Initial fluid resuscitation following adjusted body weight dosing is associated with improved mortality in obese patients with suspected septic shock

Analysis of pathogenic factors on the death rate of sepsis patients

BACKGROUND

The Surviving Sepsis Campaign (SSC) believed that early identification of septic shock, aggressive fluid resuscitation and maintenance of effective perfusion pressure should be carried out. However, some of the current research focused on a single death factor for sepsis patients, based on a limited sample, and the research results of the relationship between comorbidities and sepsis related death also have some controversies.

METHOD

Therefore, our study used data from a large sample of 9,544 sepsis patients aged 18-85 obtained from the MIMIC-IV database, to explore the risk factors of death in patients with sepsis. We used the general clinical information, organ dysfunction scores, and comorbidities to analyze the independent risk factors for death of these patients.

RESULTS

The death group had significantly higher organ dysfunction scores, lower BMI, lower body temperature, faster heart rate and lower urine-output. Among the comorbidities, patients suffering from congestive heart failure and liver disease had a higher mortality rate.

CONCLUSION

This study helps to identify sepsis early, based on a comprehensive evaluation of a patient's basic information, organ dysfunction scores and comorbidities, and this methodology could be used for actual clinical diagnosis in hospitals.

The Effect of Fluid Resuscitation Timing in Early Sepsis Resuscitation

PURPOSE

The dose and timing of early fluid resuscitation in sepsis remains a debated topic. The objective of this study is to evaluate the effect of fluid timing in early sepsis management on mortality and other clinical outcomes.

METHODS

Single-center, retrospective cohort study of emergency-department-treated adults (>18 years, n = 1032) presenting with severe sepsis or septic shock. Logistic regression evaluating the impact of 30 mL/kg crystalloids timing and mortality-versus-time plot controlling for mortality in emergency department sepsis score, lactate, antibiotic timing, obesity, sex, systemic inflammatory response syndrome criteria, hypotension, and heart and renal failures. This study is a subanalysis of a previously published investigation.

RESULTS

Mortality was 17.1% (n = 176) overall and 20.4% (n = 133 of 653) among those in septic shock. 30 mL/kg was given to 16.9%, 32.2%, 16.2%, 14.5%, and 20.3% of patients within ≤1, 1 ≤ 3, 3 ≤ 6, 6 ≤ 24, and not reached within 24 h, respectively. A 24-h plot of adjusted mortality versus time did not reach significance, but within the first 12 h, the linear function showed a per-hour mortality increase (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.02-1.67) which peaks around 5h, although the quadratic function does not reach significance (P = .09). When compared to patients receiving 30 mL/kg within 1 h, increased mortality was observed when not reached within 24 h (OR 2.69, 95% CI 1.37-5.37) but no difference when receiving this volume between 1 and 3 (OR 1.11, 95% CI 0.62-2.01), 3 and 6 (OR 1.83, 95% CI 0.97-3.52), or 6 and 24 h (OR 1.51, 95% CI 0.75-3.06). Receiving 30 mL/kg between 1 and 3 versus <1 h increased the incidence of delayed hypotension (OR 1.83, 95% CI 1.23-2.72) but did not impact need for intubation, intensive care unit admission, or vasopressors.

CONCLUSIONS

We observed weak evidence that supports that earlier is better for survival when reaching fluid goals of 30 mL/kg, but benefits may wane at later time points. These findings should be viewed as hypothesis generating.

Effect of Fluid Resuscitation Strategies for Obese Patients with Sepsis and Septic Shock: A Systematic Review

Purpose

As the Surviving Sepsis Campaign (2021) recommended, patients with sepsis should be given a liquid infusion of 30 ml/kg (ideal body weight). However, the strategy may result in insufficient resuscitation for obese patients with sepsis. Therefore, we conducted a systematic evaluation of the effectiveness of the initial resuscitation strategy in obese sepsis patients.

Materials and methods

A computer search of PubMed, Embase, Cochrane library, and other databases collected cohort studies from the beginning of the survey to December 2021 to include articles evaluating initial resuscitation strategies for sepsis-obese patients.

Results

Of the six studies included, five used ideal body weight infusion strategies, and three used actual body weight infusion strategies. Differences in fluid volume were observed between the two strategies, but no significant difference was observed in the mortality of obese sepsis patients. In addition, there may be an infusion strategy other than the above two infusion methods, and the safety and efficacy of the new infusion strategy are unclear. The obesity paradox has been observed in most infusion strategies.

