Clinicians' opinions on alarm limits and urgency of therapeutic responses

To survey the routine use of bedside multivariable monitors in monitoring cardiac postoperative patients, 23 experienced anesthesiologists and cardiac surgeons were first asked to list which variables and what limit alarms they used. Then they defined to what extent the variables' values were allowed to deviate before therapeutic actions were needed. Typically, limit alarms were applied to heart rate and end-tidal CO2. For clinical assessment of a patient's state, the clinicians usually observed the heart rate and the systemic arterial blood pressures, but placed less emphasis on the pulmonary arterial pressures. Clinicians had similar opinions on alert limits for monitoring less extensive physiological deviations and on alarm limits for warning of a critical situation. Person-to-person tolerance of suboptimal monitored values varied. No correlation was found between the limit values and how long these values were tolerated without therapeutic response. However, the inquiry provided information on setting limits for alerts and alarms, and on experienced clinicians' decision-making during postoperative intensive care of cardiac patients.