Senthil G. Krishna

The relationship between head and neck position and endotracheal tube intracuff pressure in the pediatric population

Over the past few years, there has been a change in clinical practice with a transition to the use of cuffed instead of uncuffed endotracheal tubes (ETTs) in pediatric patients. These changes have led to concerns regarding unsafe intracuff pressures in pediatric patients, which may result in postoperative morbidity. To avoid these issues, it is generally suggested that the intracuff pressure be maintained at ≤30 cmH2O. The current study prospectively assesses the changes in intracuff pressure related to alterations in head and neck position in pediatric patients.

A technique to measure the intracuff pressure continuously: an in vivo demonstration of its accuracy.

A major concern with the use of cuffed endotracheal tubes (cETT) in children is hyperinflation of the cuff which may compromise tracheal mucosal perfusion. To measure the intracuff pressure (CP), we devised a method using the transducer of an invasive pressure monitoring device. The objective of the study was to test the accuracy and validity of this device for instantaneous and continuous CP monitoring.

Changes in intracuff pressure of a cuffed endotracheal tube during prolonged surgical procedures

BACKGROUND With the introduction of redesigned cuffed endotracheal tubes (ETTs), there has been an increasing trend toward their use in pediatric patients. Despite improvements in design, an unintended and prolonged hyperinflation of the cuff can compromise tracheal mucosal perfusion. The current study prospectively monitors changes in intracuff pressure continuously in pediatric patients undergoing prolonged surgical procedures. METHODS The study was conducted on pediatric patients who were scheduled to undergo prolonged surgical procedures (more than 4h) with a cuffed ETT. After placement of the cuffed ETT, the cuff was inflated using the air-leak test with a CPAP of 20cmH2O in the anesthesia circuit. After inflation, the inflating port of the pilot balloon was connected to the transducer of the invasive pressure monitoring device using our previously described technique to continuously measure the intracuff pressure. Measurements were recorded every 15min for the first 1h, and then every 30min throughout the surgical procedure. RESULTS The study cohort included 30 patients who ranged in age from 1.2 to 17.6 years and in weight from 9.4 to 113.4kg. There were 16 boys and 14 girls. The size of the cuffed ETT ranged from 3.5mm to 8.0mm ID. The baseline intracuff pressure at the time of inflation was 17.6±8.8cmH2O. The absolute change in the intraoperative intracuff pressure when compared to the baseline intracuff pressure ranged from -25.8 to +16.3cmH2O. In 9 patients (30%), the decrease of the intracuff pressure was ≥10cmH2O. In 6 patients (20%), the increase of the intracuff pressure was ≥10cmH2O. In 5 of 30 patients (17%), the absolute intracuff pressure was greater than 30cmH2O at least once intraoperatively. In no patient, did the intracuff pressure remain the same as the baseline throughout the procedure. CONCLUSION We noted significant variations in the intracuff pressure during prolonged surgical procedures. These unintended changes, both increases and decreases, may impact the perioperative course of patients. Our study suggests the need for continuously monitoring intracuff pressure if a cuffed ETT is used in children for prolonged surgical procedures.

An in vitro and in vivo validation of a novel monitor for intracuff pressure in cuffed endotracheal tubes

The clinical practice of pediatric anesthesiology has changed with increasing use of cuffed endotracheal tubes (cETTs) in infants and children. To limit the risk of tracheal mucosal damage, regular monitoring of intracuff pressure (CP) is necessary. This study evaluates the efficacy and accuracy of a novel syringe device that provides a digital readout of the CP.

Cuffed endotracheal tubes in children: the effect of the size of the cuffed endotracheal tube on intracuff pressure.

In children, the size of the cuffed endotracheal tube is based on various age‐based formulas. However, such formulas may over or underestimate the size of the cuffed endotracheal tube. There are no data on the impact of different‐sized cuffed endotracheal tubes (ETT) on the intracuff pressure in children.

Oropharyngeal oxygen and volatile anesthetic agent concentration during the use of laryngeal mask airway in children.

The laryngeal mask airway is increasingly used as an airway adjunct during general anesthesia. Although placement is generally simpler than an endotracheal tube, complete sealing of the airway may not occur, resulting in contamination of the oropharynx with anesthetic gases. Oropharyngeal oxygen enrichment may be one of the contributing factors predisposing to an airway fire during adenotonsillectomy. The current study prospectively assesses the oropharyngeal oxygen and volatile anesthetic agent concentration during laryngeal mask airway use in infants and children.

