Chad G. Ball

Intra-abdominal hypertension and the abdominal compartment syndrome: updated consensus definitions and clinical practice guidelines from the World Society of the Abdominal Compartment Syndrome

PurposeTo update the World Society of the Abdominal Compartment Syndrome (WSACS) consensus definitions and management statements relating to intra-abdominal hypertension (IAH) and the abdominal compartment syndrome (ACS).MethodsWe conducted systematic or structured reviews to identify relevant studies relating to IAH or ACS. Updated consensus definitions and management statements were then derived using a modified Delphi method and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) guidelines, respectively. Quality of evidence was graded from high (A) to very low (D) and management statements from strong RECOMMENDATIONS (desirable effects clearly outweigh potential undesirable ones) to weaker SUGGESTIONS (potential risks and benefits of the intervention are less clear).ResultsIn addition to reviewing the consensus definitions proposed in 2006, the WSACS defined the open abdomen, lateralization of the abdominal musculature, polycompartment syndrome, and abdominal compliance, and proposed an open abdomen classification system. RECOMMENDATIONS included intra-abdominal pressure (IAP) measurement, avoidance of sustained IAH, protocolized IAP monitoring and management, decompressive laparotomy for overt ACS, and negative pressure wound therapy and efforts to achieve same-hospital-stay fascial closure among patients with an open abdomen. SUGGESTIONS included use of medical therapies and percutaneous catheter drainage for treatment of IAH/ACS, considering the association between body position and IAP, attempts to avoid a positive fluid balance after initial patient resuscitation, use of enhanced ratios of plasma to red blood cells and prophylactic open abdominal strategies, and avoidance of routine early biologic mesh use among patients with open abdominal wounds. NO RECOMMENDATIONS were possible regarding monitoring of abdominal perfusion pressure or the use of diuretics, renal replacement therapies, albumin, or acute component-parts separation.ConclusionAlthough IAH and ACS are common and frequently associated with poor outcomes, the overall quality of evidence available to guide development of RECOMMENDATIONS was generally low. Appropriately designed intervention trials are urgently needed for patients with IAH and ACS.

Hand-Held Thoracic Sonography for Detecting Post-Traumatic Pneumothoraces: The Extended Focused Assessment With Sonography For Trauma (EFAST)

BACKGROUND Thoracic ultrasound (EFAST) has shown promise in inferring the presence of post-traumatic pneumothoraces (PTXs) and may have a particular value in identifying occult pneumothoraces (OPTXs) missed by the AP supine chest radiograph (CXR). However, the diagnostic utility of hand-held US has not been previously evaluated in this role. METHODS Thoracic US examinations were performed during the initial resuscitation of injured patients at a provincial trauma referral center. A high frequency linear transducer and a 2.4 kg US attached to a video-recorder were used. Real-time EFAST examinations for PTXs were blindly compared with the subsequent results of CXRs, a composite standard (CXR, chest and abdominal CT scans, clinical course, and invasive interventions), and a CT gold standard (CT only). Charts were reviewed for in-hospital outcomes and follow-up. RESULTS There were 225 eligible patients (207 blunt, 18 penetrating); 17 were excluded from the US examination because of battery failure or a lost probe. Sixty-five (65) PTXs were detected in 52 patients (22% of patients), 41 (63%) being occult to CXR in 33 patients (14.2% whole population, 24.6% of those with a CT). The US and CXR agreed in 186 (89.4%) of patients, EFAST was better in 16 (7.7%), and CXR better in 6 (2.9%). Compared with the composite standard, the sensitivity of EFAST was 58.9% with a likelihood ratio of a positive test (LR+) of 69.7 and a specificity of 99.1%. Comparing EFAST directly to CXR, by looking at each of 266 lung fields with the benefit of the CT gold standard, the EFAST showed higher sensitivity over CXR (48.8% versus 20.9%). Both exams had a very high specificity (99.6% and 98.7%), and very predictive LR+ (46.7 and 36.3). CONCLUSION EFAST has comparable specificity to CXR but is more sensitive for the detection of OPTXs after trauma. Positive EFAST findings should be addressed either clinically or with CT depending on hemodynamic stability. CT should be used if detection of all PTXs is desired.