Conclusion

The association between obesity and infusion strategy has rarely been investigated in patients with sepsis and septic shock, and the existing results are conflicting. The risk of bias in all included studies was moderate or high. Before providing broad recommendations on the optimal first resuscitation approach to lower the chance of mortality, further clinical trials, and prospective research need to be done.

Challenges With Using a Weight-Based Approach to Bolus Fluid Dosing in Obese Critically Ill Patients

At least 30 mL/kg of crystalloid fluid administration within the first 3 hours of resuscitation is suggested by the current Surviving Sepsis Campaign guidelines for management of sepsis and septic shock. This commentary discusses the challenges with using a weight-based approach to bolus fluid dosing during the early phase of resuscitation of adult, obese patients. Based on the available literature, arguments can be made for the use of either ideal or adjusted body weight for weight-based fluid dosing, but there are concerns with fluid overload if using actual body weight to dose patients with more severe forms of obesity.

Initial fluid resuscitation (30 mL/kg) in patients with septic shock: More or less?

OBJECTIVES

The 2018 Surviving Sepsis Campaign (SSC) recommends rapid administration of 30 mL/kg crystalloid fluids for hypotension or lactate ≥4 mmol/L in patients with septic shock; however, there is limited evidence to support this recommendation. The purpose of this study was to examine the relationship between initial fluid resuscitation doses and prognosis in patients with septic shock.

METHODS

This was a multicenter prospective observational study of adult patients with septic shock who were admitted to four intensive care units (ICUs) in a total of three Jiangsu Province teaching hospitals over a 3-year span from May 8, 2018, to June 15, 2021. Each enrolled patients with septic shock was categorized into the low-volume (below 20 mL/kg fluid), medium-volume (20-30 mL/kg fluid) or high-volume (above 30 mL/kg fluid) fluid group according to the initial infusion dose given for fluid resuscitation. Various demographic attributes and other variables were collected from medical records. Logistic regression and Kaplan-Meier curve analysis were used to determine the relationship between initial fluid resuscitation doses and patient outcomes.

MEASUREMENTS AND MAIN RESULTS

A total of 302 patients who presented to the ICU were diagnosed with septic shock. The 28-day mortality was highest in the high-volume group (48.3%) and lowest in the medium-volume group (26.3%, P < 0.05). Patients who completed 30 mL/kg initial fluid resuscitation in the first 1-2 h had the lowest 28-day mortality rate (22.8%, P < 0.05). Logistic regression showed that a medium initial fluid volume dose was an independent protective factor, with the odds ratio (OR) indicating significantly decreased mortality (OR, 0.507; 95% confidence interval, 0.310-0.828; P = 0.007; P < 0.05). A Kaplan-Meier curve stratified by initial fluid resuscitation dose was constructed for the probability of 28-day mortality. The medium-volume fluid group showed a significantly lower 28-day mortality rate than the high-volume group or the low-volume group (log-rank test, P = 0.0016).

CONCLUSION

In septic shock patients, an initial fluid resuscitation rate of 20-30 mL/kg within the first hour may be associated with reduced 28-day mortality; however, this result needs to be confirmed by further high-quality randomized controlled clinical trials.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR-OOC-17013223. Registered 2 November 2017, http://www.chictr.org.cn/showproj.aspx?proj=22674.

Comparison of fluid resuscitation weight-based dosing strategies in obese patients with severe sepsis

OBJECTIVE

This study aims to compare the composite outcome of progression to septic shock between 30 mL/kg/ideal body weight (IBW) versus 30 mL/kg/non-IBW fluid resuscitation dosing strategies in obese patients with severe sepsis.

METHODS

We retrospectively evaluated obese patients admitted to an academic tertiary care center for the management of severe sepsis. Patients were included if they had a fluid bolus order placed using the sepsis order set between Oct 2018 and Sept 2019. The primary objective was the composite of progression to septic shock, defined as either persistent hypotension within 3 h after the conclusion of the 30 mL/kg fluid bolus administration or the initiation of vasopressor(s) within 6 h of the bolus administration.

RESULTS

Of 72 included patients, 49 (68%) were resuscitated using an IBW-based and 23 (32%) using a non-IBW-based dosing strategy. There were similar rates of progression to septic shock in the IBW and non-IBW groups (18% vs. 26%; p = 0.54). Median ICU and hospital LOS in the IBW group versus non-IBW group were (0 [IQR 0] vs. 0 [IQR 0 to 4] days; p = 0.13) and (6 [IQR 3 to 10] vs. 8 [IQR 5 to 12] days; p = 0.07), respectively. In-hospital mortality rates were similar between the groups.

