A "crush" course on rhabdomyolysis: risk stratification and clinical management update for the perioperative clinician.

Rhabdomyolysis, the release of myoglobin and other cellular breakdown products from necrotic muscle tissue, is seen in patients with crush injuries, drug overdose, malignant hyperthermia, muscular dystrophy, and with increasing frequency in obese patients undergoing routine procedures. For the perioperative clinician, managing the resultant shock, hyperkalemia, acidosis, and myoglobinuric acute kidney injury can present a significant challenge. Prompt recognition, hydration, and correction of metabolic disturbances may reduce or eliminate the need for long-term renal replacement therapy. This article reviews the pathophysiology and discusses key issues in the perioperative diagnosis, risk stratification, and management of rhabdomyolysis.

Platelet transfusion as treatment for factor V deficiency in the parturient: a case report.

BACKGROUND: Congenital factor V deficiency, also called parahemophilia, is a rare hematological disorder that can be treated with platelet transfusion. CASE PRESENTATION: A 27-year-old G2P0100 with factor V deficiency was admitted for induction of labor and requested labor epidural analgesia. Throughout her hospital course, factor V levels were managed per recommendation from her hematologist, which included transfusing fresh frozen plasma (FFP) to maintain a factor V level of 50% before any neuraxial technique and 40% for postpartum hemostasis. The parturient required multiple transfusions of FFP to stay at this level, which eventually resulted in pulmonary edema. Given the request to maintain high levels of factor V, the parturient was transfused with platelets as an alternative source of factor V. The parturient eventually delivered a healthy neonate without signs of postpartum hemorrhage or epidural hematoma. CONCLUSION: A major learning point from this case is that platelet transfusion is an effective alternative in the management of factor V deficiency. Factor V released by platelets has enhanced procoagulant function, resulting in local factor V concentrations 100 times more than that of plasma, and has a significantly extended half-life. Platelet transfusion should be considered as a therapy in treating parturients with factor V deficiency.

The association of macronutrient deficit with functional status at discharge from the intensive care unit: a retrospective study from a single-center critical illness registry.

BACKGROUND: Nutrition is often thought to influence outcomes in critically ill patients. However, the relationship between macronutrient delivery and functional status is not well characterized. Our goal was to investigate whether caloric or protein deficit over the course of critical illness is associated with functional status at the time of intensive care unit (ICU) discharge. METHODS: We performed a retrospective analysis of surgical ICU patients at a teaching hospital in Boston, MA. To investigate the association of caloric or protein deficit with Functional Status Score for the ICU (FSS-ICU), we constructed linear regression models, controlling for age, sex, race, body mass index, Nutritional Risk in the Critically Ill score, and ICU length of stay. We then dichotomized caloric as well as protein deficit, and performed logistic regressions to investigate their association with functional status, controlling for the same variables. RESULTS: Linear regression models (n = 976) demonstrated a caloric deficit of 238 kcal (237.88; 95%CI 75.13-400.63) or a protein deficit of 14 g (14.23; 95%CI 4.46-24.00) was associated with each unit decrement in FSS-ICU. Logistic regression models demonstrated a 6% likelihood (1.06; 95%CI 1.01-1.14) of caloric deficit ≥6000 vs. <6000 kcal and an 8% likelihood (1.08; 95%CI 1.01-1.15) of protein deficit ≥300 vs. <300 g with each unit decrement in FSS-ICU. CONCLUSION: In our cohort of patients, macronutrient deficit over the course of critical illness was associated with worse functional status at discharge. Future studies are needed to determine whether optimized macronutrient delivery can improve outcomes in ICU survivors.

Intraoperative Provocative Testing in Patients with Obstructive Hypertrophic Cardiomyopathy Undergoing Septal Myectomy.

