatose. After perfusion-fixation sacrifice, brain histopathologic damage scores correlated with insult time, as did ND scores. Deep hypothermia can allow 60-90 min of circulatory arrest with good neurologic recovery, even after a period of severe hemorrhagic shock. This technique may allow repair of otherwise lethal injuries and survival without brain damage.