Incidence and risk factors for sepsis in surgical patients: A cohort study

doi:10.1016/j.jcrc.2011.08.001

Journal of Critical Care

Volume 27, Issue 2, April 2012, Pages 159-166

https://doi.org/10.1016/j.jcrc.2011.08.001 Get rights and content

Abstract

Purpose

The aim of the study was to evaluate risk factors for infection and sepsis in surgical patients admitted to the intensive care unit (ICU).

Materials and Methods

Data were prospectively collected from a cohort of surgical patients from January 2005 to December 2007. We analyzed the incidence of infection and sepsis and certain other variables from the pre-, intra-, and postoperative periods as risk factors for infection and sepsis.

Results

We studied 625 surgical patients. The mortality rate was 18.2%, and the mean age of the subjects was 53.1 ± 18.8 years. The incidences of severe sepsis and septic shock were 5% and 11.5%, respectively. A multivariate analysis showed that the following variables were associated with sepsis in the postoperative period: urgent surgery (odds ratio, 2.63; 95% confidence interval [CI], 1.50-4.63), fluid resuscitation (odds ratio, 1.90; 95% CI, 1.18-3.05), vasoactive drugs (odds ratio, 2.58; 95% CI, 1.61-4.14), and mechanical ventilation (odds ratio, 5.51; 95% CI, 3.07-9.89). A Sequential Organ Failure Assessment was associated with infection or sepsis upon ICU admission (area under the curve, 0.737 ± 0.019; 95% CI, 0.748-0.825).

Conclusions

This study showed that sepsis has high incidence and mortality in surgical patients admitted to the ICU. Urgent surgeries, mechanical ventilation, fluid resuscitation, and vasoactive drugs in the postoperative period and Sequential Organ Failure Assessment at ICU admission were risk factors for sepsis.

Introduction

Surgical patients are vulnerable to infectious complications during hospitalization because of several factors, including old age, preexisting chronic conditions, poor nutritional status, prolonged periods of hospitalization, extensive surgical trauma, emergency surgeries, and severe disturbances in immune defenses [1], [2], [3], [4], [5], [6], [7], [8], [9], [10]. Several attempts have been made to identify patients who are at higher risk for developing complications to better plan pre- and intraoperatory management and to decrease mortality [10], [11], [12], [13], [14], [15], [16], [17].

A large observational study reported postoperative complications in only 12.5% of surgical procedures, but these patients accounted for more than 80% of the related deaths [18]. Cardiovascular complications are the traditional focus when studying surgical patients, but few studies exist on the frequency of sepsis in critically ill patients in the postoperative period [8], [9], [15].

In a case-control study of 198 patients, patient-related factors were described that represented higher risks for developing postoperative sepsis, and these included coma before sepsis, low serum albumin levels, need for parenteral nutrition, and preexisting comorbidities [3]. More recently, a multicenter study described a 4% incidence of sepsis in patients that occurred more frequently 8 to 30 days into the postoperative period [19]. A recent epidemiological study described sepsis as the main cause of morbidity in patients having noncardiac surgeries, which occurred in 24.7% of the cases [8].

Sepsis seems to be a common complication in the postoperative period, and prompt recognition and early intervention are effective ways of reducing mortality in this condition. The objective of this study was to evaluate the incidence and risk factors for infection and sepsis in surgical patients admitted to the intensive care unit (ICU).

Section snippets

Methods

This prospective cohort study was performed from January 2005 to December 2007 in a university hospital in Londrina, Brazil. This public hospital has 330 beds, 7 operating rooms in its surgical center, and 17 ICU beds, and it receives medical and surgical patients. This study was approved by the local ethics committee, and according to the principles of the Declaration of Helsinki, the need for written consent was waived.

