Mapping sources of noise in an intensive care unit.

Excessive noise in hospitals adversely affects patients' sleep and recovery, causes stress and fatigue in staff and hampers communication. The World Health Organization suggests sound levels should be limited to 35 decibels. This is probably unachievable in intensive care units, but some reduction from current levels should be possible. A preliminary step would be to identify principal sources of noise. As part of a larger project investigating techniques to reduce environmental noise, we installed a microphone array system in one with four beds in an adult general intensive care unit. This continuously measured locations and sound pressure levels of noise sources. This report summarises results recorded over one year. Data were collected between 7 April 2017 and 16 April 2018 inclusive. Data for a whole day were available for 248 days. The sound location system revealed that the majority of loud sounds originated from extremely limited areas, very close to patients' ears. This proximity maximises the adverse effects of high environmental noise levels for patients. Some of this was likely to be appropriate communication between the patient, their caring staff and visitors. However, a significant proportion of loud sounds may originate from equipment alarms which are sited at the bedside. A redesign of the intensive care unit environment to move alarm sounds away from the bed-side might significantly reduce the environmental noise burden to patients.

Go/no-go decision in anaesthesia: wide variation in risk tolerance amongst anaesthetists.

BACKGROUND: The variability in risk tolerance in medicine is not well understood. Parallels are often drawn between aviation and anaesthesia. The aviation industry is perceived as culturally risk averse, and part of preflight checks involves a decision on whether the flight can operate. This is sometimes termed a go/no-go decision. This questionnaire study was undertaken to explore the equivalent go/no-go decision in anaesthesia. We presented anaesthetists with a range of situations in which additional risk might be expected and asked them to decide whether they would proceed with the case. METHODS: An electronic questionnaire was distributed to anaesthetic colleagues of all grades in one National Health Service Trust. Eleven scenarios, all drawn from critical incident data, were presented. Participants were invited to consider whether they would proceed, how they would modify their anaesthetic technique, and to predict whether a colleague with similar experience would make the same decision. Textual responses were analysed qualitatively. RESULTS: The scenario response rate was 28%. Consultants were significantly more likely to proceed than trainees. In no scenario was there absolute agreement over whether to proceed, even in scenarios where national guidelines would suggest a case should be cancelled. Thematic analysis suggested a wide variability in what anaesthetists consider acceptable or professional behaviour. CONCLUSIONS: It is clear that safety decisions cannot be made in isolation and that clinicians must consider operational requirements, such as throughput, when making a go/no-go decision. The level of variability in decision-making was surprising, particularly for scenarios that appeared to go against guidelines.