Effects of wearing surgical masks on fraction of inspired oxygen in spontaneously breathing patients: improving safety for frontline healthcare professionals under pandemic situations

BACKGROUND

During pandemic situations, many guidelines recommend that surgical masks be worn by both healthcare professionals and infected patients in healthcare settings. The purpose of this study was to clarify the levels and changes of oxygen concentration over time while oxygen was administered over a surgical mask.

METHODS

Patients scheduled to undergo general anesthesia (n = 99) were enrolled in this study. First, patients were administered oxygen at 6 L/min via an oxygen mask over a surgical mask for 5 min. The patients removed the surgical mask and then took a 3-min break; thereafter, the same amount of oxygen was administered for another 5 min via the oxygen mask. We measured the fraction of inspired oxygen (FiO₂), the end-tidal CO₂ (EtCO₂), and respiratory frequency every minute for 5 min, both while administering oxygen with and without a surgical mask. The FiO₂ was measured at the beginning of inspiration and the EtCO₂ was measured at the end of expiration.

RESULTS

The FiO₂ at 5 min was significantly lower when breathing with a surgical mask than that without it (mean difference: 0.08 [95% CI: 0.067-0.10]; p <  0.001). In contrast, the EtCO₂ at 5 min was significantly higher when breathing with a surgical mask than that without it (mean difference: 11.9 mmHg [95% CI: 10.9-12.9]; p <  0.001).

CONCLUSION

The FiO₂ was lower when oxygen was administered over surgical masks than when patients did not wear surgical masks. Oxygen flow may need to be adjusted in moderately ill patients requiring oxygen administration.

Benefit of an operating vehicle preventing peritonitis in peritoneal dialysis patients: a retrospective, case-controlled study

BACKGROUND

Peritonitis, which is one of the leading complications of peritoneal dialysis (PD) worldwide, severely affected morbidity and mortality of the PD patients. Although many efforts have been made to prevent PD-related peritonitis, it seems impossible to prevent it completely. Many causes have been reported to lead to peritonitis, and contamination during bag exchange is one of the important risk factors for peritonitis.

METHODS

Here, we introduce an operating vehicle, which we invented to provide a sterile and safe space for bag exchange. A single-center, retrospective, case-control study was undertaken to determine whether this operating vehicle has a protective role in preventing peritonitis. In total, 462 continuous ambulatory peritoneal dialysis patients were included in this study from October 2014 to March 2017. According to their personal will, these patients chose to use operating vehicle or traditional method during their bag exchange. The demographic, clinical and laboratory data of these patients in the two groups were collected, analyzed and compared.

RESULTS

Of 462 patients with home dialysis, operating vehicle group consisted of 61 patients, and control group consisted of 401 patients. In the control group, over 677 patient-years, peritonitis occurred in 69 of 401 patients (17.2%), while in the operating vehicle group, over 60 patient-years, only 4 of 61 patients (6.6%) had episodes of peritonitis. The number of patients suffered from peritonitis was significantly decreased in the operating vehicle group (P = 0.034). Besides, there were a total of 99 episodes of peritonitis, and the rate was 1 episode every 7.2 patient-years in control group and 1 episode every 12 patient-years in the operating vehicle group. There was significant difference between the two groups (0.013). Positive dialysate cultures were obtained in majority of the peritonitis episodes (60.6%).

CONCLUSION

Operating vehicle might help to reduce PD-related peritonitis by preventing contamination during bag exchange. Further studies are still needed to demonstrate the protective role of the operating vehicle in preventing peritonitis.