Fever in hospitalized patients. With special reference to the medical service

Prevalence of Drug Fever among Cases of Nosocomial Fever: A Systematic Review and Meta-analysis

Objective Drug fever is defined as a fever that temporally coincides with the start of a culprit drug and disappears after discontinuation of the drug. It is a common cause of nosocomial fever, which refers to a fever that develops beyond the first 48 h after hospital admission. However, the exact prevalence of drug fever among cases of nosocomial fever is unclear, as is the variation in prevalence depending on the clinical setting and most common causative drugs. Methods PubMed MEDLINE, Dialog EMBASE, Cochrane Central Register of Controlled Trials, World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov were systematically searched. Studies that reported the prevalence of drug fever in patients with nosocomial fever were included. Two of the four reviewers conducted independent assessments of the inclusion, data extraction, and quality. Pooled adjusted odds ratios were generated using a random-effects model and presented with 95% confidence intervals (CIs). Results Fifteen meta-analysis from 15 studies were included. Ten studies did not report the definition of drug fever or excluded febrile patients who were admitted to the hospital within 24-48 h. The pooled prevalence of drug fever among cases of nosocomial fever was 3.0% (95% CI, 0.6-6.8%), which was largely consistent across the settings, except for at oriental medicine hospital. Only four studies reported the causative agents, and antibiotics were the most frequently reported. Conclusions The prevalence of drug fever is low in patients with nosocomial fever. Clinicians should recognize that drug fever is a diagnosis of exclusion, even in cases of nosocomial fever.

Ten common misconceptions about antibiotic use in the hospital

Antimicrobials are one of the most administered medications in hospitals. Thoughtful and rational antibiotic prescribing by clinicians are important in reducing the adverse effects to both the host that takes the antibiotic and also the individuals in the host's community. Principles informing antibiotic prescribing in the hospital are commonly rooted in misconceptions. We review 10 common myths associated with antibacterial usage in hospitalized patients and share contemporary evidence in hopes of enhancing evidence-informed practice in this patient care setting.

Blood culture utilization practices among febrile and/or hypothermic inpatients

Background

Predictors associated with the decision of blood culture ordering among hospitalized patients with abnormal body temperature are still underexplored, particularly non-clinical factors. In this study, we evaluated the factors affecting blood culture ordering in febrile and hypothermic inpatients.

Methods

We performed a retrospective study of 15,788 adult inpatients with fever (≥ 38.3℃) or hypothermia (< 36.0℃) from January 2016 to December 2017. We evaluated the proportion of febrile and hypothermic episodes with an associated blood culture performed within 24h. Generalized Estimating Equations were used to determine independent predictors associated with blood culture ordering among febrile and hypothermic inpatients.

Results

We identified 21,383 abnormal body temperature episodes among 15,788 inpatients (13,093 febrile and 8,290 hypothermic episodes). Blood cultures were performed in 36.7% (7,850/ 21,383) of these episodes. Predictors for blood culture ordering among inpatients with abnormal body temperature included fever ≥ 39℃ (adjusted odd ratio [aOR] 4.17, 95% confident interval [CI] 3.91–4.46), fever (aOR 3.48, 95% CI 3.27–3.69), presence of a central venous catheter (aOR 1.36, 95% CI 1.30–1.43), systemic inflammatory response (SIRS) plus hypotension (aOR 1.33, 95% CI 1.26–1.40), SIRS (aOR 1.26, 95% CI 1.20–1.31), admission to stem cell transplant / medical oncology services (aOR 1.09, 95% CI 1.04–1.14), and detection of abnormal body temperature during night shift (aOR 1.06, 95% CI 1.03–1.09) or on the weekend (aOR 1.05, 95% CI 1.01–1.08).

Conclusion

Blood culture ordering for hospitalized patients with fever or hypothermia is multifactorial; both clinical and non-clinical factors. These wide variations and gaps in practices suggest opportunities to improve utilization patterns.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07748-x.

Impact of an Educational Program on Improving Nurses’ Management of Fever: An Experimental Study

Background: Despite a public information campaign “To Break the Myth of Fever”, nurses continued to overtreat fever. This study hypothesized that the campaign lacked the detailed rationale essential to alter nurses’ attitudes and behaviors. Aim: To evaluate the effect of the educational program on nurses’ knowledge, attitudes, and behaviors related to fever management. Design: A randomized experimental design using a time series analysis. Methods: A random sample of 58 medical/surgical nurses was evenly divided into an intervention and a control group. The intervention group received an educational program on fever and fever management. Both groups completed a pretest and four posttests using investigator-developed instruments: a questionnaire on knowledge and attitudes about fever management and a fever treatment checklist to audit charts. Results: The intervention group had markedly higher knowledge scores and reduced use of ice pillows at all four posttests, as well as lower use of antipyretics overall, except for the first posttest, despite no sustained change in attitude. Conclusions: An educational program for fever management can effectively improve clinical nurses’ knowledge and attitudes about fever management.

