Matthew Dolich

Standard prophylactic enoxaparin dosing leads to inadequate anti-Xa levels and increased deep venous thrombosis rates in critically Ill trauma and surgical patients

BACKGROUND Deep venous thromboses (DVT) continue to cause significant morbidity in critically ill patients. Standard prophylaxis for high risk patients includes twice-daily dosing with 30 mg enoxaparin. Despite prophylaxis, DVT rates still exceed 10% to 15%. Anti-Xa levels are used to measure the activity of enoxaparin and 12-hour trough levels <or=0.1 IU/mL have been associated with higher rates of DVT in orthopedic patients. We hypothesized that low Anti-Xa levels would be found in critically ill trauma and surgical patients and that low levels would be associated with higher rates of DVT. METHODS All patients on the surgical intensive care unit (ICU) service were prospectively followed. In the absence of contraindications, patients were given prophylactic enoxaparin and anti-Xa levels were drawn after the third dose. Trough levels <or=0.1 IU/mL were considered low. Screening duplex exams were obtained within 48 hours of admission and then weekly. Patients were excluded if they did not receive a duplex, if they had a prior DVT, or if they lacked correctly timed anti-Xa levels. DVT rates and demographic data were compared between patients with low and normal anti-Xa levels. RESULTS Data were complete for 54 patients. Eighty-five percent suffered trauma (Injury Severity Score of 25 +/- 12) and 74% were male. Overall, 27 patients (50%) had low anti-Xa levels. Patients with low anti-Xa levels had significantly more DVTs than those with normal levels (37% vs. 11%, p = 0.026), despite similar age, body mass index, Injury Severity Score, creatinine clearance, high risk injuries, and ICU/ventilator days. CONCLUSION Standard dosing of enoxaparin leads to low anti-Xa levels in half of surgical ICU patients. Low levels are associated with a significant increase in the risk of DVT. These data support future studies using adjusted-dose enoxaparin.

Predicting Performance on the American Board of Surgery Qualifying and Certifying Examinations: A Multi-institutional Study

BACKGROUND We sought to determine whether US Medical Licensing Examination (USMLE) Step 1 score, American Board of Surgery (ABS) In-Training Examination (ABSITE) score, and other variables are associated with failing the ABS qualifying and certifying examinations. Identifying such factors may assist in the early implementation of an academic intervention for at-risk residents. DESIGN Retrospective review. SETTING Seventeen general surgery training programs in the western United States. PARTICIPANTS Six hundred seven residents who graduated in 2000-2007. MAIN OUTCOME MEASURES First-time pass rates on the qualifying and certifying examinations, US vs non-US medical school graduation, USMLE Steps 1 and 2 scores, ABSITE scores, operative case volume, fellowship training, residency program type, and mandatory research. RESULTS The first-time qualifying and certifying examination pass rates for the 607 graduating residents were 78% and 74%, respectively. On multivariable analysis, scoring below the 35th percentile on the ABSITE at any time during residency was associated with an increased risk of failing both examinations (odds ratio, 0.23 [95% confidence interval, 0.08-0.68] for the qualifying examination and 0.35 [0.20-0.61] for the certifying examination), as was scoring less than 200 on the USMLE Step 1 (0.36 [0.21-0.62] for the qualifying examination and 0.62 [0.42-0.93] for the certifying examination). A mandatory research year was associated with an increased likelihood of passing the certifying examination (odds ratio, 3.3 [95% confidence interval, 1.6-6.8]). CONCLUSIONS Residents who are more likely to fail the ABS qualifying and certifying examinations can be identified by a low USMLE Step 1 score and by poor performance on the ABSITE at any time during residency. These findings support the use of the USMLE Step 1 score in the surgical residency selection process and a formal academic intervention for residents who perform poorly on the ABSITE.

Hemoperitoneum score helps determine need for therapeutic laparotomy.

PURPOSE Sonography provides a fast, portable, and noninvasive method for patient assessment. However, the benefit of providing real-time ultrasound (US) imaging and fluid quantification shortly after patient arrival has not been explored. The objective of this study was to prospectively validate a US hemoperitoneum scoring system developed at our institution and determine whether sonography can predict a therapeutic operation. METHODS For 12 months, prospective data on all patients undergoing a trauma sonogram were recorded. All sonograms positive for free fluid were given a hemoperitoneum score. The US score was compared with initial systolic blood pressure and base deficit to assess the ability of sonography to predict a therapeutic laparotomy. RESULTS Forty of 46 patients (87%) with a US score > or = 3 required a therapeutic laparotomy. Forty-six of 54 patients with a US score < 3 (85%) did not need operative intervention. The sensitivity of sonography was 83% compared with 28% and 49% for systolic blood pressure and base deficit, respectively, in determining the need for therapeutic operation. CONCLUSION We conclude that the majority of patients with a score > or = 3 will need surgery. The US hemoperitoneum scoring system was a better predictor of a therapeutic laparotomy than initial blood pressure and/or base deficit.

