Morbid obesity is an independent determinant of death among surgical critically ill patients

Associations of mood symptoms and body mass among individuals with COVID-19

Introduction

The COVID-19 pandemic has had a significant impact on mental health, and individuals with certain preexisting morbidities-such as obesity-may have disproportionately experienced pandemic-related stress. We aimed to examine whether being obese or overweight was associated with worse mood and trauma among those infected with COVID-19.

Methods

Data were collected as part of a larger longitudinal survey study (n = 591) examining the psychological impact of COVID-19. Complete baseline data for those who reported testing positive from April 2020 through June 2021 were examined.

Results and conclusions

Body mass index was correlated with depression (r = 0.13, P < .01) and generalized anxiety disorder (r = 0.10, P = .02), but not with posttraumatic stress disorder (r = 0.06, P = .16). Multivariable analyses revealed that body mass index was no longer a unique predictor, except for those with a body mass index >40 kg/m2, suggesting that other sociodemographic factors, not obesity, were driving mood symptoms for those infected with COVID-19.

Associations between body mass index, biological age and frailty in the critically ill

BACKGROUND

The relationship between body mass index (BMI) and outcomes in the acute care setting is controversial, with evidence suggesting that obesity is either protective - which is also called obesity paradox - or associated with worse outcomes. The purpose of this study was to assess whether BMI was related to frailty and biological age, and whether BMI remained predictive of mortality after adjusting for frailty and biological age.

SUBJECTS

Of the 2950 patients who had a biological age estimated on admission to the intensive care unit, 877 (30 %) also had BMI and frailty data available for further analysis in this retrospective cohort study.

METHODS

Biological age of each patient was estimated using the Levine PhenoAge model based on results of nine blood tests that were reflective of DNA methylation. Biological age in excess of chronological age was then indexed to the local study context by a linear regression to generate the residuals. The associations between BMI, clinical frailty scale, and the residuals were first analyzed using univariable analyses. Their associations with mortality were then assessed by multivariable analysis, including the use of a 3-knot restricted cubic spline function to allow non-linearity.

RESULTS

Both frailty (p = 0.003) and the residuals of the biological age (p = 0.001) were related to BMI in a U-shaped fashion. BMI was not related to hospital mortality, but both frailty (p = 0.015) and the residuals of biological age (OR per decade older than chronological age 1.50, 95 % confidence interval [CI] 1.04-2.18; p = 0.031) were predictive of mortality after adjusting for chronological age, diabetes mellitus and severity of acute illness.

CONCLUSIONS

BMI was significantly associated with both frailty and biological age in a U-shaped fashion but only the latter two were related to mortality. These results may, in part, explain why obesity paradox could be observed in some studies.

Outcomes of the overweight and obese major trauma patient in the rural setting

PURPOSE

Overweight and obese patients are more prevalent in rural and remote areas and are of major public health concern in Australia. We aimed to evaluate the mortality and morbidity of overweight and obese trauma patients in the rural Australian context.

METHOD

This was a retrospective cohort study on 207 major trauma patients (injury severity score [ISS] > 12) treated at the Mackay Base Hospital between 2018 and 2021. Data was extracted from the Mackay Base Hospital trauma database and hospital records. Outcomes were compared between body mass index (BMI) groups.

RESULTS

There were 164 males (79%) and 43 females (21%). The average BMI was 27.09 (standard deviation 5.46). 7 patients (3%) were in the underweight category (BMI < 18.5 kg/m²), 70 (34%) were of normal weight (BMI 18.5-24.9 kg/m²), 79 (38%) were overweight (BMI 25-29.9 kg/m²), and 51 (25%) were obese (BMI > 30 kg/m²). The majority of trauma was blunt (n = 203, 98%). Compared to patients with normal BMI, obese patients were significantly more likely to require intubation, intensive care unit (ICU) admission, and have a longer ICU stay. There were no significant differences in requirement for surgery, duration of surgery, hospital length of stay, ventilator time, or mortality (P > 0.05). However, subgroup analysis of the obese patient group showed an increased rate of complications (sepsis, acute kidney injury, fluid overload and pneumonia), longer ventilation times, hospital and ICU length of stay with increasing BMI in these patients.

CONCLUSION

The majority of trauma presentations in our regional community are in overweight or obese patients. Overweight and obese patients are more likely to require intubation and have a longer intensive care unit admission than normal weight counterparts. Amongst obese patients, those with BMI > 40 (obesity class 3) are at significantly increased risk of complications.

Effect of Body Mass Index on Outcomes of Percutaneous Nephrolithotomy: A Systematic Review and Meta-Analysis

Objective

The current study aimed to assess the efficacy and safety of percutaneous nephrolithotomy (PCNL) in obese and overweight individuals based on body mass index (BMI).

Methods

We electronically explored the databases of PubMed, CENTRAL, ScienceDirect, Embase, and Google Scholar databases for all types of comparative studies investigating the role of BMI on PCNL outcomes. Only studies defining obesity as >30 kg/m² were included. Efficacy outcomes were stone-free rates and operating time while safety outcomes were complications and length of hospital stay (LOS).

Results

Eighteen studies with 101,363 patients were included. We noted no difference in the stone-free rates after PCNL for morbid obese vs normal BMI patients (OR: 0.78 95% CI, 0.57, 1.08 I²= 7% p = 0.13), overweight vs normal (OR: 1.01 95% CI, 0.89, 1.15 I²= 1% p = 0.83) and obese vs normal patients (OR: 1.00 95% CI, 0.87, 1.16 I²= 0% p = 0.95). PCNL operative time was significantly increased in morbid obese (MD: 9.36 95% CI, 2.85, 15.88 I²= 76% p = 0.005) and obese patients as compared with normal patients (MD: 2.15 95% CI, 1.20, 3.10 I²= 0% p < 0.00001), but not for overweight patients. There was no difference in the odds of complications between morbid obese vs normal (OR: 1.26 95% CI, 0.93, 1.72 I²= 0% p = 0.13), overweight vs normal (OR: 1.11 95% CI, 0.96, 1.28 I²= 0% p = 0.15), and obese vs normal patients (OR: 1.07 95% CI, 0.91, 1.27 I²= 0% p = 0.40). LOS was significantly reduced in obese patients (MD: −0.12 95% CI, −0.20, −0.04 I²= 0% p = 0.004) as compared to normal patients, but not for morbid obese or overweight patients.

Conclusion

PCNL has similar efficacy and safety in morbidly obese, obese, and overweight patients as compared to normal BMI patients with no difference in the stone-free and complication rates. Evidence suggests that operating time is increased in morbidly obese and obese patients and the latter may have shorter LOS.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/, identifier: CRD42022313599.

The effect of body mass index on the development of acute kidney injury and mortality in intensive care unit: is obesity paradox valid?

BACKGROUND

The conflicting results of studies on intensive care unit (ICU) mortality of obese patients and obese patients with acute kidney injury (AKI) reveal a paradox within a paradox. The aim of this study was to determine the effects of body mass index and obesity on AKI development and ICU mortality.

METHODS

The 4,459 patients treated between January 2015 and December 2019 in the ICU at a Tertiary Care Center in Turkey were analyzed retrospectively.

RESULTS

AKI developed more in obese patients with 69.8% (620). AKI development rates were similar in normal-weight (65.1%; 1172) and overweight patients (64.9%; 1149). The development of AKI in patients who presented with cerebrovascular diseases was higher in obese patients (81; 76.4%) than in normal-weight (158; 62.7%) and overweight (174; 60.8%) patients (p < 0.05). The risk of developing AKI was approximately 1.4 times (CI 95% = 1.177-1.662) higher in obese patients than in normal-weight patients. Dialysis was used more frequently in obese patients (24.3%, p < 0.001), who stayed longer in the ICU (p < 0.05). It was determined that the development of AKI in normal-weight and overweight patients increased mortality (p < 0.001) and that there was not a difference in mortality rates between obese patients with and without AKI.

