NM-199
Cuff pressures in pediatric patients: does the leak pressure correlate with cuff pressure manometers?
1Kiberd M, 2Swenson-Schalkwyk A, 2Caruso T
1 Stanford University, Palo Alto, USA, Palo Alto, CA, USA; 2Stanford University, Palo Alto, USA, Palo Alto, CA, United states
Introduction: Measurement of cuff pressure after placement of an endotracheal tube (ETT) is standard practice for most pediatric anesthesiologists. Low cuff pressures increase the risk of aspiration and ventilator associated pneumonia. Elevated pressures greater than 25-30 cm H2O exceed transcapillary pressure, potentially leading to tracheal tissue ischemia. Pediatric patients are susceptible to long-term complications from ETT placement. 1,2 Despite complications from under or over-pressurizing ETT cuffs, they are commonly
used because they reduce the number of intubations compared to uncuffed ETTs. 3 One method to ensure appropriate pressure in a cuffed ETT is to measure the pressure with a manometer. Cuff pressure manometers are commonly used by many pediatric anesthesiologists and are required monitors in some countries.4 There are multiple cuff measurement devices commercially available, and the Posey®
Cufflatorâ„¢ is commonly used at our institution. It performs two functions: a manometer that is applied to the pilot balloon to measure the ETT cuff pressure, and a hand pump that allows air to be inserted into or released from the cuff. A quality assurance study was conducted at our institution to assess cuff pressure practices.
Methods: A convenience sample of 50 patients was selected. After induction of anesthesia, intubation and ETT being secured, anesthesiologist estimated and adjusted cuff-pressures in the standard fashion by auscultating a leak. After the anesthesiologist had recorded the leak pressure on the EMR, the study personal would enter the room unannounced and check the cuff pressure using the Posey® Cufflator™. Pressures and demographic data were recorded.
Results: After the study period 50 patients had cuff pressures checked. Median age was 5 (IQR 2,14) and Median weight 36 kg (IQR 12,57). Patients had a variety of surgeries 34% urology, 24% orthopedic, 18% general surgery, 16% ENT, 8% other. Mean cuff pressure by leak test 19.3 cmH20 (95% CI +/-2.8 cmH20) versus 23.2cmH20 (95% CI +/-19 cmH20) by manometer, p-value 0.09 and effect size (Cohen’s d) 0.27. The absolute mean difference was 11.3 cmH20. Overall, 24% of cuff pressures measured by manometer were > 30cmH2O and 12% were over 40 cmH2O.
Discussion: Cuff pressure measurement by manometer is more accurate than by listening for a leak and can identify dangerous cuff pressures. At our institution,24% of cuffs were overinflated when checked with a manometer, despite 85% of charted cuff leak pressures being charted between 18-22 cmH2O. Incidentally, during this QI study we found that by doing spot checks leaks were created. The small amount of air required to fill the manometer deadspace can cause a leak in small cuffs. A small amount of air is leaked from the cuff every time the cuff pressure is checked. In smaller endotracheal tubes this resulted in the formation of a new leak.
Conclusion: Using a manometer for cuff pressure management may be more accurate than the leak test. If using a manometer spot checks may result in a leak.
1. Guyton, D Chest 100, 1076–1081 (1991).
2. Ratnaraj, J J. Neurosurg. 97, 176–9 (2002).
3. Krishna, S. G Paediatr. Anaesth. 27, 494–500 (2017).
4. Dobson, G. Can. J. Anaesth. 64, 65–91 (2017).
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