Preemptive airway management planning: A retrospective evaluation of the pediatric difficult airway consultation service.

BACKGROUND/AIMS: The pediatric Difficult Airway Consultation Service (pDACS) was created in 2017 to identify patients with potentially difficult airways and create airway management plans prior to airway management. METHODS: Consults were either nurse-initiated, physician-initiated, or both nurse-and-physician-initiated and were examined for demographic and clinical factors. If a child had difficult airway risk factors, a consult note with airway management recommendations was completed. RESULTS: We included 419 consults from the 4-year study period for analysis. Sixty-one patients had chronic tracheostomies in place and thus, were analyzed separately. Of the remaining 358 consults, 50% (n = 179) were nurse-initiated, 30.2% (n = 108) physician-initiated, and 19.8% (n = 71) nurse-and-physician-initiated consults. Differences in observed frequency of airway edema (difference, 6.3%; 95%CI 0.1%-12.5%; p = .04), cleft lip/palate (difference, 8.1%; 95%CI 0.07%-16.3%, p = .04), craniofacial abnormalities (difference, 12.3%; 95%CI 1.9%-22.7%, p = .02), and trauma/burn (difference, 6.5%; 95%CI 0.09%-12.8%, p = .04) were calculated. Observed frequencies were higher in physician-initiated compared to nurse-initiated consults. Airway edema was also more prevalent in dual nurse-and-physician-initiated consults (difference, 8.7%; 95%CI 1.6%-15.8%; p = .01). Physician-initiated consults were associated with a greater proportion of high-risk difficult airways than nurse-initiated consults (difference, 26.7%; 95%CI 14.0%-39.4%, p < .001). Approximately 41.9% of patients at high-risk for having a difficult airway were identified by nurse-screening only. Using bag-valve-mask was often the primary ventilation recommendation (89.3%, n = 108) and supraglottic airway placement was the most common tertiary plan (74.2%, n = 83). Direct laryngoscopy (47.1%, n = 65) and videolaryngoscopy (40.6%, n = 56) were the most recommended modes of intubation. Three patients with airway emergencies had previously documented airway management plans and were successfully intubated without complications following the primary intubation technique recommended in their consult note. CONCLUSIONS: In our study, nurse-screening identified patients at high-risk for a difficult airway that would likely not have been identified prior to initiation of a screening protocol. Furthermore, airway management plans outlined prior to an emergent difficult airway event may increase first-attempt success at securing the difficult airway, reducing morbidity and mortality.

Nebulized caffeine alleviates airway hyperresponsiveness in a murine asthma model.

The clinical definition of "difficult asthma" has expanded recently to include an ever-growing subset of patients with symptoms that cannot be controlled by conventional means, forcing the medical community to develop innovative therapeutics. Beneficial effects of coffee for subjects with asthma, primarily the effect of methylxanthine components, have long been described. Methylxanthines, including theophylline and caffeine, inhibit phosphodiesterases and downstream cAMP signaling to prevent mast cell degranulation while promoting immunomodulation (Peleman RA, Kips JC, Pauwels RA. Clin Exp Allergy 28: 53-56, 1998; Deshpande DA, Wang WCH, McIlmoyle EL, Robinett KS, Schillinger RM, An SS, Sham JSK, Liggett SB. Nat Med 16: 1299-1304, 2010). Caffeine is also a bitter taste receptor agonist, binding to taste-sensing type 2 receptors (TAS2R) before releasing calcium to hyperpolarize airway smooth muscle membranes, inducing bronchodilation (Workman AD, Palmer JN, Adappa ND, Cohen NA. Curr Allergy Asthma Rep 15: 72, 2015; Devillier P, Naline E, Grassin-Delyle S. Pharmacol Ther 155: 11-21, 2015). Theophylline is conventionally used to treat asthma, whereas, according to the literature, the dosage required for orally administered caffeine has yielded modest improvement (Alfaro TM, Monteiro RA, Cunha RA, Cordeiro CR. Clin Respir J 12: 1283-1294, 2018). We sought to determine whether aerosolization of ultrafine caffeine particles (2.5-4 µm) directly to the lungs of susceptible A/J mice challenged with methacholine would improve pulmonary function via forced oscillation technique. In addition, we assessed whether nebulization of caffeine leads to changes in lung pathophysiology and bronchoalveolar lavage cell profiles. We found that mice that received aerosolized caffeine had statistically significant decreases in maximum airway resistance [6.3 vs. 3.9 cmH2O·s/mL at 62.5 mg/mL caffeine; confidence interval (CI) = -4.3, -0.4; P = 0.02] and significant delays in the time required to reach maximum resistance compared with that of controls (64.7 vs. 172.1 sec at 62.5 mg/mL caffeine, CI = 96.0, 118.9; P < 0.0001). Nebulized caffeine yielded a consistent effect on airway hyperresponsiveness at a range of doses without evidence of significant pathology relative to vehicle control.NEW & NOTEWORTHY For decades, coffee has been shown to improve symptoms in patients with asthma. One component, theophylline, is conventionally used to treat asthma, whereas the dosage required for orally administered caffeine has yielded modest improvement. We sought to determine whether aerosolization of caffeine directly to the lungs of susceptible A/J mice challenged with methacholine would alter pulmonary function via forced oscillation technique. We found nebulized caffeine yielded a consistent improvement on murine AHR.