Nosocomial Fever in General Medical Wards: A Prospective Cohort Study of Clinical Characteristics and Outcomes

Purpose

Nosocomial fever (NF) is a common sign of healthcare-associated infection; however, infection is not always followed up. We studied the etiology, clinical characteristics, and outcomes of nosocomial fever in hospitalized patients.

Patients and Methods

Between October 2019 and December 2020, we enrolled subjects from general medical wards who developed fever ≥48 hours after hospital admission or who were admitted with fever, defervesced, and then developed a fever ≥7 days later that was unrelated to the cause for admission. Subjects with NF underwent a comprehensive clinical evaluation and laboratory investigations.

Results

Eighty-six cases of NF were identified and completely followed, the mean age was 69.29 years, and 35 were male. Fifty-seven were from infectious etiologies, 28 from non-infectious etiologies, and one case was unable to be determined. Hospital-associated pneumonia (47.4%) and urinary tract infection (22.8%) were the most common infectious causes, and malignancy (17.8%) and large hematoma (14.3%) were the most common non-infectious causes. The median day of onset of NF following hospitalization was 12 (4.7–21.2) days. Acute physiology and chronic health evaluation II (APACHE II) score (14.70 vs 11.97, p = 0.02), sequential organ failure assessment (SOFA) scores (4 vs 2, p < 0.01), pertinent clinical findings (82.5% vs 42.9%, p < 0.01), blood urea nitrogen (BUN) (37.30 vs 21.10, p = 0.03) and creatinine (1.41 vs 0.97, p = 0.05) levels, and abnormal chest radiography (45.6% vs 3.6%, p < 0.01) had significant differences between infectious and non-infectious etiologies. Twenty-three subjects (26.7%) died. The presence of end-stage renal disease (ESRD) [OR 19.49 (1.77–214.18), p = 0.015], SOFA score >6 [OR 5.18 (1.04–25.90), p = 0.045], and abnormal chest radiography [OR 3.45 (1.16–10.29), p = 0.026] were significantly associated with mortality.

Conclusion

Nosocomial infections, malignancy, and hematoma were the leading causes of NF. Severity scores, clinical findings, renal function tests, and chest radiography were distinguishing features between infectious and non-infectious etiologies. ESRD, high SOFA scores, and abnormal chest radiography were associated with mortality.

Comprehensive Analysis of Temperature in Hospitalized Patients

BACKGROUND

Human body temperature is believed to be linked to clinical diagnoses. However, most of the available data stems from healthy individuals, with no large-scale studies addressing body temperature in the inpatient setting, which is the focus of our study.

MATERIALS AND METHODS

This is a retrospective analysis of a total of 695,107 temperature readings from 16,245 patients hospitalized over a 1-year period at a tertiary medical center, ages 0-105 years, 50% female, with rectal, monotherm, axillary, oral, temporal and tympanic measurement sites. The average temperature (T_ave) per patient and per measurement site was used in all calculations. Descriptive statistics, Student's t-test, and Pearson's correlation were used, where appropriate, with statistical significance set at P < 0.05.

RESULTS

T_ave from all measurement sites was 98.13 ± 0.48(SD)F(36.74 ± 0.27°C). T_ave varied by the site of measurement, in decreasing order highest-to-lowest being rectal, monotherm, axillary, oral, temporal, and tympanic, all of which were higher than the available reported averages for healthy subjects. T_ave decreased as patients' age increased. There was only slight and likely clinically insignificant difference between the sexes. There were differences in T_ave between the intensive care units (ICUs), listed from highest-to-lowest: Neuro ICU, Pediatric ICU, Surgical ICU, Cardiac ICU and Medical ICU. However, there was no difference between all ICU and non-ICU patients.

CONCLUSIONS

Our inpatient data demonstrate that previously identified body temperature trends among healthy subjects are preserved, to an extent, in the inpatient setting. To our knowledge, ours is the first study that evaluates the temperatures of all hospitalized patients at a large tertiary medical center.

