Endoscope decontamination; wearing rings under gloves; effects of Chinese herbal medicines; anesthetic adverse events

Efficacy of routine endoscope decontamination

American Journal of Infection Control

June 2006

Endoscopy is an important tool for monitoring severely ill patients, many of whom are immunocompromised and thus are at an increased risk for contracting an infection that may be introduced during the procedure. Indeed, such patients are likely to harbor high levels of bacteria and viruses, which may lead to contamination of the instruments that are used.

Flexible endoscopes, including gastrointestinal endoscopes, cannot withstand steam sterilization, so current guidelines for reprocessing require meticulous cleaning followed by a high-level disinfection process. Additionally, some guidelines, including those from Australia, recommend that duodenoscopes be sampled monthly, colonoscopes and gastroscopes every four months, and the automated decontamination system monthly. These recommendations have been developed from general principles; however, few direct attempts have been made to validate the recommendations for sampling and laboratory monitoring of decontamination procedures. The purpose of this study was to determine the efficacy of decontamination procedures related to patient and procedural parameters and to changes in the unit staffing or processing in a busy endoscopy unit.¹

During an 80-week period, each patient undergoing a procedure in the endoscopy unit was invited to participate in the study. The researchers collected data on patient demographics; diagnoses; and clinical and procedural information, including hepatitis status, type of endoscopy, biopsy retrieval, individual instrument used, attending medical and nursing personnel, and the name of the staff member who cleaned the endoscope. Additionally, the first 500 patients were contacted by telephone one month after their procedure and asked about any complications related to the procedure.

Endoscopes were reprocessed in accordance with guidelines from the Gastroenterological Society of Australia. The decontamination process involved three steps:

• •precleaning, in which the endoscope exterior was wiped and detergent was aspirated through the suction channel;
• •manual cleaning, in which the endoscope was immersed in an enzymatic detergent and the exterior and interior surfaces were cleaned using appropriate brushes; and
• •automated disinfection in a washer-disinfector using 2% gluteraldehyde for 20 minutes, followed by flushing with sterile water and then with isopropanol before undergoing forced air drying.

After completion of the decontamination cycle, wash samples from the internal surface of patient-ready endoscopes were obtained by flushing the endoscope biopsy channel with 20 mL of sterile diethyl pyrocarbonate-treated, phosphate-buffered saline. Samples were obtained from 14 endoscopes used on patients positive for hepatitis B and 48 endoscopes used on patients positive for hepatitis C. Samples from randomly selected washes negative for microbial growth from 56 gastroscopes and 53 colonoscopes also were assessed using polymerase chain reaction (PCR) to detect coliforms, which were used as a surrogate marker for biofilm in the endoscopes. Additionally, 58 gastroscopes used on patients with confirmed Helicobacter pylori (H pylori) infections were assessed for nucleic acid detection by PCR. Common statistical procedures, including the chi-square test, Fisher exact test, and linear regression techniques, were used to analyze the data.

Findings. None of the 500 patients who were telephoned after their endoscopy procedure had any complication that could be related to the procedure. Wash samples from patient-ready gastroscopes (n = 1,376) and colonoscopes (n = 987) were equally likely to grow bacteria (1.9% versus 1.8% contamination rate), with low numbers of bacteria commonly isolated from the nasopharynx or feces. The number of times a patient-ready endoscope was contaminated correlated with frequency of use (P < .001), and colonoscopes used on patients with gastrointestinal disease were significantly more likely to remain contaminated through the decontamination process (P < .05).

Coliform DNA suggesting biofilm presence was detected by PCR in 44 of 109 (40%) of the culture-negative washes; however, H pylori DNA was not detected on any of the 58 wash samples obtained from gastroscopes used on patients with confirmed H pylori. All other patient, staff member, and decontamination system parameters were not statistically significant.