All patients who were admitted to the ICU within 24 hours after a surgical

Results

During the study period, 1385 surgical patients were admitted into the ICU, and 760 were excluded because of previous infections or use of antibiotics (Fig. 1). This resulted in a sample size of 625 patients with a median age of 54.7 years (interquartile range, 39.8-66.6 years), 56.3% male, and mean APACHE II score and SOFA D1 of 13.3 ± 7.9 and 5.7 ± 3.8, respectively. Surgeries were classified as elective in 70.2% of the patients, and neurosurgery was the most common surgical procedure

Discussion

The present study detected a high incidence of infectious complications in surgical patients, which resulted in high mortality rates. Patients who are at a higher risk for infectious and sepsis complications are those who are undergoing urgent surgical procedures, need mechanical ventilation during their ICU stay, and/or have higher SOFA scores at ICU admission [31]. Risk factors associated with sepsis during the perioperative period were easily detectable, and knowledge of these factors may be

Conclusions

We found a high incidence of sepsis complications and mortality in surgical patients. Mechanical ventilation was the strongest independent variable associated with sepsis. Others risk factors for sepsis occurrence in surgical patients were urgent surgeries and fluid resuscitation and vasoactive drugs in the postoperative period. The SOFA scores on ICU admission were the best score predictor for sepsis.

Key points

•
Sepsis is a common complication in surgical patients.
•
Sepsis in the postoperative period is associated with an increase in mortality.
•
Patients who are at a higher risk for infectious and sepsis complications are those who are undergoing emergency or urgent surgical procedures, need mechanical ventilation during their ICU stay, and/or have higher SOFA scores at ICU admission.