Ten key points for the appropriate use of antibiotics in hospitalised patients: a consensus from the Antimicrobial Stewardship and Resistance Working Groups of the International Society of Chemotherapy

The Antibiotic Stewardship and Resistance Working Groups of the International Society for Chemotherapy propose ten key points for the appropriate use of antibiotics in hospital settings. (i) Get appropriate microbiological samples before antibiotic administration and carefully interpret the results: in the absence of clinical signs of infection, colonisation rarely requires antimicrobial treatment. (ii) Avoid the use of antibiotics to 'treat' fever: use them to treat infections, and investigate the root cause of fever prior to starting treatment. (iii) Start empirical antibiotic treatment after taking cultures, tailoring it to the site of infection, risk factors for multidrug-resistant bacteria, and the local microbiology and susceptibility patterns. (iv) Prescribe drugs at their optimal dosing and for an appropriate duration, adapted to each clinical situation and patient characteristics. (v) Use antibiotic combinations only where the current evidence suggests some benefit. (vi) When possible, avoid antibiotics with a higher likelihood of promoting drug resistance or hospital-acquired infections, or use them only as a last resort. (vii) Drain the infected foci quickly and remove all potentially or proven infected devices: control the infection source. (viii) Always try to de-escalate/streamline antibiotic treatment according to the clinical situation and the microbiological results. (ix) Stop unnecessarily prescribed antibiotics once the absence of infection is likely. And (x) Do not work alone: set up local teams with an infectious diseases specialist, clinical microbiologist, hospital pharmacist, infection control practitioner or hospital epidemiologist, and comply with hospital antibiotic policies and guidelines.

Accuracy of peripheral thermometers for estimating temperature: a systematic review and meta-analysis

BACKGROUND

Body temperature is commonly used to screen patients for infectious diseases, establish diagnoses, monitor therapy, and guide management decisions.

PURPOSE

To determine the accuracy of peripheral thermometers for estimating core body temperature in adults and children.

DATA SOURCES

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL Plus from inception to July 2015.

STUDY SELECTION

Prospective studies comparing the accuracy of peripheral (tympanic membrane, temporal artery, axillary, or oral) thermometers with central (pulmonary artery catheter, urinary bladder, esophageal, or rectal) thermometers.

DATA EXTRACTION

2 reviewers extracted data on study characteristics, methods, and outcomes and assessed the quality of individual studies.

DATA SYNTHESIS

75 studies (8682 patients) were included. Most studies were at high or unclear risk of patient selection bias (74%) or index test bias (67%). Compared with central thermometers, peripheral thermometers had pooled 95% limits of agreement (random-effects meta-analysis) outside the predefined clinically acceptable range (± 0.5 °C), especially among patients with fever (-1.44 °C to 1.46 °C for adults; -1.49 °C to 0.43 °C for children) and hypothermia (-2.07 °C to 1.90 °C for adults; no data for children). For detection of fever (bivariate random-effects meta-analysis), sensitivity was low (64% [95% CI, 55% to 72%]; I2 = 95.7%; P < 0.001) but specificity was high (96% [CI, 93% to 97%]; I2 = 96.3%; P < 0.001). Only 1 study reported sensitivity and specificity for the detection of hypothermia.

LIMITATIONS

High-quality data for some temperature measurement techniques are limited. Pooled data are associated with interstudy heterogeneity that is not fully explained by stratified and metaregression analyses.

CONCLUSION

Peripheral thermometers do not have clinically acceptable accuracy and should not be used when accurate measurement of body temperature will influence clinical decisions.

PRIMARY FUNDING SOURCE

None.

Pharmacotherapy of fever control among hospitalized adult patients

INTRODUCTION

Fever is common and associated with increased mortality among hospitalized adults. This article will review the pharmacotherapy of commonly prescribed antipyretic drugs including the rationale for and against temperature control in febrile adults, as well as the evidence associated with fever control in specific patient populations.

AREAS COVERED

Though fever is common, the molecular basis of pyrexia, and the interaction of these pathways with commonly prescribed antipyretic drugs are not fully understood. Furthermore, while experimental and clinical studies clearly demonstrate that pyrexia is harmful in select patients, available clinical trial data are unable to suggest an evidence-based approach to the treatment of fever. Interestingly, this also applies to patients with an acute neurologic injury wherein the treatment of fever with antipyretic therapy has become a common management strategy.

EXPERT OPINION

Few adequately powered clinical trials have investigated temperature control strategies in febrile patients. Therefore, it is not possible to define an evidence-based approach to the control of fever in hospitalized adults. Further clinical and translational research is required to identify the patients most likely to benefit from a strategy of fever control versus permissive hyperthermia, and to determine the antipyretic therapies associated with the greatest improvement in outcome.

