Targeting the ‘Science of Uncertainty’ in the Cath Lab: Managing Occupational Hazards
Sir Williams Osler described the practice of medicine as “the science of uncertainty and the art of probability.” This is particularly true for occupational medicine, in which work-related injuries are probable but hard to predict. In interventional cardiology in particular, physicians report occupational hazards at an unprecedented rate. Specifically, disability appears most prevalent among those performing prolonged cases, usually complex high-risk percutaneous coronary or peripheral vascular interventions. Patients requiring these procedures represent a fast-growing percentage of interventional practice. In a 2014 survey of Society for Cardiac Angiography and Interventions (SCAI) members, 49% of physicians reported musculoskeletal work-related injuries, with back and neck traumas being most prevalent. This is up from 42% in 2004. It is also worth noting that interventional cardiology often involves high-stress situations in which physicians must make quick decisions about life-threatening situations.
The long-term occupational consequences of working in the cath lab can be classified into 3 major categories:
1. Orthopedic injuries
The effect of standing for long hours while wearing lead aprons was first demonstrated in a 1997 cohort study comparing interventionalists with orthopedists and rheumatologists (who mostly did not wear lead). The interventionalists reported markedly higher rates of back pain and days out of work compared with the other groups. Strategies to decrease this problem included replacing lead aprons with lighter-weight materials, using zero-gravity weightlessness shields, and implementing robotic-assisted equipment. Robotic PCI has been tested in clinical trials, but its benefits remains to be determined.
2. Radiation-induced illness
The effects of radiation are perhaps the most feared occupational hazard in the cath lab, particularly because they are still unknown. X-ray injuries can be deterministic—a direct effect of radiation—or stochastic—a random effect. Historically, the association between radiation and cancer, as well as DNA mutation, has only been observed in survivors of the atomic bomb. Not surprisingly, there is evidence of a direct correlation between years of interventional practice and the presence of DNA mutations, too. To date, a consistent association between malignancies and interventional cardiology is lacking, but increased cases of left-sided brain tumors have been reported. Another one of the most common side effects of radiation exposure is the development of cataracts. Initially, these were considered a deterministic effect with a specific cumulative radiation threshold; however, new data suggest that cataracts are also caused stochastically.
Despite these possible risks, at least 28 percent of operators in the aforementioned SCAI survey reported not consistently monitoring their exposure by wearing radiation badges. Other best practices in radiation protection include limiting exposure time; setting low-dose imaging defaults; maintaining a proper distance from the radiation source; and using shields such as lead table skirts, gloves, and head shields.
Accidental exposure can transmit blood-borne pathogens to the operator, and the rate of occupational needle-stick interventional procedures is underreported. Possible reasons for this include the time-consuming paperwork to report an incident, inability to leave the surgical suite, likelihood of being out of work after an incident, and inadequate support for making an incident report after regular hours. Similarly, the rate of glove perforations during interventions—overt and occult—is estimated up to 1%, and this rate increases with procedure length. Thus, the use of double gloves seems reasonable based on the data from cross-sectional studies. Another potential source of infection includes the spraying and splashing of blood while exchanging catheters or purging bloody syringes.
Occupation-related injuries exist in all jobs, but I have been unable to find any risk calculators that estimate the probability of disability. Specifically in medicine, a systematic review of studies on occupational disease among UK physicians showed that 80% of surgeons reported back pain while operating while 72% of otolaryngologists and 54% of ophthalmologists reported neck pain. Considering this, I can conclude that the risks of working in the highly rewarding field of interventional cardiology are no greater than those associated with any field. It is up to us, then, to maintain our own safety by following recommended precautions while working in the lab.
I’d like to acknowledge my mentors Nidal Abi Rafeh, MD, and Anand Irimpen, MD, who gave me the idea of writing about these experiences.