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As such, it is an appealing candidate to proceed with clinical testing. For instance, patients who will undergo major surgical procedures and face a high risk for infection and sepsis [47,48] may greatly benefit from pre-surgical KE administration. However, it remains to be determined how effective KE administration can be in rescuing injury once an infection has already initiated the septic response.
Sepsis is a life-threatening condition of organ dysfunction caused by dysregulated inflammation which predisposes patients to developing cardiovascular disease. The ketone β-hydroxybutyrate is reported to be cardioprotective in cardiovascular disease and this may be due to their signaling properties that contribute to reducing inflammation. While exogenous ketone esters (KE) increase blood ketone levels, it remains unknown whether KEs can reduce the enhanced inflammatory response and multi-organ dysfunction that is observed in sepsis. Thus, this study assesses whether a recently developed and clinically safe KE can effectively improve the inflammatory response and organ dysfunction in sepsis.
To assess the anti-inflammatory effects of a KE, we utilized a model of lipopolysaccharide (LPS)-induced sepsis in which an enhanced inflammatory response results in multi-organ dysfunction. Oral administration of KE for three days prior to LPS-injection significantly protected mice against the profound systemic inflammation compared to their vehicle-treated counterparts. In assessing organ dysfunction, KE protected mice from sepsis-induced cardiac dysfunction as well as renal dysfunction and fibrosis. Furthermore, KE administration attenuated the sepsis-induced inflammation in the heart, kidney, and liver. Moreover, these protective effects occurred independent of changes to enzymes involved in ketone metabolism.
These data show that the use of an exogenous KE attenuates the dysregulated systemic and organ inflammation as well as organ dysfunction in a model of severe inflammation. We postulate that this exogenous KE is an appealing and promising approach to capitalize on the protective anti-inflammatory effects of ketones in sepsis and/or other inflammatory responses.
A systematic review on risk factors associated with sepsis in patients admitted to intensive care units
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A large number of risk factors identified in our review were related to the surgery. Surgical patients are vulnerable to infectious complications during hospitalisation because of several factors such as old age, pre-existing medical conditions, and prolonged periods of hospitalisation.33 In one cohort study with a large sample33 and one case–control study,34 emergency surgery was identified as a significant and powerful predictor for sepsis in surgical patients admitted to the ICU.
We sought to systematically review data on the risk factors influencing the incidence of sepsis in patients admitted to intensive care units (ICUs).
An electronic search was undertaken in PubMed, MEDLINE, Scopus, and the Cochrane Library for studies reporting the risk factors of sepsis from the earliest available date up to December 30, 2016.
Among the 2978 articles, 14 studies met the inclusion criteria with a total of 56 164 participants from nine countries. The extracted risk factors were from the following categories: demographic, critical care interventions, surgery-related factors, pre-existing comorbidities, severity of organ injury, and biomarkers and biochemical and molecular indicators. From demographic factors, older age and male gender were associated with an increased risk of sepsis among ICU-admitted patients.
Our analysis comprehensively summarised the risk factors of sepsis in patients admitted to medical, surgical, neurologic, trauma, and general ICUs. Age, sex, and comorbidities were non-modifiable risk factors; however, critical care interventions and surgery-related factors were modifiable factors and suggest that improving the care of surgical patients and effective management of critical care interventions may play a key role in decreasing the development of sepsis in patients admitted to the ICUs.
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The Surviving Sepsis Campaign promotes the use of norepinephrine as the first-line inotropic support for patients presenting with severe sepsis or septic shock in cases of persistent hypotension, despite adequate fluid resuscitation. However, there is little published evidence on how much noradrenaline is administered to such patients when admitted to the intensive care unit (ICU). The authors report the clinical management of this group of patients, with a special focus on the total amount and duration of norepinephrine infusion required.
A chart review of the admission records of an ICU in Hong Kong was carried out in 2013. A total of 5000 patients were screened by their diagnosis of severe sepsis or septic shock (in the admissions book) between 1 January 2011 and 31 December 2013. A total of 150 of these were identified and 100 included in the study after simultaneous in-depth reviews of their case notes by two of the investigators. The analysis covers those with severe sepsis or septic shock who required ICU admission for further care. Clinical management and outcomes were analysed.
100 patients (median age 61.6; M/F ratio 2:1) met the inclusion criteria. The mean ICU stay was 13.4 days (range = 1–371). 14 patients (14%) died in the ICU, with a 28-day mortality rate of 22%. The mean period of mechanical ventilation was 6.1 days (range = 0–137). 91.5% (n = 43) of patients had been operated on immediately before admission to the ICU, and the majority of these operations had been of the emergency type (97.7%, n = 43). The mean total volumes of crystalloid and colloid administered were 3420 ml and 478 ml, respectively. The mean wean-off period for norepinephrine infusion was 4234 minutes (70.5 hours). All patients were prescribed norepinephrine for persistent hypotension despite adequate fluid resuscitation, and the mean total amount administered was 87,211 mg. Final multiple linear and logistic regression analysis showed different clinical outcomes associated with different covariates, which included: (1) total amount of crystalloid given, positively associated with the total amount and duration of norepinephrine infusion; (2) duration of mechanical ventilation, positively associated with the type of operation the patient had undergone; (3) 28-day mortality rate, positively associated with the INR.
What this study adds to knowledge about patients suffering from severe sepsis or septic shock: (1) the mean duration of norepinephrine infusion for septic shock patients in an ICU is almost three days; (2) the more crystalloid is required to correct hypoperfusion, the higher the dosage and longer the duration of norepinephrine infusion will be necessary; (3) the longer the patient's INR, the higher the chances of death within 28 days. Since not all patients have their body weight measured on or after admission to the ICU, we suggest further research into indirect estimation of body weight by other means, such as anthropometric measures, to guide the use of drugs and nutritional support in the ICU. In addition, APACHE scores should be included in further studies to compare the severity of the patient's condition in other research. Furthermore, since this study does not cover university hospital ICUs, we suggest that further research concerning such patients should compare and reflect similarities and differences between public and university hospitals in the territory.
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Describir el case-mix de los pacientes médicos y quirúrgicos ingresados en UCI y comparar ambas poblaciones.
Análisis de datos de pacientes ingresados en UCI entre 2006 y 2011, extraídos del registro ENVIN-HELICS. Estudio observacional, prospectivo, multicéntrico y de participación voluntaria.
Ciento ochenta y ocho Unidades de Cuidados Intensivos españolas.
Pacientes ingresados durante más de 24 h.
Datos demográficos, causa de ingreso, escalas de gravedad, tiempo de estancia y mortalidad.
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Los pacientes médicos no coronarios presentan mayor mortalidad, pero son los quirúrgicos urgentes los que precisan mayor uso de recursos por paciente. La escala APACHE II infraestima la mortalidad en pacientes quirúrgicos urgentes.
To describe the characteristics of the patients case-mix admitted to ICUs due to medical and surgical disease, and to compare both groups.
Analysis of data covering the period 2006-2011 in the ENVIN-HELICS registry. An observational, prospective, multicenter and voluntary participation study.
A total of 188 Spanish ICUs.
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Patients who required reintubation were significantly older (65.8 years) and were more likely to be male (55%) and to have several comorbidities, weight loss (16%), dependency (14%), or sepsis (9%). The operations complicated most commonly by unplanned intubation were gastrectomy (13%), nephrectomy (10%), colectomy (9%), pancreatectomy (8%), hepatectomy (7%), and enterectomy (6%). The most common causes and median postoperative days were sepsis (33%, day 8) and aspiration/pneumonia (31%, day 4). Sepsis was due most commonly to an abdominal or pelvic abscess (74%), which was frequently not recognized despite an inflammatory response. Aspiration occurred most commonly after upper abdominal operations (78%) despite signs of diminished bowel function.
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Sepsis is a common condition encountered in hospital environments. There is no effective treatment for sepsis, and it remains an important cause of death at intensive care units. This study aimed to discuss some methods that are available in clinics, and tests that have been recently developed for the diagnosis of sepsis.
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Sepse é uma condição comum encontrada no ambiente hospitalar. Não há terapêutica eficaz contra a sepse, que continua a ser uma importante causa de morte em unidades de terapia intensiva. Nosso objetivo foi discutir alguns métodos que estão disponíveis na clínica e os recentes testes que foram desenvolvidos no diagnóstico da sepse.
Uma revisão sistemática foi realizada por meio da análise dos descritores: sepse; métodos de diagnóstico; marcadores biológicos e citocinas.
Efeitos deletérios da sepse são causados pelo desequilíbrio entre a infectividade do patógeno e a capacidade do hospedeiro de montar uma resposta imune eficaz. Consequentemente a resposta imune falha em eliminar o patógeno permitindo assim sua disseminação causando com isso intensa resposta de mediadores inflamatórios e ativação da cascata de complemento, desse modo o tempo é um fator essencial no tratamento da sepse, quanto maior o tempo, mais difícil se torna a recuperação do paciente, aumentando inclusive a probabilidade de disfunção múltipla de órgãos. Há um aumento da incidência de sepse no mundo inteiro devido a fatores como o envelhecimento da população, o maior número de cirurgias e a quantidade de micro-organismos resistentes aos antimicrobianos existentes.
A busca por novos marcadores diagnósticos associados ao risco aumentado de desenvolvimento de sepse e moléculas que podem ser correlacionados com determinadas etapas de sepse está se tornando obrigatória. Isso permitiria um diagnóstico mais precoce, facilitando o estadiamento, prognóstico do paciente, bem como o reconhecimento da possível evolução de cada caso. Todos os outros marcadores são lamentavelmente restritos a unidades de investigação