Risk factors for intra-abdominal hypertension and abdominal compartment syndrome among adult intensive care unit patients: a systematic review and meta-analysis

IntroductionAlthough intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are associated with substantial morbidity and mortality among critically ill adults, it remains unknown if prevention or treatment of these conditions improves patient outcomes. We sought to identify evidence-based risk factors for IAH and ACS in order to guide identification of the source population for future IAH/ACS treatment trials and to stratify patients into risk groups based on prognosis.MethodsWe searched electronic bibliographic databases (MEDLINE, EMBASE, PubMed, and the Cochrane Database from 1950 until January 21, 2013) and reference lists of included articles for observational studies reporting risk factors for IAH or ACS among adult ICU patients. Identified risk factors were summarized using formal narrative synthesis techniques alongside a random effects meta-analysis.ResultsAmong 1,224 citations identified, 14 studies enrolling 2,500 patients were included. The 38 identified risk factors for IAH and 24 for ACS could be clustered into three themes and eight subthemes. Large volume crystalloid resuscitation, the respiratory status of the patient, and shock/hypotension were common risk factors for IAH and ACS that transcended across presenting patient populations. Risk factors with pooled evidence supporting an increased risk for IAH among mixed ICU patients included obesity (four studies; odds ratio (OR) 5.10; 95% confidence interval (CI), 1.92 to 13.58), sepsis (two studies; OR 2.38; 95% CI, 1.34 to 4.23), abdominal surgery (four studies; OR 1.93; 95% CI, 1.30 to 2.85), ileus (two studies; OR 2.05; 95% CI, 1.40 to 2.98), and large volume fluid resuscitation (two studies; OR 2.17; 95% CI, 1.30 to 3.63). Among trauma and surgical patients, large volume crystalloid resuscitation and markers of shock/hypotension and metabolic derangement/organ failure were risk factors for IAH and ACS while increased disease severity scores and elevated creatinine were risk factors for ACS in severe acute pancreatitis patients.ConclusionsAlthough several IAH/ACS risk factors transcend across presenting patient diagnoses, some appear specific to the population under study. As our findings were somewhat limited by included study methodology, the risk factors reported in this study should be considered candidate risk factors until confirmed by a large prospective multi-centre observational study.

Negative-pressure wound therapy for critically ill adults with open abdominal wounds: A systematic review

BACKGROUND Open abdominal management with negative-pressure wound therapy (NPWT) is increasingly used for critically ill trauma and surgery patients. We sought to determine the comparative efficacy and safety of NPWT versus alternate temporary abdominal closure (TAC) techniques in critically ill adults with open abdominal wounds. METHODS We conducted a systematic review of published and unpublished comparative studies. We searched MEDLINE, PubMed, EMBASE, Scopus, Web of Science, the Cochrane Database, the Center for Reviews and Dissemination, clinical trials registries, and bibliographies of included articles. Two authors independently abstracted data on study design, methodological quality, patient characteristics, and outcomes. RESULTS Among 2,715 citations identified, 2 randomized controlled trials and 9 cohort studies (3 prospective/6 retrospective) met inclusion criteria. Methodological quality of included prospective studies was moderate. One randomized controlled trial observed an improved fascial closure rate (relative risk [RR], 2.4; 95% confidence interval [CI], 1.0–5.3) and length of hospital stay after addition of retention sutured sequential fascial closure to the Kinetic Concepts Inc. (KCI) vacuum-assisted closure (VAC). Another reported a trend toward enhanced fascial closure using the KCI VAC versus Barker’s vacuum pack (RR, 2.6; 95% CI, 0.95–7.1). A prospective cohort study observed improved mortality (RR, 0.48; 95% CI, 0.25–0.92) and fascial closure (RR, 1.5; 95% CI, 1.1–2.0) for patients who received the ABThera versus Barker’s vacuum pack. Another noted a reduced arterial lactate, intra-abdominal pressure, and hospital stay for those fitted with the KCI VAC versus Bogotá bag. Most included retrospective studies exhibited low methodological quality and reported no mortality or fascial closure benefit for NPWT. CONCLUSION Limited prospective comparative data suggests that NPWT versus alternate TAC techniques may be linked with improved outcomes. However, the clinical heterogeneity and quality of available studies preclude definitive conclusions regarding the preferential use of NPWT over alternate TAC techniques. LEVEL OF EVIDENCE Systematic review, level III.

