Factores asociados a infecciones nosocomiales en sitio quirúrgico para craneotomía / Factors associated with nosocomial surgical-site infections for craniotomy in Mexico City hospitals

RESUMEN

Introducción: La infección nosocomial en sitio quirúrgico (INSQ) en craneotomía puede ocasionar la muerte o discapacidad que modifica la calidad de vida, por lo que se requiere encontrar factores que puedan ser utilizados para incluir en los índices de control. Por ello es necesario identificar factores asociados a esta infección y obtener el riesgo de infección atribuible y comparar su capacidad predictiva con el índice del NNISS (Sistema de Vigilancia Nacional de Infecciones Nosocomiales de Estados Unidos). Material y métodos: Se realizó un estudio de casos y controles durante dos años, en pacientes con craneotomía en hospitales del Instituto Mexicano del Seguro Social. Los pacientes cumplieron los criterios de los Centros de Control de Enfermedades de Atlanta para INSQ. Resultados: Se practicaron 737 craneotomías durante el estudio, 41 pacientes presentaron INSQ. Factores intrínsecos asociados: presencia de enfermedades crónicas (OR = 2.18) y craneotomía debida a causas no traumáticas (OR = 1.87); factores extrínsecos: turno vespertino (OR = 2.6) y la práctica de otra cirugía en el mismo sitio quirúrgico (OR = 5.2). Estos factores conformaron los índices de factores intrínsecos y extrínsecos. Con factores extrínseco se presentó 1.7 veces más riesgo en comparación con los factores intrínsecos, así como mayor área bajo la curva ROC (0.731). El riesgo con el índice NNISS con un factor fue de 1.5 y con dos a tres factores, de 4.7. Conclusiones: En esta población en estudio, los pacientes sometidos a una craneotomía tuvieron mayor asociación a INSQ con los factores extrínsecos.

ABSTRACT

BACKGROUND: Nosocomial surgical-site infection (NSSI) after craniotomy is responsible for an increase in deaths and/or disabilities that affect quality of life. It is necessary to identify factors to be included in an index for their control. The aim of this study was to a) identify intrinsic and extrinsic factors associated with NSSI after craniotomy and b) obtain the infection risk attributed to both intrinsic and extrinsic factors as well as to compare their predictive capability with the NNISS (National Nosocomial Infection Surveillance System) index. METHODS: A case-control study was conducted during a 2-year period in patients who underwent craniotomy in hospitals affiliated with the Instituto Mexicano del Seguro Social. Patients were selected according to the Centers for Disease Control and Prevention criteria for NSSI. RESULTS: During the study period 737 craniotomies were performed, 41 of which presented with NSSI. Intrinsic factors associated with NSSI were the presence of chronic diseases (OR = 2.18) and craniotomy due to nontraumatic causes (OR = 1.87), whereas extrinsic factors were procedures performed during the late shift (OR = 2.6) and another surgery at the same surgical site (OR = 5.2). These factors comprised the index with intrinsic and extrinsic factors. Extrinsic factors were 1.7 times higher than intrinsic factors, in addition to having a larger area under the ROC curve (0.731). The risk obtained with the NNISS index for patients who had one factor was 1.5, whereas that for patients who had two or three factors was 4.7. CONCLUSIONS: In the studied population, patients who underwent a craniotomy with extrinsic factors showed a higher association with NSSI.