Obesity as a Risk Factor for Nosocomial Infections in Trauma Patients

Specific and Non-specific Aspects and Future Challenges of ICU Care Among COVID-19 Patients with Obesity: A Narrative Review

PURPOSE OF REVIEW

Since the end of 2019, the coronavirus disease 2019 (COVID-19) pandemic has infected nearly 800 million people and caused almost seven million deaths. Obesity was quickly identified as a risk factor for severe COVID-19, ICU admission, acute respiratory distress syndrome, organ support including mechanical ventilation and prolonged length of stay. The relationship among obesity; COVID-19; and respiratory, thrombotic, and renal complications upon admission to the ICU is unclear.

RECENT FINDINGS

The predominant effect of a hyperinflammatory status or a cytokine storm has been suggested in patients with obesity, but more recent studies have challenged this hypothesis. Numerous studies have also shown increased mortality among critically ill patients with obesity and COVID-19, casting doubt on the obesity paradox, with survival advantages with overweight and mild obesity being reported in other ICU syndromes. Finally, it is now clear that the increase in the global prevalence of overweight and obesity is a major public health issue that must be accompanied by a transformation of our ICUs, both in terms of equipment and human resources. Research must also focus more on these patients to improve their care. In this review, we focused on the central role of obesity in critically ill patients during this pandemic, highlighting its specificities during their stay in the ICU, identifying the lessons we have learned, and identifying areas for future research as well as the future challenges for ICU activity.

The Relationship Between Body Mass Index and Long-Term Outcomes Following Traumatic Injury

INTRODUCTION

Little is known about the relationship between body mass index (BMI), a function of mass and height (masskg/height2m) and long-term outcomes among traumatic injury survivors. In this prospective cohort study, we investigate the relationship between BMI and long-term health outcomes in the trauma population.

METHODS

Adult trauma survivors with an injury severity score ≥9 admitted to one of three level 1 trauma centers, from January 1, 2015 to December 31, 2022, were surveyed via telephone between 6 and 12 mo postinjury. Participants were stratified into one of five groups by BMI at the time of trauma: L-BMI (BMI <18.5), N-BMI (BMI 18.5-24.9), H1-BMI (BMI 25-29.9), H2-BMI (BMI 30-34.9), and H3-BMI (BMI ≥35); N-BMI was used as the referent. Mental and physical health-related quality of life scores, pain, new functional limitations, and hospital readmissions were evaluated. Univariate and multivariate analyses were used to compare outcomes between study groups.

RESULTS

3830 patients were included. Of those, 124 were L-BMI (3.2%), 1495 N-BMI (39%), 1318 H1-BMI (34.4%), 541 H2-BMI (14.1%), and 352 H3-BMI (9.2%). L-BMI was associated with adverse physical (b = -3.13, CI = -5.71 to -0.55, P = 0.017) and mental health (b = -3.17, CI = -5.87 to -0.46, P = 0.022) outcomes 6-12 mo postinjury compared to the referent. H1-BMI and H2-BMI had higher odds of wo`rse physical outcomes (b = -1.47, CI = -2.42 to -0.52, P = 0.002; b = -3.11, CI = - 4.33 to -1.88, P ≤ 0.001, respectively) and chronic pain (adjusted odds ratio (aOR) = 1.24, CI = 1.04-1.47, P = 0.016; aOR = 1.52, CI = 1.21-1.90, P ≤ 0.001, respectively). Patients with H3-BMI had higher odds of worse physical outcomes compared to N-BMI (b = -4.82, CI = -6.28 to -3.37, P ≤ 0.001), chronic pain (aOR = 2.11, CI = 1.61-2.78, P ≤ 0.001), all-cause hospital readmissions (aOR = 1.62, CI = 1.10-2.34, P = 0.013), and new functional limitations (aOR = 1.39, CI = 1.08-1.79, P = 0.01).

CONCLUSIONS

BMI variance above or below N-BMI is associated with worse long-term outcomes following traumatic injury.

Relationship of Obesity and Severe Penetrating Thoracic and Abdominal Injuries in Adolescent Patients

BACKGROUND

Over 20% of United States adolescents are obese. A thicker layer of subcutaneous adiposity might provide a protective "armor" layer against penetrating wounds. We hypothesized that adolescents with obesity presenting after isolated thoracic and abdominal penetrating trauma have lower rates of severe injury and mortality than adolescents without obesity.

METHODS

The 2017-2019 Trauma Quality Improvement Program database was queried for patients between 12 and 17 years old presenting with knife or gunshot wounds. Patients with body mass index (BMI) ≥30 (obese) were compared to patients with BMI <30. Sub-analyses were performed for adolescents with isolated abdominal trauma and isolated thoracic trauma. Severe injury was defined as an abbreviated injury scale grade >3. Bivariate analyses were performed.

RESULTS

12,181 patients were identified; 1603 (13.2%) had obesity. In isolated abdominal gunshot or knife wounds, rates of severe intra-abdominal injuries and mortality were similar (all P > .05) between groups. In isolated thoracic gunshot wounds, adolescents with obesity had a lower rate of severe thoracic injury (5.1% vs 13.4%, P = .005) but statistically similar mortality (2.2% vs 6.3%, P = .053) compared to adolescents without obesity. In isolated thoracic knife wounds, rates of severe thoracic injuries and mortality were similar (all P > .05) between groups.

DISCUSSION

Adolescent trauma patients with and without obesity presenting after isolated abdominal or thoracic knife wounds had similar rates of severe injury, operative intervention, and mortality. However, adolescents with obesity presenting after an isolated thoracic gunshot wound had a lower rate of severe injury. This may impact the future work-up and management of adolescents sustaining isolated thoracic gunshot wounds.

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.

Tolerance to Glucose and Lipid High Metabolic Reactions After Burns in an Obese Rat Model

The goal of this study was to determine what effect obese body weight and a burn injury can have on the metabolism of glucose and lipids in rats. We used a 3 * 3 factorial model design to provide basic glucose and lipid metabolic data characterizing the interaction between different weight and burn injury groups. Two hundred Sprague Dawley rats were categorized into three weight groups (normal, overweight, obese) and then further divided into control, second-degree, and third-degree burn groups. Our model compared interactions between weight and burn injury factors according to the above groups. Blood glucose and lipid metabolism indicators were monitored on the 1st, 3rd, 7th, and 14th days after burn injury occurred, and burned skin and blood samples were collected for testing. Compared with the normal weight group, the overweight group's fast blood glucose, fast insulin, and homeostasis model assessment of insulin resistance were higher (P < .05), and FBG in the obese group was higher than the normal weight group (P < .05). Burn injuries combined with obese body weight had an interactive effect on fast blood glucose, fast insulin, and homeostasis model assessment of insulin resistance after burn injury (P < .05). Burn injury combined with obese body weight had an interaction on low-density lipoprotein cholesterol on the 3rd day after burn injury (P < .05). Burn injury combined with obese weight had no interaction on triglyceride, total cholesterol, and high-density lipoprotein cholesterol (P > .05). Rats in the overweight and obese weight groups were observed to develop an adaptation and tolerance to a higher metabolic rate after burn injuries occurred.

Prolonged Prehospital Time is a Risk Factor for Pneumonia in Trauma (the PRE-TRIP study): A Retrospective Analysis of the United States National Trauma Data Bank

BACKGROUND

Although multiple risk factors for development of pneumonia in patients with trauma sustained in a motor vehicle accident have been studied, the effect of prehospital time on pneumonia incidence post-trauma is unknown.

