Influence of Overweight on ICU Mortality

Obesity in trauma: outcomes and disposition trends

BACKGROUND

Obesity's effect on the outcomes of trauma patients remains inconclusive.

METHODS

A retrospective review of all falls, motor vehicle collisions (MVCs), and penetrating trauma patients admitted from January 2008 to December 2012 was performed. The outcomes evaluated included mortality, length of stay at hospital, and discharge disposition. Patients were grouped according to the body mass index (BMI) and stratified by injury severity scores.

RESULTS

Two thousand one hundred ninety six patients were analyzed; 132 penetrating, 913 falls, and 1,151 MVCs. Penetrating traumas had no significant difference in outcomes. In falls, obese patients had a lower mortality (P = .035). In MVCs, obese patients had longer hospitalizations (P = .02), and mild and moderate MVC injuries were less likely to be discharged home (P = .032 and .003). Obese patients sustained fewer head injuries in falls and MVCs (P = .005 and .043, respectively).

CONCLUSIONS

In falls, a higher BMI may benefit patients. However, an increasing BMI is associated with a longer length of stay at hospital, and decreased likelihood of discharge to home.

Relação do estado nutricional e dependência de ventilação mecânica em pacientes críticos oncológicos

O estado de má nutrição está ligado com a perda de massa muscular que, por sua vez, pode ser responsável pelo mal prognóstico de pacientes internados em unidade de terapia intensiva (UTI). A relação entre câncer e estado nutricional tem sido amplamente estudada. No entanto, a relação entre estado nutricional e tempo de permanência em ventilação mecânica invasiva (VMI) em pacientes oncológicos ainda não está totalmente esclarecida. O objetivo do estudo foi verificar a relação do estado nutricional dos pacientes oncológicos em UTI com o tempo de permanência em VMI. Participaram do estudo 57 pacientes que estiveram internados na UTI do Hospital Erasto Gaertner e necessitaram de suporte ventilatório invasivo por no mínimo 48 horas. Foram coletados dados referentes ao gênero, à idade, ao índice de massa corporal (IMC), à localização topográfica do câncer, ao estádio clínico (EC) da doença, ao exame anatomopatológico (AP), ao tratamento realizado, ao motivo de internamento na UTI e ao APACHE II. O diagnóstico de desnutrição encontrado foi de 22,81%, 50,88% eram eutróficos, 14,04% tinham sobrepeso e 12,28% eram obesos. O escore de APACHE II obteve média de 26,4 pontos e taxa prevista de mortalidade de 60%. A média geral de tempo sob VMI foi de 11,2 dias. A correlação entre índice de massa corporal e tempo de permanência sob VMI foi de r=0,076 e p=0,575. Concluímos que a maior parte dos pacientes possui classificação nutricional de eutrofia e tempo de permanência sob VMI elevado. Ainda, o estado nutricional avaliado isoladamente não está relacionado com o tempo de permanência em VMI.

Are clinical trials dealing with severe infection fitting routine practices? Insights from a large registry

Introduction

Guidelines dealing with severe sepsis and septic shock mostly rely on randomized controlled trials (RCTs) to ensure the best standards of care for patients. However, patients included in high-quality studies may differ from the routine population and alter external validity of recommendations. We aimed to determine to what extent non-inclusion criteria of RCTs dealing with severe sepsis and septic shock may affect application of their conclusions in routine care.

Methods

In a first step, the MEDLINE database was searched for RCTs treating severe sepsis and septic shock patients between 1992 and 2008, and non-inclusion criteria for these studies were abstracted. Two reviewers independently evaluated the articles, which were checked by a third reviewer. We extracted data on the study design, main intervention, primary endpoint, criteria for inclusion, and criteria for non-inclusion. In a second step, the distribution of the non-inclusion criteria was observed in a prospective multicenter cohort of severe sepsis and septic shock patients (Cub-Rea network, 1992 to 2008).

Results

We identified 96 articles out of 7,012 citations that met the screening criteria. Congestive heart failure (35%) and cancer (30%) were frequent exclusion criteria in selected studies, as well as other frequent disorders such as gastrointestinal and liver diseases and all causes of immune suppression. Of the 67,717 patients with severe sepsis and septic shock in the Cub-Rea database, 40,325 (60%) experienced at least one of the main exclusion criteria, including 11% of congestive heart failure patients and 11% of cancer patients. In addition, we observed a significant trend for increasing number of patients with these criteria along time.

Conclusion

Current exclusion criteria for RCTs dealing with severe sepsis and septic shock excluded most patients encountered in daily practice and limit external validity of the results of high-quality studies.

Obesity Does Not Increase Morbidity and Mortality after Laparotomy for Trauma

Obesity has been suggested to be a risk factor for increase morbidity and mortality after trauma and surgery. Trauma laparotomy provides an opportunity to assess the effect of body mass index (BMI) on patients subjected to both trauma and surgery. We hypothesized that obesity would have a deleterious effect on outcomes. A retrospective review was conducted of all patients 18 years of age or older undergoing laparotomy for trauma between July 2001 and June 2011. Patients were stratified according to BMI into the following four groups: underweight (16 to 22 kg/m2), normal (23 to 27 kg/m2), overweight (28 to 34 kg/m2), and obese (35 kg/m2 or higher). Data on the patient's hospital course included length of stay, mortality, respiratory failure, infectious complications, wound dehiscence, and organ failure. A total of 1,297 patients underwent laparotomy. Seven per cent of the study group was obese and 24 per cent was underweight. There was no difference among mean Injury Severity Score, percent of patients arriving in shock, and mean number of units of packed red blood cells administered during their hospital stay. Obese patients had longer intensive care unit and hospital lengths of stay. There were no differences in ventilator days or mortality. Using univariate statistics, obese patients had increased rates of respiratory and renal failure, bacteremia with and without septic shock, and abdominal wound dehiscence. Subjecting the data to logistic regression analysis, BMI was no longer an independent predictor of any complication. Although obese trauma patients do have increased infectious morbidity, wound dehiscence, and a prolonged length of stay, increased BMI is not an independent predictor of increased morbidity or mortality after trauma laparotomy.

