Corey Scurlock

Predictors and Outcome of Gastrointestinal Complications in Patients Undergoing Cardiac Surgery

Objective:To determine the incidence and independent predictors of gastrointestinal complications (GICs) following cardiac surgery. Summary Background Data:Gastrointestinal ischemia and hemorrhage represent a rare but devastating complication following heart surgery. The profile of patients referred for cardiac surgery has changed during the last decade, questioning the validity of previously reported incidence and risk factors. Methods:We retrospectively analyzed prospectively collected data from 4819 patients undergoing cardiac surgery between 1998 and 2004. Patients with GICs were compared with the entire patient population. Study endpoints were mortality, postoperative morbidities, and long-term survival. Results:GICs occurred in 51 (1.1%) patients. Etiologies were intestinal ischemia (n = 30; 59%) and hemorrhage (n = 21; 41%). The incidence decreased during the study period (1998–2001: 1.3%, 2002–2004: 0.7%; P = 0.04). The incidence per type of procedure was as follows: coronary artery bypass grafting (CABG)/valve (2.4%), aortic surgery (1.7%), valve surgery (1.0%), and CABG (0.5%; P = 0.001). Multivariate analysis revealed age (odds ratio [OR] = 2.1), myocardial infarction (OR = 2.5), CHF (OR = 2.4), hemodynamic instability (OR = 2.8), cardiopulmonary bypass time >120 minutes (OR = 6.2), peripheral vascular disease (OR = 2.2), renal (OR = 3.2), and hepatic failure (OR = 10.8) as independent predictors of GICs. The overall hospital mortality among patients with GICs was 33%. Long-term survival was significantly decreased in patients with GICs compared with the control group. Conclusions:Gastrointestinal complications following cardiac surgery remain rare with an incidence <1% in a contemporary series. The key to a lower incidence of GICs lies in systematic application of preventive measures and new advances in intraoperative management. Identification of independent risk factors would facilitate the determination of patients who would benefit from additional perioperative monitoring. Future resources should therefore be redirected to mitigate GICs in high-risk patients.

Predictive Model for Postoperative Delirium in Cardiac Surgical Patients

Delirium is a common complication following cardiac surgery, and the predictors of delirium remain unclear. The authors performed a prospective observational analysis to develop a predictive model for postoperative delirium using demographic and procedural parameters. A total of 112 adult postoperative cardiac surgical patients were evaluated twice daily for delirium using the Richmond Agitation-Sedation Scale (RASS) and Confusion Assessment Model for the ICU (CAM-ICU). The incidence of delirium was 34% (n = 38). Increased age (odds ratio [OR] = 2.5; 95% confidence interval [CI] = 1.6-3.9; P < .0001, per 10 years) and increased duration of surgery (OR = 1.3; 95% CI = 1.1-1.5; P = .0002, per 30 minutes) were independently associated with postoperative delirium. Gender, BMI, diabetes mellitus, preoperative ejection fraction, surgery type, length of cardiopulmonary bypass, intraoperative blood component administration, Acute Physiology and Chronic Health Evaluation II score, Sequential Organ Failure Assessment score, and Charlson Comorbidity Index, were not independently associated with postoperative delirium.

Early nutrition support in the intensive care unit: a US perspective.

Purpose of reviewEarly nutrition support, defined as within the first 24–48 h of ICU care, is recommended by clinical practice guidelines. The purpose of this paper is to provide an evidence-based US perspective on early nutrition support in critical illness, explain its mechanism of action, and describe its implementation using combined enteral and parenteral nutrition support. Recent findingsRecent American and Canadian guidelines recommend starting enteral nutrition within the first 24–48 h of ICU care. This is mainly due to accrued ‘energy debt’ from underfeeding in certain patients. This energy debt leads to increased risks of complications and longer lengths of stay. Strong clinical evidence, however, in the form of prospective, randomized, controlled intervention studies of early nutrition support in the setting of routine intensive insulin therapy, is lacking. SummaryEarly enteral nutrition should be first-line therapy in the ICU. If a caloric goal of 20–25 kcal/kg/day is not possible, then combined enteral and parenteral nutrition should be started. In the new age of intensive insulin therapy, parenteral nutrition has not been shown to confer significant additional infective risk. There are many unanswered questions, but a proactive posture for metabolic support in the ICU is advocated.

Critique of normoglycemia in intensive care evaluation: survival using glucose algorithm regulation (NICE-SUGAR)--a review of recent literature.

