Long exposure to operating room (OR) disinfectants and surgical smoke may significantly increase the risk of developing chronic obstructive pulmonary disease (COPD), according to a study led by Boston University School of Public Health (BUSPH) researchers.
Disinfectants and surgical smoke, the gaseous by-product produced by heat-generating surgical instruments, are among the hazardous chemicals to which physicians, nurses, and other hospital staff are exposed in operating rooms (OR) during electrosurgery and laser procedures
Published in the journal JAMA Network Open, the study focused on nurses, and found that COPD risk among them varied by nursing job type and duration in the OR. Nurses who worked in the OR for 15 or more years were 69% more likely to develop COPD, compared with nurses who had never worked in an OR and worked in an administrative or nursing education role, or a non-nurse job.
The study was an international collaboration with researchers from BUSPH, Harvard Medical School, Brigham and Women’s Hospital, and Inserm National French Institute of Health & Medical Research, and it is the first to assess the role of occupational exposure to surgical smoke and COPD risk. It was funded by the National Institutes of Health and Ethicon, a subsidiary of the Johnson & Johnson Medical Devices Companies.
For the study, researchers analysed data on OR employment history and COPD incidence among a cohort of 75,011 nurses working in US hospitals in 1984. The participants are part of the NIH-funded Nurses' Health Study (NHS), an ongoing, prospective study of more than 121,000 US female nurses ages 30-55 who have completed biennial questionnaires since 1976. OR employment duration served as a proxy for nurses’ exposure to inhaled agents, and the study adjusted for primary COPD risk factors such as cigarette smoking and chronic disease.
Compared with nurses who had no OR employment and worked in administrative or nursing education roles, or in a non-nurse job, the study found that inpatient and outpatient nurses had higher risks (31% and 24%, respectively) of developing COPD, and nurses with less than 15 years of OR experience had a 22% higher risk.
When comparing OR nursing employment only, OR employment for 15 or more years was associated with a 46% increased risk of nurses developing COPD compared to nurses with no OR employment.
“One of the inherent challenges with assessing the health risks of disinfectants and surgical smoke is that it is difficult to measure exposure with precision over an extended period of time and among a large population,” says study lead author Wubin Xie, postdoctoral association in the Department of Global Health at BUSPH.
“Our results, based on data from a large cohort of nurses, show that long-time occupational exposure to these agents in operating rooms leads to a significantly higher risk of developing COPD.”
Although the study data reflects working conditions in the OR during the 1980s, the findings are applicable to today’s OR environment, the researchers say. Disinfectant use has increased over the past decades, and there is little evidence that the hazard of surgical smoke has reduced.
“Smoke-generating laparoscopic surgery is performed in a broader range of procedures, and protective surgical masks, such as the N95 mask, cannot block the small particulates in surgical smoke,” says Xie, and smoke evacuation systems, which capture smoke aerosols and gases emitted during procedures, have not been implemented in many operating rooms.
Today’s more diversified nursing workforce and the COVID-19 pandemic are also factors that could possibly impact OR nurses’ risk of developing COPD, says study corresponding author Andrew Stokes, assistant professor of global health at BUSPH.
The NHS population was predominantly white, reflecting the demographics of registered nurses in 1976. “Additional studies with more detailed and recent exposure assessment are needed to better understand COPD risk among hospital staff exposed to toxic agents in the operating room,” says Stokes.
Study details
Association of Occupational Exposure to Inhaled Agents in Operating Rooms With Incidence of Chronic Obstructive Pulmonary Disease Among US Female Nurses
Wubin Xie, Orianne Dumas, Raphaëlle Varraso, Krislyn Boggs, Carlos Camargo Jr, , Andrew Stokes.
Published in JAMA Network on 20 September 2021
Key Points
Question Is there an association between a history of operating room (OR) employment, as proxy for exposure to inhaled agents such as surgical smoke and disinfectants, and incidence of chronic obstructive pulmonary disease among female nurses in the US?
Findings In this cohort study of 75 011 US female nurses, nurses with 15 or more years of OR employment had a 69% greater risk of developing chronic obstructive pulmonary disease compared with those who never worked in an OR and had an administrative or nursing education function or non-nursing job.
Meaning These findings suggest that exposure to inhaled agents in the OR may be associated with independent health risks to the respiratory system.
Abstract
Importance
Employment in operating rooms (ORs) may involve exposure to several inhaled agents, including surgical smoke and disinfectants, which are associated with adverse respiratory health effects. However, the association of long-term employment in ORs and chronic obstructive pulmonary disease (COPD) remains unknown.
Objective
To examine the association of working in an OR with incidence of COPD among female nurses in the US.