CONCLUSION

The risk of AKI development was higher in obese patients but not in those who were in serious conditions. Another paradox was that the development of AKI was associated with a higher mortality rate in normal-weight and overweight patients, but not in obese patients. Cerebrovascular diseases as a cause of admission pose additional risks for AKI.

Trefoil Factor Family Member 2: From a High-Fat-Induced Gene to a Potential Obesity Therapy Target

Obesity has its epidemiological patterns continuously increasing. With controlling both diet and exercise being the main approaches to manage the energy metabolism balance, a high-fat (HF) diet is of particular importance. Indeed, lipids have a low satiety potential but a high caloric density. Thus, focusing on pharmacologically targetable pathways remains an approach with promising therapeutic potential. Within this context, trefoil factor family member 2 (Tff2) has been characterized as specifically induced by HF diet rather than low-fat diet. TFF2 has also been linked to diverse neurological mechanisms and metabolic patterns suggesting its role in energy balance. The hypothesis is that TFF2 would be a HF diet-induced signal that regulates metabolism with a focus on lipids. Within this review, we put the spotlight on key findings highlighting this line of thought. Importantly, the hypothetical mechanisms pointed highlight TFF2 as an important contributor to obesity development via increasing lipids intestinal absorption and anabolism. Therefore, an outlook for future experimental activities and evaluation of the therapeutic potential of TFF2 inhibition is given. Indeed, its knockdown or downregulation would contribute to an antiobesity phenotype. We believe this work represents an addition to our understanding of the lipidic molecular implications in obesity, which will contribute to develop therapies aiming to manage the lipidic metabolic pathways including the absorption, storage and metabolism via targeting TFF2-related pathways. We briefly discuss important relevant concepts for both basic and clinical researchers.

Pharmacokinetics and Pharmacodynamics of High-Dose Piperacillin-Tazobactam in Obese Patients

Background and Objective

Standard piperacillin–tazobactam (P-T) dosing may be suboptimal in obesity, but high-dose regimens have not been studied. We prospectively evaluated the pharmacokinetics and pharmacodynamics of standard- and high-dose P-T in obese adult inpatients.

Methods

Those receiving standard-dose P-T with BMI ≥ 30 kg/m² weighing 105–139 kg or ≥ 140 kg were given up to 6.75 g or 9 g every 6 h, respectively. Patients were monitored closely for safety. Elimination phase blood samples were drawn for 28 patients on standard and high doses to calculate the pharmacokinetic values using a one-compartment model. The likelihood of pharmacodynamic target attainment (100% fT > 16/4 mg/L) on various P-T regimens was calculated using each patient’s own pharmacokinetic values.

Results

Piperacillin and tazobactam half-lives ranged from 0.5–10.6 to 0.9–15.0 h, while volumes of distribution ranged from 13.6–54.8 to 11.5–60.1 L, respectively. Predicted dose requirements for target attainment ranged from 2.25 g every 6 h in hemodialysis patients to a 27 g/24-h continuous infusion in a patient with a short P-T half-life. An amount of 4.5 g every 6 h would have met the target for only 1/12 (8%) patients with creatinine clearance ≥ 80 mL/min and 13/28 (46%) for all enrolled patients. One patient (3%) experienced an adverse event deemed probably related to high-dose P-T.

Conclusion

Some patients required high P-T doses for target attainment, but dosing requirements were highly variable. Doses up to 6.75 g or 9 g every 6 h may be tolerable; however, studies are needed to see if high dosing, prolonged infusions, or real-time therapeutic drug monitoring improves outcomes in obese patients.

Clinical trial registration (clinicaltrials.gov)

NCT01923363.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13318-021-00677-1.

The Association Between BMI and Mortality in Surgical Patients

BACKGROUND

While obesity is commonly associated with increased morbidity and mortality, in patients with chronic diseases, it has have been associated with a better prognosis, a phenomenon known as the 'obesity paradox'.

OBJECTIVE

We investigated the relationship between mortality, length of hospital stay (LOHS), and body mass index (BMI) in patients hospitalized to general surgical wards.

METHODS

We extracted data of patients admitted to the hospital between January 2011 and December 2017. BMI was classified according to the following categories: underweight (< 18.5), normal weight (18.5-24.9), overweight (25-29.9), obesity (30-34.9) and severe obesity (≥ 35). Main outcomes were mortality at 30-day mortality and at the end-of-follow-up mortality), as well as LOHS.

RESULTS

A total of 27,639 patients (mean age 55 ± 20 years; 48% males; 19% had diabetes) were included in the study. Median LOHS was longer in patients with diabetes vs. those without diabetes (4.0 vs 3.0 days, respectively), with longest LOHS among underweight patients. A 30-day mortality was 2% of those without (371/22,297) and 3% of those with diabetes (173/5,342). In patients with diabetes, 30-day mortality risk showed a step-wise decrease with increased BMI: 10% for underweight, 6% for normal weight, 3% for overweight, 2% for obese and only 1% for severely obese patients. In patients without diabetes, 30-day mortality was found to be 6% for underweight, 3% for normal weight and 1% across the overweight and obese categories. Mortality rate at the end-of-follow-up was 9% of patients without diabetes and 18% of those with diabetes (adjusted OR = 1.3, 95% CI, 1.2-1.5). In patients with diabetes, mortality risk showed an inverse association with respect to BMI: 52% for underweight, 29% for normal weight, 17% for overweight, 14% for obesity and 7% for severely obese patients, with similar trend in patients without diabetes.

CONCLUSIONS

The results support the 'obesity paradox' in the general surgical patients as those with and without diabetes admitted to surgical wards, BMI had an inverse association with short- and long-term mortality.

Obesity and Overweight Are Independently Associated with Greater Survival in Critically Ill Diabetic Patients: A Retrospective Cohort Study

BACKGROUND

The relationship between obesity and the outcomes of critically ill diabetic patients is not completely clear. We aimed to assess the effects of obesity and overweight on the outcomes among diabetic patients in the intensive care unit (ICU).

METHODS

Critically ill diabetic patients in the ICU were classified into three groups according to their body mass index. The primary outcomes were 30-day and 90-day mortality. ICU and hospital length of stay (LOS) and incidence and duration of mechanical ventilation were also assessed. Cox regression models were developed to evaluate the relationship between obesity and overweight and mortality.

RESULTS

A total of 6108 eligible patients were included. The 30-day and 90-day mortality in the normal weight group were approximately 1.8 times and 1.5 times higher than in the obesity group and overweight group, respectively (P < 0.001, respectively). Meanwhile, the ICU (median (IQ): 2.9 (1.7, 5.3) vs. 2.7 (1.6, 4.8) vs. 2.8 (1.8, 5.0)) and hospital (median (IQ): 8.3 (5.4, 14.0) vs. 7.9 (5.1, 13.0) vs. 8.3 (5.3, 13.6)) LOS in the obesity group and overweight group were not longer than in the normal weight group. Compared with normal weight patients, obese patients had significantly higher incidence of mechanical ventilation (58.8% vs. 64.7%, P < 0.001) but no longer ventilation duration (median (IQ): 19.3 (7.0, 73.1) vs. 19.0 (6.0, 93.7), P = 1). Multivariate Cox regression showed that obese and overweight patients had lower 30-day (HR (95% CI): 0.62 (0.51, 0.75); 0.76 (0.62, 0.92), respectively) and 90-day (HR (95% CI): 0.60 (0.51, 0.70); 0.79 (0.67, 0.93), respectively) mortality risks than normal weight patients.

CONCLUSIONS

Obesity and overweight were independently associated with greater survival in critically ill diabetic patients, without increasing the ICU and hospital LOS. Large multicenter prospective studies are needed to confirm our findings and the underlying mechanisms warrant further investigation.

Impact of Body Mass Index on the Mortality of Critically Ill Patients Admitted to the Intensive Care Unit: An Observational Study

Background

Obesity is a severe multifactorial disorder that carries high morbidity and mortality.