Purpose of reviewThe publication of the long awaited results of the Normoglycaemia in Intensive Care Evaluation – Survival Using Glucose Algorithm Regulation (NICE-SUGAR) trial generated intense controversy in the area of glycemic control in the critically ill. NICE-SUGAR reported results in direct contrast to the original Leuven study and challenged the legitimacy of a mortality benefit of tight glycemic control in the intensive care unit (ICU). This review of the recent literature critically examines the salient differences between NICE-SUGAR and the original Leuven study. Recent findingsDifferences in glycemic targets within the control and intervention groups, variability with patients reaching these set targets, and the disparity in study execution and nutritional strategies are some of the methodological differences explaining the observed differences in mortality and morbidity between the two studies. The Leuven study should be viewed as a ‘proof-of-concept’ study with future studies aimed at confirming its finding and optimizing clinical algorithms to safely implement it in various ‘real world’ settings. Discrepancies in implementation and nutrition make direct comparison of NICE-SUGAR and the original Leuven study impracticable. SummaryAccurate replication of the original Leuven methodology may be the limiting factor for achieving the benefits gained by intensive insulin therapy (IIT). Determination of ICU capability (physicians, nurses, standardization of equipment, etc.) is crucial to implementing tight glycemic targets. If IIT is not achievable due to adverse outcomes such as hypoglycemia, more lax and reachable glucose control should be sought.

A multicenter population-based effectiveness study of teleintensive care unit–directed ventilator rounds demonstrating improved adherence to a protective lung strategy, decreased ventilator duration, and decreased intensive care unit mortality

PURPOSE OF THE STUDY The purpose of the study is to determine if teleintensive care unit (ICU)-directed daily ventilator rounds improved adherence to lung protective ventilation (LPV), reduced ventilator duration ratio (VDR), and ICU mortality ratios. METHOD USED A retrospective observational longitudinal quarterly analysis of adherence to low tidal volume LPV (<7.5 mL/kg predicted body weight; Pao2/fraction of inspired oxygen<300), ventilator duration, and ICU mortality ratios (Acute Physiology and Chronic Health Evaluation IV-adjusted). The teleICU practice used Philips (Andover, MA) VISICU eCareManagerTM (Andover, MA) platform, providing ICU care and process improvement. RESULTS Before ventilator rounds implementation, there was wide variation in hospital adherence to low tidal volume (29.5±18.2; range 10%-69%). Longitudinal improvement was seen across hospitals in the 3 Qs after implementation, reaching statistical significance by Q3 postimplementation (44.9±15.7; P<.002 by 2-tailed Fisher exact test), maintained at 2 subsequent Qs (48% and 52%; P<.001). Ventilator duration ratio also showed preimplementation variability (1.08±.34; range 0.71-1.90). After implementation, absolute and significant mean VDR reduction was observed (0.92±.28; -15.8%, P<.05). Intensive care unit mortality ratio demonstrated longitudinal improvement, reaching significance after the Q3 postimplementation (0.94 vs 0.67; P<.04), and this was sustained in the most recent Q analyzed (0.65; P<.03). CONCLUSIONS Implementation of teleICU-directed ventilator rounds was associated with improved and durable adherence to LPV and significant reductions in both VDR and ICU mortality.

Impact of new technologies on metabolic care in the intensive care unit.

Purpose of reviewTechnological innovations in the ICU have lead to extraordinary advances in modern critical care. Renal replacement therapy (RRT) innovations and ventricular assist devices (VAD) are now becoming common interventions in the ICU environment. The purpose of this article is to describe the impact of RRT and VAD on critical care medicine with particular reference to metabolic care. Recent findingsContinuous venovenous hemofiltration and slow low efficient daily dialysis are effective modalities of RRT in hemodynamically unstable patients. These continuous forms of RRT can result in accentuated protein and nutrient losses but also provide an opportunity for intradialytic parenteral nutrition support. VAD patients typically have cardiac cachexia and develop chronic critical illness syndrome. Intensive metabolic support, incorporating trophic, concentrated, semielemental enteral nutrition, supplemental parenteral nutrition, and intensive insulin therapy is a rational strategy to implement in VAD patients. Unfortunately, there is insufficient evidence at this time to support the routine use of these nutritional interventions with RRT and VAD. SummaryPatients requiring RRT or VAD are at high nutritional risk, which negatively affects ICU outcome. Prompt nutritional risk assessment and early optimization of metabolic care is crucial in this patient population.

A Model to Create an Efficient and Equitable Admission Policy for Patients Arriving to the Cardiothoracic ICU

Objective:To develop queuing and simulation-based models to understand the relationship between ICU bed availability and operating room schedule to maximize the use of critical care resources and minimize case cancellation while providing equity to patients and surgeons. Design:Retrospective analysis of 6-month unit admission data from a cohort of cardiothoracic surgical patients, to create queuing and simulation-based models of ICU bed flow. Three different admission policies (current admission policy, shortest-processing-time policy, and a dynamic policy) were then analyzed using simulation models, representing 10 yr worth of potential admissions. Important output data consisted of the “average waiting time,” a proxy for unit efficiency, and the “maximum waiting time,” a surrogate for patient equity. Setting:A cardiothoracic surgical ICU in a tertiary center in New York, NY. Patients:Six hundred thirty consecutive cardiothoracic surgical patients admitted to the cardiothoracic surgical ICU. Interventions:None. Measurements and Main Results:Although the shortest-processing-time admission policy performs best in terms of unit efficiency (0.4612 days), it did so at expense of patient equity prolonging surgical waiting time by as much as 21 days. The current policy gives the greatest equity but causes inefficiency in unit bed-flow (0.5033 days). The dynamic policy performs at a level (0.4997 days) 8.3% below that of the shortest-processing-time in average waiting time; however, it balances this with greater patient equity (maximum waiting time could be shortened by 4 days compared to the current policy). Conclusions:Queuing theory and computer simulation can be used to model case flow through a cardiothoracic operating room and ICU. A dynamic admission policy that looks at current waiting time and expected ICU length of stay allows for increased equity between patients with only minimum losses of efficiency. This dynamic admission policy would seem to be a superior in maximizing case-flow. These results may be generalized to other surgical ICUs.

