Healthcare­associated infections in intensive care unit patients with and without COVID-19: a single center prospective surveillance study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic led to a global increase in healthcare-associated infections (HAI) among intensive care unit (ICU) patients. Whether this increase is directly attributable to COVID-19 or whether the pandemic indirectly (via staff shortages or breaches in infection prevention measures) led to this increase, remains unclear. The objectives of this study were to assess HAI incidence and to identify independent risk factors for HAI in COVID-19 and non-COVID-19 ICU patients. METHODS: We established a monocentric prospective HAI surveillance in the medical ICU of our tertiary care center from September 1st 2021 until August 31st 2022, during circulation of the SARS-CoV-2 delta and omicron variants. We consecutively included patients ≥ 18 years of age with an ICU length of stay of > 2 calendar days. HAI were defined according to the European Centre for Disease Prevention and Control definitions. HAI rate was calculated per 1,000 patient-days or device-days; risk ratios (RR) and corresponding 95% confidence intervals (CI) for COVID-19 versus non-COVID-19 patients were calculated. We used multivariable Cox regression to identify independent risk factors for HAI. As a proxy for institutional COVID-19 burden, weekly COVID-19 density (i.e. percentage of COVID-19 patients among all ICU patients) was included in the model as time-dependent co-variable. RESULTS: We included 254 patients, 64 (25.1%) COVID-19 and 190 (74.9%) non-COVID-19 patients; 83 HAI in 72 patients were recorded, thereof 45 ventilator-associated lower respiratory tract infections (VA-LRTI) (54.2%) and 18 blood stream infections (BSI) (21.6%). HAI incidence rate was 49.1/1,000 patient-days in COVID-19 and 22.5/1,000 patient-days in non-COVID-19 patients (RR 2.2, 95%-CI 1.4-3.4). This result was mainly due to different VA-LRTI rates (40.3 vs. 11.7/1,000 ventilator days, p < 0.001), whereas BSI rates were not statistically different (9.4 vs. 5.6/1,000 patient days, p = 0.27). Multivariable analysis identified COVID-19 as main risk factor for HAI development, whereas age, mechanical ventilation and COVID-19 density were not significant. CONCLUSIONS: These data from the fourth and fifth wave of the pandemic show a higher HAI incidence in COVID-19 than in non-COVID-19 ICU patients, mainly due to an increase in pulmonary infections. A diagnosis of COVID-19 was independently associated with HAI development, whereas institutional COVID-19 burden was not.

Efeito do verapamil e do sulfato de estreptomicina sobre a contratilidade cardíaca / Effect of verapamil and streptomycin sulfate on myocardial contractility

O efeito inibitório do verapamil sobre a atividade contráctil do miocárdio, foi comparado com o do sulfato de estreptomicina em coraçäo isolado perfundido de cobaio. O verapamil apresentou um efeito inotrópico negativo, que atingiu o máximo entre 120 a 180 segundos e aos 1.200 segundos a força de contraçäo retornou a níveis normais. O sulfato de estreptomicina apresentou efeito inotrópico negativo máximo aos 30 segundos e a atividade contráctil retornou à níveis normais em aproximadamente 180 a 240 segundos. O efeito inibitório do verapamil diminui com a repetiçäo das injeçöes, enquanto que a repetiçäo das doses de sulfato de estreptomicina näo modifica sua açäo. Ao alterarmos a concentraçäo de cálcio do líquido perfusor observa-se que para o verapamil também foi diminuido o efeito inibitório ao aumentar a concentraçäo de cálcio. O sulfato de estreptomicina produz aumento do efeito inibitório proporcional ao aumento da concentraçäo do íon cálcio