Pete G. Kovatsis

Airway management complications in children with difficult tracheal intubation from the Pediatric Difficult Intubation (PeDI) registry: a prospective cohort analysis

BACKGROUND Despite the established vulnerability of children during airway management, remarkably little is known about complications in children with difficult tracheal intubation. To address this concern, we developed a multicentre registry (Pediatric Difficult Intubation [PeDI]) to characterise risk factors for difficult tracheal intubation, establish the success rates of various tracheal intubation techniques, catalogue the complications of children with difficult tracheal intubation, and establish the effect of more than two tracheal intubation attempts on complications. METHODS The PeDI registry consists of prospectively collected tracheal intubation data from 13 childrens hospitals in the USA. We established standard data collection methods before implementing the secure web-based registry. After establishing standard definitions, we collected and analysed patient, clinician, and practice data and tracheal intubation outcomes. We categorised complications as severe or non-severe. FINDINGS Between August, 2012, and January, 2015, 1018 difficult paediatric tracheal intubation encounters were done. The most frequently attempted first tracheal intubation techniques were direct laryngoscopy (n=461, 46%), fibre-optic bronchoscopy (n=284 [28%]), and indirect video laryngoscopy (n=183 [18%]) with first attempt success rates of 16 (3%) of 461 with direct laryngoscopy, 153 (54%) of 284 with fibre-optic bronchoscopy, and 101 (55%) of 183 with indirect video laryngoscopy. Tracheal intubation failed in 19 (2%) of cases. 204 (20%) children had at least one complication; 30 (3%) of these were severe and 192 (19%) were non-severe. The most common severe complication was cardiac arrest, which occurred in 15 (2%) patients. The occurrence of complications was associated with more than two tracheal intubation attempts, a weight of less than 10 kg, short thyromental distance, and three direct laryngoscopy attempts before an indirect technique. Temporary hypoxaemia was the most frequent non-severe complication. INTERPRETATION More than two direct laryngoscopy attempts in children with difficult tracheal intubation are associated with a high failure rate and an increased incidence of severe complications. These results suggest that limiting the number of direct laryngoscopy attempts and quickly transitioning to an indirect technique when direct laryngoscopy fails would enhance patient safety. FUNDING None.

Apnea after Awake Regional and General Anesthesia in Infants: The General Anesthesia Compared to Spinal Anesthesia Study-Comparing Apnea and Neurodevelopmental Outcomes, a Randomized Controlled Trial

Background:Postoperative apnea is a complication in young infants. Awake regional anesthesia (RA) may reduce the risk; however, the evidence is weak. The General Anesthesia compared to Spinal anesthesia study is a randomized, controlled trial designed to assess the influence of general anesthesia (GA) on neurodevelopment. A secondary aim is to compare rates of apnea after anesthesia. Methods:Infants aged 60 weeks or younger, postmenstrual age scheduled for inguinal herniorrhaphy, were randomized to RA or GA. Exclusion criteria included risk factors for adverse neurodevelopmental outcome and infants born less than 26 weeks gestation. The primary outcome of this analysis was any observed apnea up to 12 h postoperatively. Apnea assessment was unblinded. Results:Three hundred sixty-three patients were assigned to RA and 359 to GA. Overall, the incidence of apnea (0 to 12 h) was similar between arms (3% in RA and 4% in GA arms; odds ratio [OR], 0.63; 95% CI, 0.31 to 1.30, P = 0.2133); however, the incidence of early apnea (0 to 30 min) was lower in the RA arm (1 vs. 3%; OR, 0.20; 95% CI, 0.05 to 0.91; P = 0.0367). The incidence of late apnea (30 min to 12 h) was 2% in both RA and GA arms (OR, 1.17; 95% CI, 0.41 to 3.33; P = 0.7688). The strongest predictor of apnea was prematurity (OR, 21.87; 95% CI, 4.38 to 109.24), and 96% of infants with apnea were premature. Conclusions:RA in infants undergoing inguinal herniorrhaphy reduces apnea in the early postoperative period. Cardiorespiratory monitoring should be used for all ex-premature infants.