Design, Setting, and Participants
This cohort study used data from the Nurses’ Health Study for US female registered nurses who provided information on questionnaires regarding OR employment history in 1984 and job type in 1982 and who had no history of COPD in 1984 (baseline). Data analyses were conducted from April 1, 2020, to January 31, 2021.
Main Outcomes and Measures
The associations of any employment as an OR nurse, duration of employment, and duration and job type with incidence of self-reported, physician-diagnosed COPD. Hazard ratios (HRs) and 95% CIs were estimated using Cox proportional hazards regression models stratified by age and calendar year. Models were adjusted for covariates, with model 1 adjusting for age, model 2 also adjusting for cigarette smoking status and pack-year of smoking, and model 3 also adjusting for race and ethnicity, US Census region, and body mass index.
Results
Among 75 011 female nurses included in the analyses, the mean (SD) age at baseline was 50.5 (7.2) years; 29% had a history of employment in an OR, and 3% had 15 or more years of OR experience. In model 3, employment in an OR for 15 or more years was associated with a 46% increased risk of developing COPD compared with no history of OR employment (HR, 1.46; 95% CI, 1.10-1.93). Compared with nurses who never worked in an OR and had an administrative or nursing education function or a nonnursing job in 1982, the risk of developing COPD was greater among nurses who provided outpatient care (HR, 1.24; 95% CI, 1.04-1.47) and nurses employed in inpatient units (HR, 1.31; 95% CI, 1.07-1.59) who had no history of OR employment and was 69% greater among nurses with OR experience of 15 years or more (HR, 1.69; 95% CI, 1.25-2.28).
Conclusions and Relevance
In this cohort study, OR employment of 15 years or more was associated with an increased risk of developing COPD among female nurses. Additional studies with more recent and direct environmental monitoring data of multiple occupational exposures are needed to assess the relative role of exposure to surgical smoke and disinfectants in the observed association.
Introduction
Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide and in the US. Although tobacco smoking is the primary factor associated with COPD, increasing evidence suggests that occupational exposure is another important contributor to the burden of disease.
Health care is among the largest sectors in the US economy, with more than 18 million individuals employed, and nearly 80% are women. Disinfectants and surgical smoke, a visible acrid gaseous by-product from laser tissue ablation, electrocautery, and ultrasonic scalpel tissue dissection, are among the widely studied hazardous chemicals that are present in health care settings. Disinfectants used in health care settings contain a large variety of active ingredients, such as formaldehyde, hypochlorite, hydrogen peroxide, glutaraldehyde, all of which are capable of causing injury to the airway epithelium and oxidative stress and may be associated with neutrophilic inflammation.
Surgical smoke consists of carbon monoxide, polyaromatic hydrocarbons, nitriles, fatty acids, phenols, benzene, hydrogen cyanide, formaldehyde, viable and nonviable cellular materials, viruses, and bacteria and has been shown to induce inflammatory pulmonary changes in animals after repeated exposure and to have mutagenic potential in laboratory and animal studies. Many studies have documented increased incidence or prevalence of asthma or respiratory symptoms associated with exposure to disinfectants among individuals with different occupations, although these studies largely focused on asthma.
The level of exposure to disinfectants tends to vary by specific job types. Previous studies have suggested that operating room (OR) nurses have the highest level of self-reported disinfectant use, followed by nurses employed in emergency departments or inpatient units. In addition to disinfectant exposure, OR nurses are also exposed to surgical smoke, another respiratory irritant that has been shown to be associated with acute respiratory toxicity. Despite studies showing irritant properties of chemicals contained in disinfectants and surgical smoke, the association of long-term employment in an OR (and prolonged exposure to these respiratory irritants) with COPD remains unknown.
Investigations of the long-term potential health risks of exposure to surgical smoke and disinfectants are rare because of the inherent challenges to obtaining valid estimates of exposure to surgical smoke over extended periods in a large population cohort. Using the duration of operating room nursing (ORN) as a proxy for cumulative surgical smoke exposure, Gates et al found no association of ORN with lung cancer prospectively assessed for a maximum 16 years of follow-up among a cohort of US nurses. Other studies have used nursing job type (eg, education or administration, outpatient care or other nursing role, emergency department or inpatient care, and OR) as a proxy for disinfectant exposure levels to assess asthma control and risk of developing COPD.
To our knowledge, the association of OR employment history with COPD has not been investigated in a large population. Using data from the Nurses’ Health Study (NHS), a large prospective cohort study of US female nurses, we assessed the association of OR employment with COPD by incorporating both duration of ORN and job type to proxy potential exposure to disinfectants and surgical smoke. We hypothesised that, independent of cigarette smoking and other important confounders, nurses with any history of employment in an OR would be more likely to develop COPD compared with those with no OR employment history.
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