Today’s Pediatric Anesthesia Article of the Day continues a long tradition first started by the late Dr. Ron Litman of blessed memory of reviewing classic articles that substantially changed the current practice of pediatric anesthesiology, critical care medicine, and pain management. Over the past 18 months, I’ve asked several giants of our profession to review some of their own pioneering work and studies and to give us the background story of how and why they did their research. I’ve known today’s PAAD contributor, Dr. Rob Friesen, a Robert M. Smith award winner, for more than 35 years and consider myself fortunate indeed to be his friend. A review of his many contributions can be found in a biography published in Pediatric Anesthesia 2017; 27:991-996 Myron Yaster MD
Original article: Friesen RH, Honda AT, Thieme RE. Changes in anterior fontanel pressure in preterm neonates during tracheal intubation. Anesth Analg 1987;66:874-878. PMID: 3619094
The recent PAAD “No Pain No Gain or More Pain Less Gain”? (July 25, 2022) concerning the consequences of procedural pain in the preterm neonate recalled to me an era when anesthetic and surgical procedures were performed on preterm neonates more frequently than they are today. The field of neonatology in the 1970s and 1980s—as is the case with all fields of medicine—had not progressed to the level that is enjoyed today. Diseases such as necrotizing enterocolitis and patent ductus arteriosus that are often successfully managed or prevented medically today frequently required surgical intervention at that time.
A serious nonsurgical morbidity of prematurity was the development of intracranial hemorrhage (ICH), which was thought to be associated, among other factors, with fluctuations in blood pressure, cerebral blood flow, and intracranial pressure. Since these fluctuations are often observed intraoperatively in the critically ill neonate, my colleagues and I wondered whether the perianesthetic period was one of increased risk for the development of ICH? In a study comparing preoperative and postoperative cranial ultrasound tests in preterm neonates, we did not observe either development or progression of ICH (1). The Ladd monitor of anterior fontanel pressure (AFP) is a valid and accurate indirect measure of intracranial pressure (2,3). Using it, we determined that the administration of four anesthetics to preterm neonates was associated with clinically mild decreases in AFP (4).
We also used the Ladd monitor to study tracheal intubation, and the resulting article (cited above as the PAAD) had more significant implications than did the others mentioned above. Anesthesia for the neonate was a relatively young field, and one of the commonly recommended practices at that time was that neonates and infants were to be intubated awake lest their airways be lost following induction of anesthesia (5). We knew that maintenance of the airway by mask in the anesthetized neonate was generally not difficult and that tracheal suctioning of the preterm neonate was associated with increased intracranial pressure (6), so we postulated that awake tracheal intubation would increase AFP in preterm neonates. Our study demonstrated that awake intubation was associated with an increase of AFP of 197%, while intubation following administration of a muscle relaxant, an anesthetic, and mask ventilation was associated with no change in AFP. We believe that the observed motor response to awake intubation (struggling, breath holding, coughing) was the main cause of increased AFP, so the muscle relaxant may have been as important as the anesthetic. We like to believe that our article helped to convince anesthesiologists to abandon routine awake intubation (except where specifically indicated) in neonates. However, since it was published in an anesthesia journal, rather than a pediatric one, I don’t know whether it had an impact on neonatologists. I suspect that awake intubation qualifies as a painful, noxious procedure as discussed in the PAAD of July 25, 2022.
References:
1. Friesen RH, Honda AT, Thieme RE. Perianesthetic intracranial hemorrhage in preterm neonates. Anesthesiology 1987;67:814-816.
2. Vidyasagar D, Raju TN. A simple noninvsive technique of measuring intracranial pressure in the newborn. Pediatrics 1977;59:957-961.
3. Hill A, Volpe JJ. Measurement of intracranial pressure using the Ladd intracranial pressure monitor. J Pediatr 1981;98:974-976.
4. Friesen RH, Thieme RE, Honda AT, Morrison JE Jr. Changes in anterior fontanel pressure in preterm neonates receiving isoflurane, halothane, fentanyl, or ketamine. Anesth Analg 1987;66:431-434.
5. Smith RM. Anesthesia for infants and children, 4th ed. CV Mosby, St. Louis, 1980, pp 176-180.
6. Perlman JM, Volpe JJ. Suctioning in the preterm infant: effects on cerebral blood flow velocity, intracranial pressure, and arterial blood pressure. Pediatrics 1983;72:329-334.