Objectives

This study aimed to evaluate the possible association between body mass index (BMI) and mortality in patients admitted to intensive care units (ICU).

Methods

In this cross-sectional study, all patients admitted to the ICU were studied. The demographic characteristics, ICU, and hospital length of stay, organ failure, mortality, duration of mechanical ventilation, the occurrence of nosocomial infection, and type of admission were recorded for all patients. Patients were categorized based on their BMI.

Results

In total, 502 patients were studied who 53.2% of them were male. Most of the death (28.6%) were recorded in the obesity class II patients, while the lowest rate (3.9%) was for the normal-weight patients (P value < 0.001). The APACHE II and waist circumference had a statistically significant association with the mortality rate (P value < 0.001). After adjusting for age and gender, a significant association was found between waist circumference and mortality rate (OR = 1.15, 95% CI = 1.03 - 1.29; P value = 0.014), APACHE II score, and mortality rate (OR = 2.79, 95% CI = 1.91 - 4.07, P value < 0.001); but there was no significant association between BMI and mortality rate.

Conclusions

This study demonstrated that BMI is associated with an increased risk of mortality, regardless of age and gender. However, after adjusting for age and gender as confounding factors, BMI didn’t have a significant effect on mortality, while the APACHE II score and waist circumference affected the mortality rate.

Is There an Obesity Paradox in Critical Illness? Epidemiologic and Metabolic Considerations

PURPOSE OF REVIEW

Obesity represents a global epidemic with serious implications in public health due to its increasing prevalence and its known association with a high morbidity and mortality burden. However, a growing number of data support a survival benefit of obesity in critical illness. This review summarizes current evidence regarding the obesity paradox in critical illness, discusses methodological issues and metabolic implications, and presents potential pathophysiologic mechanisms.

RECENT FINDINGS

Data from meta-analyses and recent studies corroborate the obesity-related survival benefit in critically ill patients as well as in selected populations such as patients with sepsis and acute respiratory distress syndrome, but not trauma. However, this finding warrants a cautious interpretation due to certain methodological limitations of these studies, such as the retrospective design, possible selection bias, the use of BMI as an obesity index, and inadequate adjustment for confounding variables. Main pathophysiologic mechanisms related to obesity that could explain this phenomenon include higher energy reserves, inflammatory preconditioning, anti-inflammatory immune profile, endotoxin neutralization, adrenal steroid synthesis, renin-angiotensin system activation, cardioprotective metabolic effects, and prevention of muscle wasting. The survival benefit of obesity in critical illness is supported from large meta-analyses and recent studies. Due to important methodological limitations, more prospective studies are needed to further elucidate this finding, while future research should focus on the pathophysiologic role of adipose tissue in critical illness.

Weight as a Risk Factor for Mortality in Critically Ill Patients

OBJECTIVES

To explore the hypothesis that obesity is associated with increased mortality and worse outcomes in children who are critically ill.

METHODS

Secondary analysis of the Assessment of Worldwide Acute Kidney Injury, Renal Angina, and Epidemiology study, a prospective, multinational observational study. Patients between 3 months and 25 years across Asia, Australia, Europe, and North America were recruited for 3 consecutive months. Patients were divided into 4 groups (underweight, normal weight, overweight, and obese) on the basis of their BMI percentile for age and sex.

RESULTS

A total of 3719 patients were evaluated, of whom 542 (14%) had a primary diagnosis of sepsis. One thousand fifty-nine patients (29%) were underweight, 1649 (44%) were normal weight, 423 (11%) were overweight, and 588 (16%) were obese. The 28-day mortality rate was 3.6% for the overall cohort and 9.1% for the sepsis subcohort and differed significantly by weight status (5.8%, 3.1%, 2.2%, and 1.8% for subjects with underweight, normal weight, overweight, and obesity, respectively, in the overall cohort [P < .001] and 15.4%, 6.6%, 3.6%, and 4.7% in the sepsis subcohort, respectively [P = .003]). In a fully adjusted model, 28-day mortality risk was 1.8-fold higher in the underweight group versus the normal weight group in the overall cohort and 2.9-fold higher in the sepsis subcohort. Patients who were overweight and obese did not demonstrate increased risk in their respective cohorts. Patients who were underweight had a longer ICU length of stay, increased need for mechanical ventilation support, and a higher frequency of fluid overload.

CONCLUSIONS

Patients who are underweight make up a significant proportion of all patients in the PICU, have a higher short-term mortality rate, and have a more complicated ICU course.

Effect of high-protein nutrition in critically ill patients: A retrospective cohort study

BACKGROUND & AIMS

Early provision of a high-protein nutrition improves the prognosis of patients in intensive care units (ICUs). However, high protein intake increases blood urea nitrogen (BUN). No study has compared outcomes according to protein intake, and the clinical significance of changes in BUN (ΔBUN) in ICU patients is unclear. Here, we investigated the association of high protein intake with outcomes and BUN and assessed the clinical significance of ΔBUN.

METHODS

This was a single-center retrospective cohort study. Between 1 January 2016 and 30 September 2019, 295 ICU patients received enteral nutrition for at least 3 days while undergoing mechanical ventilation. After applying the exclusion criteria of an age of <18 years, gastrointestinal disease, maintenance dialysis, renal replacement therapy after admission, kidney transplantation, and death within 7 days of commencing enteral nutrition, 206 patients remained.

INTERVENTIONS

Participants were divided into those receiving >1.2 g/kg/day of protein (high-protein group; n = 111) and those receiving ≤1.2 g/kg/day of protein (non-high-protein group; n = 95). The groups were balanced by propensity score matching. The primary endpoint was 28-day mortality, and the secondary endpoints were 90-day mortality, length of ICU stay, number of ventilator-free days in the first 28 days, and ΔBUN.

RESULTS

The high-protein group had significantly lower 28- and 90-day mortality and significantly greater ΔBUN, including after propensity score matching. ΔBUN might not be associated with outcomes.

CONCLUSIONS

Provision of >1.2 g/kg/day of protein may be associated with lower mortality of tube-fed and mechanically ventilated patients. Furthermore, while high protein intake may be associated with higher BUN, these changes may not be adversely associated with outcomes.

An increase in alveolar fluid clearance induced by hyperinsulinemia in obese rats with LPS-induced acute lung injury

A lower mortality rate is observed in obese patients with acute lung injury (ALI), which is referred to as the obesity paradox, in several studies and recent meta-analyses. Hyperinsulinemia is characterized as the primary effect of obesity, and exogenous insulin attenuates LPS-induced pulmonary edema. The detailed mechanism responsible for the effect of hyperinsulinemia on pulmonary edema and alveolar filling needs to be elucidated. SD rats were fed with a high-fat diet (HFD) for a total of 14 weeks. SD rats were anesthetized and intraperitoneally injected with 10 mg/kg lipopolysaccharide (LPS), while control rats received only saline vehicle. Insulin receptor antagonist S961 (20 nmol/kg) was given by the tail vein and serum, and glucocorticoid-induced protein kinase-1 (SGK-1) inhibitor EMD638683 (20 mg/kg) was administrated intragastrically prior to LPS exposure. The lungs were isolated for the measurement of alveolar fluid clearance. The protein expression of epithelial sodium channel (ENaC) was detected by Western blot. Insulin level in serum was significantly higher in HFD rats compared with normal diet rats in the presence or absence of LPS pretreatment. Hyperinsulinemia induced by high fat feeding increased alveolar fluid clearance and the abundance of α-ENaC, β-ENaC, and γ-ENaC in both normal rats and ALI rats. Moreover, these effects were reversed in response to S961. EMD638683 prevented the simulation of alveolar fluid clearance and protein expression of ENaC in HFD rats with ALI. These findings suggest that hyperinsulinemia induced by obesity results in the stimulation of alveolar fluid clearance via the upregulation of the abundance of ENaC in clinical acute lung injury, whereas theses effects are prevented by an SGK-1 inhibitor.

