Revisiting Mars and Venus: understanding gender differences in critical illness

Gender differences in community-acquired pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) is the most common type of lower respiratory tract infection and a major cause of morbidity and mortality in adults worldwide. Sex and gender play an active role in the incidence and outcomes of major infectious diseases, including CAP.

EVIDENCE ACQUISITION

We searched the following electronic databases from January 2001 to December 2018: MEDLINE, EMBASE, CINHAIL, CENTRAL (Cochrane Central register of Controlled Trials), DARE (Database of Abstracts of Reviews of Effectiveness), Cochrane Database of Systematic Reviews and ACP Journal Club database.

EVIDENCE SYNTHESIS

Several studies have reported higher male susceptibility to pulmonary infections and higher risk of death due to sepsis. Biological differences (e.g. hormonal cycles and cellular immune-mediated responses) together with cultural, behavioral and socio-economic differences are important determinants of the course and outcome of CAP. However, gender-related bias in the provision of care and use of hospital resources has been reported among women, resulting in delayed hospital admission and consequently necessary care.

CONCLUSIONS

CAP is more severe in males than in females, leading to higher mortality in males, especially in older age. To identify gender differences in CAP can guide patient's prognostication and management.

Factors associated with intensive care admission in patients with lung cancer: a population-based observational study of 26, 731 patients

BACKGROUND

Lung cancer is the most common cause of cancer related death worldwide and survival is poor. Patients with lung cancer may develop a critical illness, but it is unclear what features are associated with an Intensive Care Unit (ICU) admission.

METHODS

This retrospective, observational, population-based study of linked cancer registration, ICU, hospital discharge and mortality data described the factors associated with ICU admission in patients with lung cancer. The cohort comprised all incident cases of adult lung cancer diagnosed between 1st January 2000 and 31st December 2009 in the West of Scotland, UK, who were subsequently admitted to an ICU within 2 years of cancer diagnosis. Multiple logistic regression was used to determine factors associated with admission.

RESULTS

26,731 incident cases of lung cancer were diagnosed with 398 (1.5%) patients admitted to an ICU. Patients were most commonly admitted with respiratory conditions and there was a high rate of invasive mechanical ventilation. ICU, in-hospital and six-month survival were 58.5, 42.0 and 31.2%, respectively. Surgical treatment of lung cancer increased the odds of ICU admission (OR 7.23 (5.14-10.2)). Odds of admission to ICU were reduced with older age (75-80 years OR 0.69 (0.49-0.94), > 80 years OR 0.21 (0.12-0.37)), female gender (OR 0.73 (0.59-0.90)) and radiotherapy (OR 0.54 (0.39-0.73)) or chemotherapy treatment (OR 0.52 (0.38-0.70)).

CONCLUSION

1.5% of patients diagnosed with lung cancer are admitted to an ICU but both short term and long term survival was poor. Factors associated with ICU admission included age < 75 years, male gender and surgical treatment of cancer.

Association of Gender With Outcome and Host Response in Critically Ill Sepsis Patients

OBJECTIVE

To determine the association of gender with the presentation, outcome, and host response in critically ill patients with sepsis.

DESIGN AND SETTING

A prospective observational cohort study in the ICU of two tertiary hospitals between January 2011 and January 2014.

PATIENTS

All consecutive critically ill patients admitted with sepsis, involving 1,815 admissions (1,533 patients).

INTERVENTIONS

The host response was evaluated on ICU admission by measuring 19 plasma biomarkers reflecting organ systems implicated in sepsis pathogenesis (1,205 admissions) and by applying genome-wide blood gene expression profiling (582 admissions).

MEASUREMENTS AND MAIN RESULTS

Sepsis patients admitted to the ICU were more frequently males (61.0%; p < 0.0001 vs females). Baseline characteristics were not different between genders. Urosepsis was more common in females; endocarditis and mediastinitis in men. Disease severity was similar throughout ICU stay. Mortality was similar up to 1 year after ICU admission, and gender was not associated with 90-day mortality in multivariate analyses in a variety of subgroups. Although plasma proteome analyses (including systemic inflammatory and cytokine responses, and activation of coagulation) were largely similar between genders, females showed enhanced endothelial cell activation; this difference was virtually absent in patients more than 55 years old. More than 80% of the leukocyte blood gene expression response was similar in male and female patients.

CONCLUSIONS

The host response and outcome in male and female sepsis patients requiring ICU admission are largely similar.