Clinical implications. The results of this study revealed that the recommended decontamination procedures for endoscopes did not entirely eliminate persistence of low numbers of organisms on a few of the endoscopes; however, this is unlikely to result in serious consequences for patients. Additionally, it is known that biofilm is difficult to remove and therefore is likely to be a reason for the low level of bacterial persistence after routine decontamination. Perioperative managers should seriously consider instituting a microbiologic process including laboratory monitoring to periodically validate the effectiveness of their endoscope reprocessing procedures. In addition, they should encourage manufacturers to develop more effective cleaning and disinfection products and be prepared to assist in evaluating new techniques and products to eliminate biofilm.

Bacterial counts in gloves on hands with rings versus hands without rings

American Journal of Infection Control

September 2006

The surgical scrub is recognized as a critical step in preparing to perform a surgical procedure. It is recommended that surgeons and team members remove jewelry, including rings, before they perform a surgical scrub. Although most surgical team members are compliant with this recommendation, some are not physically able to remove their rings and others choose to be noncompliant. Noncompliance to this requirement is a concern because it is believed that

• •bacterial counts are higher under a ring,
• •there is an increased risk of glove perforation at the ring site, and
• •consequently, there is an increase in patients' risk for the development of surgical site infections.

The purpose of this study was to determine whether there is a difference between bacterial counts in surgical gloves of people wearing rings compared to people who were not wearing rings after a proper aseptic hand preparation and three hours of wear.²

Twenty veterinary medical students from Ohio State University, Columbus, Ohio, volunteered for the study. Participants in group I (n = 12) continuously wore a smooth ring band without projections or mounted stones on their ring finger for at least one month before the study. Participants in group II (n = 8) did not wear a ring. All the participants had nail lengths less than 5 mm and had not washed their hands with antiseptic surgical scrub for at least three days before the study began.

All the participants donned sterile gloves, and 20 mL of glove juice solution (ie, 0.075 mol/L phosphate-buffered normal saline solution containing 0.05% polysorbate 80) was instilled inside each glove separately. The glove was sealed to the participant's wrist with a rubber band and the participant rubbed the solution down the fingers of the glove using the opposite hand. With sterile technique being maintained, 5 mL to 10 mL of the liquid was removed from the cupped palm of the gloved hand with a catheter attached to a 20 mL syringe. The glove juice was transferred to a sterile container and sent for culture.

After the prescrub samples were taken, all the participants scrubbed their hands with a chlorhexidine gluconate scrub brush for five minutes using a standard hand-scrub process. The participants then donned sterile gowns and gloves and practiced soft tissue dissection on dog cadavers for three hours. Postscrub glove juice samples were collected at the end of the three hours.

Participants were asked to record suspected glove punctures throughout the surgical procedure and any obvious leakage of solution from their gloves during sampling. Gloves were then tested for perforation using the water pressure test, which involved filling the gloves with 1 L of water and sealing the cuff of the glove. The exterior surface was then blotted dry, and gentle pressure was exerted to examine all surfaces for leaks. Common statistical procedures were used to analyze the data.

Findings. One of the ring-wearing participants dropped out of the study because of illness. There was a statistically significant reduction in bacterial counts as measured by colony-forming units (CFU) between all prescrub (median 47.5 × 102 CFU/mL) and postsurgical (median 0.13 × 102 CFU/mL) bacterial counts. There was no difference in the change in bacterial counts before and after surgery between the ring and nonring hands for both the ring group and the all-participant group (ring-wearing participants only: 38.0 versus 12.25 median CFU/mL, P = 1.00; all participants: 38.0 versus 40.5 median CFU/mL, P = .74).

Eight of the 19 participants perforated at least one glove after three hours of surgery with the majority of perforations occurring at the fingertips (63.6%). Eight of the 11 perforations (73%) were made in the left (ie, ringed) hand with only one perforation made at the ring site.

Clinical implications. The results of this study demonstrated that there was no detectable difference in prescrub bacterial counts in ringed versus nonringed hands for both the ring-wearing group and the all-participant group. Perioperative managers should realize that this was a small study, and although this study did not find a difference in bacterial counts on ringed hands versus nonringed hands, further clinical studies are needed to determine whether individuals who wear rings under gloves increase bacterial loads in wounds or increase the risk of surgical site infections.