Effect of comorbidities on clinical outcome of patients with burn injury - An analysis of the German Burn Registry

BACKGROUND

Severe burn injuries are associated with high morbidity and mortality. Well-implemented scoring systems for patients with major burns exist in the literature. A major disadvantage of these scores is the partial non-consideration of patient-related comorbidities. Published data on this matter is limited to small study cohorts and/or single center studies. Further, the effect of comorbidities on clinical outcome of patients with severe burn injuries has not yet been examined nationwide in a large cohort in Germany. Hence, the aim of this study was to examine the influence of comorbidities on clinical outcome of these patients based on data from the national registry.

METHODS

Anonymized data from a total of 3455 patients with documented burns of 1% or more Total Burn Surface Area (TBSA) and over 16 years of age included in the German Burn Registry between 2017 and 2018 were analyzed retrospectively. Data included burn extent, body weight, age, burn depth, inhalation injury, comorbidities, mortality, number of operations and length of hospital stay (LOS).

RESULTS

In the logistic regression analysis age (OR 1.07 [1.06-1.09], p < 0.001), TBSA (OR 1.09 [1.08-1.11], p < 0.001), IHT (OR 2.15 [1.44-3.20], p < 0001), third degree burn (OR 2.08 [1.39-3.11], p < 0.001), Chronic Obstructive Pulmonary Disease (COPD) (OR 2.45 [1.38-4.35], p = 0.002) and renal insufficiency (OR 2.02 [1.13-3.59], p = 0.017) influenced mortality significantly. If a patient had more than one comorbidity, mortality was higher and in-hospital length of stay (LOS) longer. Renal insufficiency was significantly (p < 0.001) associated with the most prolonged LOS by 11.44 days. TBSA (p < 0.001), Abbreviated Burn Severity Index (ABSI) > 3 (p < 0.001) and IHT (p = 0.001) correlated with the amount of required surgeries and significantly predicted the need for intubation. Patients with arrhythmia significantly required more surgeries (p = 0.041), whereas patients with COPD required significantly less surgical interventions (p = 0.013).

CONCLUSION

Preexisting comorbidities have a significant impact on the clinical outcome of patients with severe burn injuries. Further investigation is warranted in order to supplement existing prognostic scores with new mortality-associated parameters.

Dose-Response Meta-Analysis of the Impact of Body Mass Index on Mortality in the Intensive Care Unit

INTRODUCTION

Both low and high body mass index (BMI) are associated with mortality in the intensive care unit (ICU). Although many studies have been done to determine the relationship between BMI and risk of mortality in the ICU, their results were inconsistent. This study aimed to conduct a dose-response meta-analysis of published observational studies to assess the effect of BMI on the risk of mortality in patients admitted to the ICU.

METHODS

PubMed, Scopus, and Google Scholar were searched to identify articles up to May 2019. A total of 31 relevant articles, with 238,961 patients and a follow-up period of 1 month to 11 years, were analyzed.

RESULTS

Linear analysis showed a 0.6% decrease in mortality rate per unit (kg/m² ) increase in BMI (odds ratio: 0.99; 95% CI, 0.98-0.99). In addition, nonlinear analysis showed a decrease in risk of mortality for a BMI of 35 (P < .001) and then increased the risk of mortality with a BMI > 35 (P < .001).

CONCLUSION

This dose-response meta-analysis revealed that a BMI ≤ 35 can be a protective agent against mortality, but a BMI > 35 is a life-threatening factor in patients admitted to the ICU.

Does obesity impact the outcome of severely burned patients?

Although obesity appears to be an important predictor of mortality and morbidity, little data about the impact of body mass index (BMI) on the outcome of severely burned patients are available. Patients admitted to the General Hospital Vienna between 1994 and 2014, who underwent surgery because of burn injuries, were enrolled in this study. BMI was used to divide patients into five groups: BMI 18.5 to 24.9, 25 to 29.9, 30 to 34.9, 35 to 39.9, and > 40. The groups were compared in terms of difference of mortality and morbidity. Of 460 patients, 34.3% (n = 158) died. Mortality rates were the lowest in patients with obesity class III and the highest in patients with BMI 35 to 39.9 (BMI 18.5‐24.9: 30.5%, BMI 25‐29.9: 31.5%, BMI 30‐34.9: 41.3%, BMI 35‐39.9: 55.5%, BMI > 40: 30%; P = .031). BMI was not found to be an independent risk factor when corrected with age, percent total body surface area burned, full‐thickness burns, and inhalation injury. No significant differences in length of stay, inhalation trauma, pneumonia, wound infection, sepsis, and invasive ventilation were observed. BMI as an independent risk factor for severely burned patients could not be confirmed via multivariate analysis.

The paradox prevails: Outcomes are better in critically ill obese patients regardless of the comorbidity burden

During critical illness, obese patients have better outcomes compared to patients with normal BMI, and this is known as the obesity paradox. The difference in comorbidity burden have been implied to be responsible for the paradox. We performed a retrospective review from 2001 to 2012 of critically ill patients from the Medical Information Mart for Intensive Care database. We included 11,433 patients and classified them according to body mass index (BMI) and comorbidity burden (Elixhauser comorbidity measure). The odds of inpatient mortality were lower in obese patients compared to patients with normal BMI; in group with the least comorbidity score (Elixhauser <0) [OR: 0.47, CI (0.28-0.80), p-value 0.006] and higher comorbidity scores, (Elixhauser 1-5) [(OR: 0.66, CI (0.46-0.95), p-value 0.02)] and (Elixhauser 6-13) [OR: 0.69, CI (0.53-0.92), p-value 0.01]. 30-day mortality was also significantly lower in obese patients, in groups with the lowest (Elixhauser <0) [OR:49, CI (0.31-0.77), p-value 0.002] as well as the highest comorbidity burden (Elixhauser >14) [OR:0.59, CI (0.45-0.77), p-value <.001]. Subgroup analysis in patients with various comorbidities showed better outcomes in obese patients. These findings show that the decreased odds of mortality in critically ill obese patients is independent of the comorbidity burden or type of comorbidity.

The ABCDs of Managing Morbidly Obese Patients in Intensive Care Units

More than one-third of the US adult population and 17% of the youth are now obese, and obesity is associated with more than $147 billion a year in health care costs. Critical care nurses should understand the physiological differences and practice guidelines for patients with a body mass index greater than 30. The ABCD approach encompasses key clinical concepts in the management of critically ill obese and morbidly obese patients, including management of airways and breathing, minimizing nurses' back and other injuries, increasing awareness of bias, circulation problems, risks of decubitus ulcers and other skin breakdown, differences in drug calculations and metabolism, limitations in diagnostic equipment and imaging, diet and nutritional recommendations, and concerns with durable medical equipment.

Factors Associated with Functional Recovery among Older Intensive Care Unit Survivors

RATIONALE

Most of the 1.4 million older adults who survive the intensive care unit (ICU) annually in the United States face increased disability, but little is known about those who achieve functional recovery.

OBJECTIVES

Our objectives were twofold: to evaluate the incidence and time to recovery of premorbid function within 6 months of a critical illness and to identify independent predictors of functional recovery among older ICU survivors.

METHODS

Potential participants included 754 persons aged 70 years or older who were evaluated monthly in 13 functional activities (1998-2012). The analytic sample included 218 ICU admissions from 186 ICU survivors. Functional recovery was defined as returning to a disability count less than or equal to the pre-ICU disability count within 6 months. Twenty-one potential predictors were evaluated for their associations with recovery.

MEASUREMENTS AND MAIN RESULTS

Functional recovery was observed for 114 (52.3%) of the 218 admissions. In multivariable analysis, higher body mass index (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.03-1.12) and greater functional self-efficacy (HR, 1.05; 95% CI, 1.02-1.08), a measure of confidence in performing various activities, were associated with recovery, whereas pre-ICU impairment in hearing (HR, 0.38; 95% CI, 0.22-0.66) and vision (HR, 0.59; 95% CI, 0.37-0.95) were associated with a lack of recovery.