IMPAIRED POSTOPERATIVE HYPERGLYCEMIC STRESS RESPONSE ASSOCIATED WITH INCREASED MORTALITY IN PATIENTS IN THE CARDIOTHORACIC SURGERY INTENSIVE CARE UNIT

OBJECTIVE To describe the association of tight glycemic control with intensive insulin therapy and clinical outcome among patients in the cardiothoracic surgery intensive care unit. METHODS All patients who underwent cardiothoracic surgery and were admitted to the cardiothoracic surgery intensive care unit between September 13, 2007, and November 1, 2007, were enrolled. Clinical and metabolic data were prospectively collected. All patients received intensive insulin therapy using a nurse-driven dynamic protocol targeting blood glucose values of 80 to 110 mg/dL. Four stages of critical illness were defined as follows: acute critical illness (intensive care unit days 0-2), prolonged acute critical illness (intensive care unit 3 or more days), chronic critical illness (tracheotomy performed), and recovery (liberated from ventilator). RESULTS One hundred fourteen patients were enrolled. Seventy-three (64%) recovered during acute critical illness, 26 (23%) recovered during prolonged acute critical illness, and 15 (13%) progressed to chronic critical illness. All 6 deaths were among patients in chronic critical illness. Admission blood glucose and average blood glucose values for the first 12 hours were lower in patients who developed chronic critical illness and died and were higher in patients who developed chronic critical illness and survived (P = .007 and P = .007, respectively). Severe hypoglycemia (blood glucose <40 mg/dL) occurred once (0.03% of all measurements). Lower initial blood glucose values, which reflect an impaired stress response immediately after surgery, were associated with increased mortality, and a significant delay in achieving tight glycemic control with intensive insulin therapy was associated with prolonged intensive care unit course, but no increase in mortality. CONCLUSION The study findings suggest that acute postoperative hyperglycemia and its prompt correction with intensive insulin therapy are associated with favorable outcomes in patients in the cardiothoracic surgery intensive care unit.

The economics of glycemic control in the ICU in the United States.

Purpose of reviewCurrently the USA has an aging population, with increasing deficits and a healthcare system that most would agree is in need of repair. Finding ways to curtail costs is urgently needed. Attention to glycemic control and metabolic care offers a cost-effective method of treatment to reduce complications. Recent findingsHealthcare-related expenses occupy an expanding portion of gross domestic product in the US and are a driver of the deficit. Despite all of this spending, the US receives average marks on outcomes and is not obtaining value in its healthcare. Any movements toward healthcare reform must focus on improving outcomes per healthcare dollar spent, and increasing value. The Affordable Care Act will place greater emphasis on preventing complications and reducing hospital-acquired infections. The original Leuven trial demonstrated that proper implementation of glycemic control can reduce morbidity and mortality. More recent studies have shown that there is a cost-benefit to glycemic control as well, through reduction of hospital stay and prevention of complications. On the basis of these changes, physicians who practice metabolic care and provide glycemic control are well positioned to add value in this era of healthcare reform. SummaryGlycemic control is inherently valuable in the care of ICU patients as it decreases infectious complications, reduces lengths of stay, and has a positive effect on morbidity and mortality. Further studies should be completed to delineate the exact amount of cost-savings that can be obtained by proper implementation of glycemic control in the ICU.

Intensive Metabolic Support: Evolution and Revolution

OBJECTIVE To describe a new aspect of critical care termed intensive metabolic support. METHODS We performed a MEDLINE search of the English-language literature published between 1995 and 2008 for studies regarding the metabolic stages of critical illness, intensive insulin treatment, and intensive metabolic support in the intensive care unit, and we summarize the clinical data. RESULTS Intensive metabolic support is a 3-component model involving metabolic control and intensive insulin therapy, early nutrition support, and nutritional pharmacology aimed at preventing allostatic overload and the development of chronic critical illness. To improve clinical outcome and prevent mortality, intensive metabolic support should start on arrival to the intensive care unit and should end only when patients are in the recovery phase of their illness. CONCLUSIONS Intensive metabolic support should be an essential part of the daily treatment strategy in critical care medicine. This will involve a newfound and extensive collaboration between the endocrinologist and the intensivist. We call for well-designed future studies involving implementation of this protocol to decrease the burden of chronic critical illness.