Assessing the relationship between obesity and asthma in adolescent patients: a review

The parallel rise in the prevalence of obesity and asthma over the last several decades has led to an extensive line of investigation into the relationship between these two conditions. This review will discuss evidence from laboratory-based studies, observational clinical studies, and clinical trials that suggests that obesity adversely influences asthma through multiple mechanisms. The effect of obesity on asthma during adolescence, including asthma incidence, the severity and control of existing asthma, lung function, and exacerbations, will be reviewed.

Being overweight or obese is associated with decreased mortality in critically ill patients: a retrospective analysis of a large regional Italian multicenter cohort

PURPOSE

To describe the epidemiology of obesity in a large cohort of intensive care unit (ICU) patients and study its impact on outcomes.

METHODS

All 3902 patients admitted to one of 24 ICUs in the Piedmont region of Italy from April 3 to September 29, 2006, were included in this retrospective analysis of data from a prospective, multicenter study.

RESULTS

Mean body mass index (BMI) was 26.0 ± 5.4 kg/m(2): 32.8% of patients had a normal BMI, 2.6% were underweight, 45.1% overweight, 16.5% obese, and 2.9% morbidly obese. ICU mortality was significantly (P < .05) lower in overweight (18.8%) and obese (17.5%) patients than in those of normal BMI (22%). In multivariate logistic regression analysis, being overweight (OR = 0.73; 95%CI: 0.58-0.91, P = .007) or obese (OR = 0.62; 95%CI: 50.45-0.85, P = .003) was associated with a reduced risk of ICU death. Being morbidly obese was independently associated with an increased risk of death in elective surgery patients whereas being underweight was independently associated with an increased risk of death in patients admitted for short-term monitoring and after elective surgery.

CONCLUSIONS

In this cohort, overweight and obese patients had a reduced risk of ICU death. Being underweight or morbidly obese was associated with an increased risk of death in some subgroups of patients.

[Guidelines for specialized nutritional and metabolic support in the critically ill-patient. Update. Consensus of the Spanish Society of Intensive Care Medicine and Coronary Units-Spanish Society of Parenteral and Enteral Nutrition (SEMICYUC-SENPE): obese patient]

As a response to metabolic stress, obese critically-ill patients have the same risk of nutritional deficiency as the non-obese and can develop protein-energy malnutrition with accelerated loss of muscle mass. The primary aim of nutritional support in these patients should be to minimize loss of lean mass and accurately evaluate energy expenditure. However, routinely-used formulae can overestimate calorie requirements if the patient's actual weight is used. Consequently, the use of adjusted or ideal weight is recommended with these formulae, although indirect calorimetry is the method of choice. Controversy surrounds the question of whether a strict nutritional support criterion, adjusted to the patient's requirements, should be applied or whether a certain degree of hyponutrition should be allowed. Current evidence suggested that hypocaloric nutrition can improve results, partly due to a lower rate of infectious complications and better control of hyperglycemia. Therefore, hypocaloric and hyperproteic nutrition, whether enteral or parenteral, should be standard practice in the nutritional support of critically-ill obese patients when not contraindicated. Widely accepted recommendations consist of no more than 60-70% of requirements or administration of 11-14 kcal/kg current body weight/day or 22-25 kcal/kg ideal weight/day, with 2-2.5 g/kg ideal weight/day of proteins. In a broad sense, hypocaloric-hyperprotein regimens can be considered specific to obese critically-ill patients, although the complications related to comorbidities in these patients may require other therapeutic possibilities to be considered, with specific nutrients for hyperglycemia, acute respiratory distress syndrome (ARDS) and sepsis. However, there are no prospective randomized trials with this type of nutrition in this specific population subgroup and the available data are drawn from the general population of critically-ill patients. Consequently, caution should be exercised when interpreting these data.

[Severe bacterial infection: increased mortality in elderly women with low body weight taking drugs prolonging the QTc interval]

AIMS

Women have a higher risk of acquired long QT syndrome which could be of vital importance in severe bacterial infections when macrolides or fluoroquinolones are administered. This study evaluated whether age, drugs prolonging the QTc interval and body weight were additional influencing factors on mortality in the critically ill with respect to gender.

METHODS

In an exploratory investigation 204 intensive care unit (ICU) patients (78 f, 126 m, 61.1±16.1 years) with severe bacterial infections were studied (mortality probability model II(0) 49.1±28%). Antibiotic therapy was carried out following standard guidelines. In 65.2% of patients potentially QTc prolonging drugs were administered for ≥48 h. Body weight was ascertained on ICU admission.

RESULTS

By comparable severity of illness and comparable effect of antibiotic therapy, age, QTc prolonging drugs and less body weight showed significant effects on survival in women (p<0.001, 0.008 and 0.009, respectively). For women mortality increased with age ≥60 years (p=0.01). The division between survival versus non-survival was intensified by addition of QTc prolonging medication and body weight. As such a best risk assessment in women was achieved if age, QTc prolonging therapy and less body weight were combined (p<0.001). In a direct comparison to men, women with at least two of these factors had a significantly poorer outcome (OR 2.37; 95% CI 1.13-4.98; p=0.022).

CONCLUSIONS

Age, QTc prolonging drugs and lower body weight can additionally increase mortality in critically ill women. If negative outcome is attributed to a higher dosage, an adjustment for body weight must be carried out. Until now it should be considered whether it would be better to replace QTc prolonging antibiotics in routinely performed drug alternation in elderly lean women.

Obesity is not associated with increased mortality and morbidity in critically ill children

AIM

To evaluate the effect of obesity on mortality, length of mechanical ventilation, and length of stay (LOS) in critically ill children.

METHODS

Retrospective cohort study in 2- to 18-year-olds, admitted to the pediatric intensive care unit (PICU) at the Children's Hospital of Wisconsin from 2005-2009 who required invasive ventilation. Weight z score was used to categorize patients as normal (-1.89 to 1.04), overweight (1.05-1.65), obese (1.66-2.33), and severely obese (>2.33). Underweight patients were excluded. Age, gender, admission type, Pediatric Index of Mortality 2 score, operative status, trauma status, admission Pediatric Outcome Performance Category, and diagnosis categories were also collected. The outcomes were mortality, total ventilator days, and PICU LOS. Univariate analysis was used to compare the groups, and multivariate logistic regression was used to compare mortality. Total ventilation days and LOS were modeled with linear regression.