The odorant receptor OR2W3 on airway smooth muscle evokes bronchodilation via a cooperative chemosensory tradeoff between TMEM16A and CFTR.

The recent discovery of sensory (tastant and odorant) G protein-coupled receptors on the smooth muscle of human bronchi suggests unappreciated therapeutic targets in the management of obstructive lung diseases. Here we have characterized the effects of a wide range of volatile odorants on the contractile state of airway smooth muscle (ASM) and uncovered a complex mechanism of odorant-evoked signaling properties that regulate excitation-contraction (E-C) coupling in human ASM cells. Initial studies established multiple odorous molecules capable of increasing intracellular calcium ([Ca2+]i) in ASM cells, some of which were (paradoxically) associated with ASM relaxation. Subsequent studies showed a terpenoid molecule (nerol)-stimulated OR2W3 caused increases in [Ca2+]i and relaxation of ASM cells. Of note, OR2W3-evoked [Ca2+]i mobilization and ASM relaxation required Ca2+ flux through the store-operated calcium entry (SOCE) pathway and accompanied plasma membrane depolarization. This chemosensory odorant receptor response was not mediated by adenylyl cyclase (AC)/cyclic nucleotide-gated (CNG) channels or by protein kinase A (PKA) activity. Instead, ASM olfactory responses to the monoterpene nerol were predominated by the activity of Ca2+-activated chloride channels (TMEM16A), including the cystic fibrosis transmembrane conductance regulator (CFTR) expressed on endo(sarco)plasmic reticulum. These findings demonstrate compartmentalization of Ca2+ signals dictates the odorant receptor OR2W3-induced ASM relaxation and identify a previously unrecognized E-C coupling mechanism that could be exploited in the development of therapeutics to treat obstructive lung diseases.

Pediatric Difficult Airway Response Team Utilization in the Emergency Department: A Case Series.

OBJECTIVES: A multidisciplinary pediatric difficult airway team was created at our institution to respond to hospital-wide airway emergencies. We report the characteristics, indications, and outcomes of these activations that occur in the pediatric emergency department (PED). METHODS: Retrospective, single-center cohort study comprised all difficult airway team activations occurring in the PED from the program's inception in 2008 to 2018. Ages of ≤18 years were included. For each case, detailed information was abstracted, including patient factors, PED context and milieu, airway interventions, and airway outcomes. RESULTS: There were 15 difficult airway response team activations in the PED during the study period, or 1.4 activations per year. The most common indications for activation were contaminated airways (n = 7; 47%) and history of difficult intubation (n = 4; 27%). Definitive airway management was successful in all cases, except for a single case where intervention was unnecessary. The most commonly performed definitive airway intervention was direct laryngoscopy (n = 6; 40%). There were no instances of emergency front-of-neck access. CONCLUSIONS: Difficult airways in the PED were uncommon. Most cases were resolved with familiar equipment including direct laryngoscopy, video laryngoscopy, and supraglottic airways.

