Mary C. Mone

Survey of intensive care physicians on the recognition and management of intra-abdominal hypertension and abdominal compartment syndrome*

Objective:To assess current understanding and clinical management of intra-abdominal hypertension and abdominal compartment syndrome among critical care physicians. Design:A ten-question, written survey. Setting:University health sciences center. Subjects:Physician members of the Society of Critical Care Medicine (SCCM). Interventions:The survey was sent to 4,538 SCCM members with a response rate of 35.7% (1622). Measurements and Main Results:Primary training, intensive care unit type, and methods for management of abdominal compartment syndrome were assessed. Surgically trained intensivists managed the highest number of abdominal compartment syndrome cases (47% managed 4–10 cases, 16% managed >10 cases). No cases were seen by 25% of medically trained and pediatric trained intensivists. Respondents agreed that bladder pressures and clinical variables were needed to diagnose abdominal compartment syndrome (70%) vs. bladder pressure (7%) or clinical variables (20%) alone. Two percent of surgical intensivists were unaware of a bladder pressure measurement procedure compared with 24% (p < .0001) of pediatric and 23% (p < .0001) of medical intensivists. Forty-two percent of respondents believed bladder pressures of 20–27 mm Hg may cause physiologic compromise. However, 25–27% of pediatric, medicine, or anesthesia trained intensivists believed that compromise occurs between 12 and 19 mm Hg compared with 18% of surgeons. No respondent believed that physiologic compromise occurred at <8 mm Hg. Thirty-eight percent of pediatric intensivists believed that physiologic compromise was patient dependent vs. 7–17% from other specialties (p < .0001; all comparisons). In managing intra-abdominal hypertension, 33% of pediatric intensivists and 19.6% of medical intensivists would never use decompression laparotomy to treat abdominal compartment syndrome compared with 3.6% of intensivists with surgical training (p < .0001; both comparisons). Conclusions:Significant variation across medical training exists in the management of intra-abdominal hypertension and abdominal compartment syndrome. A significant percentage of intensivists may be unaware of current approaches to abdominal compartment syndrome management including monitoring bladder pressures and decompression laparotomy. Future research and education are necessary to establish clear diagnostic criteria and standards for treatment of this relatively common life-threatening disease process.

Resuscitation of thermally injured patients with oxygen transport criteria as goals of therapy

Resuscitation from shock based on oxygen transport criteria has been widely used in trauma and surgical patients, but has not been examined in thermally injured patients. To study the possible efficacy of this type of resuscitation, the oxygen transport characteristics of burn resuscitation were studied in nine adults, of whom six had inhalation injuries, with a mean burn size of 45% total body surface area and a mean age of 33.4 years, who were resuscitated based on oxygen transport criteria. Pulmonary artery balloon flotation catheters were placed and hemodynamic and oxygen transport parameters (Fick method) were measured hourly for 6 hours. Patients received fluid boluses in addition to resuscitation calculated by the Parkland formula, until the pulmonary artery wedge pressure reached 15 mm Hg, after which dobutamine infusions (5 micrograms/kg/min) were initiated. Cardiac index increased from 2.51 to 6.57 L/min/m2 (p < 0.05), whereas systemic vascular resistance fell from 1534 to 584 dyne sec/cm5 (p < 0.05). Oxygen delivery (DO2I) and oxygen consumption (VO2I) indexes increased significantly during the study period (573 +/- 47 to 1028 +/- 57, and 132 +/- 8 to 172 +/- 16 ml/min/m2, respectively; p < 0.05). VO2I appeared dependent on DO2I at levels of DO2I less than 800 ml/min/m2. In this study, depressed cardiovascular function in patients with burn injuries responded to volume loading and inotropic support much as it does in patients with shock of other etiologies. Whether oxygen transport-based resuscitation is effective in improving survival or the incidence of multiple organ failure is unknown and will need to be evaluated in randomized trials.