Splanchnic perfusion evaluation during hemorrhage and resuscitation with gastric near-infrared spectroscopy

OBJECTIVE The purpose of this study was to use a prototype side-illuminating near-infrared spectroscopy (NIRS) nasogastric probe to continuously measure changes in gastric tissue oxygen saturation (Sto2) in a pig hemorrhage model. METHODS Swine (n = 12; 6 per group) underwent laparotomy and placement of a gastric NIRS probe, jejunal tonometer, superior mesenteric artery (SMA) flow probe, and a portal vein catheter. Animals underwent hemorrhage (28 mL/kg) t = 0 to 20 minutes (where t = time). Pigs in group I were resuscitated (t = 20-40 minutes) with lactated Ringers solution (84 mL/kg), whereas group II had no resuscitation. RESULTS A significant decrease in mean arterial pressure and SMA flow was observed after hemorrhage. SMA flow significantly correlated in group I with both NIRS Sto2 (r = 0.58, p = 0.0001) and regional CO2 (r = -0.54, p = 0.0001). In group II, superior mesenteric flow correlated with NIRS Sto2 (r = 0.30, p = 0.03), but not regional CO2 (r = -0.23, p = 0.09). CONCLUSION Direct measurement of tissue oxygen saturation with a prototype side-illuminating near-infrared spectroscopy gastric probe appeared to rapidly reflect changes in splanchnic perfusion.

Predictive Factors of In-Hospital Mortality in Colon and Rectal Surgery

BACKGROUND Knowledge of the independent risk factors for mortality in colon and rectal surgery can aid surgeons in surgical decision making and in providing patients with appropriate information about the risks of surgery. This study endeavors to identify the risk factors for mortality that are associated with colon and rectal surgery. STUDY DESIGN Using the Nationwide Inpatient Sample database, we examined the clinical data of patients who underwent colon and rectal resection from 2006 to 2008. Multivariate regression analysis was performed to identify factors predictive of in-hospital mortality. RESULTS A total of 975,825 patients underwent colon and rectal resection during this period. Overall, the rate of in-hospital mortality was 4.50% (elective surgery, 1.42% vs emergent surgery, 8.76%; p < 0.01). Mortality was lower after laparoscopic compared with open operation (1.43% vs 4.74%; p < 0.01). Using multivariate regression analysis, significant risk factors for in-hospital mortality were emergent surgery (adjusted odds ratio [AOR] = 3.53), liver disease (AOR = 3.02), age older than 65 years (AOR = 2.92), total colectomy (AOR = 2.88), chronic renal failure (AOR = 2.37), malignant tumor (AOR = 2.0), open operation (AOR = 1.85), peripheral vascular disease (AOR = 1.81), diverticulitis (AOR = 1.77), transverse colectomy (AOR = 1.43), chronic lung disease (AOR = 1.41), ulcerative colitis (AOR = 1.40), left colectomy (AOR = 1.31), alcohol abuse (AOR = 1.21), male sex (AOR = 1.12), nonteaching hospital (AOR = 1.11), and African-American race (AOR = 1.09). There was no association between hypertension, diabetes, congestive heart failure, obesity, smoking, proctectomy, sigmoidectomy, or Crohn disease and in-hospital mortality. CONCLUSIONS In patients undergoing colorectal surgery, emergent surgery, liver disease, total colectomy, age older than 65 years, chronic renal failure, and malignant tumor are the major risk factors for in-hospital mortality.

Effect of the 16-hour work limit on general surgery intern operative case volume: a multi-institutional study.