Characteristics of fever, etiologic factors, antibiotic use and prognosis in febrile dermatology inpatients

BACKGROUND

Generally, fever is observed in >30% of hospitalized patients. However, little is known about fever in dermatology inpatients.

OBJECTIVES

The aim of this study was to investigate and document the incidence, characteristics, and etiologic factors of fever in febrile dermatology inpatients and to describe the practice of antibiotic use and prognosis in the same group.

METHODS

The medical records for 928 inpatients were retrospectively analyzed.

RESULTS

The incidence of fever was found to be 16.2%. Mean length of hospital stay was found to be longer in febrile patients. Of the 176 febrile episodes, 79 (44.9%) occurred in patients without infections, 43 (24.4%) in patients with community-acquired infections, 25 (14.2%) in patients with healthcare-associated infections, 18 (10.2%) in patients classified with fever of non-infectious/infectious causes, and 11 (6.3%) in a group for whom the etiologic factors of fever were undetermined. Antibiotic treatment was started in 36.2% of febrile inpatients. The overall mortality rate was 0.6%.

CONCLUSIONS

This is the first study to investigate febrile episodes in dermatology inpatients. Fever is a frequently encountered symptom in dermatology inpatients. Febrile episodes resulted from mostly non-infectious entities, mainly consisting of inflammatory dermatologic disorders. Antibiotics were ordered in a higher percentage of patients in the febrile group. Dermatologists started prophylactic or empiric antibiotic therapy in febrile patients with non-infectious or inflammatory diagnoses on the assumption that these patients had an increased risk for infection as a result of impaired skin integrity and use of immunosuppressive drug therapy. The overall mortality rate was very low in the study group of dermatology inpatients.

Hyperthermia during anaesthesia and intensive care unit stay

Nosocomial hyperthermia (fever) occurs in about 30% of all medical patients at some time during their hospital stay. In patients admitted to the intensive care unit with severe sepsis the incidence of hyperthermia is greater than 90%, while in a specialized neurological critical care unit the incidence is reported as 47%. In contrast, hyperthermia during anaesthesia is rare owing to the impairment of thermoregulation by anaesthetic agents. This article is designed to give an overview on the various causes of hyperthermia with special emphasis on fever during general and regional anaesthesia in general and neurological critical care patients.

Risk factors for increased mortality from hospital-acquired versus community-acquired infections in febrile medical patients

BACKGROUND

Risk factors for hospital-acquired infection and attributable mortality in surgical and critically ill patients are well-known. We sought to identify factors associated with increased mortality from hospital-acquired infections as compared with community-acquired infections in patients with new-onset fever and a presumed infectious focus (n = 212), in a department of internal medicine.

METHODS

Demographic, clinical, and laboratory variables were studied for 2 days after inclusion. Septic shock and outcome were monitored for up to 7 and 28 days after inclusion, respectively.

RESULTS

Of the 212 patients, 54 had hospital-acquired and 158 community-acquired infection, with septic shock rates of 15% and 4% and mortality rates of 24% and 6% (P = .001), respectively. Prior neurologic disease was associated with death. Patients with hospital-acquired infection had more often (intravascular) devices and underwent more often interventions, had a different distribution of infectious foci, and had more often bacteremia. Bacteremia-associated septic shock was associated with nonsurvival in both infection groups. The causative agents were not associated with outcome, and the clinical and laboratory host response associated with nonsurvival generally did not differ among infection groups.

CONCLUSION

Our data suggest that hospital-acquired infections carry a higher crude mortality rate than community-acquired infection in febrile medical patients, mainly because of more frequent use of devices and hospital interventions and resultant bacteremia and septic shock, rather than by differences in underlying diseases, causative agents, and clinical and laboratory host responses. The observations thus emphasize the continued importance of preventive measures on medical wards of our hospital and can be used for comparison with future studies.

Antibiotic adverse reactions and drug interactions

When contemplating antibiotic use, intensivists must consider possible beneficial and harmful drug interactions. After antibiotics are instituted, adverse reactions must be anticipated. Acute illness, comorbidities, and concurrent medications affect the presentation and management of antibiotic-related adverse events. Intensivists should use the fewest possible antibiotics, carefully choosing agents that maximize antimicrobial activity and minimize potential drug interactions and adverse reactions.