RESEARCH QUESTION

Is prolonged prehospital time an independent risk factor for pneumonia?

STUDY DESIGN AND METHODS

We retrospectively analyzed prospectively collected clinical data from 806,012 motor vehicle accident trauma incidents from the roughly 750 trauma hospitals contributing data to the National Trauma Data Bank between 2010 and 2016.

RESULTS

Prehospital time was independently associated with development of pneumonia post-motor vehicle trauma (p < 0.001). This association was primarily driven by patients with low Glasgow Coma Scale scores. Post-trauma pneumonia was uncommon (1.5% incidence) but was associated with a significant increase in mortality (p < 0.001, 4.3% mortality without pneumonia vs. 12.1% mortality with pneumonia). Other pneumonia risk factors included age, sex, race, primary payor, trauma center teaching status, bed size, geographic region, intoxication, comorbid lung disease, steroid use, lower Glasgow Coma Scale score, higher Injury Severity Scale score, blood product transfusion, chest trauma, and respiratory burns.

INTERPRETATION

Increased prehospital time is an independent risk factor for development of pneumonia and increased mortality in patients with trauma caused by a motor vehicle accident. Although prehospital time is often not modifiable, its recognition as a pneumonia risk factor is important as prolonged prehospital time may need to be considered in subsequent decision making.

CLINICAL TRIAL REGISTRATION

Not applicable.

The incidence and characteristics of ventilator-associated pneumonia in a regional nontertiary Australian intensive care unit: A retrospective clinical audit study

BACKGROUND

Ventilator-associated pneumonia (VAP) is a common complication of mechanical ventilation in the intensive care unit. The incidence, patient characteristics, and outcomes have not been described in a regional Australian setting.

OBJECTIVES

Τhe primary objective was to establish the incidence of VAP in a regional intensive care unit using predetermined diagnostic criteria. The secondary objective was to compare the agreement between criteria-based and physician-based diagnostic processes. The tertiary objectives were to compare patient characteristics and clinical outcomes of cases with and without VAP.

METHODS

A retrospective clinical audit was performed of adult patients admitted to Rockhampton Intensive Care Unit, Australia, between 2013 and 2016. We included all patients ventilated for ≥72 h and not diagnosed with a pneumonia before or during the first 72 h of ventilation.

RESULTS

A total of 170 cases met the inclusion criteria. The incidence of VAP as per the criteria-based diagnosis was 27.3 cases per 1000 ventilator days (95% confidence interval [CI]: 18.4-36.2) and as per the physician-based diagnosis was 25.8 cases per 1000 ventilator days (95% CI: 17.1-34.4). There was a moderate chance-corrected agreement between the criteria- and physician-based diagnosis. Very obese cases (body mass index [BMI] ≥40) were nearly four times more likely to develop VAP than cases with normal BMI (BMI <30) (odds ratio: 3.664; 95% CI: 1.394-9.634; p = 0.008). After controlling for sex, BMI category, comorbidities, and Acute Physiology and Chronic Health Evaluation II scores, there was a trend (p = 0.283) for higher adjusted mortality rate for cases with VAP (10.1%, 95% CI: 4.8-21.5) than for those without VAP (6.1%, 95% CI: 3.0-12.4). Cases with VAP had a higher total hospital cost ($123,223 AUD vs $66,425 AUD, p < 0.001), than cases without VAP.

CONCLUSIONS

This is the first study reporting incidence of VAP in an Australian regional intensive care unit setting. An increased length of stay and significantly higher hospital costs warrant research investigating reliable and valid clinical prediction rules to forecast those at risk of VAP.

Relationship Between Obesity and Ventilator-Associated Pneumonia: A Post Hoc Analysis of the NUTRIREA2 Trial

BACKGROUND

Patients with obesity are at higher risk for community-acquired and nosocomial infections. However, no study has specifically evaluated the relationship between obesity and ventilator-associated pneumonia (VAP).

RESEARCH QUESTION

Is obesity associated with an increased incidence of VAP?

STUDY DESIGN AND METHODS

This study was a post hoc analysis of the Impact of Early Enteral vs Parenteral Nutrition on Mortality in Patients Requiring Mechanical Ventilation and Catecholamines (NUTRIREA2) open-label, randomized controlled trial performed in 44 French ICUs. Adults receiving invasive mechanical ventilation and vasopressor support for shock and parenteral nutrition or enteral nutrition were included. Obesity was defined as BMI ≥ 30 kg/m² at ICU admission. VAP diagnosis was adjudicated by an independent blinded committee, based on all available clinical, radiologic, and microbiologic data. Only first VAP episodes were taken into account. Incidence of VAP was analyzed by using the Fine and Gray model, with extubation and death as competing risks.

RESULTS

A total of 699 (30%) of the 2,325 included patients had obesity; 224 first VAP episodes were diagnosed (60 and 164 in obese and nonobese groups, respectively). The incidence of VAP at day 28 was 8.6% vs 10.1% in the two groups (hazard ratio, 0.85; 95% CI 0.63-1.14; P = .26). After adjustment on sex, McCabe score, age, antiulcer treatment, and Sequential Organ Failure Assessment at randomization, the incidence of VAP remained nonsignificant between obese and nonobese patients (hazard ratio, 0.893; 95% CI, 0.66-1.2; P = .46). Although no significant difference was found in duration of mechanical ventilation and ICU length of stay, 90-day mortality was significantly lower in obese than in nonobese patients (272 of 692 [39.3%] patients vs 718 of 1,605 [44.7%]; P = .02). In a subgroup of patients (n = 123) with available pepsin and alpha-amylase measurements, no significant difference was found in rate of abundant microaspiration of gastric contents, or oropharyngeal secretions between obese and nonobese patients.

INTERPRETATION

Our results suggest that obesity has no significant impact on the incidence of VAP.

Obesity and risk of catheter-related infections in the ICU. A post hoc analysis of four large randomized controlled trials

PURPOSE

Obesity increases the risk of nosocomial infection, but data regarding the role of body mass index (BMI) in catheter related infections are scarce. We used the data gathered from four randomized, controlled trials (RCTs) to investigate the association between body mass index (BMI) and intravascular catheter infections in critically ill obese patients.

METHODS

Adult obese patients who required short-term central venous, arterial or dialysis catheter insertion in the intensive care unit (ICU) were analyzed. The association between BMI and major catheter-related infection (MCRI), catheter-related bloodstream infection (CRBSI) and catheter tip colonization was estimated using univariate and multivariate marginal Cox models. Exploratory analysis using dressing disruptions was added.

RESULTS

A total of 2282 obese patients and 4275 catheters from 32 centers were included in this post-hoc analysis. Overall, 66 (1.5%) MCRI, 43 (1%) CRBSI and 399 (9.3%) catheter colonizations were identified. The hazard ratio (HR) for MCRI, CRBSI and colonization increased with BMI. After adjustment for well-known infection risk factors, the BMI ≥ 40 group had an increased risk for MCRI (HR 1.88, 95% CI 1.13-3.12, p = 0.015), CRBSI (HR 2.19, 95% CI 1.19-4.04, p = 0.012) and colonization (HR 1.44, 95% CI 1.12-1.84, p = 0.0038) compared to the BMI < 40 group. The mean dressing disruption per catheter was increased in the BMI ≥ 40 group (2.03 versus 1.68 in the BMI < 40 group, p = 0.05).