Adverse events and use of traditional Chinese herbal medicines

Anesthesiology

September 2006

The use of traditional Chinese herbal medicines (TCHMs) is widespread, and because they are considered to be effective and to have few side effects, they are increasingly being used throughout the world. There is growing evidence, however, about the potential harmful effects of some herbal medicines during the perioperative period, and the current recommendation is that all herbal medicines should be discontinued two weeks before surgery.

The most common adverse effects of herbal medicines relevant to anesthesiologists and surgeons include impaired coagulation, cardiovascular side effects, electrolyte disturbances, and prolongation of the effects of anesthetic agents. Patients do not routinely disclose their herbal medicine use, so anesthesia care providers and surgeons often are unable to make specific associations between potential medication-herbal interactions.

Generally, TCHMs prescribed by registered traditional Chinese medicine practitioners are prepared as a decoction, which is more potent and produces faster onset of action than TCHMs administered as a tablet. Consequently, it is hypothesized that the use of TCHMs prescribed by registered traditional Chinese medicine practitioners would be associated with an increased risk of perioperative events. The purpose of this cohort study was to determine the incidence and risk of TCHM-related perioperative events.³

Between January 2003 and September 2004 with a hiatus from March to June 2003 during the severe acute respiratory syndrome outbreak in Hong Kong, patients undergoing major elective surgery at a teaching hospital in Hong Kong that is affiliated with the Chinese University of Hong Kong were enrolled in the study. Patients undergoing liver transplantation, emergency surgery, or cesarean delivery and patients who had undergone a previous surgical procedure within 14 days or who had a history of cognitive impairment were excluded. Each week, patients from designated ORs were randomly selected using a computer-generated random table and were prospectively followed from the time of admission through discharge.

All the participants were interviewed by one of the investigators on the day before their surgery using a standardized questionnaire divided into three sections. Section I elicited the patient's general characteristics, including biographical and medical information. Section II dealt with information about the patient's regular use of Western medicine and TCHM within the two weeks before admission. Section III asked whether the patient had been seen by a traditional Chinese medicine practitioner within the two weeks before admission and asked about any herbal prescriptions he or she had received.

The attending anesthesiologist was blinded to the patient's detailed TCHM history, which was classified into one of three levels:

• •level 1—nonusers, defined as patients with no TCHM use;
• •level 2—self-prescribed users, defined as patients using herbal teas, herbal soups, and over-the-counter TCHM preparations but no TCHMs by prescription; and
• •level 3—users of TCHMs by prescription, defined as patients taking herbal medicines prescribed by a traditional Chinese practitioner.

Outcome measures were unanticipated perioperative events categorized as preoperative, intraoperative, and postoperative, occurring within 14 days before surgery to 24 hours after surgery. Common statistical procedures, including the chi-square test and analysis of variance, were used to analyze the data.

Findings. Of the 601 patients, 483 (80%) took self-prescribed TCHMs, 47 (8%) took prescribed TCHMs, and 71 (12%) did not take any form of TCHM in the two weeks before surgery. The most common form of self-prescribed TCHMs used by 525 patients were herbal soups (ie, 79%); herbal teas (ie, 37%); and prepacked, over-the-counter preparations (ie, 33%).

All patients were alive at hospital discharge. Overall, the crude incidence of combined preoperative, intraoperative, and postoperative events was 23% (95% confidence interval [CI], 19% to 26%); 74% (95% CI, 71% to 78%); and 63% (95% CI, 59% to 66%), respectively. Multivariate analysis revealed that patients who took TCHMs by prescription were more likely to have a preoperative event (adjusted relative risk 2.21, 95% CI, 1.14-4.29) than nonusers after adjusting for significant patient characteristics. Preoperative TCHM-related hypokalemia occurred in three patients, with one requiring oral potassium chloride supplements before surgery.

Clinical implications. The results of this study revealed that users of prescribed TCHMs were more than twice as likely to experience hypokalemia or impaired hemostasis than nonusers preoperatively. Perioperative nurses should be aware of the potential preoperative risk associated with prescribed TCHMs and should inquire about the patient's history of TCHM use during the preoperative assessment. Additionally, perioperative nurses should educate patients to stop using TCHMs, particularly those that are prescribed, before surgery.