Evaluation and treatment of fever in intensive care unit patients

Fever is a common complaint in hospitalized patients, with estimates that more than 30% of ward patients and as much as 90% of critically ill patients will experience fever. Much of the treatment of fever, however, is based on tradition and the belief the fever is harmful to the patient rather than on scientific evidence. There is a need to determine via analysis of the literature the best evidence-based approach to the identification and treatment of fever with attention to appropriate measurement of body temperature, diagnostic evaluation, changing of indwelling catheters, administration of antipyretics, and alteration in antimicrobial therapy. The advanced practice nurse is uniquely capable of gathering this evidence and implementing a plan of care that meets the individual needs of the patient, family, nursing staff, and healthcare system.

Brief report: incidence, etiology, risk factors, and outcome of hospital-acquired fever: a systematic, evidence-based review

OBJECTIVES

Temperature is universally measured in the hospitalized patient, but the literature on hospital-acquired fever has not been systematically reviewed. This systematic review is intended to provide clinicians with an overview of the incidence, etiology, and outcome of hospital-acquired fever.

DATA SOURCES

We searched MEDLINE (1970 to 2005), EMBASE (1988 to 2004), and Web of Knowledge. References of all included articles were reviewed. Articles that focused on children, fever in the developing world, classic fever of unknown origin, or specialized patient populations were excluded.

REVIEW METHODS

Articles were reviewed independently by 2 authors before inclusion; a third author acted as arbiter.

RESULTS

Of over 1,000 studies reviewed, 7 met the criteria for inclusion. The incidence of hospital-acquired fever ranged from 2% to 17%. The etiology of fever was infection in 37% to 74%. Rates of antibiotic use for patients with a noninfectious cause of fever ranged from 29% to 55% for a mean duration of 6.6 to 9.6 days. Studies varied widely in their methodology and the patient population studied.

CONCLUSIONS

Limited information is available to guide an evidence-based approach to hospital-acquired fever. We propose criteria to help standardize future studies of this important clinical situation.

Fever: a concept analysis

AIM

The purpose of this paper is to critically analyse the current state of the science literature in order to develop an accurate conception of fever.

RATIONALE

The measurement of body temperature and treatment of fever have long been considered to be within the domain of nursing practice. What body temperature constitutes 'fever', however, is often not clear from nursing protocols or the literature.

METHODS

Literature for this concept analysis was obtained by computerized searches of PubMed, CINAHL and BIOSYS for the years 1980-2004. Additional sources were obtained after reviewing the bibliographies of the literature identified by the initial search. The Wilsonian method of concept analysis provided the framework for the analysis.

FINDINGS

Fever has characteristically been recognized as a cardinal sign of illness and has traditionally had negative connotations for patient well-being. Substantive advances over the past 20 years in immunology and neurophysiology have expanded understanding of the process of fever. This new knowledge has shifted the perception of fever as part of the acute-phase response to one of an adaptive nature. This knowledge has yet to be fully translated into changes in the fever management practices of nurses.

CONCLUSIONS

Consistent usage of terminology in relation to fever should lead to improved and evidence-based care for patients, and to fever management practices consistent with current research. It is important to use clear language about fever and hyperthermia in discussions and documentation between nurses and among disciplines. By creating clarity in our language, we may help to achieve praxis.

Body temperature alterations in the critically ill

OBJECTIVE

To determine the incidence of body temperature (BT) alterations in critically ill patients, and their relationship with infection and outcome.

DESIGN

Prospective, observational study. SETTING. Thirty-one bed, medico-surgical department of intensive care.

PATIENTS

Adult patients admitted consecutively to the ICU for at least 24 h, during 6 summer months.

INTERVENTIONS

None.

RESULTS

Fever (BT > or =38.3 degrees C) occurred in 139 (28.2%) patients and hypothermia (BT< or =36 degrees C) in 45 (9.1%) patients, at some time during the ICU stay. Fever was present in 52 of 100 (52.0%) infected patients without septic shock, and in 24 of 38 (63.2%) patients with septic shock. Hypothermia occurred in 5 of 100 (5.0%) infected patients without septic shock and in 5 of 38 (13.1%) patients with septic shock. Patients with hypothermia and fever had higher Sequential Organ Failure Assessment (SOFA) scores on admission (6.3+/-3.7 and 6.4+/-3.3 vs 4.6+/-3.2; p<0.01), maximum SOFA scores during ICU stay (7.6+/-5.2 and 8.2+/-4.7 vs 5.4+/-3.8; p<0.01) and mortality rates (33.3 and 35.3% vs 10.3%; p<0.01). The length of stay (LOS) was longer in febrile patients than in hypothermic and normothermic (36 degrees C<BT<38.3 degrees C) patients [median 6 (1-57) vs 5 (2-28) and 3 (1-33) days, p=0.02 and p=0.01, respectively). Among the septic patients hypothermic patients were older than febrile patients (69+/-9 vs 54+/-7 years, p=0.01). Patients with septic shock had a higher mortality if they were hypothermic than if they were febrile (80 vs 50%, p<0.01).