CONCLUSIONS

Among older adults who survived an ICU admission with increased disability, pre-ICU hearing and vision impairment were strongly associated with poor functional recovery within 6 months, whereas higher body mass index and functional self-efficacy were associated with recovery. Future research is needed to evaluate whether interventions targeting these factors improve functional outcomes among older ICU survivors.

Maternal super obesity and risk for intensive care unit admission in the MFMU Cesarean Registry

INTRODUCTION

Obesity is a risk factor for intensive care unit (ICU) admission in nonpregnant populations. Less is known about maternal obesity and ICU admission risk. The objective of this study was to estimate the association between maternal obesity and ICU admission among women who delivered via cesarean section or vaginal birth after cesarean section (VBAC).

MATERIAL AND METHODS

This is a retrospective cohort analysis of women who delivered via VBAC or cesarean section in the Maternal-Fetal Medicine Unit (MFMU) Cesarean Registry. We defined exposure as body mass index (BMI) at delivery stratified as non-obese (BMI 18.5-29.9 kg/m² ), class I or II obese (BMI 30-39.9 kg/m² ), morbidly obese (BMI 40-49.9 kg/m² ), and super obese (BMI ≥ 50 kg/m² ). The primary outcome was ICU admission. Modified Poisson regression models estimated relative risk (RR) of ICU admission by obesity strata, after adjusting for confounders. Mediation analysis was used to estimate the proportion of ICU admission risk attributable specifically to obesity.

RESULTS

We included 68 455 women; 40% non-obese, 46% class I or II obese, 12% morbidly obese, and 2% super obese. Super obese women were at higher risk for ICU admission compared with non-obese women (0.7 vs. 1.3%, adjusted RR 1.61; 95% CI 1.01-2.65), after adjusting for confounders. Among super obese women, medical comorbidities mediated 58% of ICU admission risk, suggesting that a significant proportion of ICU admission is driven by maternal obesity.

CONCLUSIONS

Super obese women who deliver by cesarean section or VBAC are at increased risk of peripartum ICU admission. Obstetricians and critical care specialists should consider possible ICU admission during delivery planning.

Body Mass Index and Intensive Care Unit Outcomes in African American Patients

PURPOSE

We sought to determine whether body mass index (BMI) is associated with worse intensive care unit (ICU) outcomes among Black patients.

METHODS

Patients admitted to the medical ICU during 2012 were categorized into six BMI groups based on the World Health Organization criteria. ICU mortality, ICU and hospital length of stay (LOS), need for and duration of mechanical ventilation and organ failure rate were assessed.

RESULTS

A total of 605 patients with mean age 58.9 ± 16.0 years were studied. Compared with those with normal BMI, obese patients had significant higher rates of hypertension, diabetes mellitus and obstructive sleep apnea diagnoses (P<.001 for all). A total of 100 (16.5%) patients died during their ICU stay. Obesity was not associated with increased odds of ICU mortality (OR=.58; 95% CI, .16-2.20). Moreover, improved survival was observed for class II obese patients (OR, .031; 95% CI, .001-.863). There were no differences in the need for and duration of mechanical ventilation between the BMI groups. However, ICU and hospital LOS were significantly longer in patients with obesity.

CONCLUSION

Obesity was not associated with increased ICU mortality; however, obesity was associated with increased comorbid illness and with significant longer ICU and hospital length of stay.

Effect of body mass index on the outcome of surgical patients receiving extracorporeal devices (VV ECMO, pECLA) for respiratory failure

INTRODUCTION

To determine whether obese surgical patients are at a significant disadvantage in terms of outcomes after extracorporeal device (ECD) support, such as veno-venous extracorporeal membrane oxygenation (VV ECMO) or pumpless extracorporeal lung assist (pECLA), for respiratory failure, the relationship between body mass index (BMI) and hospital outcomes was analyzed.

METHODS

This retrospective study included data on patients who were supported with an ECD between January 1, 2008 and December 31, 2014. The analysis included 89 patients (74 male).

RESULTS

The median BMI was 30 kg/m2 (19-88.5). The median duration of the ECD support was 9.0 days, with a maximum of 37.1 days. The median LOS (length of stay) in the intensive care unit (ICU) was 21 days (range 0.06-197.6). The median hospital LOS was 34.9 days (range 0.1-213.8). VV ECMO was performed 72 times, and pECLA was performed 18 times. The number of patients successfully weaned off the ECD was 54 (60.6%). Survival at the discharge from the hospital was 48.3%.

CONCLUSIONS

54 (60.6%) patients were successfully weaned off the ECD; 43 (48.3%) patients survived and were discharged from the hospital. The analysis of correlations between BMI and outcomes of surgical patients treated with ECD showed no association between BMI and mortality. Complications (especially oxygenator clotting) were not more frequent in obese and extremely obese patients. We hypothesized that patients with higher or morbid BMIs would have increased mortality after ECD support. A BMI of 30.66 kg/m2 corresponded to the desired sensitivity and specificity to predict mortality. This finding applied only to the study group. Treatment with ECD in obese patients presents unique challenges, including percutaneous cannulation and increased staff requirements. However, based on these data, obesity should not be an exclusion criterion for ECD therapy.

Can body mass index predict clinical outcomes for patients with acute lung injury/acute respiratory distress syndrome? A meta-analysis

BACKGROUND

The effects of body mass index (BMI) on the prognosis of acute respiratory distress syndrome (ARDS) are controversial. We aimed to further determine the relationship between BMI and the acute outcomes of patients with ARDS.

METHODS

We searched the Pubmed, Embase, Medline, Cochrane Central Register of Controlled Trials (CENTRAL), and ISI Web of Science for trials published between 1946 and July 2016, using "BMI" or "body mass index" or "overweight" or "obese" and "ARDS" or "ALI" or "acute respiratory distress syndrome" or "acute lung injury", without limitations on publication type or language. Heterogeneity and sensitivity analyses were conducted, and a random-effects model was applied to calculate the odds ratio (OR) or mean difference (MD). Review Manager (RevMan) was used to test the hypothesis using the Mann-Whitney U test. The primary outcome was unadjusted mortality, and secondary outcomes included mechanical ventilation (MV)-free days and length of stay (LOS) in the intensive care unit (ICU) and in hospital.

RESULTS

Five trials with a total of 6268 patients were pooled in our final analysis. There was statistical heterogeneity between normal-weight and overweight patients in LOS in the ICU (I ² = 71%, χ ² = 10.27, P = 0.02) and in MV-free days (I ² = 89%, χ ² = 18.45, P < 0.0001). Compared with normal weight, being underweight was associated with higher mortality (OR 1.59, 95% confidence interval (CI) 1.22, 2.08, P = 0.0006), while obesity and morbid obesity were more likely to result in lower mortality (OR 0.68, 95% CI 0.57, 0.80, P < 0.00001; OR 0.72, 95% CI 0.56, 0.93, P = 0.01). MV-free days were much longer in patients with morbid obesity (MD 2.64, 95% CI 0.60, 4.67, P = 0.01), but ICU and hospital LOS were not influenced by BMI. An important limitation of our analysis is the lack of adjustment for age, sex, illness severity, comorbid illness, and interaction of outcome parameters.

CONCLUSIONS

Obesity and morbid obesity are associated with lower mortality in patients with ARDS.

Venovenous Extracorporeal Membrane Oxygenation as a Treatment for Obesity Hypoventilation Syndrome

The mortality rate for respiratory failure resulting from obesity hypoventilation syndrome is high if it requires ventilator management. We describe a case of severe acute respiratory failure resulting from obesity hypoventilation syndrome (BMI, 60.2 kg/m²) successfully treated with venovenous extracorporeal membrane oxygenation (VV-ECMO). During ECMO management, a mucus plug was removed by bronchoscopy daily and 18 L of water was removed using diuretics, resulting in weight loss of 24 kg. The patient was weaned from ECMO on day 5, extubated on day 16, and discharged on day 21. The fundamental treatment for obesity hypoventilation syndrome in morbidly obese patients is weight loss. VV-ECMO can be used for respiratory support until weight loss has been achieved.