RESULTS

In total, 1030 patients were included in the study, with 753 normal weight, 137 overweight, 76 obese, and 64 severely obese. The risk-adjusted mortality rates in overweight (odds ratio [OR], 1.06; 95% confidence interval [CI], 0.62-1.82), obese (OR, 0.68; 95% CI, 0.31-1.48), and severely obese patients (OR, 1.02; 95% CI, 0.45-2.34) were not significantly different compared with the normal-weight group. Total ventilation days (P = .9628) and PICU LOS (P = .8431) were not significantly different between the groups after adjusting for risk factors.

CONCLUSION

Critically ill overweight, obese, and severely obese children who require invasive mechanical ventilation have similar mortality, length of stay in the PICU, and ventilator days as compared with normal-weight children.

Adipose tissue-derived adiponectin expression is significantly associated with increased post operative mortality in horses undergoing emergency abdominal surgery

REASONS FOR PERFORMING STUDY

Adipose tissue is an important source of inflammatory cytokines (adipokines) and adiposity has been identified as having a significant effect on human morbidity and mortality. Obesity is also an emerging welfare problem in the UK horse population, but the role that it plays in secondary diseases is unclear.

OBJECTIVES

To examine the expression of inflammation-related adipokine genes in retroperitoneal adipose tissue of horses undergoing emergency abdominal surgery and to explore associations with adiposity and post operative survival.

METHODS

Retroperitoneal adipose tissue samples were obtained from 76 horses undergoing emergency abdominal surgery. Real-time PCR was used to measure gene expression for leptin, adiponectin, tumour necrosis factor-alpha, macrophage chemoattractant protein-1, macrophage inhibitory factor, serum amyloid A, haptoglobin and interleukin-1. Multivariate patterns of adipokine expression were explored with principal component analysis (PCA), whilst univariable associations with post operative survival were tested in a Cox proportional hazards model.

RESULTS

Leptin gene expression was higher in overweight and obese horses than in lean animals. Expression of mRNA encoding adiponectin mRNA in visceral adipose tissue was positively associated with increased post operative mortality (hazard ratio 1.31, 95% CI 1.05-1.65). However, PCA did not demonstrate multivariable patterns of adipokine gene expression from visceral adipose tissue associated with body mass index or with survival.

CONCLUSIONS

In horses presented with acute intestinal disease, increased adiponectin gene expression from retroperitoneal adipose tissue is associated with an increased risk of mortality. Obesity assessed by BMI had no association with increased post operative mortality in horses with primary gastrointestinal disease.

POTENTIAL RELEVANCE

Further study is warranted on the expression and effects of adipokines, particularly adiponectin, and correlation with postoperative outcome.

Direct peritoneal resuscitation improves obesity-induced hepatic dysfunction after trauma

BACKGROUND

The metabolic syndrome and associated fatty liver disease are thought to contribute to poor outcomes in trauma patients. Experimentally, obesity compromises liver blood flow. We sought to correlate the effect of obesity, injury severity, and liver dysfunction with trauma outcomes. We hypothesized that obesity-related liver dysfunction could be mitigated with the novel technique of adjunctive direct peritoneal resuscitation (DPR).

STUDY DESIGN

This study has clinical and experimental arms. The clinical study was a case-controlled retrospective analysis of ICU trauma patients (n = 72 obese, n = 187 nonobese). The experimental study was a hemorrhagic shock model in obese rats to assess the effect of DPR on liver blood flow, liver function, and inflammatory mediators.

RESULTS

In trauma patients, univariate and multivariate analyses demonstrated increasing mortality (p < 0.05), septic complications (p < 0.05), liver dysfunction (p < 0.001), and renal impairment (p < 0.05) with increasing body mass index and injury severity score. Obesity in rats impairs liver blood flow, liver function, renal function, and inflammation (interleukin [IL]-1β, IL-6, high mobility group protein B1[HMGB-1]). The addition of DPR to shock resuscitation restores liver blood flow, improves organ function, and reverses the systemic proinflammatory response.

CONCLUSIONS

Our clinical review substantiates that obesity worsens trauma outcomes regardless of injury severity. Obesity-related liver and renal dysfunction is aggravated by injury severity. In an obese rat model of resuscitated hemorrhagic shock, the addition of DPR abrogates trauma-induced liver, renal, and inflammatory responses. We conclude that the addition of DPR to the clinical resuscitation regimen will benefit the obese trauma patient.

The impact of comorbid [corrected] conditions on critical illness

OBJECTIVE

To review the current knowledge of common comorbidities in the intensive care unit, including diabetes mellitus, chronic obstructive pulmonary disease, cancer, end-stage renal disease, end-stage liver disease, HIV infection, and obesity, with specific attention to epidemiology, contribution to diseases and outcomes, and the impact on treatments in these patients.

DATA SOURCE

Review of the relevant medical literature for specific common comorbidities in the critically ill.

RESULTS

Critically ill patients are admitted to the intensive care unit for various reasons, and often the admission diagnosis is accompanied by a chronic comorbidity. Chronic comorbid conditions commonly seen in critically ill patients may influence the decision to provide intensive care unit care, decisions regarding types and intensity of intensive care unit treatment options, and outcomes. The presence of comorbid conditions may predispose patients to specific complications or forms of organ dysfunction. The impact of specific comorbidities varies among critically ill medical, surgical, and other populations, and outcomes associated with certain comorbidities have changed over time. Specifically, outcomes for patients with cancer and HIV have improved, likely related to advances in therapy. Overall, the negative impact of chronic comorbidity on survival in critical illness may be primarily influenced by the degree of organ dysfunction or the cumulative severity of multiple comorbidities.

CONCLUSION

Chronic comorbid conditions are common in critically ill patients. Both the acute illness and the chronic conditions influence prognosis and optimal care delivery for these patients, particularly for adverse outcomes and complications influenced by comorbidities. Further work is needed to fully determine the individual and combined impact of chronic comorbidities on intensive care unit outcomes.