CONCLUSIONS

Our study results suggest that in obese septic patients, fluid administration using an IBW-dosing strategy did not affect the progression to septic shock.

Sepsis Fluid Metric Compliance and its Impact on Outcomes of Patients with Congestive Heart Failure, End-Stage Renal Disease or Obesity

BACKGROUND

Emergency physicians express concern administering a 30-cc/kg fluid bolus to septic shock patients with pre-existing congestive heart failure (CHF), end-stage renal disease (ESRD), or obesity, due to the perceived risk of precipitating a fluid overload state.

OBJECTIVE

Our aim was to determine whether there is a difference in fluid administration to septic shock patients with these pre-existing conditions in the emergency department (ED). Secondary objectives focused on whether compliance impacts mortality, need for intubation, and length of stay.

METHODS

We conducted a retrospective chart review of 470,558 ED patient encounters at a single urban academic center during a 5-year period.

RESULTS

Of 847 patients with septic shock, 308 (36.36%) had no pre-existing condition and 199 (23.49%), 17 (2.01%), and 154 (18.18%) had the single pre-existing condition of CHF, ESRD, and obesity, respectively, and 169 (19.95%) had multiple pre-existing conditions. Weight-based fluid compliance was achieved in 460 patients (54.31%). There was a lower likelihood of compliance among patients with CHF (adjusted odds ratio [aOR] 0.35; 95% confidence interval [CI] 0.24-0.52; p < 0.001), ESRD (aOR 0.11, 95% CI 0.04-0.32; p < 0.001), and obesity (aOR 0.29, 95% CI 0.19-0.44; p < 0.001) compared with patients with no pre-existing conditions. Compliance decreased further in patients with multiple pre-existing conditions (aOR 0.49, 95% CI 0.33-0.72; p < 0.001). Compliance was not associated with mortality in patients with CHF and ESRD, but was protective in patients with obesity and those with no pre-existing conditions.

CONCLUSIONS

Septic shock patients with pre-existing CHF, ESRD, or obesity are less likely to achieve compliance with a 30-cc/kg weight-based fluid goal compared with those without these pre-existing conditions.

Medication Regimen Complexity Score as an Indicator of Fluid Balance in Critically Ill Patients

BACKGROUND

Critically ill patients are at increased risk for fluid overload, but objective prediction tools to guide clinical decision-making are lacking. The MRC-ICU scoring tool is an objective tool for measuring medication regimen complexity.

OBJECTIVE

To evaluate the relationship between MRC-ICU score and fluid overload in critically ill patients.

METHODS

In this multi-center, retrospective, observational study, the relationship between MRC-ICU and the risk of fluid overload was examined. Patient demographics, fluid balance at day 3 of ICU admission, MRC-ICU score at 24 hours, and clinical outcomes were collected from the medical record. The primary outcome was relationship between MRC-ICU and fluid overload. To analyze this, MRC-ICU scores were divided into tertiles (low, moderate, high), and binary logistic regression was performed. Linear regression was performed to determine variables associated with positive fluid balance.

RESULTS

A total of 125 patients were included. The median MRC-ICU score at 24 hours of ICU admission for low, moderate, and high tertiles were 9, 15, and 21, respectively. For each point increase in MRC-ICU, a 13% increase in the likelihood of fluid overload was observed (OR 1.128, 95% CI 1.028-1.238, p = 0.011). The MRC-ICU score was positively associated with fluid balance at day 3 (β-coefficient 218.455, 95% CI 94.693-342.217, p = 0.001) when controlling for age, gender, and SOFA score.

CONCLUSIONS

Medication regimen complexity demonstrated a weakly positive correlation with fluid overload in critically ill patients. Future studies are necessary to establish the MRC-ICU as a predictor to identify patients at risk of fluid overload.

The Obese Patient: Facts, Fables, and Best Practices

The prevalence of obesity continues to rise worldwide, and anesthesiologists must be aware of current best practices in the perioperative management of the patient with obesity. Obesity alters anatomy and physiology, which complicates the evaluation and management of obese patients in the perioperative setting. Gastric point-of-care ultrasound (PoCUS) is a noninvasive tool that can be used to assess aspiration risk in the obese patient by evaluating the quantity and quality of gastric contents. An important perioperative goal is adequate end-organ perfusion. Standard noninvasive blood pressure (NIBP) is our best available routine surrogate measurement, but is vulnerable to greater inaccuracy in patients with obesity compared to the nonobese population. Current NIBP methodologies are discussed. Obese patients are at risk for wound and surgical site infections, but few studies conclusively guide the exact dosing of intraoperative prophylactic antibiotics for them. We review evidence for low-molecular-weight heparins and weight-based versus nonweight-based administration of vasoactive medications. Finally, intubation and extubation of the patient with obesity can be complicated, and evidence-based strategies are discussed to mitigate danger during intubation and extubation.