CONCLUSIONS

Using the largest dataset ever collected from large multicentric RCTs, we showed that patients with BMI ≥ 40 had an increased risk for intravascular catheter infections. Targeted prevention measures should focus on this population with a particular attention to catheter care and dressing disruption.

Prevalence and Predictive Factors for Nosocomial Infection in the Military Hospitals: A Systematic Review and Meta-Analysis

Background:

To assess prevalence and predictive factors for Nosocomial Infection (NI) in the military hospitals.

Methods:

PubMed, Scopus, Cochrane and PreQuest databases were systematically searched for studies published between Jan 1991 and Oct 2017 that reported the prevalence of NI and predictive factors among military hospitals. We performed the meta-analysis using a random effects model. Subgroup analysis was done for heterogeneity and the Egger test to funnel plots was used to assess publication bias.

Results:

Twenty-eight studies with 250,374 patients were evaluated in meta-analysis. The overall pooled estimate of the prevalence of NI was 8% (95% 6.0–9.0). The pooled prevalence was 2% (95% CI: 2.0–3.0) when we did sensitivity analysis and excluding a study. The prevalence was highest in burn unit (32%) and ICU (15%). Reported risk factors for NI included gender (male vs female, OR: 1.45), age (Age≥65, OR: 2.4), diabetes mellitus (OR: 2.32), inappropriate use of antibiotics (OR: 2.35), received mechanical support (OR: 2.81), co-morbidities (OR: 2.97), admitted into the ICU (OR: 2.26), smoking (OR: 1.36) and BMI (OR: 1.09).

Conclusion:

The review revealed a difference of prevalence in military hospitals with other hospitals and shows a high prevalence of NI in burn units. Therefore careful disinfection and strict procedures of infection control are necessary in places that serve immunosuppressed individuals such as burn patient. Moreover, a vision for the improvement of reports and studies in military hospitals to report the rate of these infections are necessary.

Morbid Obesity Is a Risk Factor for Infection Recurrence Following Debridement, Antibiotics, and Implant Retention for Periprosthetic Joint Infection

BACKGROUND

Although morbid obesity is an established risk factor for periprosthetic joint infection following total hip arthroplasty and total knee arthroplasty, little is known regarding the infection control rate of this cohort following debridement, antibiotics, and implant retention (DAIR). The purpose of this study is to investigate the infection control rate following DAIR in a morbidly obese patient cohort compared to a nonobese patient cohort and discern the relationship between time from diagnosis to treatment and risk of DAIR failure.

METHODS

Results of all DAIR procedures were retrospectively reviewed across 4 institutions. Those with a body mass index of at least 40 kg/m² were matched 2:1 on the basis of patient age, sex, date of surgery, and presence of staphylococcal species in culture to a cohort of patients with body mass index of <30 kg/m². Demographic variables were collected for each patient. Kaplan-Meier survivorship curves were constructed and multivariable Cox regression was performed for analysis.

RESULTS

The morbidly obese group experienced a higher treatment failure rate (57.9%) compared to the nonobese group (36.8%; P = .035). Morbid obesity and major depressive disorder/generalized anxiety disorder diagnosis significantly increased the risk of failure, with hazard ratios of 1.82 and 2.09, respectively. Morbidly obese patients who received DAIR within 48 hours of symptom presentation did not face an increased risk of reinfection compared to nonobese patients.

CONCLUSION

Our findings suggest morbidly obese patients face an increased risk of DAIR failure; however, this risk can be mitigated if DAIR is received within 48 hours of symptom onset.

Efficacy and Safety of Eravacycline in Obese Patients: A Post Hoc Analysis of Pooled Data From the IGNITE1 and IGNITE4 Clinical Trials

Background

The increasing prevalence of obesity worldwide merits an examination of the efficacy and safety profiles of agents dosed by weight.

Methods

Data for patients (n = 1037) were obtained from the pooled IGNITE1 and IGNITE4 randomized double-blind trials in which patients with complicated intra-abdominal infections received eravacycline 1 mg/kg (actual body weight [ABW]) every 12 hours or comparator (ertapenem 1 g every 24 hours or meropenem 1 g every 8 hours) intravenously. This post hoc analysis evaluated clinical cure rates, adverse events, and drug discontinuation rates stratified by body mass index (BMI) categories of BMI >40 kg/m² (Obese, Class III), BMI 35–39.9 kg/m² (Obese, Class II), BMI 30–34.9 kg/m² (Obese, Class I), BMI 25–29.9 kg/m² (Overweight), BMI 18.5–24.9 kg/m² (Healthy weight), and BMI <18.5 kg/m² (Underweight).

Results

Clinical cure rates were high across BMI categories and ranged from 82% to 94% in the eravacycline group and 88.5%–100% in the comparator group. Similar cure rates were observed among eravacycline-treated healthy weight (126/134; 94%), overweight (127/146; 87%), and obese (BMI ≥30 kg/m²; 110/129; 85.3%) patients. In the comparator group, a similar proportion of patients demonstrated clinical response (healthy weight [132/145; 91%], overweight [130/144; 90.3%], and obese [115/129; 89.1%]). Of the treatment-emergent adverse events that occurred in eravacycline-treated obese patients, a larger proportion were gastrointestinal-related (ie, nausea and vomiting); however, discontinuation rates were low and similar between eravacycline and carbapenems.

Conclusions

This post hoc analysis demonstrates the therapeutic utility and acceptable safety profile of eravacycline dosed by ABW in obese patients (BMI ≥30 kg/m²).

The Impact of BMI on Adult Blunt Trauma Outcomes

Traumatic injuries account for 10% of all mortalities in the United States. Globally, it is estimated that by the year 2030, 2.2 billion people will be overweight (BMI ≥ 25) and 1.1 billion people will be obese (BMI ≥ 30). Obesity is a known risk factor for suboptimal outcomes in trauma; however, the extent of this impact after blunt trauma remains to be determined. The incidence, prevalence, and mortality rates from blunt trauma by age, gender, cause, BMI, year, and geography were abstracted using datasets from 1) the Global Burden of Disease group 2) the United States Nationwide Inpatient Sample databank 3) two regional Level II trauma centers. Statistical analyses, correlations, and comparisons were made on a global, national, and state level using these databases to determine the impact of BMI on blunt trauma. The incidence of blunt trauma secondary to falls increased at global, national, and state levels during our study period from 1990 to 2015, with a corresponding increase in BMI at all levels ( P < 0.05). Mortality due to fall injuries was higher in obese patients at all levels ( P < 0.05). Analysis from Nationwide Inpatient Sample database demonstrated higher mortality rates for obese patients nationally, both after motor vehicle collisions and mechanical falls ( P < 0.05). In obese and nonobese patients, regional data demonstrated a higher blunt trauma mortality rate of 2.4% versus 1.2%, respectively ( P < 0.05) and a longer hospital length of stay of 4.13 versus 3.26 days, respectively ( P = 0.018). The obesity rate and incidence of blunt trauma secondary to falls are increasing, with a higher mortality rate and longer length of stay in obese blunt trauma patients.