Age-Related Changes in Upper Airway Anatomy Via Ultrasonography in Pediatric Patients.

PURPOSE: Ultrasonography is a portable, noninvasive tool that may be used to evaluate the upper airway. The purpose of our study was to present a systematic approach to identify salient features of the pediatric airway and determine whether ultrasonography can identify anatomical changes that occur with growth and development. METHODS: We present a prospective, observational trial where patients included were between 1 day and 10 years of age presenting for elective surgery who had no known history of unfavorable airway pathology. We sequentially obtained 5 ultrasound views under anesthesia: (1) sagittal sternal notch view of the trachea, (2) sagittal longitudinal view of trachea (LT), (3) axial view at the level of the vocal cords (AVC), (4) axial view at the level of the cricoid membrane (AC), and (5) sagittal longitudinal submental space view (SM). A broadband linear array transducer was used to identify airway structures and perform measurements. RESULTS: Eighty-four percent of enrolled patients underwent airway imaging and were analyzed using multiple regression and Spearman correlation (ρ). In view 1, tracheal diameter via sagittal sternal notch view was immeasurable because of air disturbance. In the LT view, the distance from the skin to the cricothyroid membrane (LT1) did not statistically increase with age in days (P = 0.06); however, the distance from the cricoid to thyroid cartilage (LT2) did correlate to age (P < 0.001; 99% confidence interval [CI], 1.8 × 10-5, 7.7 × 10-5; ρ = 0.77, P = 0.001). We found a statistically significant relationship between age and the distance between the anterior and posterior commissures (AVC2; P < 0.001; 99% CI, 1.0 × 10-4, 1.7 × 10-4; ρ = 0.80, P < 0.001), the distance from the skin to the posterior commissure (AVC3; P < 0.001; 99% CI, 9.6 × 10-5, 2.0 × 10-4; ρ = 0.73, P < 0.001), the distance to the cricoid cartilage (AC; P < 0.001; 99% CI, 2.0 × 10-5, 7.7 × 10-5; ρ = 0.66, P < 0.001), and the distance from the tongue base to the soft palate (SM2; P < 0.001; 9% CI, 1.8 × 10-4, 3.9 × 10-4; ρ = 0.85, P < 0.001). There were no significant relationships between age and AVC1 (P = 0.16) and SM1 (P = 0.44). CONCLUSIONS: Airway ultrasound is a feasible tool to evaluate the pediatric airway in children younger than 10 years; however, the detection of age-related changes of certain structures is limited to select measurements.

Laryngoscopy Grade Improvement and Difficult Airway Resolution in Infants With Robin Sequence Undergoing Mandibular Distraction Osteogenesis: A Multi-Institutional Study.

OBJECTIVE: Mandibular distraction osteogenesis (MDO) aims to relieve tongue-based airway obstruction in Robin Sequence (RS). We investigated direct laryngoscopy grade (DLG) improvement and difficult airway (DA) resolution following MDO. DESIGN: Retrospective cohort analysis. SETTING: Three tertiary care institutions. PATIENTS: Sixty-four infants with RS who underwent a single MDO procedure in their first year of life were identified from January 2010 to January 2019. MAIN OUTCOME MEASURES: The primary outcome was DLG pre- and post-MDO. Secondary outcomes included DA designation, pre- and post-MDO polysomnographic assessment for obstructive sleep apnea (OSA), length of stay, need for gastrostomy, and major/minor adverse events. RESULTS: Median DLG improved from II pre-MDO to I at the time of distractor removal (n = 43, P < .001). No significant change was seen in patients with a third recorded time point (eg, palatoplasty; n = 78, P = .52). Twenty-six (47%) of 55 patients were designated as DA pre-MDO, and 10 (18%) of 55 patients retained the label post-MDO (P < .01). Five (50%) of these 10 patients appeared to be inappropriately retained. Median obstructive apnea-hypopnea index improved from 38.6 (range 31.2-62.8) pre-MDO to 2.9 (range 1-3.9) post-MDO (n = 12; P = .002). CONCLUSION: Mandibular distraction osteogenesis allowed for DLG improvement that was stably maintained as well as functional improvement in OSA, with minimal morbidity. Difficult airway designation persisted in the electronic record of some infants despite clinical resolution.

