Healthcare providers and law enforcement utilize spit socks to prevent exposure to communicable diseases transmitted by bodily fluid projection from agitated individuals. There are cases in which death is reported due to breathing being limited by a spit sock. There are no formally published studies on their use and safety. The aim of this study was to evaluate whether wearing a spit sock causes a clinically significant impact on breathing.

Subjects sat with the spit mask over their heads for 15 min and their vital signs and ventilatory parameters were recorded after 5 min, 10 min and 15 min. Data were compared to baseline using Student's t-test with 95% confidence intervals using SPSS.

The median age of the 15 subjects was 28 years and 53% were male. There was no significant difference between baseline and wearing the spit sock for 5, 10 or 15 min for heart rate (p = 0.250, p = 0.181, p = 0.546), oxygen saturation (p = 0.334, p = 1.00, p = 0.173), end-tidal pCO₂ (p = 0.135, p = 0.384, p = 0.187), and diastolic blood pressure (p = 0.485, p = 0.508, p = 0.915). The respiratory rate was not significantly different after 5 and 10 min (p = 0.898, p = 0.583), but decreased at 15 min (p = 0.048). The systolic blood pressure was lower after 5 and 10 min (p = 0.028, p = 0.045), but not significantly different at 15 min (p = 0.146). No subject indicated distress nor did the study need to be terminated due to pre-determined concerning vital signs or ventilatory parameters.

In healthy subjects there were no clinically significant changes in the physiologic parameters of breathing while wearing a spit sock.