Intensive care admission of cancer patients: a comparative analysis

The aim of this study was to obtain insight into which proportion of cancer patients is admitted to an Intensive Care Unit (ICU) and how their survival, demographic, and clinical characteristics relate to cancer patients not admitted to the ICU. Data from patients registered with cancer between 2006 and 2011 in four hospitals in the Netherlands were linked to the Dutch National Intensive Care Evaluation registry. About 36,860 patients with cancer were identified, of whom 2,374 (6.4%) were admitted to the ICU. Fifty-six percent of ICU admissions were after surgery, whereas 44% were for medical reasons. The risk for ICU admission was highest among cancer patients treated with surgery either alone or combined with chemotherapy and/or radiation therapy. Only 80 of 1,073 medical ICU admissions (3.3%) were for cancer-specific reasons. Although more women (54.0%) than men were registered with cancer, the proportion of male cancer patients admitted to an ICU was much higher (9.3 vs. 4.0%, P < 0.001). Five-year survival of cancer patients admitted to the ICU was substantial (41%) although median survival was much lower (1,104 days) than in patients not admitted to the ICU (median survival time not reached, P < 0.001). These results show that one out of 16 cancer patients was admitted to an ICU and that ICU support for this group should not be considered futile.

Sepsis in AIDS patients: clinical, etiological and inflammatory characteristics

INTRODUCTION

Intensive care mortality of HIV-positive patients has progressively decreased. However, critically ill HIV-positive patients with sepsis present a worse prognosis. To better understand this condition, we propose a study comparing clinical, etiological and inflammatory data, and the hospital course of HIV-positive and HIV-negative patients with severe sepsis or septic shock.

METHODS

A prospective observational study enrolling patients with severe sepsis or septic shock associated or not with HIV infection, and admitted to intensive care unit (ICU). Clinical, microbiological and inflammatory parameters were assessed, including C-reactive protein (CRP), procalcitonin (PCT), interleukin-6, interleukin-10 and TNF-α. Outcome measures were in-hospital and six-month mortality.

RESULTS

The study included 58 patients with severe sepsis/septic shock admitted to ICU, 36 HIV-positive and 22 HIV-negative. All HIV-positive patients met the criteria for AIDS (CDC/2008). The main foci of infection in HIV-positive patients were pulmonary and abdominal (p=0.001). Fungi and mycobacteria were identified in 44.4% and 16.7% of HIV-positive patients, respectively. In contrast, the main etiologies for sepsis in HIV-negative patients were Gram-negative bacilli (36.4%) and Gram-positive cocci (36.4%) (p=0.001). CRP and PCT admission concentrations were lower in HIV-positive patients (130 vs. 168 mg/dL p=0.005, and 1.19 vs. 4.06 ng/mL p=0.04, respectively), with a progressive decrease in surviving patients. Initial IL-10 concentrations were higher in HIV-positive patients (4.4 pg/mL vs. 1.0 pg/mL, p=0.005), with moderate accuracy for predicting death (area under receiver-operating characteristic curve =0.74). In-hospital and six-month mortality were higher in HIV-positive patients (55.6 vs. 27.3% p=0.03, and 58.3 vs. 27.3% p=0.02, respectively).

CONCLUSIONS

The course of sepsis was more severe in HIV-positive patients, with distinct clinical, etiological and inflammatory characteristics.

Surveillance of infection severity: a registry study of laboratory diagnosed Clostridium difficile

BACKGROUND

Changing clinical impact, as virulent clones replace less virulent ones, is a feature of many pathogenic bacterial species and can be difficult to detect. Consequently, innovative techniques monitoring infection severity are of potential clinical value.

METHODS AND FINDINGS

We studied 5,551 toxin-positive and 20,098 persistently toxin-negative patients tested for Clostridium difficile infection between February 1998 and July 2009 in a group of hospitals based in Oxford, UK, and investigated 28-day mortality and biomarkers of inflammation (blood neutrophil count, urea, and creatinine concentrations) collected at diagnosis using iterative sequential regression (ISR), a novel joinpoint-based regression technique suitable for serial monitoring of continuous or dichotomous outcomes. Among C. difficile toxin-positive patients in the Oxford hospitals, mean neutrophil counts on diagnosis increased from 2003, peaked in 2006-2007, and then declined; 28-day mortality increased from early 2006, peaked in late 2006-2007, and then declined. Molecular typing confirmed these changes were likely due to the ingress of the globally distributed severe C. difficile strain, ST1. We assessed the generalizability of ISR-based severity monitoring in three ways. First, we assessed and found strong (p<0.0001) associations between isolation of the ST1 severe strain and higher neutrophil counts at diagnosis in two unrelated large multi-centre studies, suggesting the technique described might be useful elsewhere. Second, we assessed and found similar trends in a second group of hospitals in Birmingham, UK, from which 5,399 cases were analysed. Third, we used simulation to assess the performance of this surveillance system given the ingress of future severe strains under a variety of assumptions. ISR-based severity monitoring allowed the detection of the severity change years earlier than mortality monitoring.

CONCLUSIONS

Automated electronic systems providing early warning of the changing severity of infectious conditions can be established using routinely collected laboratory hospital data. In the settings studied here these systems have higher performance than those monitoring mortality, at least in C. difficile infection. Such systems could have wider applicability for monitoring infections presenting in hospital.