Although nasal intubation is used more commonly than oral intubation for anesthesia in children undergoing cardiopulmonary bypass surgery, it appears to carry a higher risk for postoperative infection in children 6 months of age or older, according to a recent study.
Led by Warwick Ames, MBBS, associate professor of anesthesiology at Duke University School of Medicine, in Durham, N.C., the investigators queried the Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database for patients under 18 years of age who underwent surgery between January 2010 and December 2015. The retrospective study drew on data from nearly 27,000 operations at 50 hospitals in the United States. Patients with a preoperative endotracheal tube, a tracheostomy or known airway anomalies were excluded from the analysis.
The investigators assessed the association between the route of tracheal intubation and infection risk—including wound infection, mediastinitis, septicemia, pneumonia and endocarditis—as well as length of intubation, hospital length of stay and airway complications, including accidental extubations. Data on weight, age, comorbidities, case complexity and individual center attributes also were included to adjust for these characteristics (Table).
|Table. Baseline Characteristics|
|Oral n=19,146 (%)||Nasal n=7,642 (%)||P Value|
|Sex, male||10,390 (54.3)||4,154 (54.4)||0.6627|
|Prematurity (<37 weeks)||3,061 (16.0)||1,158 (15.2)||0.0022|
|Weight at surgery, kg||10.7||6.0||<0.0001|
|Mechanical ventilatory support||537 (2.8)||288 (3.8)||<0.0001|
|Neurologic deficit||640 (3.3)||472 (6.2)||<0.0001|
Neonates (0-28 days)
|Race, white||10,760 (56.2)||4,236 (55.4)||<0.0001|
|Any noncardiac/genetic abnormality||4,662 (24.3)||2,288 (29.9)||<0.0001|
|Any chromosomal abnormality||3,680 (19.2)||1,834 (24.0)||<0.0001|
|Any syndromes||4,448 (23.2)||2,029 (26.6)||<0.0001|
|Any preoperative risk factor||5,233 (27.3)||2,548 (33.3)||<0.0001|
|Mechanical circulatory support||80 (0.4)||13 (0.2)||0.0019|
|Renal failure||146 (0.8)||43 (0.6)||0.0776|
In the unadjusted analysis, the investigators found that nasal intubation was associated with a higher composite infection rate (2.9% vs. 2.3%; P=0.004), a longer duration of intubation (23.0 vs. 12.4 hours; P<0.0001) and a longer postoperative length of stay (eight vs. six days; P<0.0001).
Nasal Intubation Best In Neonates
After stratifying the unadjusted data by age—into neonates, infants, toddlers, school-age children and adolescents—they found that in neonates, nasal intubation appeared to be protective for accidental extubation (0% vs. 0.4%; P=0.02).
Moreover, a subanalysis of patients younger than 6 years at higher-volume centers—defined as fielding over 100 cases per year—showed that age and intubation route were significantly correlated with infection risk, with a higher risk for infection from nasal intubation occurring at 6 months of age and older (Figure). The investigators speculated that the change in risk “may be related to the timing of maxillary and ethmoid sinus development and/or development of adenoid tissue, acting as a source of bacteria for nasal endotracheal tubes.”
Nathaniel Greene, MD, FAAP, director of research in pediatric anesthesia at Duke, who presented the study findings, said the risk for infection from nasal intubation, particularly in older children, had been demonstrated, but the research team wanted to see whether this risk also extended to neonates and infants.
“We wanted to be sure that when we associated the nasal tube with postoperative infection, we weren’t just associating the overall level of sickness with infection, and actually looking at the contribution that a nasal tube has versus an oral tube,” Dr. Greene said. “What was interesting was, when we performed the subanalysis, we found that there was not a significant risk posed by a nasal endotracheal tube in that cohort of neonates and infants together,” he added. “This unexpected result prompted a sensitivity analysis within this age group specifically, which suggested nasal tubes may be beneficial in neonates up until 6 months of age.”
Dr. Greene said although further prospective research would be beneficial, he and his colleagues suggest that clinicians strongly consider nasal intubation in patients up to 6 months of age, due to the decreased risk for infection and accidental extubation.
Benefits of STS Database
Gregory Latham, MD, associate professor of anesthesiology at the University of Washington, in Seattle, and attending physician at Seattle Children’s Hospital, said the findings came as a surprise.
“Typically in my practice, I maintain nasal intubation up to an endotracheal tube size of 4.5, into the older toddler years, and these findings have led me to change my practice and switch over to oral intubation at an earlier age,” Dr. Latham said.
He added that he would not categorically recommend that other providers follow suit, but rather should consider the risks and benefits at their particular institutions in determining which intubation route to use for each patient.
Dr. Latham also said the study highlights the benefits of maintaining large databases, such as the STS database, for research purposes.
“They looked at nearly 27,000 patients. For any hospital to prospectively look at children, you’re never going to get those numbers. It would take decades and decades to do that,” he said. “This is one of the first anesthesia-specific studies to utilize the data in this database, and I think a lot of us, after years of entering data, are excited to see this come to fruition.”
The findings were originally presented at the 2017 meeting of the Society for Pediatric Anesthesia/American Academy of Pediatrics Section on Anesthesiology and Pain Medicine (abstract OS1-104).