BACKGROUND: Resolution of left ventricular outflow tract (LVOT) obstruction predicts symptom relief postmyectomy. Intraoperative measurement of LVOT gradients thus is essential for surgical guidance. We hypothesized that (1) hypertrophic cardiomyopathy patients have lower LVOT gradients when measured intraoperatively with transesophageal echocardiography (TEE) compared with preoperative measurements with transthoracic echocardiography (TTE) and that (2) intraoperative provocative testing can help evaluate the adequacy of surgical resection. METHODS: We compared resting LVOT gradients on preoperative TTE to intraoperative TEE. We also compared intraoperative resting and provoked gradients pre- and postresection. Either isoproterenol 10 µg/kg/min or dobutamine 20 µg/kg/min was used. Patients with provoked LVOT gradients >30 mm Hg were considered for further resection based on LVOT/mitral valve morphology and clinical comorbidities. RESULTS: Of 315 patients identified, 293 patients were included in the analysis. There was a statistically significant difference between preoperative TTE and intraoperative TEE resting LVOT gradients (60.9 ± 39.4 mm Hg vs 42.0 ± 30.5 mm Hg, P < .0001). Out of 197 patients who had significant resting obstruction preoperatively, 82 (41.6%) demonstrated mild or no dynamic obstruction under general anesthesia. Provocative testing with both isoproterenol and dobutamine increased peak gradients (116.8 ± 33 mm Hg isoproterenol vs 107.5 ± 33 mm Hg dobutamine, P = .03). Post-cardiopulmonary bypass, seven patients (2.3%) had LVOT gradients > 30 mm Hg at rest, while 63 patients (21.5%) had residual gradients >30 mm Hg only with provocation. Elevated gradients, persistent systolic anterior motion of the mitral valve with near contact, and/or significant mitral regurgitation with provocative testing resulted in return to cardiopulmonary bypass in 41 patients (14%). CONCLUSIONS: Resting intraoperative TEE LVOT gradients are significantly lower than preoperative TTE gradients, with systolic anterior motion of the MV and outflow obstruction often not visualized after inducing general anesthesia. Intraoperative pharmacologic provocation can identify patients who may benefit from further surgical intervention, facilitating procedural success.

Nutrition Risk in Critically Ill Versus the Nutritional Risk Screening 2002: Are They Comparable for Assessing Risk of Malnutrition in Critically Ill Patients?

BACKGROUND: Malnutrition influences clinical outcomes. Although various screening tools are available to assess nutrition status, their use in the intensive care unit (ICU) has not been rigorously studied. Our goal was to compare the Nutrition Risk in Critically Ill (NUTRIC) to the Nutritional Risk Screening (NRS) 2002 in terms of their associations with macronutrient deficit in ICU patients. METHODS: We performed a retrospective analysis to investigate the relationship between NUTRIC vs NRS 2002 and macronutrient deficit (protein and calories) in critically ill patients. We performed linear regression analyses, controlling for age, sex, race, body mass index, and ICU length of stay. We then dichotomized our primary exposures and outcomes to perform logistic regression analyses, controlling for the same covariates. RESULTS: The analytic cohort included 312 adults. Mean NUTRIC and NRS 2002 scores were 4 ± 2 and 4 ± 1, respectively. Linear regression demonstrated that each increment in NUTRIC score was associated with a 49 g higher protein deficit (ß = 48.70: 95% confidence interval [CI] 29.23-68.17) and a 752 kcal higher caloric deficit (ß = 751.95; 95% CI 447.80-1056.09). Logistic regression demonstrated that NUTRIC scores >4 had over twice the odds of protein deficits ≥300 g (odds ratio [OR] 2.35; 95% CI 1.43-3.85) and caloric deficits ≥6000 kcal (OR 2.73; 95% CI 1.66-4.50) compared with NUTRIC scores ≤4. We did not observe an association of NRS 2002 scores with macronutrient deficit. CONCLUSION: Our data suggest that NUTRIC is superior to NRS 2002 for assessing malnutrition risk in ICU patients. Randomized, controlled studies are needed to determine whether nutrition interventions, stratified by NUTRIC score, can improve patient outcomes.

Vitamin D Status Is Associated With Development of Hospital-Acquired Pressure Injuries in Critically Ill Surgical Patients.

BACKGROUND: Hospital-acquired pressure injuries (HAPIs) typically develop following critical illness due to immobility and suboptimal perfusion. Vitamin D helps to maintain epithelial cell integrity, particularly at barrier sites such as skin. It is unclear whether vitamin D status is a modifiable risk factor for HAPIs in critically ill patients. Our goal was to investigate the relationship between admission 25-hydroxyvitamin D (25OHD) levels with the development of HAPIs in surgical intensive care unit (ICU) patients. METHODS: We performed a retrospective cohort study of patients admitted to surgical ICUs at a major teaching hospital in Boston, Massachusetts. To investigate the association of 25OHD levels with subsequent development of HAPIs, we performed logistic regression analyses, controlling for body mass index, Nutrition Risk in the Critically Ill score, ICU length of stay, and cumulative ICU caloric or protein deficit. RESULTS: A total of 402 patients comprised our analytic cohort. Each unit increment in 25OHD was associated with 11% decreased odds of HAPIs (odds ratio [OR] 0.89; 95% CI 0.840.95). When vitamin D status was dichotomized, patients with 25OHD <20 ng/mL were >2 times as likely to develop HAPIs (OR 2.51; 95% CI 1.065.97) compared with patients with 25OHD >20 ng/mL. CONCLUSION: In our cohort of critically ill surgical patients, vitamin D status at ICU admission was linked to subsequent development of HAPIs. Randomized, controlled trials are needed to assess whether optimizing 25OHD levels in the ICU can reduce the incidence of HAPIs and improve other clinically relevant outcomes in critically ill patients.