Propofol Associated with a Shorter Duration of Mechanical Ventilation than Scheduled Intermittent Lorazepam: A Database Analysis Using Project Impact

Background:

While one prospective controlled study in medical intensive care unit (ICU) patients demonstrated that sedation with propofol leads to a shorter duration of mechanical ventilation compared with scheduled intermittent intravenous lorazepam, its conclusions may not be applicable to surgical ICU patients and institutions not using daily sedation interruption.

Objective:

To compare the duration of mechanical ventilation between medical and surgical ICU patients receiving propofol versus scheduled intermittent lorazepam in routine clinical practice.

Methods:

Retrospective data (January 2001–December 2005) were obtained from the Project IMPACT database for medical and surgical ICU patients at Tufts-New England Medical Center, a 450 bed academic hospital. These patients had been mechanically ventilated for 24 hours or more and had received 24 hours or more of either propofol or scheduled intermittent lorazepam as the sole sedative. Clinically relevant variables were identified a priori, and their influence on duration of mechanical ventilation was evaluated. Differences in these variables between propofol and scheduled intermittent lorazepam groups within the ICU cohorts were then measured.

Results:

Of 4608 database patients, 287 met criteria. Factors associated with a prolonged duration of mechanical ventilation for the medical ICU cohort included sedation use for 5 or more days (OR 13.8; 95% CI 8.3 to 19.4), narcotic use (OR 7.6; 95% CI 2.3 to 13), and scheduled intermittent lorazepam use (OR 7.0; 95% CI 0.4 to 13.7). For the surgical ICU cohort, these factors included sedation use for 5 or more days (OR 15; 95% CI 11.4 to 19.4), APACHE II (Acute Physiology and Chronic Health Evaluation II) score equal to or greater than 18 (OR 4.1; 95% CI 0.4 to 7.8), and scheduled intermittent lorazepam use (OR 4.0; 95% CI 0.2 to 7.7). Duration of mechanical ventilation was the only variable that differed significantly between propofol and scheduled intermittent lorazepam in both the medical ICU, with a median (range) of 6 (3–12) versus 11 (5–25; p = 0.03), and surgical ICU, with a median of 4 (2–15) versus 9 (4–20; p = 0.001), groups.

Conclusions:

Sedation with propofol in the naturalistic setting appears to be associated with a shorter duration of mechanical ventilation compared with scheduled intermittent lorazepam in both medial and surgical ICU patients when only one sedative drug is used. Data from this uncontrolled observational study are consistent with findings from a randomized clinical trial.

State of the Art Reviews: Relationship Between Diet/ Physical Activity and Health

Obesity and 4 of the leading causes of death—heart disease, cancer, stroke, and type 2 diabetes mellitus—are related to lifestyle. The combination of a healthy weight, prudent diet, and daily physical activity clearly plays a role in primary, secondary, and tertiary prevention of these and other chronic diseases. Because nearly 65% of the adult population is overweight or obese, weight loss and maintenance are central to this review article. Improved lipid profiles, blood pressure, insulin sensitivity, and euglycemia are associated with weight loss or a normal body weight; thus, maintaining a healthy weight is a universal recommendation for health. The methods for improving lifestyle described in the section on obesity include assessing nutritional status and stages of change of the client, setting realistic goals, eating a diet high in fruits and vegetables with low-fat sources of dairy and protein, and achieving appropriate physical activity levels. The importance of physicians discussing weight with clients and vice versa is stressed. The common features of lifestyle-related diseases make them amenable to similar lifestyle interventions.

The Role of Obesity in Sepsis Outcome among Critically Ill Patients: A Retrospective Cohort Analysis

Background. The objective of this study was to assess the correlation between sepsis, obesity, and mortality of patients admitted to an Intensive Care Unit (ICU). Subjects and Methods. Data of all patients admitted to the ICU of a tertiary hospital during a 28-month period were retrospectively analyzed and included in the study. Results. Of 834 patients included, 163 (19.5%) were obese, while 25 (3.0%) were morbidly obese. Number of comorbidities (P < 0.001), bloodstream infection (P  0.033), and carbapenemase-producing Klebsiella pneumoniae colonization during ICU stay (P  0.005) were significantly associated with obesity, while nonobese patients suffered more frequently from spontaneous intracranial hemorrhage (P  0.038). Total ICU mortality was 22.5%. Increased mortality among obese ICU patients was observed. Sepsis was the main condition of admission for which obese patients had statistically lower survival than normal weight subjects (76.3% versus 43.7%; P  0.001). Mortality of septic patients upon admission was independently associated with SOFA score upon ICU admission (P  0.003), obesity (P  0.014), pneumonia (P  0.038), and development of septic shock (P  0.015). Conclusions. Our study revealed that sepsis upon ICU admission is adversely influenced by obesity but further studies are needed in order to assess the role of obesity in sepsis outcome.

The Critical Care Obesity Paradox and Implications for Nutrition Support

Obesity is a leading cause of preventable death worldwide. The prevalence of obesity has been increasing and is associated with an increased risk for other co-morbidities. In the critical care setting, nearly one third of patients are obese. Obese critically ill patients pose significant physical and on-physical challenges to providers, including optimization of nutrition therapy. Intuitively, obese patients would have worse critical care-related outcome. On the contrary, emerging data suggests that critically ill obese patients have improved outcomes, and this phenomenon has been coined "the obesity paradox." The purposes of this review will be to outline the historical views and pathophysiology of obesity and epidemiology of obesity, describe the challenges associated with obesity in the intensive care unit setting, review critical care outcomes in the obese, define the obesity-critical care paradox, and identify the challenges and role of nutrition support in the critically ill obese patient.

Obesity enhances sepsis-induced liver inflammation and injury in mice

OBJECTIVE

How obesity affects the response to sepsis was not completely understood. It was hypothesized that obesity alters adipose and hepatic tissue inflammation through signal transducer and activator of transcription (STAT3) activation.

METHODS

Male C57BL/6 mice at 6 weeks of age were randomized to a high-fat diet (60% kcal fat) or normal diet (16% kcal fat) for 6 to 7 weeks. Sepsis was then induced by cecal ligation and puncture, and animals were monitored for survival or sacrificed and tissue collected.

RESULTS

High-fat diet-fed mice gained more weight, had increased fat mass, and were glucose intolerant compared with normal diet-fed mice. Obesity increased hepatic neutrophil infiltration and injury after sepsis. Mice with obesity had higher plasma leptin levels compared with mice without obesity. Adipose tissue expression of adiponectin receptor 2, tumor necrosis factor-α, and peroxisome proliferator activated receptor gamma was altered during sepsis and affected by obesity, but the greatest change in adipose tissue expression was in leptin. Septic mice with obesity had lower plasma interleukin-17a, interleukin-23, and tumor necrosis factor-α levels and increased hepatic STAT3 and activator protein-1 activation compared with septic mice without obesity. Ultimately, mice with obesity had a lower probability of survival following sepsis.

CONCLUSIONS

Mice with obesity are more susceptible to sepsis and have higher mortality, in part, through activation of the STAT3 signaling pathway and through activator protein-1 activation.