Laparoscopic treatment of post renal transplant lymphoceles

Background: Traditionally, a post transplant lymphocele (PTL) is drained by widely opening the wall connecting the lymphocele cavity to the intraperitoneal space via laparotomy. We hypothesize that laparoscopic techniques can be effectively used for the treatment of PTL.Methods: Patients requiring intervention for PTL between 1993 and 2002 were identified via a retrospective review. Results of drainage via laparotomy and laparoscopy were compared.Results: During the study period 685 renal transplants (391 cadaveric, 294 living) were performed. The incidence of lymphocele was 5% [34/685 (36 cases)]. The indications for surgical drainage were local symptoms (69%), graft dysfunction (14%), or both (17%). The mean time to surgical therapy was 4.9 months. Laparoscopic drainage was performed in 25 patients (74%) and open drainage in 9 patients (26%). Open procedures were performed in cases for: previous abdominal surgery (5), undesirable lymphocele characteristics or location (2), or with concomitant open procedures (3). There were no conversions or operative complications in either group. There was no difference in operative time for the laparoscopic group vs the open group (108 ± 6 vs 123 ± 18 min, p = 0.8). Hospital stay was significantly shorter for the laparoscopic group (1.7 ± 0.8 vs 3.8 ± 1.0, p = 0.0007), with 88% of laparoscopic patients being either overnight admissions or same day surgery. Two patients (5%) developed symptomatic recurrences requiring reoperation [1 laparoscopic (4%), 1 open (10%)].Conclusions: Laparoscopic fenestration of a peritransplant lymphocele is a safe and effective treatment. The large majority of patients treated with laparoscopic fenestration were discharged within one day of surgery. Unless contraindications exist, laparoscopy should be considered first-line therapy for the surgical treatment of posttransplant lymphocele.

Implementation of an Enoxaparin Protocol for Venous Thromboembolism Prophylaxis in Obese Surgical Intensive Care Unit Patients

Background:: Venous thromboembolism (VTE) is a serious health care issue that affects a large number of people. Few standards exist for delineating the optimal dosing strategy for VTE prevention in obese patients, especially in the setting of major surgery or trauma. Objective: To document the efficacy of a surgical intensive care unit (SICU)–specific, weight-based dosing protocol of enoxaparin 0.5 mg/kg given subcutaneously every 12 hours for VTE prophylaxis in morbidly obese (defined as body mass index [BMI] ≥35 kg/m2 or weight ≥150 kg) SICU patients, using peak anti-factor Xa levels to determine therapeutic endpoints. Methods: Data were collected retrospectively in an academic, university-based SICU on 23 morbidly obese patients who received weight-based enoxaparin for VTE prophylaxis from December 1, 2008, through June 30, 2010. Results: A weight-based dosage range of enoxaparin 50-120 mg twice daily (median 60) was given to 23 patients. The mean BMI was 46.4 kg/m2. The initial mean anti-factor Xa level (measured after the third dose) was 0.34 IU/mL (range 0.20-0.59). Patients received an average of 18 doses. Two cases required an increase or decrease in dosage based on anti-factor Xa levels. Morbidity related to this dosing included a single event of minor endotracheal bleeding and a single deep vein thrombosis that was likely present prior to treatment. Conclusions: Weight-based dosing with enoxaparin in morbidly obese SICU patients was effective in achieving anti-factor Xa levels within the appropriate prophylactic range. This regimen reduced the rate of VTE below expected levels and no additional adverse effects were reported.

Propofol is associated with favorable outcomes compared with benzodiazepines in ventilated intensive care unit patients.