IMPORTANCE The 80-hour work-week limit for all residents was instituted in 2003 and studies looking at its effect have been mixed. Since the advent of the 16-hour mandate for postgraduate year 1 residents in July 2011, no data have been published regarding the effect of this additional work-hour restriction. OBJECTIVE To determine whether the 16-hour intern work limit, implemented in July 2011, has adversely affected operative experience. DESIGN, SETTING, AND PARTICIPANTS A retrospective review of categorical postgraduate year 1 Accreditation Council for Graduate Medical Education case logs from the intern class (N = 52) (with 16-hour work limit) compared with the 4 preceding years (2007-2010; N = 197) (without 16-hour work limit). A total of 249 categorical general surgery interns from 10 general surgery residency programs in the western United States were included. MAIN OUTCOMES AND MEASURES Total, major, first-assistant, and defined-category case totals. RESULTS As compared with the preceding 4 years, the 2011-2012 interns recorded a 25.8% decrease in total operative cases (65.9 vs 88.8, P = .005), a 31.8% decrease in major cases (54.9 vs 80.5, P < .001), and a 46.3% decrease in first-assistant cases (11.1 vs 20.7, P = .008). There were statistically significant decreases in cases within the defined categories of abdomen, endocrine, head and neck, basic laparoscopy, complex laparoscopy, pediatrics, thoracic, and soft tissue/breast surgery in the 16-hour shift intern era, whereas there was no decrease in trauma, vascular, alimentary, endoscopy, liver, and pancreas cases. CONCLUSIONS AND RELEVANCE The 16-hour work limit for interns, implemented in July 2011, is associated with a significant decrease in categorical intern operative experience. If the 16-hour shift were to be extended to all postgraduate year levels, one can anticipate that additional years of training will be needed to maintain the same operative volume.

Imaging of penetrating thoracic trauma.

The management of penetrating chest injuries has evolved significantly over the past few years, with an increasing emphasis on less invasive diagnostic and therapeutic modalities. Only 15% of patients need a therapeutic operative procedure. The challenge is to detect and treat these injuries rapidly while maximizing the use of noninvasive examinations and decreasing costs. The areas potentially at risk for injury include the heart, major vessels, thoracoabdomen, neck, spine, and aerodigestive tract. A review of injuries to these areas, including the use of new diagnostic modalities such as echocardiography and computed tomography (CT) scans, are discussed.

General Surgery Resident Remediation and Attrition: A Multi-institutional Study

OBJECTIVE To determine the rates and predictors of remediation and attrition among general surgery residents. DESIGN, SETTING, AND PARTICIPANTS Eleven-year retrospective analysis of 348 categorical general surgery residents at 6 West Coast programs. MAIN OUTCOME MEASURES Rates and predictors of remediation and attrition. RESULTS Three hundred forty-eight categorical general surgery residents were included. One hundred seven residents (31%) required remediation, of which 27 were remediated more than once. Fifty-five residents (15.8%) left their programs, although only 2 were owing to failed remediation. Remediation was not a predictor of attrition (20% attrition for those remediated vs 15% who were not [P = .40]). Remediation was most frequently initiated owing to a deficiency in medical knowledge (74%). Remediation consisted of monthly meetings with faculty (79%), reading assignments (72%), required conferences (27%), therapy (12%), and repeating a clinical year (6.5%). On univariate analysis, predictors of remediation included receiving honors in the third-year surgery clerkship, United States Medical Licensing Examination (USMLE) step 1 and/or step 2, and American Board of Surgery In-Training Examination scores at postgraduate years 1 through 4. On multivariable regression analysis, remediation was associated with receiving honors in surgery (odds ratio, 1.9; P = .01) and USMLE step 1 score (odds ratio, 0.9; P = .02). On univariate analysis, the only predictor of attrition was the American Board of Surgery In-Training Examination score at the postgraduate year 3 level (P = .04). CONCLUSIONS Almost one third of categorical general surgery residents required remediation during residency, which was most often owing to medical knowledge deficits. Lower USMLE step 1 scores were predictors of the need for remediation. Most remediated residents successfully completed the program. Given the high rates of remediation and the increased educational burden on clinical faculty, medical schools need to focus on better preparing students to enter surgical residency.

Comparison of laparoscopic versus open appendectomy for acute nonperforated and perforated appendicitis in the obese population

BACKGROUND Use of laparoscopic appendectomy (LA) has been increasing in obese patients. We evaluated the outcomes of LA compared with open appendectomy (OA) in obese patients. METHODS By using the Nationwide Inpatient Sample database, clinical data of obese patients who underwent LA and OA for suspected acute appendicitis (perforated or nonperforated) from 2006 to 2008 were examined. RESULTS A total of 42,426 obese patients underwent an appendectomy during this period. In acute nonperforated cases, LA had a lower overall complication rate (7.17% vs 11.72%; P < .01), mortality rate (.09% vs .23%; P < .01), mean hospital charges (

Elevated serum pancreatic enzyme levels after hemorrhagic shock predict organ failure and death.

25,193 vs