Preoperative skin antisepsis using chlorhexidine may reduce surgical wound infections in lower limb trauma surgery when compared to povidone-iodine - a prospective randomized trial

BACKGROUND

For the prevention of surgical wound infections (SSIs), local microorganism counts can be lowered by skin antisepsis prior to surgical incisions. Until now, it has been unclear which antiseptic is the most effective.

METHODS

This prospective randomized trial analyzed the efficacy of 2 frequently used agents in the reduction of postoperative wound complication rates after aseptic trauma surgery on the lower leg and foot. In the study, 279 consecutive participants were randomized; 112 received surgical skin preparations using chlorhexidine (CHX) (ChloraPrep; Becton Dickinson, Franklin Lakes, NJ) and 167 received preparations with povidone-iodine (PVP-I) (Braunoderm; B. Braun Melsungen AG, Melsungen, Germany). Primary clinical endpoints were SSIs and wound healing disorders (WHDs) within 6 months after surgery. Secondary outcome variables included demographic and perioperative risk factors for SSIs.

RESULTS

Rates of WHDs and SSIs were significantly higher in the PVP-I treatment group, which experienced 9 SSIs and 12 WHDs (n = 21; 12.6%), compared to the CHX treatment group, which had 2 SSIs and 3 WHDs (n = 5; 4.5%) (P = .022). Perioperative risk factors for WHDs were obesity and longer surgery time, whereas SSIs were increased in participants with cardiovascular diseases and suction drainage. Logistic regression analysis showed that the odds of complications of wound healing were 3.5 times higher for PVP-I than for CHX (odds ratio = 3.5; 95% confidence interval, 1.1-11.2; P = .032).

CONCLUSIONS

Preoperative skin antisepsis for trauma surgery of the lower leg and foot using CHX led to significantly fewer complications of wound healing when compared to PVP-I.

Surgical Site Infection Prevention Bundle in Cardiac Surgery

BACKGROUND

Surgical site infections (SSI) are among the most prevalent infections in healthcare institutions, attributing a risk of death which varies from 33% to 77% and a 2- to 11-fold increase in risk of death. Patients submitted to cardiac surgery are more susceptible to SSI, accounting for 3.5% to 21% of SSI. The mortality rate attributable to these causes is as high as 25%. Prevention of SSI in cardiac surgery is based on a bundle of preventive measures, which focus on modifiable risks.

OBJECTIVE

The objective of this study was to identify SSI risk factors in clean cardiac surgery.

METHODS

A retrospective cohort study analyzed 1,846 medical records from patients who underwent clean cardiac surgery. Fisher's exact test was used for bivariate comparison, and Poisson regression was used for independent analysis of SSI risk, considering a significance level of p < 0.05.

RESULTS

The results of the study comprised a multivariate analysis. The variables that were associated with the diagnosis of SSI were: surgical risk index (OR: 2.575; CI: 1.224-5.416), obesity (OR: 2.068; CI: 1.457-2.936), diabetes mellitus (OR: 1,678; CI: 1.168-2.409), and blood glucose level (OR: 1.004; CI: 1.001-1.007).

CONCLUSIONS

This study evidenced that complete adherence to the bundle was not associated with a reduction in the risk of surgical infections. Diabetes mellitus, obesity, and surgical risk index assessment were, however, identified to increase association and consequently risk of SSI in cardiac surgery.

Obesity in the critically ill: a narrative review

The World Health Organization defines overweight and obesity as the condition where excess or abnormal fat accumulation increases risks to health. The prevalence of obesity is increasing worldwide and is around 20% in ICU patients. Adipose tissue is highly metabolically active, and especially visceral adipose tissue has a deleterious adipocyte secretory profile resulting in insulin resistance and a chronic low-grade inflammatory and procoagulant state. Obesity is strongly linked with chronic diseases such as type 2 diabetes, hypertension, cardiovascular diseases, dyslipidemia, non-alcoholic fatty liver disease, chronic kidney disease, obstructive sleep apnea and hypoventilation syndrome, mood disorders and physical disabilities. In hospitalized and ICU patients and in patients with chronic illnesses, a J-shaped relationship between BMI and mortality has been demonstrated, with overweight and moderate obesity being protective compared with a normal BMI or more severe obesity (the still debated and incompletely understood "obesity paradox"). Despite this protective effect regarding mortality, in the setting of critical illness morbidity is adversely affected with increased risk of respiratory and cardiovascular complications, requiring adapted management. Obesity is associated with increased risk of AKI and infection, may require adapted drug dosing and nutrition and is associated with diagnostic and logistic challenges. In addition, negative attitudes toward obese patients (the social stigma of obesity) affect both health care workers and patients.

Targeting Catheter-Associated Urinary Tract Infections in a Trauma Population: A 5-S Bundle Preventive Approach

Complications from catheter-associated urinary tract infections (CAUTIs) can cause morbidity and mortality. Our institution's Trauma Quality and Improvement Program analysis identified CAUTIs as an outlier complication in our trauma population. This study aimed to determine whether implemented measures would reduce CAUTI rates in trauma population. A 5-S CAUTI bundle was implemented. Its effects were measured on a prospectively collected dataset of adult trauma patients using our Trauma Registry during the 4-year study period. Implemented measures included (1) staff education, (2) bladder catheter stabilization, (3) patient and caregiver education, (4) keeping the collection bag below the bladder and above the floor, and (5) daily evaluations for discontinuation. Chi-squared and t-test analyses were used with significance defined as p < .05. Twelve thousand nine hundred and sixty-two trauma patients were admitted to trauma service during the 4-year study period. Of these, 94 developed CAUTIs, with an average age of 67 years and 56% were females. The average injury severity score was 16 in patients with CAUTIs compared with 9 in non-CAUTI patients (p < .0002). In the index year, CAUTIs occurred in 41 out of 3,054 (1.34%), the following year there were 34 out of 3,455 (0.98%), in 2016 there were 11 out of 3,246 (0.33%), and 8 out of 3,207 (0.25%) in 2017 (p < .001). Results demonstrated an 80% reduction in CAUTI rate. Execution of the 5-S CAUTI bundle resulted in a significant 80% reduction in CAUTI rate in our trauma population.

Bidirectional association between gallstones and renal stones: Two longitudinal follow-up studies using a national sample cohort

The present study evaluated the associations between gallstones and renal stones using a national sample cohort of the Korean population. The Korean National Health Insurance Service-National Sample Cohort was collected from 2002 to 2013. We designed two different longitudinal follow-up studies. In study I, we extracted gallstone patients (n = 20,711) and 1:4-matched control I subjects (n = 82,844) and analyzed the occurrence of renal stones. In study II, we extracted renal stone patients (n = 23,615) and 1:4-matched control II subjects (n = 94,460) and analyzed the occurrence of gallstones. Matching was performed for age, sex, income, region of residence, and history of hypertension, diabetes mellitus, and dyslipidemia. Crude and adjusted hazard ratios (HRs) were calculated using a Cox proportional hazards model, and the 95% confidence intervals (CIs) were calculated. Subgroup analyses were performed according to age and sex. The adjusted HR of renal stones was 1.93 (95% CI = 1.75–2.14) in the gallstone group (P < 0.001). The adjusted HR of gallstones was 1.97 (95% CI = 1.81–2.15) in the renal stone group (P < 0.001). The results were consistent in all subgroup analyses. Gallstones increased the risk of renal stones, and renal stones increased the risk of gallstones.