Effects of Obstructive Sleep Apnea and Obesity on Morphine Pharmacokinetics in Children.

BACKGROUND: Obesity increases susceptibility to chronic pain, increases metabolism, and is associated with obstructive sleep apnea syndrome (OSAS), all which can complicate perioperative pain management of patients. In addition, obesity and OSAS can cause elevation of the adipose-derived hormone leptin, which increases metabolism. We hypothesized that obesity along with sleep apnea and leptin independently enhance morphine pharmacokinetics. METHODS: Children 5-12 years of age who were presenting for surgery were administered a morphine dose of 0.05 mg/kg. Blood was collected at baseline and at subsequent preset times for pharmacokinetic analysis of morphine and its metabolites. Three groups were studied: a nonobese group with severe OSAS, an obese group with severe OSAS, and a control group. RESULTS: Thirty-four patients consisting of controls (n = 16), nonobese/OSAS (n = 8), and obese/OSAS (n = 10) underwent analysis. The obese/OSAS group had a higher dose-adjusted mean maximum morphine concentration (CMAX) over 540 minutes compared to the controls (P < .001) and those with only OSAS (P = .014). The obese/OSAS group also had lower volume of distribution (Vd) when compared to OSAS-only patients (P = .007). In addition, those in the obese/OSAS group had a higher morphine 3-glucuronide (M3G) maximum concentration (P = .012) and a higher ratio of M3G to morphine than did the control group (P = .011). Time to maximum morphine 6-glucuronide (M6G) concentration was significantly lower in both nonobese/OSAS and obese/OSAS groups than in the control group (P < .005). C-reactive protein (CRP), interleukin (IL)-10, and leptin were all higher in the obese/OSAS group than in controls (P = .004, 0.026, and <0.001, respectively), and compared to OSAS-only patients, CRP (P = .013) and leptin (P = .002) levels were higher in the obese/OSAS group. CONCLUSIONS: The combination of obesity and OSAS was associated with an increase in morphine metabolism compared with that in normal-weight controls. Our previous study in mice demonstrated that obesity from leptin deficiency decreased morphine metabolism, but that metabolism normalized after leptin replacement. Leptin may be a cause of the increased morphine metabolism observed in obese patients.

Pediatric Airway Management in COVID-19 Patients: Consensus Guidelines From the Society for Pediatric Anesthesia's Pediatric Difficult Intubation Collaborative and the Canadian Pediatric Anesthesia Society.

The severe acute respiratory syndrome coronavirus 2 (coronavirus disease 2019 [COVID-19]) pandemic has challenged medical systems and clinicians globally to unforeseen levels. Rapid spread of COVID-19 has forced clinicians to care for patients with a highly contagious disease without evidence-based guidelines. Using a virtual modified nominal group technique, the Pediatric Difficult Intubation Collaborative (PeDI-C), which currently includes 35 hospitals from 6 countries, generated consensus guidelines on airway management in pediatric anesthesia based on expert opinion and early data about the disease. PeDI-C identified overarching goals during care, including minimizing aerosolized respiratory secretions, minimizing the number of clinicians in contact with a patient, and recognizing that undiagnosed asymptomatic patients may shed the virus and infect health care workers. Recommendations include administering anxiolytic medications, intravenous anesthetic inductions, tracheal intubation using video laryngoscopes and cuffed tracheal tubes, use of in-line suction catheters, and modifying workflow to recover patients from anesthesia in the operating room. Importantly, PeDI-C recommends that anesthesiologists consider using appropriate personal protective equipment when performing aerosol-generating medical procedures in asymptomatic children, in addition to known or suspected children with COVID-19. Airway procedures should be done in negative pressure rooms when available. Adequate time should be allowed for operating room cleaning and air filtration between surgical cases. Research using rigorous study designs is urgently needed to inform safe practices during the COVID-19 pandemic. Until further information is available, PeDI-C advises that clinicians consider these guidelines to enhance the safety of health care workers during airway management when performing aerosol-generating medical procedures. These guidelines have been endorsed by the Society for Pediatric Anesthesia and the Canadian Pediatric Anesthesia Society.