Changes in intracuff pressure of a cuffed endotracheal tube during surgery for congenital heart disease using cardiopulmonary bypass

With the development of newer polyurethane cuffed endotracheal tubes (cETTs), there has been a shift in clinical practice among pediatric anesthesiologists. Despite improvements in design, excessive inflation of the cuff can still compromise tracheal mucosal perfusion. Several perioperative factors can affect the intracuff pressure (CP), and there is no consensus on safe CP in pediatric patients undergoing repair of congenital cardiac disease (CHD) utilizing cardiopulmonary bypass (CPB). In the current study, the CP was continuously monitored in pediatric patients undergoing surgery for CHD.

Response to X Wang and L Tan, regarding their comment on our paper ‘The relationship between head and neck position and endotracheal tube intracuff pressure in the pediatric population’

SIR–We would like to thank Drs. Wang and Tan for their interests in our manuscript regarding the relationship between head and neck position and endotracheal tube intracuff pressure (1). Their first query concerns the stability of the intracuff pressure measurements, mentioning their experience of unsustained changes of intracuff pressure in five children moved from spine position to lateral position. In our study, all the measurements were recorded after the intracuff pressure was stable without change at least for 30 s. Although the pressure was then measured for approximately 30–60 s longer, we cannot comment as to whether this pressure would be sustained over the ensuing minutes as this was not part of the study protocol. We appreciate the information you have provided on your evaluation involving five patients. It seems that additional investigation is needed with a larger cohort of patients in which the pressure is continuously measured following the position change to see whether this pressure is sustained or not. We also agree that the change in intracuff pressure may vary depending on whether only the head is moved from the neutral to lateral position when compared to moving the head and the patient’s entire body to the lateral position. Obviously, given the potential risks of excessive intracuff pressure and its effects on the airway, it may be that the continuous monitoring of intracuff pressure is needed during prolonged surgical procedures especially when performed in the nonsupine position (2). Secondly, we agree that several factors may affect the intracuff pressure, including the depth of the anesthesia and airway reactivity. All of the values obtained in our study were measured immediately after the induction of anesthesia and endotracheal intubation with inflation of the cuff of the endotracheal tube. None of the patients in the study demonstrated any clinical sign of reactivity to the procedure of endotracheal intubation, which was performed during general anesthesia with a combination of a volatile (sevoflurane) and intravenous (propofol and opioids) anesthetic agents. However, additional evaluation of the hemodynamic profile and the bispectral index (BIS) and the impact of these factors on the intracuff pressure are intriguing and warrant further investigation. Regarding the different baseline intracuff pressure, the cuff of the endotracheal tube was inflated by the anesthesia provider using our standard technique, which involves inflation of the cuff until there was no audible gas leak while holding continuous positive airway pressure of 20–25 cmH2O. Comparison of the changes of intracuff pressure with different baseline intracuff

Sugammadex to reverse neuromuscular blockade and provide optimal conditions for motor-evoked potential monitoring

Sugammadex is a novel pharmacologic agent, which reverses neuromuscular blockade (NMB) via a mechanism that differs completely from acetylcholinesterase inhibitors. By encapsulating rocuronium, sugammadex can provide recovery of neuromuscular function even when there is a profound degree of NMB. We report anecdotal experience with the use of sugammadex to reverse NMB to facilitate intraoperative neurophysiological monitoring (motor evoked potentials) in an adolescent with scoliosis during posterior spinal fusion. Its potential application in this unique clinical scenario is discussed, and potential dosing schemes are reviewed.

The Effect of Transesophageal Echocardiography Probe Placement on Intracuff Pressure of an Endotracheal Tube in Infants and Children

OBJECTIVES To evaluate the effects of transesophageal echocardiography (TEE) probe insertion on the endotracheal cuff pressure (CP). DESIGN Prospective observational study. SETTING Single standing, not-for-profit pediatric hospital. PARTICIPANTS A total of 80 pediatric patients (aged 6 days to 18.4 years) who underwent cardiac surgery and intraoperative TEE. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Following anesthesia induction and endotracheal intubation, the CP was recorded at 4 points: before the insertion of the TEE (P1), at TEE insertion (P2), during TEE examination (P3), and after the probe was advanced into the stomach (P4). Twenty patients were enrolled in each of the following age groups:<1 year of age; 1-4 years of age; 5-8 years of age; and 9-18 years of age. CP was compared between pairs of time points using paired t-tests, and differences in CP over time were compared among age groups using repeated-measures analysis of variance. CP at P1, P2, P3, and P4 was 18.7±11.6, 26.7±14.4, 22.3±12.4, and 20.6±12.6 cmH2O, respectively. Although CP significantly increased from P1 to P2 (p<0.001), there was no significant difference between P1 and P4 (95% CI; -0.3 to 4.1; p = 0.083). There was no significant difference in CP change based on the age of the patient. CONCLUSION Following a transient increase in CP with TEE probe insertion, the CP returned to baseline after the tip of the TEE probe was advanced into the stomach. There was no variation among age groups in the magnitude of the CP change during the study.