Predictors of Failure of Awake Regional Anesthesia for Neonatal Hernia Repair: Data from the General Anesthesia Compared to Spinal Anesthesia Study-Comparing Apnea and Neurodevelopmental Outcomes

Background:Awake regional anesthesia (RA) is a viable alternative to general anesthesia (GA) for infants undergoing lower abdominal surgery. Benefits include lower incidence of postoperative apnea and avoidance of anesthetic agents that may increase neuroapoptosis and worsen neurocognitive outcomes. The General Anesthesia compared to Spinal anesthesia study compares neurodevelopmental outcomes after awake RA or GA in otherwise healthy infants. The aim of the study is to describe success and failure rates of RA and report factors associated with failure. Methods:This was a nested cohort study within a prospective, randomized, controlled, observer-blind, equivalence trial. Seven hundred twenty-two infants 60 weeks or less postmenstrual age scheduled for herniorrhaphy under anesthesia were randomly assigned to receive RA (spinal, caudal epidural, or combined spinal caudal anesthetic) or GA with sevoflurane. The data of 339 infants, where spinal or combined spinal caudal anesthetic was attempted, were analyzed. Possible predictors of failure were assessed including patient factors, technique, experience of site and anesthetist, and type of local anesthetic. Results:RA was sufficient for the completion of surgery in 83.2% of patients. Spinal anesthesia was successful in 86.9% of cases and combined spinal caudal anesthetic in 76.1%. Thirty-four patients required conversion to GA, and an additional 23 patients (6.8%) required brief sedation. Bloody tap on the first attempt at lumbar puncture was the only risk factor significantly associated with block failure (odds ratio = 2.46). Conclusions:The failure rate of spinal anesthesia was low. Variability in application of combined spinal caudal anesthetic limited attempts to compare the success of this technique to spinal alone.

Initial experience with the air-Q as a conduit for fiberoptic tracheal intubation in infants.

reported about the successful use of the Airtraq in infants with Pierre Robin syndrome (1) and children with Treacher Collins syndrome (2). This is the first case to report the successful and fast orotracheal intubation using Airtraq in a child with Goldenhar syndrome with history of failed intubation. We suggest that whenever we anticipate difficult intubation in a child, the use of an Airtraq may be helpful and worth the trial. S A M I A K H A L I L* B A O M I N H V I N H† *Professor and †Resident Department of Anesthesiology, The University of Texas Medical School at Houston, Houston, TX, USA (email: Samia.N.Khalil@uth.tmc.edu)

Simple, reliable replacement of pilot balloons for a variety of clinical situations.

When a pilot balloon fails or is an impediment to an intubation, such as via a pediatric laryngeal mask, options are generally limited to a tracheal tube exchange. Simple and effective solutions are described to replace a pilot balloon in a variety of clinical situations by using equipment that is readily available in operating rooms. Equipment such as intravenous catheters or epidural clamp connectors provides reliable, light weight, and streamlined substitutions for pilot balloons when connected to the pilot‐cuff inflation line.

The efficacy of GlideScope ® videolaryngoscopy compared with direct laryngoscopy in children who are difficult to intubate: An analysis from the paediatric difficult intubation registry

