Impact of polyurethane on variations in tracheal cuff pressure in critically ill patients: A prospective observational study

Abstract

Objective: To determine the impact of polyurethane (PU) on variations in cuff pressure (P cuff) in intubated critically ill patients. Methods: Prospective observational before-after study performed in a ten-bed ICU. Cuff pressure was continuously recorded for 24 h in 76 intubated patients, including 26 with polyvinyl chloride (PVC), 22 with cylindrical polyurethane (CPU), and 28 with tapered polyurethane (TPU)-cuffed tracheal tubes. P cuff was manually adjusted every 8 h by nurses and was maintained around 25 cmH 2O. Time spent with cuff underinflation and overinflation was continuously measured. In addition, pepsin, a proxy for microaspiration of gastric contents, was quantitatively measured in tracheal secretions at the end of recording period. Results: A total of 1,824 h of continuous recording of cuff pressure was analyzed. Patient characteristics were similar in the three groups. No significant difference was found in percentage of time spent with underinflation (mean ± SD, 26 ± 22, 28 ± 12, 30 ± 13% in PVC, CPU, and TPU groups, respectively) and overinflation [median (IQR), 7 (2-14), 6 (3-14), 11% (5-20)] among the three groups. However, a significant difference was found in the coefficient of variation of P cuff (mean ± SD, 82 ± 48, 92 ± 47, 135 ± 67, p = 0.002). While the coefficient of P cuff variation was significantly (p < 0.017) higher in the TPU compared to CPU and PVC groups, no significant difference was found between the CPU and PVC groups. The pepsin level was significantly different among the three groups (408 ± 282, 217 ± 159, 178 ± 126 ng/ml; p < 0.001). In fact, the pepsin level was significantly lower in the CPU and TPU groups compared with the PVC group. Conclusion: PU does not impact variations in P cuff in critically ill patients. © 2010 Copyright jointly held by Springer and ESICM.