[Obesity, poor prognostic factor in pandemic influenza A (H1N1) 2009: the role of adipokines in the modulation of respiratory defenses]

Pandemic influenza A (H1N1), which occurred during 2009, revealed some unexpected epidemiologic characteristics, notably the high number of obese subjects among the severe cases of influenza. Generally, obesity seems to be associated with a weakness when it comes to respiratory infections. This susceptibility may be the result of a concurrence of mechanical and hormonal factors due to the excess weight. Obesity leads to changes in the ventilatory mechanics and an increase in the metabolic load during exercise. It is associated with immune system changes. Adipokines, cytokines produced by adipocytes, including leptin, play a central role by modulating the activity of all the cells of the immune system. Finally, obesity is associated with an increased risk of thrombosis, which has an adverse effect on the prognosis of infections. All of these observations can explain that obesity has been a risk factor in serious cases of influenza.

Obesity is associated with higher risk of intensive care unit admission and death in influenza A (H1N1) patients: a systematic review and meta-analysis

The aim of this study was to assess the association between obesity and the risk of intensive care unit (ICU) admission and death among patients hospitalized for influenza A (H1N1) viral infection. A systematic review of the Medline and Cochrane databases using 'obesity', 'hospitalization', 'influenza A viral infection', various synonyms, and reference lists of retrieved articles from January 2009 to January 2010. Studies comparing the prevalence of obesity among patients with confirmed infection for influenza A virus and who were either hospitalized or admitted to ICU/died were included. A total of 3059 subjects from six cross-sectional studies, who were hospitalized for influenza A (H1N1) viral infection, were included in this meta-analysis. Severely obese H1N1 patients (body mass index ≥ 40 kg m(-2), n = 804) were as twice as likely to be admitted to ICU or die (odds ration: 2.01, 95% confidence interval: 1.29-3.14, P < 0.002) compared with H1N1 patients who were not severely obese. Having a body mass index ≥ 30 kg m(-2) was similarly associated with a more than twofold increased risk of ICU admission or death although this did not reach statistical significance (2.14, 0.92-4.99, P < 0.07). This meta-analysis supports the view that obesity is associated with higher risks of ICU admission or death in patients with influenza A (H1N1) infection. Therefore, morbid obese patients should be monitored more intensively when hospitalized.

Relationship between vitamin D status and ICU outcomes in veterans

OBJECTIVE

Vitamin D deficiency remains a poorly recognized pandemic and is closely linked to increased health care costs in veterans. Projected health care needs in veterans are expected to increase over the next decade. Intensive care unit (ICU) costs contribute significantly to hospital costs and stem from intervention services and management of sepsis including nosocomial infections. Vitamin D has immunomodulating and antimicrobial properties through antimicrobial peptides such as cathelicidin.

DESIGN/METHODS

A retrospective study was undertaken to evaluate if vitamin D deficiency was associated with less than optimal ICU outcomes in veterans. The study included 136 veterans with 25(OH)D levels drawn within a month of admission to ICU.

RESULTS

The average 25(OH)D level was 24.6 ng/mL (normal range 30-100) with 38% of patients falling in the vitamin D-deficient category (<20 ng/mL). ICU survivors had a significantly lower rate of vitamin D deficiency compared with nonsurvivors (28% versus 53%). Twenty-nine percent of vitamin D-replete patients were in ICU 3 days or more, whereas 58% of patients with vitamin D deficiency stayed in ICU 3 days or longer. This difference was highly significant translating to twofold increased risk (2.0 Relative Risk [RR]) for 3-day or longer stay in ICU for patients with vitamin D deficiency. Moreover, the risk of death was significantly higher in ICU patients with vitamin D deficiency (RR 1.81).

CONCLUSION

A vitamin D-replete state may reduce costs and confer survival advantages in critical illness. We recommend that 25(OH)D levels be routinely checked and deficiencies treated in ICU patients.

[Mechanical ventilation in patients with most severe forms of influenza A H1N1]

BACKGROUND/AIM

Pandemic of A H1N1 influenza is noted for its rapid spreading and life-threatening consequences like acute respiratory distress syndrome (ARDS) which requires mechanical ventilation (MV) and intensive therapy (IT).The aim of the study was to determine the significance of mechanical ventilation application in the presence of comorbidities on the outcome of the disease and patients with severe forms of acute influenza caused by A H1N1 virus.

METHODS

Five patients with acute respiratory failure caused by A H1N1 influenza that required MV were included in the study. Course and outcome of the treatment were monitored in relation to age and sex of the patients, concomitant diseases, time of influenza beginning, a time of admittance in an intensive care unit, a time of an endotracheal intubation and MV beginning, MV duration and occurrence of secondary infections.

RESULTS

Three patients were on a very prolonged MV (39, 43 and 20 days, respectively) and they all survived. Two patients with a significantly shorter duration of MV (14 and 12 days, respectively) died because of a very severe clinical course and concomitant diseases. Unexpectedly, we found a positive correlation between duration of MV and survival although two patients, who were on MV for the longest period of time (43 and 39 days, respectively), developed, as a complication, secondary bacterial pneumonia.

CONCLUSION

Intensive therapy of patients with ARDS due to A H1N1 influenza virus requires MV which should be carried out according to guidelines of international expert forums. That is in accordance with our unexpected observation on negative correlation between duration of MV and fatal outcome. Intensive treatment of these patients, specially MV, can be very prolonged and, therefore, requires specialized teams of anesthesiologists, separate, isolated intensive therapy units and high level of medical staff protection, as was the case in this study, so no member of medical staff was infected.

The impact of obesity on critical care resource use and outcomes

Obese patients in the ICU present unique challenges to the health care team and specific challenges to nurses. This article reviews the science and art of resource use for obese patients in the ICU. Staff nurses and advanced practice nurses can make important contributions in evaluating optimal resource use and improving outcomes in this population of vulnerable patients.

