Effects of vacuum suctioning and strategic drape tenting on oxygen concentration in a simulated surgical field.

STUDY OBJECTIVE: To investigate the isolated and combined effects of vacuum suctioning and strategic drape tenting on oxygen concentration in an experimental setting. DESIGN: Experimental. SETTING: Clinical simulation center of a university-affiliated hospital. PARTICIPANTS: Mannequin simulation of a patient undergoing facial surgery under sedation anesthesia. Supplemental oxygen was delivered via nasal cannula. INTERVENTIONS: Vacuum suctioning and strategic drape tenting. MEASUREMENTS: The experimental trials entailed measuring oxygen concentration around the nasal cannula continuously either in the presence or absence of a standard operating room vacuum suction system and strategic tenting of surgical drapes. The primary outcome was the time required for oxygen concentration to reach 21%. MAIN RESULTS: In the control group (without suction or strategic tenting), a mean time of 180 seconds elapsed until the measured oxygen concentration reached 21% after cessation of oxygen delivery. Use of a vacuum suction device alone (110 seconds; P < .01) or in combination with strategic tenting (110 seconds; P < .01) significantly reduced this time. No significant benefit was seen when tenting was used alone (160 seconds; P < .30). CONCLUSION: Use of a vacuum suction device during surgery will lower local oxygen concentration, and this in turn may decrease the risk of operating room fires. Although strategic tenting of surgical drapes has a theoretical benefit to decreasing the pooling of oxygen around the surgical site, further investigation is necessary before its routine use is recommended.

Pulse oximetry desaturation alarms on a general postoperative adult unit: a prospective observational study of nurse response time.

BACKGROUND: Continuous pulse oximetry monitoring is recommended to improve safety during postoperative opioid use, however concerns with monitoring on general care units remain, given potential system barriers to alarm transmission, recognition, and nursing response. METHODS: This prospective, observational study evaluated unit and hospital-level factors affecting nurses' response to monitor desaturation alarms in postoperative patients on a general postoperative unit. With exemption and waiver of consent granted from the Institutional Review Board, monitoring data were downloaded from bedside monitors of postoperative patients. Alarm notification data and response times were recorded from the continuous capture of institutional surveillance data. Paging notifications were coded as clinically relevant (i.e., true oxygen desaturation with SpO2<89 for >15s) or irrelevant (i.e., artifact, inappropriate alarm threshold, or failure to delay page). Linear mixed models, and correlation coefficients were used to examine the relationships between unit staffing, shift, paging burden and response time. Means and [95% confidence intervals] are presented. RESULTS: 1616 monitoring hours in 103 patients yielded 342 desaturation events (duration 23.6s [20.99, 26.1]) and 710 notification pages, 36% of which were for clinically relevant desaturation. Nursing response time was 52.1s [46.4, 57.7], which was longer at night (63.8 [51.2, 76.35]; p=0.035), but not related to unit staffing. Missed alarm events (i.e., no notification page transmitted) occurred for 26% of the clinically relevant events, and were associated with higher paging burden (p=0.04), lower SpO2 values (81.8 [80.5, 83.0] vs. 83.2 [82.6, 83.8]; p=0.026), and higher odds of intervention (OR 3.5 [1.38, 8.9]). 65% of patients with desaturation events received interventions which correlated with the number of pages (rho=0.422; p<0.01) and events (rho=0.57; p<0.01), desaturation duration (rho=0.505; p<0.01), and SpO2 (rho=-0.324; p<0.01). CONCLUSIONS: One-third of pulse oximetry alarm notifications were for clinically relevant oxygen desaturation, facilitating timely nursing response and intervention for most patients. Unit staffing and false alarm frequency were not associated with response time, suggesting a high level of attention on this unit. The nature and degree of missed alarm events suggests patient safety concerns posed by hospital-level transmission systems warranting further strategies to ensure monitoring safety.