Endotracheal Cuff Pressure Monitoring: Another Alarm in the ICU?

Abstract

I read with interest the article by Sole and colleagues1 on continuous monitoring of cuff pressure. The authors evaluated the impact of an intervention to reduce underinflation and overinflation of tracheal cuffs in intensive care unit (ICU) patients.During the intervention period, cuff pressure was continuously monitored and an alarm was used to inform nurses that cuff pressure was out of range (20–30 cm H2O) in order to adjust it. The intervention was successful because the percentage of cuff pressure values out of range was significantly reduced during the intervention period compared with the control period (11.1% vs 57.1%, p <0.001). However, an alarm sounded 7 to 190 times/day/patient during the intervention period (mean 35, SD, 35). The authors stated that most of these alarms did not require intervention and were transient high-pressure alarms associated with coughing, suction, turning, and agitation. Adjustment of cuff pressure was only performed if a low alarm (<20 cm H2O) was sustained for more than 15 seconds, or a high alarm (>30 cm H2O) was sustained for more than 15 minutes. Surprisingly, the number of intervention was small mean ±SD 8±3 (range 2–14 per patient).Reducing the time spent with overinflation and underinflation of cuff pressure is probably beneficial for ICU patients because previous studies suggested that this kind of intervention might reduce micro-aspiration, VAP, and tracheal ischemic lesions.2,3 However, adding another alarm in the ICU is probably not the best intervention to reduce variations in cuff pressure. There are several available cuff pressure monitors allowing efficient continuous control of cuff pressure without human intervention and without alarm.4,5,6 Alarms and noise in the ICU are one of the major risk factors for post-traumatic stress syndrome in ICU patients and for burn-out in ICU physicians and nurses.7 In addition, alarms are one cause for sleep disturbances in the ICU. Recent studies showed that sleep was important for healing and survival of critical illness.8Although the number of nurse interventions to adjust cuff pressure was not very high, the number of alarms was high. One could argue that nurses might have first checked if the alarm lasted enough to justify an intervention or not which might have represented a large amount of time. In a busy ICU, the impact of such an intervention on nurse workload should be evaluated.Could the authors explain why adjustments were only made if a high alarm was sustained for more than 15 minutes? Previous animal and human studies clearly showed that overinflation of cuff pressure (>30 cm H2O) was associated with severe tracheal ischemic lesions and possible severe complications such as tracheal stenosis.9,10 Again, available automatic cuff regulators allow immediate and continuous cuff pressure regulation without exposing the patient to potential complications.