Time of day and anesthetic adverse events

Quality & Safety in Health Care

August 2006

It is known that human performance is negatively affected by sleep deprivation, circadian rhythm disruption, and long work hours, leading to loss in cognitive and psychomotor abilities and consequently increasing the risk for accidents. Health care is a 24-hour business, so factors such as time on the job, circadian rhythms, scheduling, and staffing can result in variations in workloads over the course of the day, which may be reflected in the quality of anesthesia care being delivered.

Although studies have compared night performance with day performance and sleep-deprived practitioners with well-rested practitioners, few have considered time-of-day effects such as early morning and afternoon circadian troughs or start and end of shift. It is hypothesized that clinical performance may vary throughout the day as a result of factors such as time on the job; periods that contain circadian lows (ie, from 3 to 5 AM, from 3 to 5 PM); and times of transition in which patient care is transferred from one anesthesia team to another (ie, 7 AM, 4 to 6 PM). It is further hypothesized that the effects of these factors may result in an increased incidence of adverse events. Identifying these periods of relatively impaired OR performance is an important step in applying human factors principles to the improvement of patient care in the perioperative area. The purpose of this retrospective study was to determine whether the time of day affects the number of anesthetic adverse events that occur perioperatively.⁴

Data from all anesthetic procedures completed at Duke University Medical Center, Durham, NC, between May 1, 2000, and Aug 4, 2006, were analyzed. The data were available in a perioperative database and charting tool through which anesthesia care providers and perioperative nurses electronically record and track a patient's clinical progress. The database includes patient demographic data; surgical and anesthetic plans; and patient notes, including quality improvement event descriptors and comments from anesthesia care providers preoperatively, intraoperatively, and postoperatively.

The independent variable selected to assess the effect of the time of day on the incidence of adverse events was the start hour of care. Covariables selected were the patient's age, gender, and American Society of Anesthesiologists physical classification score; whether the procedure was emergency or nonemergency; duration of anesthesia; complexity of the procedure; and activity level of the OR suite. Response variables were anesthetic adverse events determined from health care practitioners' self-reported quality improvement events. These included errors (ie, preventable events); harm (ie, events that resulted in harm to patients); and other adverse events (ie, events that could not be definitively described as preventable or causing harm based on the information available). Statistical procedures including multiple logistic regression techniques were used to analyze the data.

Findings. The data set for the analysis was reduced from 130,912 to 90,159 because of missing start times, end times, and missing covariate data. Adverse events included 31 errors; 667 instances of harm, including postoperative nausea and vomiting (PONV) events (ie, 277 events); 1,995 other adverse events, including pain management events (ie, 1,102 events); and 9,497 delays. Compared with a reference start hour of 7 AM, other adverse events were significantly more frequent for procedures starting during the 3 PM and 4 PM hours (P < .0001). Odds ratio estimates also confirmed the afternoon effect, revealing that procedures that began between 3 and 6 PM had a higher probability of other adverse events occurring than procedures that started during the reference time of 6 to 9 AM (point estimate 1.48, 95% Wald confidence interval, 1.19 to 1.84). The analysis revealed that there were significant effects for both pain management (P < .0001) and PONV (P < .0001) in both the 24-hour and work-day analyses.

Clinical implications. The results of this study support the hypothesis that adverse events are influenced by the time of day that surgery begins. There was a significant increase in adverse events in the early morning compared to late morning and early afternoon hours. In addition, there was a significant and sizeable increase in adverse events in the late afternoon compared to early morning. Post hoc analysis revealed that this effect may have been driven primarily by the most frequent events, PONV and pain management.

Perioperative nurses and managers should understand that there are a number of reasons why adverse events may occur more often at the end of the day. These may include end of day fatigue, afternoon circadian lows, care transitions, change in make up of the care teams, change in case loads, physiological changes in the patient, or other unrecognized factors. Consequently, perioperative nurses and managers should explore strategies to address these potential threats.