Laparoscopic appendectomy for complicated appendicitis: an evaluation of postoperative factors

BackgroundThe use of laparoscopic appendectomy for complicated appendicitis is controversial. Outcomes were compared between patients who had complicated appendicitis and those who had uncomplicated appendicitisMethodsConsecutive patients (n = 304) who underwent laparoscopic appendectomy were studied. Patients undergoing open appendectomies also were compared ad hoc. Analgesia use, length of hospital stay, return to activity, and complication rates for the complicated and uncomplicated appendicitis subgroups were analyzed.ResultsComplete data were available for 243 patients (80%). There were no statistical differences in characteristics between the two groups. The operating times, lengths of hospital stay, return to activity times, complication rates, and analgesia requirements, both in the hospital and after discharge, were equivalent. A greater number of complicated cases required open conversion. Considering those with complicated appendicitis, the open group had a significantly longer mean hospital stay and a higher complication rate than those treated with laparoscopic appendectomy.ConclusionsThe minimally invasive laparoscopic technique is safe and efficacious. It should be the initial procedure of choice for most cases of complicated appendicitis.

Alpine ski and snowboarding traumatic injuries: incidence, injury patterns, and risk factors for 10 years

BACKGROUND Alpine skiing and snowboarding are popular winter sports in Canada. Every year participation in these activities results in traumatic injury. The purpose of this study was to identify the incidence and injury patterns, as well as risk factors associated with ski and snowboarding injuries. METHODS A comprehensive 10-year retrospective review of Alpine ski and snowboarding injuries from 1996 to 2006 was conducted. The Alberta Trauma Registry was used as the primary source of data. RESULTS A total of 196 patients (56.6% skiers, 43.4% snowboarders) were identified as having major traumatic injuries (Injury Severity Score, >or=12). Forty-three patients required intensive care unit support. The majority of injuries were related to falls and collisions with natural objects. Head injuries were most common, followed by chest, spinal, and extremity trauma. Seventy-nine patients required emergency surgery. CONCLUSIONS Skiing and snowboarding represent activities with high potential for traumatic injury. Safety initiatives should be developed to target this population.

Wound Protectors Reduce Surgical Site Infection A Meta-Analysis of Randomized Controlled Trials

Objective: A meta-analysis of randomized clinical trials (RCTs) was conducted to evaluate whether wound protectors reduce the risk of surgical site infection (SSI) after gastrointestinal and biliary tract surgery. Background: The effectiveness of impervious wound edge protectors for reduction of SSI remains unclear. Methods: A systematic review was conducted in Medline, EMBASE, and the Cochrane Library to identify RCTs that evaluate the risk of SSI after gastrointestinal and biliary surgeries with and without the use of an impervious wound protector. The pooled risk ratio was estimated with random-effect meta-analysis. Sensitivity analyses were performed to examine the impact of structural design of wound protector, publication year, study quality, inclusion of emergent surgeries, preoperative antibiotic administration, and bowel preparation on the pooled risk of SSI. Results: Of the 347 studies identified, 6 RCTs representing 1008 patients were included. The use of a wound protector was associated with a significant decrease in SSI (RR = 0.55, 95% CI 0.31–0.98, P = 0.04). There was a nonsignificant trend toward greater protective effect in studies using a dual ring protector (RR = 0.31, 95% CI 0.14–0.67, P = 0.003), rather than a single ring protector (RR = 0.83, 95% CI 0.38–1.83, P = 0.64). Publication year (P = 0.03) and blinding of outcome assessors (P = 0.04) significantly modified the effect of wound protectors on SSI. Conclusions: Our results suggest that wound protectors reduce rates of SSI after gastrointestinal and biliary surgery.

A caveat to the performance of pericardial ultrasound in patients with penetrating cardiac wounds.

