The use of cuffed tracheal tubes is increasingly popular in pediatric anesthesia, but investigators have found that there is a risk for increased trauma without proper diligence.
“When I was a fellow, many of my colleagues started using MicroCuff [Halyard] tracheal tubes, especially in neonatal patients, where they proved much easier for us to manage airways and ventilate,” said Madhankumar Sathyamoorthy, MBBS, assistant professor of anesthesiology at University of Mississippi Medical Center, in Jackson. “Yet, when we were talking to our neonatologists, they noted an increased incidence of stridor and wondered what had changed in our practice.
“So we decided to look back, and in doing so noticed there is very little data regarding nationwide practice patterns with respect to cuffed tracheal tube use in pediatric populations. Indeed, the last two surveys on the subject were performed in 2001 in France [Paediatr Anesth 2001;11:277-281] and in 2008 in the United Kingdom [Eur J Anaesth 2008;25:685-688], and the MicroCuff tube was not widely used back then.”
To gain more understanding of the subject, Dr. Sathyamoorthy and his colleagues electronically surveyed members of the Society of Pediatric Anesthesia. Surveys were sent between November 2013 and February 2014. Each member was permitted one response, and 805 of the 2,901 society members (28%) responded. Of these, 88% were from the United States and 83% were fellowship trained; 82% practiced pediatric anesthesia more than 50% of the time; and 65% were in academic practice. Dr. Sathyamoorthy reported the findings at the 2014 annual meeting of the American Society of Anesthesiologists (abstract A3058).
The study found that the use of cuffed tracheal tubes in elective surgery increased with patient age. Fewer than 10% of respondents said they used cuffed tubes “all of the time” in preterm patients; this increased to almost 70% of use in those between ages 2 and 8 years. Nevertheless, when compared with previous research, the study revealed that cuffed tracheal tubes are being used with increasing frequency in children of all ages. While more than 65% of respondents acknowledged that they use cuffed tubes routinely in children at least 2 years old, only 25% of respondents in the 2001 French study and less than 10% of those in the 2008 British study did the same.
The researchers also surveyed practitioners’ opinions regarding cuffed tracheal tube use. The most common reason for avoiding cuffed tracheal tubes in infants and children was concern about post-extubation stridor (39%). The most common way to determine the appropriate size of a cuffed tracheal tube was Holzman’s formula (57%), although it may be of limited use in neonates and infants. Nearly 70% of practitioners accept the size of the tracheal tube if it passes the subglottis without resistance or has a leak at 15 to 30 cm H2O.
“One of the respondents’ biggest concerns was the size of the tube,” Dr. Sathyamoorthy added. “The manufacturer’s recommendation regarding the smallest available cuff tube [3.0 mm ID] is that it be used in full-term infants [weighing] more than 3 kg. But in practice, they’re being used in preterm babies even smaller than 2 kg.” Indeed, only 8% of respondents follow package recommendations for choosing the size of the cuffed tracheal tube, which drew a warning from Dr. Sathyamoorthy. “Yes, the cuffed tube offers advantages,” he said, “but you still have to pay attention to the size of the tube or you’re going to cause more trauma.”
Interestingly, more than 60% of respondents said they do not monitor cuff pressure during anesthesia, contrary to recommended practice guidelines. “All the cuffed tube studies recommended measuring the cuff pressure,” he noted. “In real practice, however, it’s not being done. Even if you are using cuffed tubes in older children, you still have to pay attention to the cuff pressure.
“So the take-away message here is that the cuffed tracheal tubes make our practice easier, but practitioners have to pay attention.”
According to D. John Doyle, MD, PhD, the study is an important reminder that tracheal intubation is not always the benign procedure that anesthesiologists often think it is. “This caution is especially true in the pediatric population, whose smaller-diameter airway can make tracheal edema from contact pressure a cause for special concern,” said Dr. Doyle, now the chief of general anesthesiology at the Cleveland Clinic Abu Dhabi, in the United Arab Emirates.
“I would suggest that if there was one place where anesthesiologists might easily improve their clinical practice, it would be in formally measuring all tracheal tube cuff pressures and ensuring they are always under 30 cm H2O pressure,” Dr. Doyle added. “It’s worth remembering that excessive tracheal tube cuff pressures can produce airway complications ranging from sore throat and hoarseness to tracheal stenosis, tracheal necrosis and even tracheal rupture.”