Assessment of muscle activity and fatigue during laparoscopic surgery.

BACKGROUND: Cumulative musculoskeletal stress during operative procedures can contribute to the development of chronic musculoskeletal injury among surgeons. This is a concern in laparoscopic specialties where trainees may incur greater risk by learning poor operative posture or technique early in training. This study conducted an initial investigation of the physical stress encountered during the conduct of foregut laparoscopic surgery. METHODS: Subjects were divided into two groups based on their surgical experience level, high experience (HE), consisting of two attending surgeons, and low experience (LE), consisting of two fellow surgeons and a surgical chief resident. Nine distinct foregut laparoscopic procedures were observed for data collection within these groups. Electromyographic (EMG) activity was collected at the bilateral neck, shoulders, biceps, triceps, and lower back for each procedure. Physical workload was measured using percent reference voluntary contractions (%RVC) for each surgeon's muscle activities. Fatigue development was assessed using the median frequency of EMG data between two consecutive cases. Subjects completed a NASA-TLX survey when surgery concluded. RESULTS: LE surgeons experienced higher levels of %RVC in the lower back muscles compared to HE surgeons. LE fatigue level was also higher than HE surgeons across most muscle groups. A decrease in median frequency in six of the ten muscle groups after performing two consecutive cases, the largest decrements being in the biceps and triceps indicated fatigue development across consecutive cases for both surgeon groups. CONCLUSION: Surgeons developed fatigue in consecutive cases while performing minimally invasive surgery (MIS). HE surgeons demonstrated a lower overall physical workload while also demonstrating different patterns in muscle work. The findings from this study can be used to inform further ergonomic studies and the data from this study can be used to develop surgical training programs focused on the importance of surgeon ergonomics and minimizing occupational injury risk.

A Buddhist perspective on industrial engineering and the design of work.

The modern way of life is highly dependent upon the production of goods by industrial organizations that are in turn dependent upon their workers for their ongoing operations. Even though more than a century has passed since the dawn of the industrial revolution, many dangerous aspects of work, both physical and mental, remain in the workplace today. Using Buddhist philosophical principles, this paper suggests that although many sources of the problem reside within the larger society, the industrial engineer is still a key factor in bettering work and providing a workplace suitable for their fellow workers. Drawing on these insights, we present a number of work design guidelines that industrial engineers who abide by Buddhist principles could practice to help overcome some of the many sufferings produced by modern work.

Realistic distractions and interruptions that impair simulated surgical performance by novice surgeons.

HYPOTHESIS Although the risks for operating room distractions and interruptions (ORDIs) are acknowledged, most research on this topic is unrealistic, inconclusive, or methodologically unsound. We hypothesized that realistic ORDIs induce errors in a simulated surgical procedure performed by novice surgeons. DESIGN, SETTING, AND PARTICIPANTS Eighteen second-year, third-year, and research-year surgical residents completed a within-subjects experiment on a laparoscopic virtual reality simulator. Based on 9 months of operating room observations, 4 distractions and 2 interruptions were designed and timed to occur during critical stages in simulated laparoscopic cholecystectomy. The control factor was the absence or presence of ORDIs, with order randomly counterbalanced across the subjects. MAIN OUTCOME MEASURES The primary outcome measure was surgical errors measured by the simulator as damage to arteries, bile duct, or other organs. The second outcome measure was whether the participants remembered a prospective memory task assigned prior to the procedure and important to operative conduct. RESULTS Major surgical errors were committed in 8 of 18 simulated procedures (44%) with ORDIs vs only 1 of 18 (6%) without ORDIs (P = .02). Interrupting questions caused the most errors. Sidebar conversations were the next most likely distraction to lead to errors. Ten of 18 participants (56%) forgot the prospective memory task with ORDIs, while 4 of 18 (22%) forgot the task without ORDI (P = .04). All 8 surgical errors with ORDIs occurred after 1 PM (P = .001). CONCLUSIONS Typical ORDIs have the potential to cause operative errors in surgical trainees. This performance deficit was prevalent in the afternoon.

Use of modeling to identify vulnerabilities to human error in laparoscopy.

This article describes an exercise to investigate the utility of modeling and human factors analysis in understanding surgical processes and their vulnerabilities to medical error. A formal method to identify error vulnerabilities was developed and applied to a test case of Veress needle insertion during closed laparoscopy. A team of 2 surgeons, a medical assistant, and 3 engineers used hierarchical task analysis and Integrated DEFinition language 0 (IDEF0) modeling to create rich models of the processes used in initial port creation. Using terminology from a standardized human performance database, detailed task descriptions were written for 4 tasks executed in the process of inserting the Veress needle. Key terms from the descriptions were used to extract from the database generic errors that could occur. Task descriptions with potential errors were translated back into surgical terminology. Referring to the process models and task descriptions, the team used a modified failure modes and effects analysis (FMEA) to consider each potential error for its probability of occurrence, its consequences if it should occur and be undetected, and its probability of detection. The resulting likely and consequential errors were prioritized for intervention. A literature-based validation study confirmed the significance of the top error vulnerabilities identified using the method. Ongoing work includes design and evaluation of procedures to correct the identified vulnerabilities and improvements to the modeling and vulnerability identification methods.