Influence of environmental temperature and heatwaves on surgical site infection after hip and knee arthroplasty: a nationwide study.

BACKGROUND: Previous studies reported higher incidence of surgical site infection (SSI) after procedures performed in summer or with high temperatures. However, no study used detailed climate data to assess this risk after hip and knee arthroplasty, and no study specifically investigated the role of heatwaves. AIM: To assess the impact of higher environmental temperatures and heatwaves on SSI rates after hip and knee arthroplasty. METHODS: Data on hip and knee arthroplasty procedures performed between January 2013 and September 2019 in hospitals participating in the Swiss SSI surveillance were linked to climate data extracted from weather stations located in their vicinity. The association between temperature, heatwaves and SSI was studied using mixed effects logistic regression models fitted at the patient level. Poisson mixed models were fitted for both calendar year and month of the year to investigate the SSI incidence trajectory over time. RESULTS: We included 116,981 procedures performed in 122 hospitals. Significantly higher SSI rates were observed for procedures performed in the summertime (incidence rate ratio 1.39, 95% CI (1.20-1.60), P<0.001; reference: autumn) or in calendar months in which the mean temperature was above 20 °C (reference 5-10 °C; odds ratio 1.59, 95% CI (1.27, 1.98), P<0.001). We observed a slight but non-significant increase in the rate of SSI during heatwaves (1.44% versus 1.01%, P=0.2). CONCLUSION: SSI rates after hip and knee replacement appear to increase with higher environmental temperature. To establish whether, and to what extent, heatwaves increase the risk of SSI, studies involving geographical areas with larger variability in temperature are needed.

Cefepime neurotoxicity: thresholds and risk factors. A retrospective cohort study.

OBJECTIVES: Toxic serum cefepime trough concentrations are not well defined in the current literature. We aimed to define a more precise plasma trough concentration threshold for this antibiotic's neurological toxicity and to identify individuals at risk for developing neurotoxic side effects. METHODS: Retrospective study including all individuals who underwent cefepime therapeutic drug monitoring (TDM) between 2013 and 2017. Individuals with cefepime concentrations other than trough were excluded. The primary outcome was to assess the incidence of neurotoxicity and its relationship with cefepime plasma trough concentrations. Secondary outcomes were the relationship of renal function, cefepime daily dose, age, and cerebral and general co-morbidities with the occurrence of neurotoxicity. We also compared the mortality rate during hospitalization in individuals with and without neurotoxicity, and the possible impact of neuroprotective co-medications on outcomes. RESULTS: Cefepime concentrations were determined in 584 individuals. Among 319 individuals with available trough concentrations included, the overall incidence of neurotoxicity was 23.2% (74 of 319 individuals). Higher cefepime plasma trough concentrations were significantly associated with risk of neurotoxicity (no neurotoxicity 6.3 mg/L (interquartile range (IQR) 4.1-8.6) versus with neurotoxicity 21.6 mg/L (IQR 17.0-28.6), p <0.001). Individuals with presumed cefepime neurotoxicity had a significantly lower renal function (estimated glomerular filtration rate 82.0 mL/min/1.73 m2 (IQR 45.0-105.0) versus 35.0 mL/min/1.73 m2 (IQR 23.3-53.3], p <0.001), and significantly higher in-hospital mortality (19 (7.8%) versus 26 (35.1%) individuals, p <0.001). No neurotoxic side effects were seen below a trough concentration of 7.7 mg/L. Levels ≥38.1 mg/L always led to neurological side effects. CONCLUSION: In individuals with risk factors for cefepime neurotoxicity, such as renal insufficiency, TDM should be systematically performed, aiming at trough concentrations <7.5 mg/L.