Obesity-related risks and prevention strategies for critically ill adults

In America today, more than one third of adults are obese. Increasingly, obese patients are admitted to critical care units. Critical care nurses must have additional knowledge and skills to identify health risks to obese patients and implement interventions to prevent untoward problems. Critical care nurses are also at risk when taking care of obese patients. The purpose of this article is to identify risks to both patients and nurses and to provide recommendations to address those risks.

Obesity and the orthopedic trauma patient: a review of the risks and challenges in medical and surgical management

The medical and surgical care of obese trauma patients presents a variety of unique and important challenges. Over the past 30 years, this population has increased dramatically in number, and the optimization of their care demands the attention of the medical community. The problems of caring for an obese trauma patient begin before the actual traumatic event occurs due to their substantially higher incidence of serious comorbidities, such as diabetes mellitus, hypertension, and cardiopulmonary issues. In the setting of trauma, important considerations for the obese patient include careful and expeditious preoperative medical optimization; appropriate deep vein thrombosis prophylaxis; planning for and preventing operative and postoperative challenges (eg, pulmonary and wound complications); and ensuring adequate hospital equipment and staffing resources in the acute and rehabilitative phases of care. This article outlines the scope of the obesity epidemic, reviews the medical consequences of obesity, and highlights surgical considerations specific to the care of orthopedic injuries in the obese trauma patient.

Mortality and disability: the effect of overweight and obesity

CONTEXT

Prevalence of obesity is increasing globally. The effect of obesity on mortality and morbidity and its implication on the future prevalence of disability in the older population has not been conclusively analyzed.

OBJECTIVE

To determine the influence of overweight and obesity on mortality and disability by quantifying the effect in terms of disability-free life expectancy and years lost to disability (YLD) in the older people.

DESIGN, SETTING AND PARTICIPANTS

For 5980 participants from the Rotterdam Study cohort, regression techniques were used to estimate the association of body mass index (BMI) and waist circumference (WC) separately with mortality, incident disability and recovery from disability. Disability was assessed using the Stanford Health Assessment Questionnaire Disability Index, an activity of daily living scale. Multistate life table methodology was used to calculate life expectancies.

MAIN OUTCOME MEASURES

In total, 15-year mortality risk, 6-year disability incidence, total life expectancy, healthy life expectancy and years of disabled life expectancy.

RESULTS

We observed 2388 deaths. Our analysis revealed no association between body mass index, or WC and mortality in the healthy population. Body mass index and WC were related to disability ('overweight' 25 < or =BMI <30, odd ratio (OR)=1.33, 95% confidence interval (CI) (1.10; 1.61), 'obesity I' 30< or = BMI <35, OR=2.03, 95% CI (1.55; 2.65)) and negatively to recovery from disability. We observed an increase of years lost to disability with increasing weight for men ('normal weight'-4.69 years, 'overweight'-5.87 years and 'obesity I'-7.06 years) and for women ('normal weight'-10.95 years, 'overweight'-12.82 years, 'obesity I'-15.17 years and 'obesity II/III'-13.13 years).

CONCLUSION

Results do not support the hypothesis that an increased body weight reduces total life expectancy in the older people. Although increased body weight was associated with a higher risk of becoming and remaining disabled. These results remained using WC.

Intra-abdominal pressure and the morbidly obese patients: the effect of body mass index

BACKGROUND

Abdominal compartment syndrome and intra-abdominal hypertension cause morbidity and mortality. Body mass index (BMI) may affect intra-abdominal pressure (IAP). Knowledge of the baseline IAP in the obese and the effect of BMI are not clearly defined.

METHODS

IAPs were measured in 37 morbidly obese patients undergoing elective gastric bypass. Measurements were obtained via bladder pressure using a standard technique. IAP was measured after intubation (P1) and postoperatively after extubation (P2). Data collected included age, gender, BMI, previous surgeries, comorbidities, IAP, and laparoscopic versus open procedure.

RESULTS

Mean BMI was 47.7 kg/m (range, 37-71.8 kg/m), and mean age was 45 years (range, 32-64 years). P1 mean was 9.4 mm Hg +/- 0.6 mm Hg, and P2 mean was 10.0 mm Hg +/- 0.6 mm Hg. Laparoscopic versus open procedure was unrelated to postoperative IAP. Previous surgeries and comorbidities were unrelated to IAP. P1 increased as BMI increased. For each unit increase of BMI, IAP increased by 0.14 mm Hg +/- 0.07 mm Hg (p = 0.05). Higher BMI and age were independent predictors of increased P2, with IAP increased 0.23 mm Hg +/- 0.07 mm Hg for each unit BMI (p = 0.0015) and 0.20 mm Hg +/- 0.06 mm Hg for each year increase in age (p = 0.0014).

CONCLUSIONS

Baseline IAP in the obese is greater than normal weight population (0-6 mm Hg), but not in range of intra-abdominal hypertension (>12 mm Hg). Postoperative status is unrelated to IAP. Elevated BMI does impact IAP, but the incremental value is small. Markedly increased IAP should not be attributed solely to elevated BMI and should be recognized as a pathologic condition.

The body mass index as a prognostic factor of critical care

BACKGROUND/AIMS

Obesity is a worldwide concern, but its influence on critical care outcomes is not well understood. We tested the hypothesis that abnormal body mass index (BMI) would be an independent predictor of higher mortality rates in intensive care unit (ICU).

METHODS

We retrospectively reviewed patients who had admitted to the ICU from January 2007 to December 2007. Admission BMI was analyzed as both a three categorical (underweight, < 18.5 kg/m(2); normal weight, 18.5 to 24.9 kg/m(2); overweight and obese, > or = 25 kg/m(2)) and continuous variables among all patients with an ICU length of stay > or = 4 days. The primary outcome was ICU mortality.

RESULTS

The multivariate analysis on ICU mortality selected Mortality Prediction Model-Admission (MPM at time zero) (hazard ratio [HR], 1.024; p = 0.001; 95% confidence interval [CI], 1.010 to 1.037), failed extubation (HR, 5.092; p = 0.0001; 95% CI, 2.742 to 9.456) as significant risk factors. When controlling these variables, none of the BMI group and BMI as a continuous variable had an independent association with ICU mortality.