The effects of cryopreserved red blood cell transfusion on tissue oxygenation in obese trauma patients

BACKGROUND

Low tissue oxygenation (StO2) is associated with poor outcomes in obese trauma patients. A novel treatment could be the transfusion of cryopreserved packed red blood cells (CPRBCs), which the in vitro biochemical profile favors red blood cell (RBC) function. We hypothesized that CPRBC transfusion improves StO2 in obese trauma patients.

METHODS

Two hundred forty-three trauma patients at five Level I trauma centers who required RBC transfusion were randomized to receive one to two units of liquid packed RBCs (LPRBCs) or CPRBCs. Demographics, injury severity, StO2, outcomes, and biomarkers of RBC function were compared in nonobese (body mass index [BMI] < 30) and obese (BMI ≥ 30) patients. StO2 was also compared between obese patients with BMI of 30 to 34.9 and BMI ≥ 35. StO2 was normalized and expressed as % change after RBC transfusion. A p value less than 0.05 indicated significance.

RESULTS

Patients with BMI less than 30 (n = 141) and BMI of 30 or greater (n = 102) had similar Injury Severity Score, Glasgow Coma Scale, and baseline StO2. Plasma levels of free hemoglobin, an index of RBC lysis, were lower in obese patients after CPRBC (125 [72-259] μg/mL) versus LPRBC transfusion (230 [178-388] μg/mL; p < 0.05). StO2 was similar in nonobese patients regardless of transfusion type, but improved in obese patients who received CPRBCs (104 ± 1%) versus LPRPCs (99 ± 1%, p < 0.05; 8 hours after transfusion). Subanalysis showed improved StO2 after CPRBC transfusion was specific to BMI of 35 or greater, starting 5 hours after transfusion (p < 0.05 vs. LPRBCs). CPRBCs did not improve clinical outcomes in either group.

CONCLUSION

CPRBC transfusion is associated with increased StO2 and lower free hemoglobin levels in obese trauma patients, but did not improve clinical outcomes. Future studies are needed to determine if CPRBC transfusion in obese patients attenuates hemolysis to improve StO2.

LEVEL OF EVIDENCE

Therapeutic, level IV.

The impact of body mass index on resource utilization and outcomes of children admitted to a pediatric intensive care unit

Introduction:

Obesity is associated with poor health outcomes but may be protective in intensive care unit patients. The objective of this study is to describe the characteristics of underweight, normal weight, and obese children, and to compare their length of stay, resource utilization, and mortality.

Methods:

The charts of 1447 patients who were admitted to a tertiary-level pediatric intensive care unit during 1 calendar year were reviewed. Patients were divided into three groups: underweight (<5th percentile), normal (5th–95th percentiles), and obese (>95th percentile). Body mass index for age percentile was used for children older than age 2 years, and weight-for-height percentile was used for children younger than age 2 years. Demographic data, Pediatric Index of Mortality 2 score, Pediatric Index of Mortality 2 risk of mortality, hospital mortality, hospital length of stay, the use and duration of ventilator support, hemodynamic support, and dialysis were determined.

Results:

Fifteen percent of children were underweight, while 61.5% were normal weight and 23.5% were obese; 54.9% of the patients were male. The overall mortality was 1.87%, with no significant difference between the three weight groups. The racial distribution, prevalence, and duration of invasive and noninvasive ventilation, and the use of vasopressors, central venous lines, and dialysis were similar between three groups. Tube feeding and parenteral nutrition were used more often in the underweight group. Pediatric intensive care unit and hospital lengths of stays were higher in underweight children. Underweight children were younger when compared to normal or obese children. Pediatric Index of Mortality 2 scores and Pediatric Index of Mortality 2 risk of mortality scores were higher in underweight children.

Conclusion:

There were no significant differences between the three weight groups in mortality. Underweight children were younger and sicker, and received tube feeding and parenteral nutrition more frequently.

Higher BMI is associated with reduced mortality but longer hospital stays following ICU discharge in critically ill Asian patients

BACKGROUND & AIMS

Asians with similar body mass index (BMI) as the Caucasians are at higher health risk as compared to their counterparts. Although the mean weight of patients admitted to the intensive care unit (ICU) is increasing but the relation between BMI with 28-day mortality and length of stay (LOS) following ICU discharge in Asian patients is not well studied.

METHODS

We included all adult patients admitted to the ICU of a tertiary hospital who received mechanical ventilation (MV) for at least 48 hours between October 2013 and September 2014. Demographics, BMI, MV, comorbidities, ICU scores (Acute Physiology And Chronic Health Evaluation (APACHE) II and sequential organ failure assessment (SOFA)), use of vasopressor, renal replacement therapy and calorie supplementation were collected from the ICU database. BMI was categorized into four groups according to the World Health Organization's Asian BMI recommendation. Post-ICU LOS (days) was calculated from ICU discharge to hospital discharge in hospital survivors. We used multivariable logistic regression to identify factors associated with 28-day mortality and post-ICU LOS of more than 7 days.

RESULTS

In a cohort of 273 patients (male 62%, mean age 58.4 ± 17 years), the prevalence of overweight/obesity was 53%. In the bivariate analysis, 28-day mortality was lower (p = 0.014) and post-ICU LOS longer (p = 0.01) in the overweight/obese groups. In the multivariable logistic regression analysis, APACHE II (Odds ratio, OR 1.10, CI 1.05-1.16), SOFA (OR 1.17, CI 1.05-1.31), duration of MV (days, OR 1.14, CI 1.05-1.25) were associated with increased and higher BMI groups (p < 0.001) with decreased 28-day mortality. Further analysis of 196 hospital survivors showed age (OR 1.04, CI 1.02-1.06), duration of MV (days, OR 1.14, CI 1.02-1.27) and higher Asian BMI (p = 0.042) were associated with longer post-ICU LOS. The odds of longer post-ICU LOS amongst overweight and obese patients were 1.27 (CI 0.59-2.73) and 1.62 (CI 0.69-3.81) times that of those with normal BMI respectively.

CONCLUSION

In multiethnic critically ill Asian patients, the prevalence of overweight/obesity was high. Although higher BMI was associated with reduced risk of 28-day mortality, obese patients stayed significantly longer in the hospital following ICU discharge.

Obesity in the Polytrauma Patient

The rates of obesity continue to increase in the United States and the overall impact of obesity on health care spending and patient outcomes after trauma is considerable. The unique physiology of the obese places them at higher risk for complications, including infection, failure of fixation, nonunion, multiorgan failure, and death. These physiologic differences and overall patient size can make orthopedic care in obese patients with trauma more difficult, but appropriate initial resuscitation, careful preoperative planning, meticulous surgical technique, diligent postoperative medical management, and specialized rehabilitation give these patients their best opportunity for a good outcome.

Complications of obesity

Global obesity rates have increased exponentially in recent decades. People are becoming obese younger, morbid obesity is increasing and the full health implications are only beginning to be seen. This article discusses the latest epidemiological data on obesity in adults and children, and systemically reviews the complications associated with the condition.

Impact of weight reduction on selected immune system response among Hepatitis C virus Saudi patients

Background

Recently, about 2.35% of the world populations are estimated to be chronically infected with hepatitis C virus (HCV). Previous cohort studies indicated that obesity increases risk of hepatic steatosis and fibrosis in non-diabetic patients with chronic hepatitis C infection due to diminished response to anti-viral therapy and as a result obesity is considered as an important factor in the progression of chronic HCV. However, there is a strong association between BMI and the human immune system among HCV patients.

