Challenging Residual Contamination of Instruments for Robotic Surgery in Japan.

BACKGROUND Recently, robotic surgery has been introduced in many hospitals. The structure of robotic instruments is so complex that updating their cleaning methods is a challenge for healthcare professionals. However, there is limited information on the effectiveness of cleaning for instruments for robotic surgery. OBJECTIVE To determine the level of residual contamination of instruments for robotic surgery and to develop a method to evaluate the cleaning efficacy for complex surgical devices. METHODS Surgical instruments were collected immediately after operations and/or after in-house cleaning, and the level of residual protein was measured. Three serial measurements were performed on instruments after cleaning to determine the changes in the level of contamination and the total amount of residual protein. The study took place from September 1, 2013, through June 30, 2015, in Japan. RESULTS The amount of protein released from robotic instruments declined exponentially. The amount after in-house cleaning was 650, 550, and 530 µg/instrument in the 3 serial measurements. The overall level of residual protein in each measurement was much higher for robotic instruments than for ordinary instruments (P<.0001). CONCLUSIONS Our data demonstrated that complete removal of residual protein from surgical instruments is virtually impossible. The pattern of decline differed depending on the instrument type, which reflected the complex structure of the instruments. It might be necessary to establish a new standard for cleaning using a novel classification according to the structural complexity of instruments, especially for those for robotic surgery. Infect Control Hosp Epidemiol 2017;38:143-146.

Time-dependent influence on assessment of contaminated environmental surfaces in operating rooms.

BACKGROUND: There is no established method to assess the contamination of environmental surfaces because the results change with time. We evaluated current methods for assessment of contamination of environmental surfaces in the operating room (OR). METHODS: Contamination of environmental surfaces in the OR was assessed using an adenosine triphosphate (ATP) test and bacterial culture. We collected 480 ATP test samples from 17 surfaces in 6 ORs to determine the influence of surface features, including frequency of touching and surface orientation on contamination, after completion of daily scheduled operations. Another 54 pairs of ATP and microbial samples were taken from 3 surfaces in each of the same OR except 1 to determine the time course of the results of ATP and microbial tests when ORs were not used. RESULTS: Multivariate analysis demonstrated that the ATP results were strongly influenced by frequency of touching and orientation of environmental surfaces. The microbial counts declined over time, whereas the ATP results remained at a high level. CONCLUSION: The ATP test result could be used as a relatively stable trace of contamination of environmental surfaces; however, it is not a surrogate indicator of the number of viable microbes which declines over time.

Occult risk of broken instruments for endoscopy-assisted surgery.

BACKGROUND: The influence of broken sophisticated surgical instruments on the safety of surgery has yet to be determined, in spite of an assumption that breakage of surgical instruments is not associated with critical incidents. The purpose of the present study was to delineate the risk from breakage of surgical instruments used in surgery assisted by endoscopy. METHODS: A retrospective analysis was conducted to determine the frequency of breakage of instruments used in 39,817 operations from 2007 to 2011. Data of breakage were collected using incident/near-incident reports and the request forms for repair of broken instruments. RESULTS: During the study period, 441 instruments were reported to be broken intraoperatively, and 7,541 were found to be broken on inspection. The incidence of breakage adjusted by the number of operations and the number of uses suggested that instruments for endoscopy-assisted surgery are broken more frequently intraoperatively than are any other type of instruments (visceral surgery: 0.039 versus 0.017, P = 0.0002, RR = 2.318; obstetrics/gynecology: 0.023 versus 0.0067, P < 0.0001, RR = 3.461; thoracic surgery: 0.019 versus 0.004, P = 0.0772, RR = 5.212). Inappropriate use and wearing out were two major possible causes of breakage of instruments. The predominant adverse events were suggested to be attributable to parts falling off broken instruments because of inappropriate use. CONCLUSIONS: Our results demonstrated that surgery assisted by endoscopy has its own occult risk, which has not been previously highlighted. Minimally invasive surgery is not necessarily safe with respect to breakage of surgical instruments. Our data provide substantial evidence for higher risk of instrument breakage in endoscopy-assisted surgery, as well as its possible detrimental effect on patient safety.

A prospective randomized multicenter comparative study of BLM-240 (desflurane) versus sevoflurane in Japanese patients.

The present study was conducted to evaluate the efficacy and safety of BLM-240 (desflurane) in comparison to sevoflurane in Japanese patients. A total of 216 patients were enrolled in this randomized comparative study at 15 medical institutions. The patients received either BLM-240 with 50-70 % N2O in O2 (n = 111), BLM-240 with 30 % O2 in air (n = 55), or sevoflurane with 50-70 % N2O in O2 (n = 50). Efficacy was evaluated by an efficacy rate based on an efficacy evaluation criteria and recovery time to extubation from the discontinuation of the anesthetics. Safety was evaluated by incidence of adverse drug reactions (ADR) and other clinical indicators. The efficacy rate of BLM-240 was 98.8 % (164/166 patients), indicating that BLM-240 is effective as an anesthetic. Time from discontinuation of anesthetic delivery to extubation was 9.7 ± 0.6 min in the BLM-240/N2O group and 14.3 ± 0.9 min in the sevoflurane/N2O group, meeting the pre-defined non-inferiority criteria of BLM-240 to sevoflurane. There was no statistically significant difference in the incidence of total ADR between the BLM-240 group (62.0 %) and sevoflurane group (48.0 %). The results indicate that BLM-240 is an effective and safe inhalation anesthetic in Japanese patients.

Prevention of medical accidents caused by defective surgical instruments.

BACKGROUND: The malfunctioning of surgical instruments may lead to serious medical accidents. Limited information is available on the risk of defective instruments. The purpose of these study is to demonstrate the features of defective surgical instruments, to establish a strategy to reduce the risk of medical accidents. METHODS: We studied 19,474 consecutive operations during 2007 to 2009 at our hospital. The data on defective instruments were collected based on the orders for repair of broken instruments and reports of near-miss incidents. Adverse events caused by defective instruments were also identified from reports of near-miss incidents. RESULTS: A total of 1,775 nonfunctioning instruments were identified during the study period. Of these, 112 were found during operation. More than half of the defective instruments were tissue-grasping instruments, bone-boring/gnawing instruments, and instruments for endoscopic surgery. Wearing out and inappropriate use of instruments were 2 major causes of defects. The rest of the causes consisted of inadequate inspection and factory defects. Two near-miss incidents (incidence 10 per 100,000 operations) in endoscopic surgery were potentially critical, but the postoperative course was uneventful in each patient. The incidence of defects adjusted by the number of operations demonstrated that bone-boring/gnawing instruments and instruments for endoscopic surgery tend to be broken during surgery. Without inspection by the manufacturer, the incidence would be much higher for endoscopic instruments. CONCLUSION: Our data suggest that the appropriate use and adequate inspection of particular types of instruments are key for reducing the risk of medical accidents caused by defective surgical instruments.

Molecular cloning, mRNA expression and chromosomal localization of mouse angiotensin-converting enzyme-related carboxypeptidase (mACE2).

We isolated two mouse cDNA clones which show significant similarities with human angiotensin-converting enzyme-related carboxypeptidase (ACE2). The cDNAs were 2746 and 1995 bp in length and seemed to arise from the same gene by alternative splicing. The longer cDNA encoded a 798-amino acid protein containing the sequence motif conserved among zinc metallopeptidases. Mouse ACE2 showed 83% identity with human ACE2. Northern blot analysis revealed that 2.8- and 2.0-kb transcripts were expressed mainly in the kidney and the lungs. The mouse ACE2 gene was mapped to chromosome X 70.5 cM.