Background We analysed data from the Paediatric Difficult Intubation Registry examining the use of direct laryngoscopy and GlideScope® videolaryngoscopy. Methods Data collected by a multicentre, paediatric difficult intubation registry from 1295 patients were analysed. Rates of success and complications between direct laryngoscopy and GlideScope videolaryngoscopy were analysed. Results Initial (464/877 = 53% vs 33/828 = 4%, Z-test = 22.2, P < 0.001) and eventual (720/877 = 82% vs. 174/828 = 21%, Z-test = 25.2, P < 0.001) success rates for GlideScope were significantly higher than direct laryngoscopy. Children weighing <10 kg had lower success rates with the GlideScope than the group as a whole. There were no differences in complication rates per attempt between direct laryngoscopy and GlideScope. The direct laryngoscopy group had more complications associated with the greater number of attempts needed to intubate. There were no increased risks of hypoxia or trauma with GlideScope use. Each additional attempt at intubation with either device resulted in a two-fold increase in complications (odds ratio: 2.0, 95% confidence interval: 1.5-2.5, P < 0.001). Conclusions During difficult tracheal intubation in children, direct laryngoscopy is an overly used technique with a low chance of success. GlideScope use was associated with a higher chance of success with no increased risk of complications. GlideScope use in children with difficult tracheal intubation has a lower success rate than in adults with difficult tracheal intubation. Children weighing less than 10 kilograms had lower success rates with either device. Attempts should be minimized with either device to decrease complications.

E-cylinder-powered mechanical ventilation may adversely impact anesthetic management and efficiency

Anesthesiologists often administer care outside the operating room. These locations may depend on gas cylinders for their oxygen source more than the operating suites supplied by dedicated central pipelines. Using full E-cylinders, we determined the oxygen consumption of two often used, pneumatically driven anesthesia ventilators to answer three questions: How much time is available when mechanically ventilating patients in the setting of absent or malfunctioning central oxygen pipeline? How much oxygen is used by the ventilator to drive the bellows? How does changing the inspiratory to expiratory ratio and the inspiratory flow (Narkomed ventilator only) influence oxygen use? At a ventilation of 5 L/min, we found that mechanical ventilation consumes between 59% and 85% of the available oxygen in an E-cylinder to drive the ventilator at fresh gas flows ranging from 1 to 10 L/min. The time span until the low oxygen alarm sounded ranged from 38 to 99 min. Alteration of the inspiratory flow but not the inspiratory to expiratory ratio had a significant impact. Clinicians must recognize that mechanical ventilation using E-cylinders rapidly depletes this sole oxygen source and could jeopardize patient safety. Conversely, manual or spontaneous ventilation with low fresh gas flows minimizes oxygen depletion.

Continuous ventilation during flexible fiberscopic‐assisted intubation via supraglottic airways