CONCLUSIONS

BMI did not have a significant influence on ICU mortality. The ICU mortality was influenced more strongly by severity of illness and failed extubation rather than BMI.

The association between body-mass index and patient outcome in septic shock: a retrospective cohort study

BACKGROUND

It is unknown whether body-mass index (BMI) and commonly defined BMI categories are associated with mortality in patients with septic shock.

METHODS

The database of a multidisciplinary intensive care unit (ICU) was retrospectively screened for adult patients with septic shock. BMI, demographic, clinical and laboratory variables together with outcome measures were collected in all patients. Subjects were categorized as follows: underweight, BMI < 18.5; normal weight, BMI 18.5-24.9; overweight, BMI 25-29.9; obesity, BMI >or= 30. Bivariate and multivariate logistic regression models were used to evaluate the association between BMI and outcome parameters.

RESULTS

In total, 301 patients with septic shock were identified. BMI was bivariately associated with ICU mortality (OR 0.91; 95% CI 0.86-0.98; P = 0.007). There was no significant association between BMI and ICU mortality in the multivariate model but an increasing BMI tended to be associated with lower ICU mortality (OR 0.93; 95% CI 0.86-1.01; P = 0.09). Although overweight (OR 0.43; 95% CI 0.19-0.98; P = 0.04) and obese (OR 0.28; 95% CI 0.08-0.93; P = 0.04) patients had an independently lower risk of ICU death than those with normal weight, there was no difference in the risk of ICU death between normal weight and underweight patients (P = 0.22). A high BMI was independently associated with a lower frequency of acute delirium (P = 0.04) and a lower need for ICU re-admission (P = 0.001) but with a higher rate of ICU-acquired urinary tract infections (P = 0.02).

CONCLUSIONS

BMI up to 50 does not appear to be associated with worse ICU and hospital mortality in patients with septic shock. In contrast, a high BMI may reduce the risk of death from septic shock.

Obesity-induced hepatic hypoperfusion primes for hepatic dysfunction after resuscitated hemorrhagic shock

BACKGROUND

Obese patients (BMI>35) after blunt trauma are at increased risk compared to non-obese for organ dysfunction, prolonged hospital stay, infection, prolonged mechanical ventilation, and mortality. Obesity and non-alcoholic fatty liver disease (NAFLD) produce a low grade systemic inflammatory response syndrome (SIRS) with compromised hepatic blood flow, which increases with body mass index. We hypothesized that obesity further aggravates liver dysfunction by reduced hepatic perfusion following resuscitated hemorrhagic shock (HEM).

METHODS

Age-matched Zucker rats (Obese, 314-519 g & Lean, 211-280 g) were randomly assigned to 4 groups (n = 10-12/group): (1) Lean-Sham; (2) Lean, HEM, and resuscitation (HEM/RES); (3) Obese-Sham; and (4) Obese-HEM/RES. HEM was 40% of mean arterial pressure (MAP) for 60 min; RES was return of shed blood/5 min and 2 volumes of saline/25 min. Hepatic blood flow (HBF) using galactose clearance, liver enzymes and complete metabolic panel were measured over 4 h after completion of RES.

RESULTS

Obese rats had increased MAP, heart rate, and fasting blood glucose and BUN concentrations compared to lean controls, required less blood withdrawal (mL/g) to maintain 40% MAP, and RES did not restore BL MAP. Obese rats had decreased HBF at BL and during HEM/RES, which persisted 4 h post RES. ALT and BUN were increased compared to Lean-HEM/RES at 4 h post-RES.

CONCLUSION

These data suggest that obesity significantly contributes to trauma outcomes through compromised vascular control or through fat-induced sinusoidal compression to impair hepatic blood flow after HEM/RES resulting in a greater hepatic injury. The pro-inflammatory state of NAFLD seen in obesity appears to prime the liver for hepatic ischemia after resuscitated hemorrhagic shock, perhaps intensified by insidious and ongoing hepatic hypoperfusion established prior to the traumatic injury or shock.

Cardiovascular Evaluation and Management of Severely Obese Patients Undergoing Surgery

Obesity is associated with comorbidities that may lead to disability and death. During the past 20 years, the number of individuals with a body mass index >30, 40, and 50 kg/m 2 , respectively, has doubled, quadrupled, and quintupled in the United States. The risk of developing comorbid conditions rises with increasing body mass index. Possible cardiac symptoms such as exertional dyspnea and lower-extremity edema occur commonly and are nonspecific in obesity. The physical examination and electrocardiogram often underestimate cardiac dysfunction in obese patients. The risk of an adverse perioperative cardiac event in obese patients is related to the nature and severity of their underlying heart disease, associated comorbidities, and the type of surgery. Severe obesity has not been associated with increased mortality in patients undergoing cardiac surgery but has been associated with an increased length of hospital stay and with a greater likelihood of renal failure and prolonged assisted ventilation. Comorbidities that influence the preoperative cardiac risk assessment of severely obese patients include the presence of atherosclerotic cardiovascular disease, heart failure, systemic hypertension, pulmonary hypertension related to sleep apnea and hypoventilation, cardiac arrhythmias (primarily atrial fibrillation), and deep vein thrombosis. When preoperatively evaluating risk for surgery, the clinician should consider age, gender, cardiorespiratory fitness, electrolyte disorders, and heart failure as independent predictors for surgical morbidity and mortality. An obesity surgery mortality score for gastric bypass has also been proposed. Given the high prevalence of severely obese patients, this scientific advisory was developed to provide cardiologists, surgeons, anesthesiologists, and other healthcare professionals with recommendations for the preoperative cardiovascular evaluation, intraoperative and perioperative management, and postoperative cardiovascular care of this increasingly prevalent patient population.

The impact of obesity on outcomes after critical illness: a meta-analysis

PURPOSE

To assess whether obesity is associated with mortality or other adverse intensive care unit (ICU) and post-ICU outcomes.

METHODS

A meta-analysis of studies from PubMed and EMBASE databases.