CONCLUSIONS

Both hypothermia and fever are associated with increased morbidity and mortality rates. Patients with hypothermia have a worse prognosis than those with fever.

Circulating inflammatory mediators predict shock and mortality in febrile patients with microbial infection

The host response to microbial infection is associated with the release of inflammatory mediators. We hypothesized that the type and degree of the systemic response as reflected by levels of circulating mediators predict morbidity and mortality, according to the invasiveness of microbial infection. We prospectively studied 133 medical patients with fever and culture-proven microbial infection. For 3 days after inclusion, the circulating levels of activated complement C3a, interleukin (IL)-6, and secretory phospholipase A(2) (sPLA(2)) were determined daily. Based on results of microbiological studies performed for up to 7 days, patients were classified as having local infections (Group 1, n = 80 positive local cultures or specific stains for fungal or tuberculous infections) or bacteremia (Group 2, n = 52 plus 1 patient with malaria parasitemia). Outcome was assessed as the development of septic shock and as mortality up to 28 days after inclusion. Fifteen patients (11%) developed septic shock and overall mortality was 18% (n = 24). Bacteremia was associated with shock and shock predisposed to death. Circulating mediator levels were generally higher in Group 2 than in Group 1. Circulating levels of IL-6 and sPLA(2) were higher in patients developing septic shock and in nonsurvivors, particularly in Group 1. High C3a was particularly associated with nonsurvival in Group 2. In Group 1, the area under the curve (AUC) of the receiver operating characteristic (ROC) curve for the peak sPLA(2) for shock development was 0.79 (P < 0.05). The AUC of the ROC curve of the peak IL-6 and sPLA(2) for mortality was 0.69 and 0.68 (P < 0.05), respectively. In Group 2, the AUC of the ROC for peak C3a predicting mortality was 0.73 (P < 0.05). In conclusion, in medical patients with fever and microbial infection, the systemic inflammatory host response predicts shock and death, at an early stage, dependent on the invasiveness of microbial infection. The results suggest a differential pathogenetic role of complement activation on the one hand and release of cytokine and lipid mediators on the other in bacteremic and local microbial infections, respectively. They may partly explain the failure of strategies blocking proinflammatory cytokines or sPLA(2) in human sepsis and may extend the basis for attempts to inhibit complement activation at an early stage in patients at risk of dying from invasive microbial infections.

Circulating inflammatory mediators in patients with fever: predicting bloodstream infection

The systemic host response to microbial infection involves clinical signs and symptoms of infection, including fever and elevated white blood cell (WBC) counts. In addition, inflammatory mediators are released, including activated complement product C3a, interleukin 6 (IL-6), and the acute-phase reactant secretory phospholipase A(2) (sPLA(2)). To compare the value of the latter with the former in predicting (the degree of) microbial infection at the bedside, we determined clinical variables and took blood samples daily for 3 consecutive days in 300 patients with a new fever (>38.0 degrees C rectally or >38.3 degrees C axillary). Microbiological culture results for 7 days after inclusion were collected. Patients were divided into clinical and microbial categories: those without and with a clinical focus of infection and those with negative cultures, with positive local cultures or specific stains for fungal (n = 13) or tuberculous infections (n = 1), and with positive blood cultures, including one patient with malaria parasitemia. The area under the curve (AUC) of the receiver operating characteristic (ROC) for prediction of positive cultures was 0.60 (P < 0.005) for peak temperature and 0.59 (P < 0.01) for peak WBC count, 0.60 (P < 0.005) for peak C3a, 0.63 (P < 0.001) for peak IL-6, and 0.61 (P < 0.001) for peak sPLA(2). The AUC under the ROC curve for prediction of positive blood cultures was 0.68 (P < 0.001) for peak temperature and 0.56 for peak WBC count (P < 0.05). The AUC for peak C3a was 0.69, that for peak IL-6 was 0.70, and that for sPLA(2) was 0.67 (for all, P < 0.001). The degree of microbial invasion is thus a major determinant of the clinical and inflammatory host response in patients with fever. Moreover, circulating inflammatory mediators such as C3a and IL-6 may help to predict positive blood cultures, together with clinical signs and symptoms of the host response to microbial infection, even before culture results are available. This may help in the designing of entry criteria for therapeutic intervention studies.