The Effect of Body Mass Index and Weight-Adjusted Fluid Dosing on Mortality in Sepsis

PURPOSE

The Surviving Sepsis Campaign guidelines recommend 30 mL/kg of fluids within 3 hours (30by3) of sepsis-induced hypoperfusion, but a national mandate released an allowance for dosing based on ideal instead of actual body weight (IBW/ABW) for obese patients. This study aims to determine the dose-effect of 30by3 for patients with severe sepsis or septic shock (SS/SS) with respect to body mass index (BMI) categories and secondarily, examine the clinical impact of IBW vs. ABW-based dosing.

METHODS

Retrospective cohort study of adults (≥18 years; n = 1,032) with SS/SS presenting to an urban, tertiary-care emergency department. Models include MEDS score, antibiotic timing, lactate, renal and heart failure, among others.

RESULTS

The cohort was 10.2% underweight and 28.7% obese. Overall mortality was 17.1% with 20.4% shock mortality. An exponential increase in mortality was observed for each 5 mL/kg under 30by3 for underweight (p = 0.02), but not obese patients. ABW vs IBW-30by3 dosing was reached in 80.0 vs 52.4% (underweight), 56.4 vs 56.9% (normal/overweight), and 23.3 vs 46.0% (obese). Across all BMI categories, there was increased mortality for not reaching ABW-based 30by3 dosing (OR 1.78, 95% CI 1.18-2.69) with no significant impact for IBW (OR 1.28, 95% CI 0.87 -1.91). The increased mortality for failing to reach ABW-dosed 30by3 remained for underweight patients ABW (OR 5.82, 95% CI 1.32-25.57) but not obese patients. Longer ICU stays were observed for not reaching 30by3 based on ABW (β = 2.40, 95% CI 0.84-3.95) and IBW dosing (β = 1.58, 95% CI 0.07-3.08) overall. This effect remained for obese and underweight (except IBW dosing) patients.

CONCLUSIONS

An exponential, dose-effect increase in mortality was observed for underweight patients not receiving 30by3. Therefore, the mortality impact of under-dosing may be amplified using ABW for underweight patients. Fluid dosing did not impact mortality for obese patients, but we caution against deviation from guidelines without further studies.

Microcirculation-guided protection strategy in hemodynamic therapy

Microcirculatory shock is a condition defined by the presence of tissue hypoperfusion despite the normalization of systemic and regional blood flow. Currently, more evidence shows that intrinsic septic shock is microcirculatory shock, which results in septic shock that is difficult to resuscitate. At present, treatments are aimed at recovering macro-circulation functions and include fluid resuscitation, vasoactive drugs, positive inotropic drugs, de-obstruction, and even mechanical assistance to improve oxygen delivery. However, the application of these treatments to more accurately improve microcirculation or avoid further microcirculatory damage is more important in clinics. In this article, we discuss the need for microcirculation protection and microcirculation-guided protection strategies in hemodynamic therapies.

Assessment of fluid resuscitation on time to hemodynamic stability in obese patients with septic shock

PURPOSE

Assess time to hemodynamic stability (HDS) in obese patients with septic shock who received <30 vs. ≥30 ml/kg of initial fluid resuscitation based on actual body weight (ABW).

MATERIALS AND METHODS

Multicenter, retrospective, cohort analysis of 322 patients.

RESULTS

Overall 216 (67%) patients received <30 ml/kg of initial fluid resuscitation. Initial fluid received was lower in the <30 ml/kg vs. ≥30 ml/kg group (16 vs. 37 ml/kg). The ≥30 ml/kg group had shorter time to HDS (multivariable p = 0.038) and lower riskof in-hospital death (multivariable p = 0.038). An exploratory subgroup analysis (n = 227) was performed, classifying patients by dosing strategy [ABW, adjusted body weight (AdjBW), ideal body weight (IBW)] based on fluid received at 3 h divided by 30 ml/kg. ABW dosed patients had a shorter time to HDS (multivariable p = 0.013) and lower risk of in-hospital death (multivariable p = 0.008) vs. IBW. Similar outcomes were observed between ABW vs. AdjBW.