RATIONALE Mechanically ventilated intensive care unit (ICU) patients are frequently managed using a continuous-infusion sedative. Although recent guidelines suggest avoiding benzodiazepines for sedation, this class of drugs is still widely used. There are limited data comparing sedative agents in terms of clinical outcomes in an ICU setting. OBJECTIVES Comparison of propofol to midazolam and lorazepam in adult ICU patients. METHODS Data were obtained from a multicenter ICU database (2003-2009). Patient selection criteria included age greater than or equal to 18 years, single ICU admission with single ventilation event (>48 h), and treatment with continuously infused sedation (propofol, midazolam, or lorazepam). Propensity score analysis (1:1) was used and mortality measured. Cumulative incidence and competing risk methodology were used to examine time to ICU discharge and ventilator removal. MEASUREMENTS AND MAIN RESULTS There were 2,250 propofol-midazolam and 1,054 propofol-lorazepam matched patients. Hospital mortality was statistically lower in propofol-treated patients as compared with midazolam- or lorazepam-treated patients (risk ratio, 0.76; 95% confidence interval [CI], 0.69-0.82 and risk ratio, 0.78; 95% CI, 0.68-0.89, respectively). Competing risk analysis for 28-day ICU time period showed that propofol-treated patients had a statistically higher probability for ICU discharge (78.9% vs. 69.5%; 79.2% vs. 71.9%; P < 0.001) and earlier removal from the ventilator (84.4% vs. 75.1%; 84.3% vs. 78.8%; P < 0.001) when compared with midazolam- and lorazepam-treated patients, respectively. CONCLUSIONS In this large, propensity-matched ICU population, patients treated with propofol had a reduced risk of mortality and had both an increased likelihood of earlier ICU discharge and earlier discontinuation of mechanical ventilation.

Predictors of Mortality in Pulmonary Contusion

BACKGROUND Associated injuries and central nervous system (CNS) trauma are historically associated with poor outcome in patients with pulmonary contusions, but the value of specific factors reflecting shock, fluid resuscitation requirement and pulmonary parenchymal injury in predicting mortality in this population is not well established. METHODS The medical records of 100 consecutive patients with pulmonary contusion, admitted over a 5-year period, were retrospectively reviewed. Survivors and nonsurvivors were compared in terms of age, Injury Severity Score (ISS), Glasgow Coma Score (GCS), PaO2/FiO2 (oxygenation ratio), the severity and adequacy of shock resuscitation reflected in plasma lactate, resuscitation volume and transfusion requirements, using one-way ANOVA. To determine the contribution of individual, interdependent variables to mortality, the data were then analyzed using multivariable analysis. RESULTS ISS and transfusion requirement were significantly higher, and GCS and PaO2/FiO2 at 24 and 48 hours after admission were significantly lower in nonsurvivors than in survivors. After multiple regression analysis, the factors most strongly associated with mortality included patient age, oxygenation ratio at 24 hours after admission, and resuscitation volume. CONCLUSIONS Outcome in patients with pulmonary contusion is dependent upon a number of variables including the severity of pulmonary parenchymal injury as reflected in PaO2/FiO2 ratio.

Decreased mortality from necrotizing pancreatitis

BACKGROUND Necrotizing pancreatitis has been associated with mortality rates of 25% to 80%. We reviewed our experience to determine whether aggressive debridement and comprehensive critical care improves survival. METHODS The records of 989 patients with the diagnosis of pancreatitis admitted between January 1990 and September 1997 were retrospectively reviewed. Twenty-six patients required surgery for necrotizing pancreatitis and are the subjects of this review. RESULTS Five of twenty-six patients (19%) died. For all patients, mean Ransons score was 4.3 of 11, mean admission APACHE II score was 17.2, and mean Multiple Organ Dysfunction (MOD) score was 9.1. Poor outcome was associated with infected pancreatic necrosis (P = 0.03), elevated APACHE II score on admission (P = 0.04), and progression of MOD during the week after admission (P = 0.02). CONCLUSIONS This review demonstrates improved survival in seriously ill patients with necrotizing pancreatitis as a result of comprehensive surgical and critical care.

