Letter to the Editor

Cannula-related infection in adult medical intensive care unit patients undergoing extracorporeal life support and extracorporeal membrane oxygenation

Patients with prolonged duration of extracorporeal membrane oxygenation support (ECMO) are a vulnerable population for sepsis, particularly ventilator-associated pneumonia and bloodstream infections. Rates differ between venous–arterial and venous–venous ECMO patients and according to the cannulation technique used. The presence of particular organisms depends on local epidemiology, antibiotic exposure, and the duration of the intervention; patients undergoing ECMO for more than three weeks present a high risk of persistent candidemia. Recognizing predisposing factors, and establishing the best preventive interventions and therapeutic choices are critical to optimizing the management of these complications. Infection control practices, including shortening the period of the indwelling devices, and reducing antibiotic exposure, must be followed meticulously. Innovations in oxygenator membranes require an updated approach. Hand hygiene and avoiding breaking the circuit-oxygenator sterility are cornerstones. ECMO management would benefit from clearer definitions, optimization of infection control strategies, and updated infectious clinical practice guidelines.

El objetivo de este estudio es analizar la incidencia de infección en los niños tratados con ECMO, el tratamiento y su evolución.

Se realizó un estudio retrospectivo basado en una base de datos prospectiva en el que se incluyeron los niños menores de 18 años asistidos con ECMO entre septiembre de 2006 y noviembre de 2015. Se recogieron las características de los pacientes, la ECMO, los cultivos y el tratamiento de la infección.

Se estudiaron 100 pacientes de 11 meses de edad mediana. El diagnóstico fue de cardiopatía en 94 pacientes. Se sospechó una infección y se inició antibioterapia en 51 pacientes, aunque solo se confirmó microbiológicamente en 22. Las infecciones más frecuentes fueron la sepsis (49%), neumonía (35,3%) e infección urinaria (9,8%). No existieron diferencias en los parámetros hematológicos y reactantes de fase aguda entre los niños con infección y el resto. Los niños que fallecieron presentaron mayor incidencia, no estadísticamente significativa, de infección durante la ECMO (60,4%) que los supervivientes (40,3%) (p = 0,07). La duración de ingreso en la UCIP fue mayor, sin significación estadística, en los pacientes con infección que en el resto: 57 frente a 37 días (p = 0,067).

La frecuencia de infección en niños con ECMO es elevada, pero menos de la mitad son confirmadas microbiológicamente, sin existir parámetros específicos de infección. No se ha encontrado relación estadísticamente significativa de la infección con la mortalidad y la duración de ingreso en la UCIP.

The aim of this study was to analyse the incidence, treatment and evolution of infections in children treated with ECMO.

A retrospective study based on a prospective database was performed. Children under the age of 18 years treated with ECMO from September 2006 to November 2015 were included. The patients’ clinical characteristics were collected, together with ECMO technique, cultures and treatment of infection.

One hundred patients with a median age of 11 months were analysed. Heart disease was diagnosed in 94 patients. An infection was suspected and antibiotic treatment was initiated in 51 patients, although only 22 of them were microbiologically confirmed. The most common infection was sepsis (49%), followed by pneumonia (35.3%) and urinary tract infection (9.8%). There were no differences in haematological parameters and acute phase reactants between children with infection and those without. Children who died had a higher incidence of infection during ECMO (60.4%) than the survivors (40.3%), but the difference did not reach statistical significance (P = .07). The duration of admission in the PICU was 57 days in patients with infection vs 37 days in patients without infection but the difference was not statistically significant (P = .067).

Infection in children with ECMO is common. There are no specific infection parameters and less than half of the clinical infections are confirmed microbiologically. There was no statistically significant correlation between infection and mortality or duration of PICU stay.

Continuous renal replacement therapy (CRRT) is a specialized type of dialysis. However, the characteristics and factors associated with nosocomial pneumonia in patients undergoing CRRT have received little attention to date. Therefore, this study investigated the characteristics of and factors contributing to nosocomial pneumonia in patients receiving CRRT.

The clinical data of 1160 patients undergoing CRRT during the period January 2008 to December 2015 were analyzed retrospectively. Of these 1160 cases, 145 (12.5%) were included in the nosocomial pneumonia group, while 1015 were included in the control group.

The primary pathogen in the 145 cases of nosocomial pneumonia in the CRRT patients was Staphylococcus aureus (58.57%); the morbidity rate was 12.5%. Multivariate logistic regression analysis revealed that age (odds ratio (OR) 2.209), initial curative time (OR 1.960), underlying diseases (OR 1.820), consciousness disorder (OR 1.616), organ failure (OR 2.154), the Acute Physiology and Chronic Health Evaluation II score (APACHE II) (OR 1.186), and the Charlson Comorbidity Index score (CCI) (OR 1.278) were risk factors for nosocomial pneumonia (all p < 0.05). Conversely, the serum white blood cell count (OR 0.585), albumin (OR 0.673), and hemoglobin (OR 0.712) levels were protective factors (all p < 0.05).

Results from this study indicate that by modifying risk factors, such as providing adequate nutrition, earlier treatment of underlying diseases, and controlling organ failure, the risks associated with nosocomial pneumonia may be reduced.