Obesity in the intensive care unit: risks and complications

The steady growing prevalence of critically ill obese patients is posing diagnostic and management challenges across medical and surgical intensive care units. The impact of obesity in the critically ill patients may vary by type of critical illness, obesity severity (obesity distribution) and obesity-associated co-morbidities. Based on pathophysiological changes associated with obesity, predominately in pulmonary reserve and cardiac function, critically ill obese patients may be at higher risk for acute cardiovascular, pulmonary and renal complications in comparison to non-obese patients. Obesity also represents a dilemma in the management of other critical care areas such as invasive mechanical ventilation, mechanical ventilation liberation, hemodynamic monitoring and pharmacokinetics dose adjustments. However, despite higher morbidity associated with obesity in the intensive care unit (ICU), a paradoxical lower ICU mortality ("obesity paradox") is demonstrated in comparison to non-obese ICU patients. This review article will focus on the unique pathophysiology, challenges in management, and outcomes associated with obesity in the ICU.

Variability Among US Intensive Care Units in Managing the Care of Patients Admitted With Preexisting Limits on Life-Sustaining Therapies

IMPORTANCE

Although the end-of-life care patients receive is known to vary across nations, regions, and centers, these differences are best explored within a group of patients with presumably similar care preferences.

OBJECTIVE

To examine the proportions of patients admitted to the intensive care unit (ICU) with limitations on life-sustaining treatments and the proportions of such patients who receive aggressive care across individual ICUs.

DESIGN, SETTINGS, AND PARTICIPANTS

Retrospective cohort study using the Project IMPACT database (from April 1, 2001, to December 31, 2008) including 141 ICUs in 105 hospitals in the United States and 277,693 ICU patient visits. We used logistic regression analysis models adjusted for available patient characteristics and clustered visits by individual ICU. The full analysis was last performed in October 2014.

MAIN OUTCOMES AND MEASURES

Outcomes included the provision of (1) cardiopulmonary resuscitation, (2) new forms of life support, and the (3) addition or (4) reversal of treatment limitations.

RESULTS

Of the ICU admissions evaluated, 4.8% (95% CI, 4.7%-4.9%) had previously established treatment limitations. Patients admitted with treatment limitations were more likely to be older with more functional limitations and comorbidities. Among patients who survived to hospital discharge, more experienced reversals of existing treatment limitations during the ICU stay (17.8% [95% CI, 17.0%-18.7%]) than additions of new limits (11.7% [95% CI, 11.1%-12.4%]) (P < .01). Among patients who died, 15.7% (95% CI, 14.7-16.8%) had received cardiopulmonary resuscitation. After risk adjustment, ICUs varied widely in the proportions of patients admitted with treatment limitations (median, 4.0%; range, <1.0%-20.9%), the proportions of those who received cardiopulmonary resuscitation (37.7% [95% CI, 3.8%-92.4%]), the proportions of new forms of life support (30.0% [95% CI, 6.0%-84.2%]), and, among survivors, the proportion who had new treatment limitations established (11.2% [95% CI, 1.9%-57.3%]) and reversal of treatment limitations during or following ICU admission (20.2% [95% CI, 1.8%-76.2%]). The observed variability could not be consistently explained using measurable center-level characteristics.

CONCLUSIONS AND RELEVANCE

Intensive care units vary dramatically in how they manage care for patients admitted with treatment limitations. Among patients who survive, escalations in the aggressiveness of care are more common during the ICU stay than are de-escalations in aggressiveness. This study cannot directly measure whether care received was consistent with patients' preferences but suggests that ICU culture and physicians' practice styles contribute to the aggressiveness of care.

Does obesity affect outcomes of adult burn patients?

BACKGROUND

Obesity negatively affects outcomes after trauma and surgery; results after burns are more limited and controversial. The purpose of this study was to determine the effect of obesity on clinical and economic outcomes after thermal injury.

METHODS

The National Inpatient Sample was queried for adults from 2005-2009 with International Classification of Diseases-9 codes for burn injury. Demographics and clinical outcomes of obese and nonobese cohorts were compared. Univariate and multivariate analysis using logistic regression models were performed. Data are expressed as median (interquartile range) or mean ± standard deviation and compared at P < 0.05.

RESULTS

In 14,602 patients, 3.3% were obese (body mass index ≥30 kg/m(2)). The rate of obesity increased significantly by year (P < 0.001). Univariate analysis revealed significant differences between obese and nonobese patients in incidence of wound infection (7.2% versus 5.0%), urinary tract infection (7.2% versus 4.6%), deep vein thrombosis in total body surface area (TBSA) ≥10% (3.1% versus 1.1%), pulmonary embolism in TBSA ≥10% (2.3% versus 0.6%), length of stay [6 d (8) versus 5 d (9)], and hospital costs ($10,122.12 [$18,074.72] versus $7892.07 [$17,191.96]) (all P < 0.05). Death occurred less frequently in the obese group (1.9% versus 4%, P = 0.021). Significant predictors of grouped adverse events (urinary tract infection, wound infection, deep vein thrombosis, and pulmonary embolism) on multivariate analysis include obesity, TBSA ≥20%, age, and black race (all P ≤ 0.05).

CONCLUSIONS

Obesity is an independent predictor of adverse events after burn injury; however, obesity is associated with decreased mortality. Our findings highlight the potential clinical and economic impact of the obesity epidemic on burn patients nationwide.

The Effect of Body Mass Index on Posttraumatic Transfusion after Pelvic Trauma

The impact of body mass index (BMI) on posttraumatic blood transfusion after pelvic trauma is not well known. We conducted a retrospective review of trauma registry data over a 5-year period. Patients were stratified by BMI as normal: less than 25 kg/m2, overweight: 25 to 29.9 kg/m2, obese: 30 to 39.9 kg/m2, and morbidly obese: 40 kg/m2 or greater. Fractures were identified as “likely to receive transfusion” based on literature. Multivariable logistic regression modeling evaluated the relationship between BMI and initial posttraumatic transfusion. A second regression model was created to test the effect of BMI after adjusting for fractures “less likely to receive transfusion.” Sixty-six of 244 patients (27.3%) received transfusion (mean: 1.1 ± 2.3 units). Morbid obesity was associated with transfusion (less than 55.6 vs 24.8%; P < 0.05) and units of total blood transfused (2.2 ± 2.9 vs 1.0 ± 2.2 mL; P < 0.05). The average age of patients who received a blood transfusion was significantly older compared with patients who did not receive a transfusion (45.4 ± 18.8 vs 36.1 ± 16.1 years; P < 0.05). After adjusting for potential confounders, morbid obesity was a significant risk factor for transfusion (odds ratio [OR], 4.1; 95% confidence interval [CI], 1.4 to 12.0). Adjusting by age and fracture patterns “less likely to receive transfusion,” morbid obesity remained a risk factor for transfusion (OR, 4.5; 95% CI, 1.5 to 12.9). Morbid obesity represented a significant risk factor for posttraumatic transfusion in isolated pelvic trauma, even for fracture patterns “less likely to receive transfusion.”

Variation in decisions to forgo life-sustaining therapies in US ICUs

BACKGROUND

The magnitude and implication of variation in end-of-life decision-making among ICUs in the United States is unknown.

METHODS

We reviewed data on decisions to forgo life-sustaining therapy (DFLSTs) in 269,002 patients admitted to 153 ICUs in the United States between 2001 and 2009. We used fixed-effects logistic regression to create a multivariable model for DFLST and then calculated adjusted rates of DFLST for each ICU.

RESULTS

Patient factors associated with increased odds of DFLST included advanced age, female sex, white race, and poor baseline functional status (all P < .001). However, associations with several of these factors varied among ICUs (eg, black race had an OR for DFLST from 0.18 to 2.55 across ICUs). The ICU staffing model was also found to be associated with DFLST, with an open ICU staffing model associated with an increased odds of a DFLST (OR = 1.19). The predicted probability of DFLST varied approximately sixfold among ICUs after adjustment for the fixed patient and ICU effects and was directly correlated with the standardized mortality ratios of ICUs (r = 0.53, 0.41-0.68).

CONCLUSION

Although patient factors explain much of the variability in DFLST practices, significant effects of ICU culture and practice influence end-of-life decision-making. The observation that an ICU's risk-adjusted propensity to withdraw life support is directly associated with its standardized mortality ratio suggests problems with using the latter as a quality measure.