CONCLUSIONS

Obese patients given ≥30 ml/kg based on ABW had a shorter time to HDS and a lower risk of in-hospital death. Exploratory results suggest improved outcomes resuscitating by ABW vs. IBW; ABW showed no strong benefit over AdjBW. Further prospective studies are needed to confirm the optimal fluid dosing in obese patients.

The Crashing Obese Patient

The obesity pandemic now affects hundreds of millions of people worldwide. As obesity rates continue to increase, emergency physicians are called on with increasing frequency to resuscitate obese patients. This article discusses important anatomic, physiologic, and practical challenges imposed by obesity on resuscitative care. Impacts on hemodynamic monitoring, airway and ventilator management, and pharmacologic therapy are discussed. Finally, several important clinical scenarios (trauma, cardiac arrest, and sepsis), in which alterations to standard treatments may benefit obese patients, are highlighted.

Initial Fluid Resuscitation Following Adjusted Body Weight Dosing in Sepsis and Septic Shock

INTRODUCTION

Fluid administration is considered a fundamental part of early sepsis treatment. Despite abundant research, fundamental questions about the amount of fluids to be given remain unanswered. Recently, the idea of adjusting the fluid load to the ideal body weight emerged, as obesity rates are increasing, and fluid overload was proven to increase mortality.

AIM OF THE STUDY

The study aimed to determine whether advanced haemodynamic monitoring supports the adjustment of the initial fluid load to the ideal body weight (IBW).

METHODS

Seventy-one patients with sepsis and septic shock were enrolled in the study. The initial fluid resuscitation was performed using local protocols. The haemodynamic status was assessed after the initial fluid load by transpulmonary thermos-dilution technique and the renal outcome recorded at twenty-four hours.

RESULTS

68.6% of the patients included in the study had weight disorders ranging from BMI+20% to morbid obesity. Before IBW adjustment, only 49.3% received the 30 ml/kg fluid load recommended by Surviving Sepsis Campaign Guidelines (2016) (SSC). After IBW adjustment, 70.4% received the recommended fluid dose. The difference in fluid load/kg before and after the bodyweight adjustment was statistically significant (p<0.01). After the initial fluid load, the majority of the macro haemodynamic parameters were in the targeted range. There was no statistically significant difference between the urinary output outcome at 24 hours or the 28 days mortality rates between the patients resuscitated by the SSC and those who received less fluid.

CONCLUSIONS

Advanced haemodynamic monitoring was in favour of adjusting the initial fluid load to the IBW. There were no statistically significant differences either in the urinary output outcome at twenty-four hours, or in the twenty-eight-day mortality rates between the patients who received the 30 ml/kg IBW and those who received less than 30 ml/kg IBW.

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.

Impact of body mass index on survival of medical patients with sepsis: a prospective cohort study in a university hospital in China

OBJECTIVE

To evaluate the impact of body mass index (BMI) on survival of a Chinese cohort of medical patients with sepsis.

DESIGN

A single-centre prospective cohort study conducted from May 2015 to April 2017.

SETTING

A tertiary care university hospital in China.

PARTICIPANTS

A total of 178 patients with sepsis admitted to the medical intensive care unit (ICU) were included.

MAIN OUTCOME MEASURES

The primary outcome was 90-day mortality while the secondary outcomes were in-hospital mortality, length of ICU stay and length of hospital stay.

RESULTS

The median age (IQR) was 78 (66-84) years old, and 77.0% patients were older than 65 years. The 90-day mortality was 47.2%. The in-hospital mortality was 41.6%, and the length of ICU stay and hospital stay were 12 (5-22) and 15 (9-28) days, respectively. Cox proportional hazard regression analysis identified that Sequential Organ Failure Assessment score (HR=1.229, p<0.001), Acute Physiology and Chronic Health Evaluation II score (HR=1.050, p<0.001) and BMI (HR=0.940, p=0.029) were all independently associated with the 90-day mortality. Patients were divided into four groups based on BMI (underweight 33 (18.5%), normal 98 (55.1%), overweight 36 (20.2%) and obese 11 (6.2%)). The 90-day mortality (66.7%, 48.0%, 36.1% and 18.2%, p=0.015) and in-hospital mortality (60.6%, 41.8%, 30.6% and 18.2%, p=0.027) were statistically different among the four groups. Differences in survival among the four groups were demonstrated by Kaplan-Meier survival analysis (p=0.008), with the underweight patients showing a lower survival rate.

CONCLUSIONS

BMI was an independent factor associated with 90-day survival in a Chinese cohort of medical patients with sepsis, with patients having a lower BMI at a higher risk of death.