BACKGROUND The pericardial window in a focused assessment with sonography for trauma (FAST) examination is highly accurate for detecting hemopericardium and, therefore, associated cardiac injury. A series of patients with false-negative pericardial ultrasound examinations, who were subsequently diagnosed with cardiac lacerations after presenting with stab wounds, are described. METHODS All patients with a normal pericardial ultrasound examination, despite subsequent diagnosis of a cardiac injury, are described (2005-2008). RESULTS Five patients with stab wounds to the precodium displayed initial and repeatedly normal pericardial windows on a FAST examination. Each patient was eventually diagnosed with a penetrating cardiac injury and concurrent laceration of their pericardial sac. This combination of injuries allowed decompression of blood from the cardiac injury into the thoracic cavity and, therefore, prevented accumulation of a hemopericardium. CONCLUSIONS The pericardial component of the FAST examination is commonly used for patients who present with penetrating wounds to the precordium. In cases of concurrent lacerations of the pericardial sac, pericardial ultrasound may not detect a cardiac injury because of associated decompression into the thoracic cavity.

Peri-operative blood transfusion and operative time are quality indicators for pancreatoduodenectomy

BACKGROUND Minimization of blood loss during pancreatoduodenectomy requires careful surgical technique and specific preventative measures. Therefore, red blood cell (RBC) transfusions and operative time are potential surgical quality indicators. The aim of the present study was to compare peri-operative RBC transfusion and operative time with 30-day morbidity/mortality after pancreatoduodenectomy. METHODS All pancreatoduodenectomies (2005 to 2008) were identified using the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP). RBC transfusions and operative time were correlated with 30-day morbidity/mortality. RESULTS Pancreatoduodenectomy was completed in 4817 patients. RBC transfusions were given to 1559 (32%) patients (1-35 units). Overall morbidity and mortality rates were 37% and 3.0%, respectively. Overall 30-day morbidity increased in a stepwise manner with the number of RBC transfusions (R = 0.69, P < 0.01). Although RBC transfusions and operative times were not statistically linked (P = 0.87), longer operative times were linearly associated with increased 30-day morbidity (R = 0.79, P < 0.001) and mortality (R = 0.65, P < 0.01). Patients who were not transfused also displayed less morbidity (33%) and mortality (1.9%) (P < 0.05). DISCUSSION Peri-operative RBC transfusion after pancreatoduodenectomy is linearly associated with 30-day morbidity. Longer operative time also correlates with increased morbidity and mortality. Therefore, blood transfusions and prolonged operative time should be considered quality indicators for pancreatoduodenectomy.

Diagnostic accuracy of computed tomographic angiography for blunt cerebrovascular injury detection in trauma patients: a systematic review and meta-analysis.

Objective:To compare the diagnostic accuracy of computed tomographic angiography (CTA) with digital subtraction angiography (DSA) for blunt cerebrovascular injury (BCVI) detection in trauma patients. Background:Controversy exists as to whether the diagnostic performance of CTA compares favorably with the reference-standard, DSA. Methods:We searched electronic databases (1950 to May 22, 2012), article bibliographies, conference proceedings (2008–2011), and clinical trial registries for studies comparing the accuracy of CTA with DSA for BCVI detection in trauma patients. Pooled estimates of sensitivity, specificity, and positive and negative likelihood ratios were calculated using bivariate random effects models. Results:Eight studies that examined 5704 carotid or vertebral arteries in 1426 trauma patients met inclusion criteria. The pooled sensitivity and specificity for BCVI detection with CTA versus DSA was 66% (95% CI, 49%–79%; I2 = 80.4%) and 97% (95% CI, 91%–99%; I2 = 94.6%), respectively. Corresponding pooled positive and negative likelihood ratios were 20.0 (95% CI, 6.9–58.4; I2 = 87.7%) and 0.35 (95% CI, 0.22–0.56; I2 = 74.9%), respectively. Although pooled sensitivity varied with the number of available CT slices, the training of interpreting radiologists, and in a pattern suggestive of differences in diagnostic threshold for judging CTA positivity, it remained 80% or less among studies that used scanners with 16 or more slices per rotation and where the CTA was read by neuroradiologists. Conclusions:Existing evidence suggests that the diagnostic performance of CTA varies considerably across studies, likely due to an implicit variation in diagnostic threshold across trauma centers. Moreover, although CTA appears to lack sensitivity to adequately rule out BCVI, it may be useful to rule in BCVI among trauma patients with a high pretest probability of injury.