Integrated Monitor Alarms and ‘Alarm Overload’

Abstract

We wish to report a critical anaesthetic incident which illustrates a shortcoming of an integrated monitoring system. A fit 22-year-old man was scheduled for an open meniscectomy. He was preoxygenated with 100% oxygen for two minutes and anaesthesia was induced with propofol and atracurium intravenously. The inspired gas concentrations were adjusted and thought to be isoflurane 1 % in nitrous oxide and oxygen (F I o 2 0.33), delivered via a Mapleson A breathing system. The patient was ventilated by mask for approximately one minute and intubated without difficulty, but he immediately became cyanosed. Extubation was performed and when the F I o 2 was adjusted to 1.0, it was noticed that the previous mixture had contained approximately 10% oxygen. The patient FIGURE I.-Screen display of Datex Cardiocap integrated monitor.

Medical Alarms: A Clinician's Viewpoint

“…Jones et al [8] describe a critical anesthetic accident related to the use of an integrated alarm system where a patient accidentally received a hypoxic gas mixture (one too low in oxygen concentration). The problem was not immediately recognized because of the existence of a single audible alarm sounding to signal the existence of three alarm conditions, one being of primary importance (low oxygen concentration) and the other two being a result of the first condition (low patient oxygen levels and high heart rate).…”

Monitoring small animal anaesthesia: where are we now?

“…We should also acknowledge the potential negative impact of the increasing use of monitoring equipment, with ‘alarm overload’ reported as a factor delaying identification and correction of problems in human anaesthesia 9 . With multiple variables being monitored with electronics, this could be an increasing problem in veterinary anaesthesia; the alarms may distract staff or cause a loss of focus on the situation, with a temptation for staff to silence or disable alarm systems 10 …”

Anaesthetic machine alarm use

“…Anaesthetic machine alarms have problems [3–5]. Surgical diathermy can interfere with oxygen saturation and ECG monitoring.…”