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Infection/SepsisIncidence and risk factors for sepsis in surgical patients: A cohort study☆,☆☆

Abstract

Purpose

Materials and Methods

Results

Conclusions

Introduction

Section snippets

Methods

Results

Discussion

Conclusions

Key points

Clinics

J Am Coll Surg

Clinics

Am J Infect Control

Chest

Chest

Prevenção da infecção da ferida cirúrgica

Complicações respiratórias no pós operatório de cirurgias eletivas e de urgências e emergências em um Hospital Universitário

J Bras Pneumol

Analysis of risk factors for nosocomial sepsis in surgical patients

Br J Surg

Incidence, risk factors and out come of severe sepsis and septic shock in adults. A multicenter prospective study in intensive care units. French ICU group for severe sepsis

JAMA

Epidemiology of sepsis and infection in ICU patients from an international multicentre cohort study

Intensive Care Med

Impact of heart failure on patients undergoing major non cardiac surgery

Anesthesiology

Identification and characterization of the high-risk surgical population in the United Kingdom

Critical Care

Epidemiologia e desfecho de pacientes cirúrgicos não cardíacos em unidades de terapia intensiva no Brasil

Rev Bras Ter Intensiva

New classification of physical status

Anaesthesiology

Guidelines for perioperative cardiovascular evaluation for noncardiac surgery. Report of American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Perioperative Cardiovascular Evaluation for Noncardiac Surgery)

J Am Coll Cardiol

POSSUM and Portsmouth POSSUM for predicting mortality

Br J Surg

Early goal-directed therapy after major surgery reduces complications and duration of hospital stay. A randomised, controlled trial

Crit Care Med

Prediction of surgical risk in adults

Surg Res Comm

Infection/Sepsis
Incidence and risk factors for sepsis in surgical patients: A cohort study☆,☆☆