Objective

This study aimed to examine effects of weight reduction program on selected immune parameters among HCV Saudi patients.

Material and methods

One-hundred obese Saudi patients with chronic HCV infection participated in this study, their age ranged from 50–58 years and their body mass index (BMI) ranged from 30–35 kg/m². All Subjects were included in two groups: The first group received weight reduction program in the form of treadmill aerobic exercises in addition to diet control whereas, the second group received no therapeutic intervention. Parameters of CD3, CD4 and CD8 were quantified; Leukocyte, differential counts and BMI were measured before and after 3 months, at the end of the study.

Results

The mean values of BMI, white blood cells, total neutrophil count, monocytes, CD3, CD4 and CD8 were significantly decreased in the training group as a result of weight loss program; however the results of the control group were not significant. Also, there were significant differences between both groups at the end of the study.

Conclusion

Weight loss modulates immune system parameters of patients with HCV.

Prevention and care of respiratory failure in obese patients

With the increase in the global prevalence of obesity, there is a parallel rise in the proportion of obese patients admitted to intensive care units, referred for major surgery or requiring long-term non-invasive ventilation (NIV) at home for chronic respiratory failure. We describe the physiological effect of obesity on the respiratory system mainly in terms of respiratory mechanics, respiratory drive, and patency of the upper airways. Particular attention is given to the prevention and the clinical management of respiratory failure in obese patients with a main focus on invasive and NIV in intensive care during the perioperative period and long-term use of NIV on return home. We also address other aspects of care of obese patients, including antibiotic dosing and catheter-related infections.

Effects of obesity on the outcome of pneumonia

Obesity is an important risk factor for both community-acquired pneumonia (CAP) and healthcare-associated pneumonia. In striking contrast, emerging data suggest that obesity is associated with more favorable outcome of pneumonia, a protective effect coined 'the obesity paradox'. Areas covered: The aim of the present review is to summarize the existing evidence on the outcome of pneumonia in obese patients and to discuss the mechanisms underpinning the association between obesity and pneumonia outcome. Several observational studies showed that obesity is associated with better outcome of CAP. In contrast, obesity represents a risk factor for adverse outcome in patients infected with pandemic influenza. Very limited data exist on the association between obesity and the outcome of healthcare-associated pneumonia. The pathophysiological mechanisms contributing to these paradoxical findings are unclear. Expert commentary: It is possible that residual confounding might partly explain the better outcome of pneumonia in obese patients. On the other hand, obesity might indeed offer a survival advantage in patients with acute diseases, including pneumonia. Clearly, larger and well-designed studies are needed to clarify the pathogenetic links between obesity and pneumonia outcome, which might represent novel therapeutic targets in the management of infectious diseases.

Obesity as a Risk Factor for Urinary Tract Infection in Children

Childhood obesity is a nationwide epidemic with an estimated 16% to 18% of children and adolescents qualifying as obese and another 21% to 24% considered overweight. Obesity has been linked to an increased risk of developing serious infections. Healthcare Cost and Utilization Project-Kids' Inpatient Database 2009 was queried to analyze national trends in patient encounters, specifically those listing patients as comorbid obese and then identified those with urinary tract infection (UTI) as primary or secondary diagnosis. Propensity matching was used to calculate risk for UTI in the inpatient obese pediatric population. A total of 86 638 pediatric hospital admissions were enrolled in the study of which 41 819 included the diagnosis of obesity, and a UTI was diagnosed in 2445 of the cases. In a propensity-matched sample, matched for age, sex, race, and diabetes mellitus, the risk of UTI was increased by 45% in obese females. Obese males did not have a significantly increased risk for UTI.

Association of Injury Factors, Not Body Mass Index, With Hospital Resource Usage in Trauma Patients

BACKGROUND

Allocating resources appropriately requires knowing whether obese patients use more resources during a hospital stay than nonobese patients.

OBJECTIVES

To determine if trauma patients with different body mass indexes differed in use of resources measured as a multifaceted outcome variable.

METHODS

A trauma registry was used for a retrospective study of adult patients admitted to a midwestern level I trauma center. Patients were stratified into 3 groups: nonobese (normal weight, overweight), obese, and morbidly obese. Three canonical correlation analyses were used to determine the relationship between patient/injury characteristics and hospital resource usage.

RESULTS

In a sample of 9771 patients, 71.2% were non-obese, 23.8% obese, and 5.0% morbidly obese. For patient/injury characteristics, Injury Severity Score and physiological complications were significant variables for all 3 groups. Scores on the Glasgow Coma Scale were significant for nonobese patients only. For resource usage, intensive care unit length of stay and procedures were significant variables for all 3 groups.

CONCLUSIONS

Associations between body mass index and outcomes have been noted when assessed as independent variables. However, when resource usage was assessed as a multifaceted outcome variable, injury factors (higher Injury Severity Score, lower scores on the Glasgow Coma Scale, more physiological complications) were associated with resource usage (increased length of stay in the intensive care unit and increased number of procedures). These findings provide clinicians a new perspective for evaluating the complex relationship between patient/injury characteristics and hospital resource usage.

Infectious complications in obese patients after trauma

BACKGROUND

Obesity is a public health concern in the United States due to its increasing prevalence, especially in younger age groups. Trauma is the most common cause of death for people under aged 40 y. The purpose of this study is to determine the association between obesity and specific infectious complications after traumatic injury.

MATERIALS AND METHODS

A retrospective analysis was conducted using data from the 2012 National Trauma Data Bank. The National Trauma Data Bank defined obesity as having a body mass index of 30 or greater. Descriptive statistics were calculated and stratified by obesity status. A hierarchical regression model was used to determine the odds of experiencing an infectious complication in patients with obesity while controlling for age, gender, diabetes, number of comorbidities, injury severity, injury mechanism, head injury, and surgical procedure.

RESULTS

Patients with a body mass index of 30 or greater compared with nonobese patients had increased odds of having an infectious complication (Odds Ratio, 1.59; 1.49-1.69). In addition to obesity, injury severity score greater than 29, age 40 y or older, diabetes, comorbid conditions, and having a surgical procedure were also predictive of an infectious complication.

CONCLUSIONS

Our results indicate that trauma patients with obesity are nearly 60% more likely to develop an infectious complication in the hospital. Infection prevention and control measures should be implemented soon after hospital arrival for patients with obesity, particularly those with operative trauma.

Being Overweight Is Associated With Greater Survival in ICU Patients: Results From the Intensive Care Over Nations Audit

OBJECTIVE

To assess the effect of body mass index on ICU outcome and on the development of ICU-acquired infection.

DESIGN

A substudy of the Intensive Care Over Nations audit.

SETTING

Seven hundred thirty ICUs in 84 countries.