The association between obesity and outcomes in critically ill patients

BACKGROUND

Obesity rates are increasing worldwide, particularly in North America. The impact of obesity on the outcome of critically ill patients is unclear.

METHODS

A prospective observational cohort study of consecutive patients admitted to a tertiary critical care unit in Canada between January 10, 2008 and March 31, 2009 was conducted. Exclusion criteria were age <18 years, admission <24 h, planned cardiac surgery, pregnancy, significant ascites, unclosed surgical abdomen and brain death on admission. Height, weight and abdominal circumference were measured at the time of intensive care unit (ICU) admission. Coprimary end points were ICU mortality and a composite of ICU mortality, reintubation, ventilator-associated pneumonia, line sepsis and ICU readmission. Subjects were stratified as obese or nonobese, using two separate metrics: body mass index (BMI) ≥ 30 kg/m(2) and a novel measurement of 75th percentile for waist-to-height ratio (WHR).

RESULTS

Among 449 subjects with a BMI ≥ 18.5 kg/m(2), both BMI and WHR were available for comparative analysis in 348 (77.5%). Neither measure of obesity was associated with the primary end points. BMI ≥ 3 0 kg/m(2) was associated with a lower odds of six-month mortality than the BMI <30 kg/m(2) group (adjusted OR 0.59 [95% CI 0.36 to 0.97]; P=0.04) but longer intubation times (adjusted RR 1.56 [95% CI 1.17 to 2.07]; P=0.003) and longer ICU length of stay (adjusted RR 1.67 [95% CI 1.21 to 2.31]; P=0.002). Conversely, measurement of 75th percentile for WHR was associated only with decreased ICU readmission (OR 0.23 [95% CI 0.07 to 0.79]; P=0.02).

CONCLUSIONS

Obesity was not necessarily associated with worse outcomes in critically ill patients.

Development of a murine model of early sepsis in diet-induced obesity

Sepsis, a global health issue, is the most common cause of mortality in the intensive care unit. The aim of this study was to develop a new model of sepsis that investigates the impact of prolonged western diet (WD) induced obesity on the response to early sepsis. Male C57BL/6 mice were fed either a high fat WD or normal chow diet (NCD) for 6, 15, or 27 weeks. Septic obese mice at 15 and 27 weeks had significantly lower levels of lung myeloperoxidase (26.3 ± 3.80 U/mg tissue) compared to age matched ad lib (44.1 ± 2.86 U/mg tissue) and diet restricted (63.2 ± 5.60 U/mg tissue) controls. Low levels of lung inflammation were not associated with changes in hepatic cytokines and oxidative stress levels. Obese mice had significantly (P < 0.0001) larger livers compared to controls. Histological examination of the livers demonstrated that WD fed mice had increased inflammation with pronounced fat infiltration, steatosis, and hepatocyte ballooning. Using this model of prolonged exposure to high fat diet we have data that agree with recent clinical observations suggesting obese individuals are protected from sepsis-induced lung injury. This model will allow us to investigate the links between damage to the hepatic microcirculation, immune response, and lung injury.

Veno-venous extracorporeal membrane oxygenation in obese surgical patients with hypercapnic lung failure

BACKGROUND

In patients with a body mass index (BMI) > 35 kg/m(2) , or in extreme cases weighting > 250 kg, we are faced with special challenges in therapy and logistics. The aim was to analyze the feasibility of the extracorporeal membrane oxygenation (ECMO) in these patients.

METHODS

We report 12 adult patients [10 male, 2 female; mean age 56.7 (34-74) years; mean BMI 47.9 (35-88.6) kg/m(2) ] with acute lung failure treated with veno-venous ECMO from 1 January 2009 to 30 June 2013. All patients were cannulated percutaneously into the right internal jugular vein and one of the femoral veins at the bedside.

RESULTS

The mean time to ECMO after admission to the intensive care unit (ICU) was 2 days (0-10), and the mean ECMO run time was 9 days (4 h-20 days). Lung failure occurred in the contexts of wound infection (two patients), anaphylactic shock (one patient), major trauma (one patients) and pneumonia after surgery (four patients), and respiratory failure in abdominal sepsis (four patients). The mean time in the ICU was 31 days (0-89), and the mean time at the hospital was 38 days (0-101). Three patients died on the system because of multiorgan failure; nine patients were weaned from ECMO (75%); and six were patients discharged from the ICU and from the hospital (survival rate 50%).

CONCLUSIONS

ECMO in obese patients is feasible and life saving. Therefore, a percutaneous cannulation remains feasible. The goals of the ECMO therapy include early spontaneous breathing, tracheotomy, rapid reduction of sedation and adequate analgesia. Rehabilitation includes nutritional therapy, as well as psychiatric therapy and bariatric surgery, as perspectives for the future.

Body mass index and mortality in Korean intensive care units: a prospective multicenter cohort study

Background

The level of body mass index (BMI) that is associated with the lowest mortality in critically ill patients in Asian populations is uncertain. We aimed to examine the association of BMI with hospital mortality in critically ill patients in Korea.

Methods

We conducted a prospective multicenter cohort study of 3,655 critically ill patients in 22 intensive care units (ICUs) in Korea. BMI was categorized into five groups: <18.5, 18.5 to 22.9, 23.0 to 24.9 (the reference category), 25.0 to 29.9, and ≥30.0 kg/m².

Results

The median BMI was 22.6 (IQR 20.3 to 25.1). The percentages of patients with BMI<18.5, 18.5 to 22.9, 23.0 to 24.9, 25.0 to 29.9, and ≥30.0 were 12, 42.3, 19.9, 22.4, and 3.3%, respectively. The Cox-proportional hazard ratios with exact partial likelihood to handle tied failures for hospital mortality comparing the BMI categories <18.5, 18.5 to 22.9, 25.0 to 29.9, and ≥30.0 with the reference category were 1.13 (0.88 to 1.44), 1.03 (0.84 to 1.26), 0.96 (0.76 to 1.22), and 0.68 (0.43 to 1.08), respectively, with a highly significant test for trend (p = 0.02).

Conclusions

A graded inverse association between BMI and hospital mortality with a strong significant trend was found in critically ill patients in Korea.

Clinical features and outcome of postoperative peritonitis following bariatric surgery

BACKGROUND

We assessed the clinical features and outcome of morbidly obese patients admitted to the intensive care unit (ICU) for management of postoperative peritonitis (POP) following bariatric surgery (BS).

METHODS

In a prospective, observational, surgical ICU cohort, we compared the clinical features, empiric antibiotic therapy, and prognosis of BS patients with those developing POP after conventional surgery (cPOP).

RESULTS

Overall, 49 BS patients were compared to 134 cPOP patients. BS patients were younger (45 ± 10 versus 63 ± 16 years; p < 0.0001), had lower rates of fatal underlying disease (39 vs. 64%; p = 0.002), and the same SOFA score at the time of reoperation (8 ± 4 vs 8 ± 3; p = 0.8) as the cPOP patients. BS patients had higher proportions of Gram-positive cocci (48 vs. 35 %; p = 0.007) and lower proportions of Gram-negative bacilli (33 vs. 44%; p = 0.03), anaerobes (4 vs. 10%; p = 0.04), and multidrug-resistant strains (20 vs. 40%; p = 0.01). Despite higher rates of adequate empiric antibiotic therapy (82 vs. 64%; p = 0.024) and high de-escalation rates (67% in BS cases and 51% in cPOP cases; p = 0.06), BS patients had similar reoperation rates (53 vs. 44%; p = 0.278) and similar mortality rates (24 vs. 32%; p = 0.32) to cPOP patients. In multivariate analysis, none of the risk factors for death were related to BS.

CONCLUSIONS

The severity of POP in BS patients resulted in high mortality rates, similar to the results observed in cPOP. Usual empiric antibiotic therapy protocols should be applied to target multidrug-resistant microorganisms, but de-escalation can be performed in most cases.