RESULTS

Twenty-two studies (n = 88,051 patients) were included. Pooled analysis demonstrated no difference in ICU mortality, but lower hospital mortality for obese and morbidly obese subjects (RR 0.76; 95% CI 0.59, 0.92; RR 0.83; 95% CI 0.66, 1.04, respectively) versus normal weight subjects. There was no association between obesity and duration of mechanical ventilation or ICU stay. Morbidly obese versus normal weight patients had longer hospitalizations. No study reported physical function, mental health, or quality of life outcomes after discharge.

CONCLUSIONS

Obesity is not associated with increased risk for ICU mortality, but may be associated with lower hospital mortality. There is a critical lack of research on how obesity may affect complications of critical illness and patient long-term outcomes.

[Operative management and fracture care of the lower leg with the Ilizarov fixator in morbidly obese patients: literature review and results]

Given the rising prevalence of obesity, surgeons and hospitals must become more familiar with the treatment and operative management of obese patients. Several additional pre- and postoperative considerations must be involved such as appropriate assessment of comorbidities and requirements for special equipment. There are still very few data regarding morbidly obese patients with BMIs >50 kg/m(2). After a general literature review of operative management of obese patients, we report on fracture care of the lower limb in such patients with custom-made Ilizarov ring fixators. We found them suited to bear enormous weight-loading but that associated comborbidities can limit successful fracture care.

Characteristics and outcome of patients admitted to the ICU following bariatric surgery

BACKGROUND

This study evaluates the characteristics and outcome of patients admitted to the ICU following bariatric surgery.

METHODS

Descriptive study. A review of a prospectively collected database of our bariatric surgery procedures from 2003 until 2006 was performed. The study was performed in a tertiary level, mixed medical and surgical, adult ICU of a large referral hospital.

RESULTS

Of the 265 patients undergoing bariatric surgery (mainly gastroplasties and Roux-en-Y gastric bypasses), 22 (8%) were admitted to the ICU, of which 14 (64%) were on an elective basis and eight (36%) emergently. Hospital length of stay (LOS) for all patients was 4.5 days and ICU LOS was 12 days. Most elective admissions were standard procedure because of obstructive sleep apnea (OSA) or super obesity, with a median ICU stay of 1 day. Emergent admissions were mainly done after emergent surgery due to surgical complications and had a median ICU stay of 8 days. Only two patients needed intensive care for more than 3 days. There were no deaths during ICU stay.

CONCLUSIONS

The ICU admission rate in our report is 8%. This study showed that 32 ICU days are needed per 100 diverse bariatric procedures. Most patients are admitted to the ICU for only a few days and the majority of the admissions is planned.

Obesity and the lung: 3. Obesity, respiration and intensive care

Obesity is a major problem from a public health perspective and a difficult practical matter for intensivists. The obesity pandemic has required treating clinicians to develop an appreciation of the substantial pathophysiological effects of obesity on the various organ systems. The important physiological concepts are illustrated by focusing on obstructive sleep apnoea, obesity hypoventilation syndrome, abdominal compartment syndrome and ventilatory management of the obese patient with acute respiratory distress syndrome.

The relationship between body mass index and postoperative mortality from critical illness

BACKGROUND

Conflicting data exist regarding the effect of body mass index (BMI) on postoperative mortality from critical illness. Few studies have examined this issue in surgical patients specifically. We tested the hypothesis that BMI is associated with mortality from surgical critical illness.

METHODS

Consecutive admissions to a university surgical intensive care unit (SICU) were analyzed from January 2005-August 2006. Admission BMI was analyzed as both a five-level categorical (underweight, <18.5 kg/m2; normal weight, 18.5-24.9 kg/m2; overweight, 25.0-29.9 kg/m2; obese, 30.0-39.9 kg/m2; morbidly obese, > or =40 kg/m2) and dichotomous (> or =40 kg/m2 vs. <40 kg/m2) variable among all patients as well as a subgroup of patients with a SICU length of stay (ULOS) > or =4 days. Multivariable logistic regression models were fit to determine the independent effect of BMI group on SICU mortality.

RESULTS

The total sample size was 946, with 490 patients admitted to the SICU for > or =4 days (51.8%). Of the variables tested, age, acute physiology and chronic health evaluation III score, gender, diabetes mellitus, and need for insulin infusion varied significantly among the five BMI groups. After adjustment for these variables, BMI was not predictive of mortality when analyzed as either a five-level categorical or dichotomous variable, regardless of ULOS.

CONCLUSION

BMI is not related to mortality of surgical critical illness. Several factors, including modern ICU care, may mitigate the risks of obesity in the SICU.

Higher body mass index predicts need for insulin but not hyperglycemia, nosocomial infection, or death in critically ill surgical patients

BACKGROUND

Strict glycemic control in critically ill patients has been an important advance in surgical critical care, as hyperglycemia is associated with a higher likelihood of death, complications, and nosocomial infections. Insulin resistance is particularly common in obese patients, but the impact of body mass index (BMI) on insulin requirements, ability to achieve euglycemia, and infectious outcomes in critically ill surgical patients has not been studied. We hypothesized that obese patients would not incur a higher likelihood of infection if euglycemia was maintained.

METHODS

Admissions to the surgical intensive care unit (ICU) from October 1, 2004, to October 31, 2006, were identified. Necessary data were available for 946 patients. The main predictor variable was BMI, which was analyzed as both a continuous and a five-level categorical variable. Data on insulin requirements as well as glycemic control were captured. The main outcome variable was the occurrence of at least one nosocomial infection. Additional outcomes were dysfunction of at least one organ system at any time during surgical ICU admission, quantified using the Multiple Organ Dysfunction Score, as well as the ICU length of stay and death. All statistical analyses were performing using SPSS version 11 for Macintosh.