PATIENTS

All adult ICU patients admitted between May 8 and 18, 2012, except those admitted for less than 24 hours for routine postoperative monitoring (n = 10,069). In this subanalysis, only patients with complete data on height and weight (measured or estimated) on ICU admission in order to calculate the body mass index were included (n = 8,829).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Underweight was defined as body mass index less than 18.5 kg/m, normal weight as body mass index 18.5-24.9 kg/m, overweight as body mass index 25-29.9 kg/m, obese as body mass index 30-39.9 kg/m, and morbidly obese as body mass index greater than or equal to 40 kg/m. The mean body mass index was 26.4 ± 6.5 kg/m. The ICU length of stay was similar among categories, but overweight and obese patients had longer hospital lengths of stay than patients with normal body mass index (10 [interquartile range, 5-21] and 11 [5-21] vs 9 [4-19] d; p < 0.01 pairwise). ICU mortality was lower in morbidly obese than in normal body mass index patients (11.2% vs 16.6%; p = 0.015). In-hospital mortality was lower in morbidly obese and overweight patients and higher in underweight patients than in those with normal body mass index. In a multilevel Cox proportional hazard analysis, underweight was independently associated with a higher hazard of 60-day in-hospital death (hazard ratio, 1.32; 95% CI, 1.05-1.65; p = 0.018), whereas overweight was associated with a lower hazard (hazard ratio, 0.79; 95% CI, 0.71-0.89; p < 0.001). No body mass index category was associated with an increased hazard of ICU-acquired infection.

CONCLUSIONS

In this large cohort of critically ill patients, underweight was independently associated with a higher hazard of 60-day in-hospital death and overweight with a lower hazard. None of the body mass index categories as independently associated with an increased hazard of infection during the ICU stay.

Interaction of obesity and infections

There is evidence that certain infections may induce obesity. Obese persons may also have more severe infections and have compromised response to therapies. The objective of this study is to review the available literature identifying infections that potentially contribute to greater body mass index (BMI) and differential responses of overweight and obese persons to infections. A systematic literature review of human studies examining associations between infections and weight gain, differential susceptibility, severity, and response to prevention and treatment of infection according to BMI status (January 1980-July 2014) was conducted. Three hundred and forty-three studies were eligible for inclusion. Evidence indicated that viral infection by human adenovirus Ad36 and antibiotic eradication of Helicobacter pylori were followed by weight gain. People who were overweight or obese had higher susceptibility to developing post-surgical infections, H1N1 influenza and periodontal disease. More severe infections tended to be present in people with a larger BMI. People with a higher BMI had a reduced response to vaccinations and antimicrobial drugs. Higher doses of antibiotics were more effective in obese patients. Infections may influence BMI, and BMI status may influence response to certain infections, as well as to preventive and treatment measures. These observations have potential clinical implications.

The Relationship of Obesity to Increasing Health-Care Burden in the Setting of Orthopaedic Polytrauma

BACKGROUND

With the rise of obesity in the American population, there has been a proportionate increase of obesity in the trauma population. The purpose of this study was to use a computed tomography-based measurement of adiposity to determine if obesity is associated with an increased burden to the health-care system in patients with orthopaedic polytrauma.

METHODS

A prospective comprehensive trauma database at a level-I trauma center was utilized to identify 301 patients with polytrauma who had orthopaedic injuries and intensive care unit admission from 2006 to 2011. Routine thoracoabdominal computed tomographic scans allowed for measurement of the truncal adiposity volume. The truncal three-dimensional reconstruction body mass index was calculated from the computed tomography-based volumes based on a previously validated algorithm. A truncal three-dimensional reconstruction body mass index of <30 kg/m(2) denoted non-obese patients and ≥ 30 kg/m(2) denoted obese patients. The need for orthopaedic surgical procedure, in-hospital mortality, length of stay, hospital charges, and discharge disposition were compared between the two groups.

RESULTS

Of the 301 patients, 21.6% were classified as obese (truncal three-dimensional reconstruction body mass index of ≥ 30 kg/m(2)). Higher truncal three-dimensional reconstruction body mass index was associated with longer hospital length of stay (p = 0.02), more days spent in the intensive care unit (p = 0.03), more frequent discharge to a long-term care facility (p < 0.0002), higher rate of orthopaedic surgical intervention (p < 0.01), and increased total hospital charges (p < 0.001).

CONCLUSIONS

Computed tomographic scans, routinely obtained at the time of admission, can be utilized to calculate truncal adiposity and to investigate the impact of obesity on patients with polytrauma. Obese patients were found to have higher total hospital charges, longer hospital stays, discharge to a continuing-care facility, and a higher rate of orthopaedic surgical intervention.

Hospital-acquired pneumonia among pediatric trauma patients treated at national trauma centers

BACKGROUND

Injury is the leading cause of hospitalization in children, and as many as 5% of hospitalized injured children require mechanical ventilation. Despite this, little is known about the complications associated with mechanical ventilation, including pneumonia.

METHODS

This is a retrospective analysis of trauma patients younger than 19 years from the National Trauma Data Bank from 2009 to 2011. Descriptive statistics were used to examine the patient population. Baseline characteristics were compared between subgroups using t tests and χ tests. Generalized linear models were used to identify risk factors for hospital-acquired pneumonia adjusting for clustering of patients by hospital.

RESULTS

A total of 252,187 patients were eligible for analysis, and 1,915 patients were diagnosed with pneumonia. Most patients were male (66.3%), were white (54.2%), had no comorbidities (88.9%), and were not considered severely injured (85.5% with an Injury Severity Score [ISS] < 16). The mean (SD) length of stay was 2.9 (5.2) days. Patients who developed pneumonia were older (16-18 years, 61.7% vs. 31.1%, p < 0.0001), had an increased length of stay (20.9 days vs. 2.8 days, p < 0.0001), more intensive care days (13.9 days vs. 0.7 days, p < 0.0001), and more ventilation days (9.5 days vs. 0.3 days, p < 0.0001) compared with those who did not develop pneumonia. The rate of pneumonia nearly doubled in patients spending 2 days on a ventilator (odds ratio [OR], 5.52; 95% confidence interval [CI], 3.45-8.84), doubled again for patients spending 3 days (OR, 10.59; 95% CI, 6.38-17.61), and doubled again for patients spending 5 days (OR, 23.72; 95% CI, 13.36-42.15) mechanically ventilated. The presence of two comorbid conditions was associated with twice the odds of developing pneumonia (OR, 2.10; 95% CI, 1.47-1.78).

CONCLUSION

Prolonged mechanical ventilation, increased injury severity, older age, and presence of multiple comorbid conditions all increase the risk of pneumonia in injured children. Preventive measures should be aggressively used in injured children at high risk for the development of pneumonia.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

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.

Association between body mass index and urinary tract infection in adult patients

Background:

Overweight and obesity have become a global public health over the last decades. Obesity has been suggested to be a risk factor for some infections, but studies often showed controversial findings. Few studies examined the relationship between body mass index (BMI) and urinary tract infection (UTI), showing inconsistent results.

Objectives:

The purpose of this study was to determine the relationship between BMI and UTI in adult patients.

Patients and Methods:

Adult patients (≥ 18 years old) who were referred to clinics or admitted in hospital with diagnosis of UTI were considered for participation in the study. Control group were selected from healthy adult normal population whom underwent medical check-ups at the same hospital and without history of UTI. Data about age, gender, history of diabetes mellitus and BMI were registered for individuals who met inclusion criteria.

Results:

A total of 116 patients with UTI and 156 people as the control group were included in the study. Two groups were matched for age, gender and history of diabetes mellitus. Mean BMI ± SD of patients was 25.2 ± 4.0 kg/m² and the controls was 25.1 ± 3.6 kg/m². There was no significant correlation between BMI and UTI (P = 0.757). Mean BMI ± SD of patients with upper UTI was 25.6 ± 4.1 kg/m² and for lower UTI was 24.9 ± 4.0 kg/m². There was no significant difference between BMI of controls and patients with any type of UTI (P = 0.573).

