Aerosol generating procedures (AGP) and risk of transmission of acute respiratory diseases (ARD): a systematic review

Abstract

Introduction/objectives: The risk of transmission of ARDs to HCWs from AGPs is not fully known. We sought to determine the evidence for the risk of transmission of acute ARDs to HCWs caring for patients undergoing and not undergoing AGPs. Method(s): We searched PubMed, Medline, Embase, Cinahl, the Cochrane Library, Univ of York CRD databases, EuroScan, LILACS, Indian Medlars, Index Medicus for SE Asia, health technology agencies and the Internet in all languages for articles from 01/01/1990 - 22/10/2010. Abstracts and full text articles were screened and included using pre-defined criteria. Disagreements were resolved by consensus and a 3rd reviewer. Data were extracted and verified by a 2nd reviewer. The outcome of interest was risk of ARD transmission. The quality of evidence was rated using the GRADE system. Result(s): We identified 5 case-control and 5 retrospective cohort studies which evaluated transmission of SARS to HCWs. Procedures with an increased risk of transmission included [n; pooled OR(95%CI)] tracheal intubation [n=8; 6.2 (3.4, 11.3)], non-invasive ventilation [n=2;OR 3.1(1.4, 6.8)], tracheotomy [n=1; 4.2 (1.5, 11.5)] and manual ventilation before intubation [n=1;OR 2.8(1.3, 6.4)]. Other intubation procedures, ET aspiration, suction of body fluids, bronchoscopy, nebulizer treatment, administration of O2, high flow O2, manipulation of O2 mask or BiPAP mask, defibrillation, chest compressions, insertion of NG tube, and collection of sputum were not significant. Conclusion(s): Our findings suggest that some procedures have been associated with increased risk of SARS transmission to HCWs with the most consistent association across multiple studies identified with tracheal intubation. These findings must be interpreted in the context of the very low quality of the studies.