The clinical host response to microbial infection in medical patients with fever

STUDY OBJECTIVES

Predictors among demographic, clinical, and laboratory variables for a microbial (nonviral/nonchlamydial) infection in hospitalized medical patients with new onset of fever (temperature > or =38.0 degrees C axillary or > or =38.3 degrees C rectal) were analyzed and compared with the criteria for the systemic inflammatory response syndrome (SIRS), including an abnormal body temperature and WBC count, tachypnea and tachycardia, and sepsis, defined as SIRS and the presence of a clinical infection.

DESIGN

A prospective cohort study.

SETTING

Department of internal medicine at a university hospital.

PATIENTS

In 300 hospitalized medical patients with new onset of fever, demographic, clinical, and laboratory variables were obtained during the first 2 days after inclusion, and peak and nadir values, when appropriate, were taken. Microbiologic results for 7 days were collected. Clinical information was used to decide on the presence of a clinical infection.

MEASUREMENTS AND RESULTS

One hundred thirty-three of 300 patients (44%) had a microbial infection: 26% suffered from local microbial infection only, 9% from bacteremia only, and 9% had bloodstream plus local microbial infections. Patients with a microbial infection had a higher World Health Organization performance score at home (p<0.05), higher peak body temperature (p<0.001), higher nadir and peak WBC counts (p<0.05), lower nadir platelet count (p<0.01), higher peak alanine and aspartate aminotransferases (p<0.01), and lower nadir albumin (p<0.001) levels in blood during the first 2 days after inclusion than those without infection. Using multivariate techniques, predictors for microbial infection or bacteremia alone, independent of age, sex, underlying disease, and clinical infection, were peak temperature, peak WBC count, and nadir platelet count and albumin level. In contrast, conventional SIRS/sepsis definitions and criteria predicted microbial infection less well, mainly because tachypnea and tachycardia were of no predictive value.

CONCLUSIONS

In febrile medical patients, microbial infection can be predicted with use of easily obtained clinical and laboratory variables, including peak temperature, peak WBC count, and nadir platelet count and albumin level within the first 2 days. The new model predicted microbial infection better than conventional SIRS/sepsis criteria. This may help to improve the clinical recognition of the systemic host response to microbial infection and to refine SIRS/sepsis definitions.

Prediction of mortality in febrile medical patients: How useful are systemic inflammatory response syndrome and sepsis criteria?

STUDY OBJECTIVES

The aim was to evaluate demographic, clinical, and laboratory variables in febrile patients, with or without a microbiologically confirmed infection, for prediction of death, in comparison to the systemic inflammatory response syndrome (SIRS) and its criteria, such as abnormal temperature, tachycardia, tachypnea, and abnormal WBC count, and to sepsis, that includes SIRS and an infection.

DESIGN

A prospective cohort study.

SETTING

Department of internal medicine at a university hospital.

PATIENTS

In 300 consecutive, hospitalized medical patients with new onset of fever, demographic, clinical, and laboratory variables were obtained during the 2 days after inclusion, while microbiological results for a follow-up period of 7 days were collected. Patients were followed up for survival or death, up to a maximum of 28 days after inclusion.

MEASUREMENTS AND RESULTS

Of all patients, 95% had SIRS, 44% had sepsis with a microbiologically confirmed infection, and 9% died. A model with a set of variables all significantly (p<0.01) contributing to the prediction of mortality was derived. The set included the presence of hospital-acquired fever, the peak respiratory rate, the nadir score on the Glasgow coma scale, and the nadir albumin plasma level within the first 2 days after inclusion. This set of variables predicted mortality for febrile patients with microbiologically confirmed infection even better. The predictive values for mortality of SIRS and sepsis were less than that of our set of variables.

CONCLUSIONS

In comparison to SIRS and sepsis, the new set of variables predicted mortality better for all patients with fever and also for those with microbiologically confirmed infection only. This type of effort may help in refining definitions of SIRS and sepsis, based on prognostically important demographic, clinical, and laboratory variables that are easily obtainable at the bedside.

Fever

Fever is a host defense response that provides a sign of an ongoing process related to infection, inflammation, drug reactions, neoplasms, autoimmune diseases, and vascular disorders. The most frequent causes of fever in acutely ill patients are infection and inflammation, but fever may be caused by one or more of a long list of pathophysiologic processes.