Conclusions:

Our findings did not found an association between BMI and UTI and does not support obesity as a risk factor for UTI in adult patients.

Influence of body mass index on skin grafting in pediatric burns

BACKGROUND

There is heterogeneous literature on the association of obese and underweight body habitus on burn outcomes in adult and pediatric literature. We examine the effect of standardized pediatric body mass index (BMI) categories skin graft utilisation.

METHODS

A retrospective chart review was performed on children who underwent burn treatment from January 1995 to November 2011. BMI was categorized by standard definitions: underweight (<5%), normal (5-85%), overweight (85-95%), obese (>95%).

RESULTS

There were 1164 patients: 77 underweight, 604 normal, 215 overweight, and 268 obese patients. No differences existed between group demographics. Grafts were performed in 39% of underweight, 27% of normal, 22% of overweight, and 27% of obese patients. Underweight children had nearly a 2 fold increase in their risk of full thickness burns and were 1.8 times more likely to undergo skin grafting than normal BMI children. Overweight children had a significant decrease in the incidence skin grafting by 23% then compared to normal weight children. There were no differences in percent TBSA burned or percent TBSA grafted using ANOVA.

CONCLUSIONS

Underweight pediatric burn victims have an increased risk for skin grafting while mildly overweight children are slightly protected from skin grafting.

Obesity and outcomes following burns in the pediatric population

PURPOSE

While obesity is associated with increased mortality and decreased functional outcomes in adult burn patients, the ramifications of larger than average body size in the pediatric burn population are less well understood. The present study examines whether obesity was associated with poor outcomes following pediatric burn injuries.

METHODS

Thermal injury data for patients ≤ 18 years of age admitted to a Level III burn center over ten years (n=536) was analyzed. Obesity was defined as ≥ 95 th percentile of weight for height according to the WHO growth charts (<2 years of age) or BMI for age according to the CDC growth charts (2-18 years of age). Outcomes were compared between thermally injured obese (n=154) and non-obese (n=382) children. All data was collected in accordance with IRB regulations.

RESULTS

Obese and non-obese thermally-injured children did not differ in TBSA, percentage of full thickness burn, or overall mortality. However, these groups were significantly different with respect to age (obese=7.16 ± 0.46 years, non-obese=9.38 ± 0.32 years, p<0.001) and days requiring mechanical ventilation (obese=4.89 ± 1.3 days, non-obese=2.67 ± 0.49 days, p<0.05). For thermally injured children admitted to the BICU without inhalation injury (n=175); the obese (n=46) and non-obese (n=129) did not differ significantly with respect to age, TBSA, percentage of full thickness burn or other outcome measures. However, significant differences between these groups were noted for ICU LOS (obese=18.59 ± 5.18 days, non-obese=9.51 ± 1.82 days, p<0.05) and number of days requiring mechanical ventilation (obese=11.65 ± 3.91 days, non-obese=3.92 ± 0.85 days, p<0.05).

CONCLUSION

These data show thermally-injured obese pediatric patients required longer and more intensive medical support in the form of BICU care and respiratory intervention. Counter to findings in adult populations, differences in mortality were not observed. Collectively, these findings suggest obesity as a risk factor for increased morbidity in the pediatric burn population.

Obesity and surgical wound healing: a current review

Objective. The correlation between obesity and deficient wound healing has long been established. This review examines the current literature on the mechanisms involved in obesity-related perioperative morbidity. Methods. A literature search was performed using Medline, PubMed, Cochrane Library, and Internet searches. Keywords used include obesity, wound healing, adipose healing, and bariatric and surgical complications. Results. Substantial evidence exists demonstrating that obesity is associated with a number of postoperative complications. Specifically in relation to wound healing, explanations include inherent anatomic features of adipose tissue, vascular insufficiencies, cellular and composition modifications, oxidative stress, alterations in immune mediators, and nutritional deficiencies. Most recently, advances made in the field of gene array have allowed researchers to determine a few plausible alterations and deficiencies in obese individuals that contribute to their increased risk of morbidity and mortality, especially wound complications. Conclusion. While the literature discusses how obesity may negatively affect health on various of medical fronts, there is yet to be a comprehensive study detailing all the mechanisms involved in obesity-related morbidities in their entirety. Improved knowledge and understanding of obesity-induced physiological, cellular, molecular, and chemical changes will facilitate better assessments of surgical risks and outcomes and create efficient treatment protocols for improved patient care of the obese patient population.

Mild obesity is protective after severe burn injury

OBJECTIVE

To assess the impact of obesity on morbidity and mortality in severely burned patients.

BACKGROUND

Despite the increasing number of people with obesity, little is known about the impact of obesity on postburn outcomes.

METHODS

A total of 405 patients were prospectively enrolled as part of the multicenter trial Inflammation and the Host Response to Injury Glue Grant with the following inclusion criteria: 0 to 89 years of age, admitted within 96 hours after injury, and more than 20% total body surface area burn requiring at least 1 surgical intervention. Body mass index was used in adult patients to stratify according to World Health Organization definitions: less than 18.5 (underweight), 18.5 to 29.9 (normal weight), 30 to 34.9 (obese I), 35 to 39.9 (obese II), and body mass index more than 40 (obese III). Pediatric patients (2 to ≤18 years of age) were stratified by using the Centers for Disease Control and Prevention and World Health Organization body mass index-for-age growth charts to obtain a percentile ranking and then grouped as underweight (<5th percentile), normal weight (5th percentile to <95th percentile), and obese (≥95th percentile). The primary outcome was mortality and secondary outcomes were clinical markers of patient recovery, for example, multiorgan function, infections, sepsis, and length of stay.

RESULTS

A total of 273 patients had normal weight, 116 were obese, and 16 were underweight; underweight patients were excluded from the analyses because of insufficient patient numbers. There were no differences in primary and secondary outcomes when normal weight patients were compared with obese patients. Further stratification in pediatric and adult patients showed similar results. However, when adult patients were stratified in obesity categories, log-rank analysis showed improved survival in the obese I group and higher mortality in the obese III group compared with obese I group (P < 0.05).

CONCLUSIONS

Overall, obesity was not associated with increased morbidity and mortality. Subgroup analysis revealed that patients with mild obesity have the best survival, whereas morbidly obese patients have the highest mortality. (NCT00257244).

Complex Interaction between Obesity and Trauma

Trauma and obesity are large-scale epidemics that can be associated with significant morbidity and mortality. In few studies, it has noted that there is the ‘obesity paradox’ (obesity has been found to be protective against mortality) due to certain causes, i.e. heart failure or cardiovascular disease. Subcutaneous fat can show great variability between individuals and increased subcutaneous fat may be protective against injuries by cushioning the internal abdominal organs against injurious forces in road traffic accidents. Many factors including the body fat distribution, body shape, and center of gravity may play an important role in the different injury patterns and severity of injury between men and women. A better understanding of how obesity influences trauma related injuries not only will help to improve the outcome but also foster the development of interventions to address the most salient and modifiable risk factors to reduce obesity related morbidity and mortality. In present article, we review the relevant literature with special considerations to understand the interactions of obesity and trauma with their impact on patient management and outcomes.

How to cite this article

Agrawal A. Complex Interaction between Obesity and Trauma. Panam J Trauma Crit Care Emerg Surg 2014;3(3):109-113.