Study: Intraoperative noise volume linked to surgical site infections
Intraoperative noise volume was found to be associated with surgical site infections (SSI) in a study of 35 patients published May 27 in the British Journal of Surgery.
A. Kurmann, MD, of the department of visceral surgery and medicine at the University of Neuchatel in Neuchatel, Switzerland, and colleagues measured the decibels of an operating room to quantify the effect of noise on SSIs.
SSIs have been noted to increase hospital stays from seven to 13 days, multiplying costs by as much as three times, Kurmann et al wrote, and procedural- and patient-related factors are important to understanding them. The most important procedurally related factors include type of surgery, duration and intraoperative blood loss. Patient-related factors include the primary diagnosis and other co-morbidities, but the two most relevant risk factors for SSI are body mass index (BMI) and duration of operation, according to the authors.
Conducted between May and December 2008, the researchers studied 35 patients undergoing elective major abdominal surgery, 17 percent of whom got a SSI. All participants received antibiotic prophylaxis and were examined during their postoperative stay. Investigators used a sound measuring device to measure noise intensity during their surgeries.
An independent experienced scrub nurse meanwhile evaluated 29 of the 35 procedures using a standard questionnaire developed to measure adherence to the principles of asepsis, according to the authors. Eight items were rated as absent or present: the lack of adherence to standard antiseptic protocol, general impression (repetitive violations present), conversation focused on the operation, non-patient-related conversation, unfocused conversation by anesthetists, intraoperative change in patient position, five or more team members replaced and 10 or more people in the operating theater.
Researchers noted that noise levels were not related to the majority of items in the discipline score, although there was an association between non-patient-related conversation and sound level. The duration of surgery was uninfluenced by sound level and there was no difference in median sound between the two types of surgery performed: colorectal and hepatopancreatobiliary. Age, sex, BMI and the American Society of Anesthesiologists fitness score were not significantly related to the development of SSI, they noted.
However, “median sound levels during surgery were significantly higher for patients who developed a SSI than for those with primary healing,” the authors wrote. “In addition, the median sound levels above baseline were significantly higher for patients who developed a SSI.”
“Measurement of operating theatre sound level has been done before. However, previous studies did not focus on a clinical outcome such as SSI,” Kermann et al wrote. “The present study showed that the median sound level and the median level above baseline were significantly higher for patients who developed a SSI.”
“Intraoperative noise volume was associated with SSI. This may be due to a lack of concentration, or a stressful environment, and may therefore represent a surrogate parameter by which to assess the behavior of a surgical team,” the authors concluded.
In an accompanying commentary, A. Darzi, MD, of the division of surgery, Imperial College London, praised Kurmann and colleagues’ study for both its size, and its investigation of the impact of noise--a stressor that most surgeons face.
“The authors are to be commended on seeking clinically important parameters concerning quality and safety against which to measure outcome,” Darzi wrote. “It is also worth noting that this research stems from a simple research question and did not involve multicentre trial, yet it produced interesting and relevant results for the surgical community. Not all great research need necessarily be on a large scale; surgeons should be encouraged to examine the day-to-day problems they encounter and seek innovative ways to investigate them.”
A. Kurmann, MD, of the department of visceral surgery and medicine at the University of Neuchatel in Neuchatel, Switzerland, and colleagues measured the decibels of an operating room to quantify the effect of noise on SSIs.
SSIs have been noted to increase hospital stays from seven to 13 days, multiplying costs by as much as three times, Kurmann et al wrote, and procedural- and patient-related factors are important to understanding them. The most important procedurally related factors include type of surgery, duration and intraoperative blood loss. Patient-related factors include the primary diagnosis and other co-morbidities, but the two most relevant risk factors for SSI are body mass index (BMI) and duration of operation, according to the authors.
Conducted between May and December 2008, the researchers studied 35 patients undergoing elective major abdominal surgery, 17 percent of whom got a SSI. All participants received antibiotic prophylaxis and were examined during their postoperative stay. Investigators used a sound measuring device to measure noise intensity during their surgeries.
An independent experienced scrub nurse meanwhile evaluated 29 of the 35 procedures using a standard questionnaire developed to measure adherence to the principles of asepsis, according to the authors. Eight items were rated as absent or present: the lack of adherence to standard antiseptic protocol, general impression (repetitive violations present), conversation focused on the operation, non-patient-related conversation, unfocused conversation by anesthetists, intraoperative change in patient position, five or more team members replaced and 10 or more people in the operating theater.
Researchers noted that noise levels were not related to the majority of items in the discipline score, although there was an association between non-patient-related conversation and sound level. The duration of surgery was uninfluenced by sound level and there was no difference in median sound between the two types of surgery performed: colorectal and hepatopancreatobiliary. Age, sex, BMI and the American Society of Anesthesiologists fitness score were not significantly related to the development of SSI, they noted.
However, “median sound levels during surgery were significantly higher for patients who developed a SSI than for those with primary healing,” the authors wrote. “In addition, the median sound levels above baseline were significantly higher for patients who developed a SSI.”
“Measurement of operating theatre sound level has been done before. However, previous studies did not focus on a clinical outcome such as SSI,” Kermann et al wrote. “The present study showed that the median sound level and the median level above baseline were significantly higher for patients who developed a SSI.”
“Intraoperative noise volume was associated with SSI. This may be due to a lack of concentration, or a stressful environment, and may therefore represent a surrogate parameter by which to assess the behavior of a surgical team,” the authors concluded.
In an accompanying commentary, A. Darzi, MD, of the division of surgery, Imperial College London, praised Kurmann and colleagues’ study for both its size, and its investigation of the impact of noise--a stressor that most surgeons face.
“The authors are to be commended on seeking clinically important parameters concerning quality and safety against which to measure outcome,” Darzi wrote. “It is also worth noting that this research stems from a simple research question and did not involve multicentre trial, yet it produced interesting and relevant results for the surgical community. Not all great research need necessarily be on a large scale; surgeons should be encouraged to examine the day-to-day problems they encounter and seek innovative ways to investigate them.”