Chemical paralysis reduces energy expenditure in patients with burns and severe respiratory failure treated with mechanical ventilation

Predictive formulas often overestimate energy requirements, particularly in patients being treated with mechanical ventilation, resulting in significant overfeeding. The purpose of this study was to quantify the effect of chemical paralysis on energy expenditure in patients with burn injuries receiving ventilation treatment, and compare measured energy expenditure with estimates of energy expenditure based on predictive formulas. The study was a retrospective review of 14 patients with burn injuries treated with mechanical ventilation that required chemical paralysis to reduce inspiratory pressures or improve oxygenation. Indirect calorimetry was performed before, during, and after paralysis. Measured energy expenditure (MEE) was compared with the energy predictions of the Harris-Benedict (HBEE) and Curreri (CEE) estimates. During paralysis, mean MEE was significantly lower than pre- or postparalysis (19.65 +/- 1.65 versus 26.00 +/- 2.42 and 29.49 +/- 2.83 kcal/kg/24 hr, respectively). Mean HBEE (2031 +/- 145 kcal/24 hr) approximated MEE pre-(1989 +/- 350 kcal/24 hr) and postparalysis (2237 +/- 269 kcal/24 hr), but overestimated MEE during paralysis (1532 +/- 208 kcal/24 hr; p < 0.05). Mean CEE (2957 +/- 229 kcal/ 24 hr) estimates significantly overestimated MEE before, during, and after paralysis (1989 +/- 350, 1532 +/- 208, and 2237 +/- 269, respectively p < 0.05). Predictive formulas significantly overestimate measured energy requirements in these patients. Indirect calorimetry should guide nutrition support in patients requiring prolonged mechanical ventilation.

Desmoid tumor: a case of mistaken identity.

Abstract:  Desmoid tumors are rare tumors accounting for only 0.03% of all neoplasms. Mainly occurring in the fourth and fifth decades of life, these tumors originate in musculoaponeurotic tissues of the limbs, neck, trunk, abdominal wall, and mesentery. We present a rare case of a chest wall desmoid tumor that was mistaken for breast cancer on both physical examination and mammography, which highlights the unique risk these tumors present for confusion with other malignant processes. Although past literature contains numerous reports of other misdiagnoses, this case is unique in reporting the potential for misdiagnosis between chest wall desmoid tumors and breast cancer. In cases where suspicious breast findings do not correlate to usual diagnostic measures, such as fine‐needle aspiration or core needle biopsy, the possibility of another pathology such as a chest wall desmoid tumor mimicking breast cancer should be considered in the differential diagnosis.

The importance of extended postoperative venous thromboembolism prophylaxis in IBD: a National Surgical Quality Improvement Program analysis.

BACKGROUND: The National Comprehensive Cancer Network recommends that patients who have colorectal cancer receive up to 4 weeks of postoperative out-of-hospital venous thromboembolism prophylaxis. Patients with IBD are at high risk for venous thromboembolism, but there are no recommendations for routine postdischarge prophylaxis. OBJECTIVE: The purpose of this study was to compare the postoperative venous thromboembolism rate in IBD patients versus patients who have colorectal cancer to determine if IBD patients warrant postdischarge thromboembolism prophylaxis. DESIGN: This study is a retrospective review of IBD patients and patients who had colorectal cancer who underwent major abdominal and pelvic surgery. PATIENTS: Data were collected from the American College of Surgeons National Surgical Quality Improvement Program (2005–2010). MAIN OUTCOME MEASURES: The primary outcome was 30-day postoperative venous thromboembolism in IBD patients and patients who had colorectal cancer. Risk factors for venous thromboembolism were analyzed with the use of univariate testing and stepwise logistic regression. RESULTS: A total of 45,964 patients were identified with IBD (8888) and colorectal cancer (37,076). The 30-day postoperative rate of venous thromboembolism in IBD patients was significantly higher than in patients who had colorectal cancer (2.7% vs 2.1%, p < 0.001). In a model with 15 significant covariates, the OR for venous thromboembolism was 1.26 (95% CI, 1.021–1.56; p = 0.03) for the IBD patients in comparison with the patients who have colorectal cancer. LIMITATIONS: This study was limited by the retrospective design and the limitations of the data included in the database. CONCLUSIONS: Patients with IBD had a significantly increased risk for postoperative venous thromboembolism in comparison with patients who had colorectal cancer. Therefore, postdischarge venous thromboembolism prophylaxis recommendations for IBD patients should mirror that for patients who have colorectal cancer. This would suggest a change in clinical practice to extend out-of-hospital prophylaxis for 4 weeks in postoperative IBD patients.