Fever in the intensive care unit

In the ICU, fever can be expected to accompany an extensive number of conditions of both infectious and noninfectious etiologies. It is crucial to identify the precise cause of fever, because certain conditions in either category may be life-threatening, whereas others require no treatment at all. It is important to rule out the most common infections that may be present based on historical and physical signs and symptoms and epidemiologic factors. The extent of evaluation should be based on the likelihood of the disease process being present and is highly variable for each individual patient. Therefore, "routine fever work-up" should not be advocated. If overt infection is not found upon initial evaluation, antibiotics should be withheld if possible. Alternatively, in the unstable patient, empiric therapy may be started, and if no infection is evident, it may be stopped within a reasonable time frame. In no case should prolonged antibiotics be given for presumed but unproven infection. Thorough knowledge of the more common infectious and noninfectious conditions, as well as the awareness of less frequent ones and their predisposing risk factors, is essential for adequate evaluation of the febrile ICU patient. Likewise, familiarity with the techniques used for diagnosis of these infections and their appropriate interpretation and limitations in specific instances is immensely helpful to the clinician providing appropriate care for the critically ill patient.

Fever of nosocomial origin: etiology, risk factors, and outcomes

OBJECTIVES

To identify the etiologies and risk factors associated with fever of nosocomial origin and compare the outcomes of patients with and without nosocomial fever.

DESIGN

A prospective study with a case-control component.

SETTING

The three medical services of a university hospital.

PATIENTS AND METHODS

We evaluated 100 patients with fever of nosocomial origin. Etiologies were assigned by the consensus of three independent reviewers using Centers for Disease Control guidelines. Predictors of bacterial etiology were identified using logistic regression methods. Controls matched for age (+/- 5 years), sex, and comorbidity were identified for 65 of the nosocomial fever cases. Cases and controls were compared with conditional logistic regression to identify risk factors for fever of nosocomial origin. Cases and controls were followed at 1 month to compare length of stay, mortality, and hospital readmission rates.

MEASUREMENTS AND MAIN RESULTS

An etiology was assigned in 81 cases: 51 had bacterial infection, 5 had nonbacterial infection, and 25 had a noninfectious etiology. Multivariate predictors of bacterial infection were the presence of diabetes mellitus (odds ratio [OR] = 5.74; 95% confidence interval of the odds ratio [CI] = 1.61 to 20.40), length of stay to fever onset after admission greater than 10 days (OR = 3.98, CI = 1.04 to 15.22), maximum temperature greater than 38.7 degrees C (OR = 3.37, CI = 1.28 to 8.88), and white blood cell count greater than 10 x 10(9)/L (OR = 4.64, CI = 1.68 to 12.77). Comparison of cases and controls indicated that patients with nosocomial fever had more invasive procedures in the 72 hours preceding enrollment in the study than controls (OR = 1.46, CI = 1.03 to 2.08). Although cases were hospitalized almost twice as long as controls (21.5 versus 12.5 days; p < 0.0001), neither 30-day mortality nor hospital readmission rates differed between cases and controls.

CONCLUSION

Nosocomial fever often does not represent nosocomial infection and may constitute a wide variety of other conditions. Since bacterial etiology of fever is a major concern, clinical and laboratory findings can be used to predict patients at high risk for an infectious process. A reduction in the number of invasive procedures may decrease the incidence of nosocomial fever. New-onset nosocomial fever leads to an increase in length of hospital stay but is not a significant predictor of mortality.

Fever in hospitalized medical patients: characteristics and significance

The occurrence of fever and the clinical profile of febrile patients on the medical service of a teaching hospital were studied prospectively. Thirty-six per cent of 972 patients developed fever (temperature exceeding 38 degrees C). Their 13% mortality rate and 13.2-day average hospital stay exceeded the 3% mortality and seven-day hospitalization for afebrile patients (p less than 0.0001 for both). Most fever episodes occurred during the first two hospital days. Approximately 30% of first and subsequent fever episodes were caused by bacterial infections; illnesses involving tissue necrosis (e.g., stroke, myocardial infarction) accounted for 20%. Five conditions comprised 53% of diagnoses: respiratory and urinary tract infections, neoplasm, myocardial infarction, and drug reaction. Only one patient had a fever of uncertain origin. Several clinical clues used frequently to identify bacterial infections were reevaluated. Patients with bacterial infections had higher temperatures on the first febrile day (mean 38.9 degrees C) and were more likely to have had prior infections than those with other causes of fever (mean 38.3 degrees C, p less than 0.001). Older patients (greater than 75 years) had a lower febrile response to bacterial infections than younger patients. Fever in hospitalized medical patients is a common and important concomitant of increased mortality and length of hospitalization.