Though the CDC has issued guidelines to limit the number of OR door openings to a minimum and to limit the number of people in the OR [14
], there is no baseline information on normal or essential OR human traffic. This study provides the baseline human traffic information in Pediatric Orthopaedic ORs. Since there was no significant change in the traffic pattern between the two phases of this study, all traffic could be considered essential. This data can be used to compare OR traffic patterns between specialties, institutions or following an intervention.
It has been shown that OR door opening decreases the effectiveness of the ventilation system to clear potential contaminants [6
]. Lynch et. al.[15
] reported that three common reasons for OR door openings were information issues (ask question, check on case status, or process paperwork), personnel entering or leaving for breaks, and supply issues. Though we didn’t study the reasons for OR door openings, it was observed in phase II, that OR personnel would open the door and communicate, without actually entering or leaving the OR. Though this didn’t affect the number of door openings in the study, it does represent an opportunity for improvement. OR personnel (nursing group and anesthetist group) entering or leaving the OR for breaks or shift changes is a frequent cause of concern during a surgical case. As expected, there was a positive correlation between the duration of surgery and number of OR personnel shift changes. The shift change is a frequent cause of distraction and interruption for the operating surgeon, and the transfer of care between OR personnel have been reported to increase the likelihood of medical errors [16
]. The supply related OR traffic disruption could be reduced by updated surgeon or procedure specific preference cards, especially for routine cases, and better communication with the OR personnel prior to the procedure.
] found an increase in the bacterial count when the OR door was left open. The proximity of the scrub sink and unsterile corridor have been implicated as the cause of OR contamination, especially when the OR door was open [17
]. In the current study, the average number of door swings per hour was approximately 40. This is similar to other studies which have found the average number of door swings per hour to range from 37 [15
] to 56 [13
]. For a longer case (e.g., spine surgery), which can last for more than 5 hours, the average number of door swings during the entire case could approximate 200. The OR personnel in the current study expressed concern when this information was shared with them.
There was a statistically significant increase in the number of OR personnel when the duration of surgery was greater than 120 minutes and during spine procedures. The explanation is that certain complex or lengthy surgical procedures, and spine procedures may need more resources and OR personnel (imaging personnel, electro physiologic monitoring personnel, implant representative, surgical assistants) and may have more observers and students, compared to a relatively short procedure. Since the number of OR personnel and duration of surgery are positively correlated to the number of door openings, the rate of traffic during such procedures is remarkably high. Pryor and Messmer [18
] analyzed 2864 clean surgical procedures and noted that duration of surgery was a statistically significant risk factor for SSI, and there was a rising trend in SSI, as number of OR personnel increased. Ritter [9
] recommended that the length of time for surgery and number of OR personnel should be reduced to decrease the environmental contamination.
We observed a trend of increased OR personnel during the middle of the surgical case, especially in longer cases. Lynch et. al. [15
] noticed an increase in the number of OR personnel in the pre-incision phase while the patient and room preparation were under way and when the staff were arriving in the OR. We didn’t initiate monitoring before the patient was in the room, since we considered the room set up and patient preparation as essential. The observed trend of increased OR personnel in the middle of the case can be attributed to the use of fluoroscopic image guidance and/or electro physiologic monitoring, and the presence of observers and vendor representatives during the middle of a surgical case and not during incision and closure.
The Hawthorne effect refers to the change in performance of subjects due to the knowledge that they are being observed or studied. It was first described by Elton Mayo, a Harvard business professor, during studies of worker productivity at the Hawthorne Works plant near Chicago. This concept has been applied to various scientific experiments like hand hygiene [19
], pain assessment [20
], or emergency room care [21
]. Our current study was performed to evaluate the behavior of OR personnel and human traffic patterns in the OR, and then to determine if there was a Hawthorne effect. Contrary to our expectation, there was no significant change in the number of door swings, maximum or minimum number of people in the OR, or changes in OR personnel in the nursing, anesthetist or surgeon group between the two phases, i.e., before and after surveillance. One reason for lack of Hawthorne effect on OR traffic pattern could be that all traffic was considered necessary by the OR personnel. Another reason could be the lack of reward or motivation and reluctance to any change by the OR personnel which could be typical in larger institutions. To achieve meaningful improvement in the OR traffic pattern, instead of just informing the OR personnel and monitoring them, future studies should include OR personnel as a part of a team in the development of the protocols, and goals and incentives should be a part of the study.
Based on this study and review of literature, several recommendations can be made to decrease the human traffic in the OR. Frequently OR personnel would enter the OR to find out the progress of the case, ask questions, or to process paperwork. The evolvement of ‘paperless’ hospital practice and introduction of computerized case tracking system, an intercom system or real-time OR video monitoring system would help in efficient communication between personnel outside and inside the OR. A measure as simple as a glass window and phone should be used for informational issues, instead of opening the OR door. The frequent change in shifts or breaks for nursing and anesthetist personnel during surgical case does not only increase the OR traffic but frequently causes distraction during a procedure. How common is it that the surgical case may just have started, and there is a change in staff? A surgical coordinator should be responsible for assigning the staff in a way that the need to switch nurses or anesthesia providers, especially during a short case, is minimized. Though all the supplies that a surgeon would need during surgery cannot be anticipated, frequently used supplies like sutures should be stored in the OR console. The surgeon and procedure-specific preference cards should be kept updated, so that the supplies and equipments needed for a particular case are readily available in the OR. Preoperative communication with the surgeon about specific requirements is imperative. An efficient way of minimizing OR traffic related to supplies would be placement of pass-through windows in the OR, thus allowing access to the supplies from inside and outside the OR with minimal traffic disruption. Visitors, observers and vendors should be educated about the importance of OR traffic. Though medical students and observers should get the opportunity to observe surgical cases, their numbers should be limited during each procedure. For complex cases or high-risk cases like joint replacement, spine surgeries or revision procedures, a sign on the door cautioning the OR personnel against entering the OR, should be encouraged. An option to decrease the number of door swings during the case would be to have an automatic door counter above the door, visible to OR personnel and then set goals on a periodic basis to facilitate improvement in the OR traffic pattern. Surgical quality improvement projects should include the OR traffic pattern as an important parameter.
One limitation of the study is its small sample size and it being limited to Pediatric Orthopaedic ORs at one institution. This study was initiated as a pilot study to achieve baseline information about OR traffic patterns and to study the effect of human surveillance. Future projects should include all surgical specialties and more sophisticated data collection. Another limitation of the study is the lack of correlation of studied parameters to OR contamination, patient factors and outcomes and thus SSI. In future studies, a patient tracking system should be incorporated within the OR traffic data collection, as it might lead to more meaningful conclusions. Also, in future studies, the OR personnel should be included as a part of study or monitoring team.