RESULTS

Both the need for insulin infusion (p = 0.0001) and the mean insulin units/day among patients receiving infusions (p = 0.03) increased significantly with increasing BMI. However, periods of euglycemia were similar among BMI groups. A total of 152 patients (16.1%) incurred at least one nosocomial infection, for a total of 169 infections. The majority (n = 107; 63.3%) were ventilator-associated pneumonias. Neither infection (p = 0.99), organ dysfunction (p = 0.14), ICU length of stay (p = 0.22), nor mortality rate (p = 0.09) differed significantly by BMI group. The need for an insulin infusion was associated significantly with nosocomial infection (p = 0.0001). Additional predictors of infection were a higher Acute Physiology and Chronic Health Evaluation (APACHE) III score (p < 0.0001), age-adjusted APACHE III score (p < 0.0001), and emergency admission (0.001). After controlling for the need for an insulin infusion, BMI was not associated with infection.

CONCLUSIONS

Increasing BMI was associated significantly with insulin resistance. Despite insulin resistance, however, obese patients did not incur longer periods of hyperglycemia. Outcomes that have been associated consistently with glycemic control, such as nosocomial infection and mortality rate, did not differ according to BMI. These data suggest that BMI is not associated with infection during critical illness, and that this absence of an association may be influenced at least partially by the ability to maintain similar glycemic control in obese and non-obese patients.

Obesity, inflammation, and the potential application of pharmaconutrition

Obesity is an emerging problem worldwide. Hospitalized obese patients often have a worse outcome than patients of normal weight, particularly in the setting of trauma and critical care. Obesity creates a low-grade systemic inflammatory response syndrome (SIRS) that is similar (but on a much smaller scale) to gram-negative sepsis. This process involves up-regulation of systemic immunity, is characterized clinically by insulin resistance and the metabolic syndrome, and puts the patient at increased risk for organ failure, infectious morbidity, and mortality. Through lipotoxicity and cytokine dysregulation, obesity may act to prime the immune system, predisposing to an exaggerated subsequent immune response when a second clinical insult occurs (such as trauma, burns, or myocardial infarction). Specialized nutrition therapy for such patients currently consists of a hypocaloric, high-protein diet. However, this approach does not address the putative pathophysiologic mechanisms of inflammation and altered metabolism associated with obesity. A number of dietary agents such as arginine, fish oil, and carnitine may correct these problems at the molecular level. Pharmaconutrition formulas may provide exciting innovations for the nutrition therapy of the obese patient.

Does body mass index affect infection-related outcomes in the intensive care unit?

BACKGROUND

Obesity is a worldwide healthcare concern, but its impact on critical care (intensive care unit; ICU) outcomes is not well understood. The general hypothesis is that obesity worsens ICU outcomes, but published reports fail to demonstrate this effect consistently. We hypothesized that increasing BMI would be an independent predictor of higher mortality rates in the surgical/trauma ICU.

METHODS

Data on patients with infections, defined by U.S. Centers for Disease Control and Prevention criteria, were collected prospectively from a single university surgical/trauma ICU. From 1996 to 2003, 807 such patients had measurable BMIs on admission to the ICU and were divided into underweight (<18.5 kg/m(2)), normal weight (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), obese (30.0-39.9 kg/m(2)), and morbidly obese (> or =40.0 kg/m(2)). The primary outcome was in-hospital death. Bivariate and multivariate analyses were performed.

RESULTS

In-hospital death was associated with increasing age, increasing average Acute Physiology and Chronic Health Evaluation (APACHE) II score, history of diabetes (p = 0.001), cardiac disease (p = 0.001), hypertension (p = 0.044), history of cerebrovascular disease (p = 0.021), renal insufficiency (p = 0.007), need for hemodialysis (p < 0.001), history of pulmonary disease (p = 0.012), requirement for mechanical ventilation while in the ICU (p = 0.107), history of malignant disease (p < 0.001), and history of liver disease (p < 0.001). The multivariate analysis selected age (odds ratio [OR] 1.03 per integer; confidence interval [CI] 1.0, 1.05), APACHE II score (OR 1.17 per integer; CI 1.12, 1.74), diabetes (OR 2.20; CI 1.32, 3.65), mechanical ventilation (OR 1.88; CI 1.21, 2.94), malignancy (OR 2.54; CI 1.43, 4.47), and liver disease (OR 5.01; CI 2.69, 9.32) as significant risk factors. When controlling for these variables, none of the BMI groups had an independent association with death compared with the normal weight group.

CONCLUSION

Contrary to the hypothesis, the data suggest no discernable independent association of increasing BMI with heightened mortality rate in the surgical/trauma ICU patient with infection.

Effect of obesity on intensive care morbidity and mortality: a meta-analysis

OBJECTIVE

To evaluate the effect of obesity on intensive care unit mortality, duration of mechanical ventilation, and intensive care unit length of stay among critically ill medical and surgical patients.

DESIGN

Meta-analysis of studies comparing outcomes in obese (body mass index of > or = 30 kg/m2) and nonobese (body mass index of < 30 kg/m2) critically ill patients in intensive care settings.

DATA SOURCE

MEDLINE, BIOSIS Previews, PubMed, Cochrane library, citation review of relevant primary and review articles, and contact with expert informants.

SETTING

Not applicable.

PATIENTS

A total of 62,045 critically ill subjects.

INTERVENTIONS

Descriptive and outcome data regarding intensive care unit mortality and morbidity were extracted by two independent reviewers, according to predetermined criteria. Data were analyzed using a random-effects model.

MEASUREMENTS AND MAIN RESULTS

Fourteen studies met inclusion criteria, with 15,347 obese patients representing 25% of the pooled study population. Data analysis revealed that obesity was not associated with an increased risk of intensive care unit mortality (relative risk, 1.00; 95% confidence interval, 0.86-1.16; p = .97). However, duration of mechanical ventilation and intensive care unit length of stay were significantly longer in the obese group by 1.48 days (95% confidence interval, 0.07-2.89; p = .04) and 1.08 days (95% confidence interval, 0.27-1.88; p = .009), respectively, compared with the nonobese group. In a subgroup analysis, an improved survival was observed in obese patients with body mass index ranging between 30 and 39.9 kg/m2 compared with nonobese patients (relative risk, 0.86; 95% confidence interval, 0.81-0.91; p < .001).

CONCLUSION

Obesity in critically ill patients is not associated with excess mortality but is significantly related to prolonged duration of mechanical ventilation and intensive care unit length of stay. Future studies should target this population for intervention studies to reduce their greater resource utilization.