SIR––Supraglottic airways (SGAs) are available to allow appropriate-sized tracheal tubes (TT) and pilot balloons to pass easily through them. Many steps are required to intubate successfully via SGAs and there are many variations in practices (1). I describe a method which allows continued ventilation using the anesthesia circuit during the intubation via SGAs. After removing the SGA’s circuit connector, the desired TT is advanced approximately half way into the SGA. This can be performed after the SGA is inserted in unexpected difficult intubations, or the TT may be preloaded into the SGA prior to patient insertion in expected difficult intubations. The TT within the SGA now becomes the circuit connector. Pediatric SGAs designed for intubation have larger diameters to accommodate pilot balloons and the use of a cuffed TT allows a seal within these SGAs. With the circuit connected to the TT, ventilation and the seals of both the SGA and the TT within the SGA are verified. A multiport adapter is placed between the TT and the anesthesia circuit allowing ventilation during fiberscopic-assisted intubation (Figure 1). For smaller fiberscopes, a piece of tape with a small perforation placed over the adapter’s fiberscope port ensures an adequate seal around the fiberscope during ventilation. In order to maintain reasonable gas exchange, a larger difference between the fiberscope’s outer diameter and the TT’s inner diameter is better. A fiberscope’s outer diameter that is at least 0.7 mm smaller than the TT’s inner diameter is preferred. With a tighter fit, passive oxygenation (CPAP 5–10 cmH2O) via the TT should be employed due to concerns of ineffective egress of gases around the fiberscope. As the initial seating of the SGA may not always provide an easily accessible laryngeal view (2), some readjustment of the SGA or external manipulation of the patient (jaw thrust, cricoid pressure, head, and neck adjustments) may be required. Adequate lubrication is crucial for the TT and pilot balloon to pass through SGAs. After the fiberscope is advanced to the carina, the TT cuff is deflated and advanced over the fiberscope with positioning confirmed by the fiberscope and auscultation. The fiberscope and the swivel adapter are removed. The patient’s respiratory parameters are reassessed and the patient is ventilated as indicated. The TT’s 15-mm circuit adapter is removed and the TT is stabilized while the SGA is removed (1,3). The 15-mm circuit adapter is replaced, breath sounds are verified, and the TT is secured. Anesthesia circuit ventilation may be maintained even during the removal of the SGA from the patient by combining two TT together (4). When a cuffed TT is used for intubation via SGAs, the second TT is trimmed such that the combined length is not longer than the pilotcuff line ending before the pilot balloon. Otherwise, the pilot balloon cannot advance through the SGA. This holds true for any TT stabilizer when used in SGAs designed to pass pilot balloons; all need to be removed from the SGA prior to passage of the pilot balloon through the SGA. If not using SGAs that allow passage of pilot balloons, then uncuffed TT or pilot balloon replacement techniques (5) may be utilized. The method described here is also a simple solution to attach a circuit to SGAs that have been cut shorter to help in the advancement and stabilization of the TT. This continuous ventilation capability is particularly beneficial in neonates and patients with poor cardiopulmonary reserve and who have a difficult intubation. Using a TT loaded into the SGA as the circuit connector during an intubation via the SGA provides improved patient stability and more time. This method has been used successfully in many diverse clinical situations including elective difficult airway Figure 1 Supraglottic airways (SGA) serving as a conduit for fiberoptic intubation. Note the disconnection of the 15 mm circuit adapter from the SGA (C), while the circuit is attached to the TT (D).

A randomized multi-institutional crossover comparison of the GlideScope® Cobalt Video laryngoscope to the flexible fiberoptic bronchoscope in a Pierre Robin manikin

The GlideScope Cobalt Video laryngoscope is being used more often in children with challenging laryngoscopy. There are, however, no pediatric trials comparing it to flexible fiberoptic bronchoscopy, the current accepted gold standard. This preliminary manikin study compares the first‐attempt intubation success of the GlideScope Cobalt video laryngoscope to the flexible fiberoptic bronchoscope when performed by attending pediatric anesthesiologists at two major pediatric centers.

Correspondence: Blind intubation through the air-Q laryngeal mask in children – A word of caution

earlier, and the median, 25 and 75 percentile values are shown in Fig 4 (1). These values are also shown in the table. As we can see from the table, the median BIS values were between 45 and 60 during most of the maintenance of anesthesia. This shows that in BIS group, any modification in the propofol infusion rate was adequate to maintain BIS in the target range. We have not reported the time for which the patients had BIS between 45 and 60 as our study was not aimed at comparing closed-loop system with manual titration of propofol. Our aim was to titrate propofol infusion based on BIS and hemodynamic parameters. We agree that automatic BIS-guided closed-loop titration of propofol may be a better method of administering propofol anesthesia. However, cost and availability of the equipment are the limiting factors. Also, its use in children is yet to be established. The sample size was adequate based on the fact that the propofol consumption in the BIS group during maintenance of anesthesia, i.e., excluding the induction dose was 108.6 ± 37.8 lgÆkgÆmin and not 190 lgÆkgÆmin. The patients did not have inadequate analgesia or anesthesia. Large standard deviations in the hemodynamic data are attributable to inclusion of children of ages varying from 2 to 12 . The normal range of heart rates and blood pressures varies at different ages. Large standard deviations indicate variation among different patients in the same group and not hemodynamic variations in the same patient. N E E R J A B H A R D W A J S A N D H Y A Y A D D A N A P U D I Department of Anaesthesia and Intensive Care, Postgraduate Institute of Medical Education and Research, Chandigarh-160012, India (email: neerja.bhardwaj@gmail.com) Reference