Impact of Clinical Guidelines on Revisits After Ambulatory Pediatric Adenotonsillectomy.

BACKGROUND: Pediatric adenotonsillectomies are common and carry known risks of potentially severe complications. Complications that require a revisit, to either the emergency department or hospital readmission, increase costs and may be tied to lower reimbursements by federal programs. In 2011 and 2012, recommendations by pediatric and surgical organizations regarding selection of candidates for ambulatory procedures were issued. We hypothesized that guideline-associated changes in practice patterns would lower the odds of revisits. The primary objective of this study was to assess whether the odds of a complication-related revisit decreased after publication of guidelines after accounting for preintervention temporal trends and levels. The secondary objective was to determine whether temporal associations existed between guideline publication and characteristics of the ambulatory surgical population. METHODS: This study employs an interrupted time series design to evaluate the longitudinal effects of clinical guidelines on revisits. The outcome was defined as revisits after ambulatory tonsillectomy for privately insured patients. Data were sourced from the Truven Health Analytics MarketScan database, 2008-2015. Revisits were defined by the most prevalent complication types: hemorrhage, dehydration, pain, nausea, respiratory problem, infection, and fever. Time periods were defined by surgeries before, between, and after guidelines publication. Unadjusted odds ratios estimated associations between revisits and clinical covariates. Multivariable logistic regression was used to estimate the impact of guidelines on revisits. Differences in revisit trends among pre-, peri-, and postguideline periods were tested using the Wald test. Results were statistically significant at P < .005. RESULTS: A total of 326,993 surgeries met study criteria. The absolute revisit rate increased over time, from 5.9% (95% confidence interval [CI], 5.8-6.0) to 6.7% (95% CI, 6.6-6.9). The proportion of young children declined slightly, from 6.4% to 5.9% (P < .001). The proportion of patients having a tonsillectomy in an ambulatory surgery center increased (16.5%-31%; P < .001), as did the prevalence of obstructive sleep apnea (7.0%-14.0%; P < .001) and sleep-disordered breathing (20.6%-35.0%; P < .001). In a multivariable logistic regression model adjusted for age, sex, comorbidities, and surgical location, odds of a revisit increased during the preguideline period (0.4% increase per month; 95% CI, 0.24%-0.54%; P < .001). This monthly increase did not continue after guidelines (P = .002). CONCLUSIONS: While odds of a postoperative revisit did not decline after guideline publication, there was a significant difference in trend between the pre- and postguideline periods. Changes in the ambulatory surgery population also suggest at least partial adherence to guidelines.

Endoscopic Versus Open Repair for Craniosynostosis in Infants Using Propensity Score Matching to Compare Outcomes: A Multicenter Study from the Pediatric Craniofacial Collaborative Group.

BACKGROUND: The North American Pediatric Craniofacial Collaborative Group (PCCG) established the Pediatric Craniofacial Surgery Perioperative Registry to evaluate outcomes in infants and children undergoing craniosynostosis repair. The goal of this multicenter study was to utilize this registry to assess differences in blood utilization, intensive care unit (ICU) utilization, duration of hospitalization, and perioperative complications between endoscopic-assisted (ESC) and open repair in infants with craniosynostosis. We hypothesized that advantages of ESC from single-center studies would be validated based on combined data from a large multicenter registry. METHODS: Thirty-one institutions contributed data from June 2012 to September 2015. We analyzed 1382 infants younger than 12 months undergoing open (anterior and/or posterior cranial vault reconstruction, modified-Pi procedure, or strip craniectomy) or endoscopic craniectomy. The primary outcomes included transfusion data, ICU utilization, hospital length of stay, and perioperative complications; secondary outcomes included anesthesia and surgical duration. Comparison of unmatched groups (ESC: N = 311, open repair: N = 1071) and propensity score 2:1 matched groups (ESC: N = 311, open repair: N = 622) were performed by conditional logistic regression analysis. RESULTS: Imbalances in baseline age and weight are inherent due to surgical selection criteria for ESC. Quality of propensity score matching in balancing age and weight between ESC and open groups was assessed by quintiles of the propensity scores. Analysis of matched groups confirmed significantly reduced utilization of blood (26% vs 81%, P < .001) and coagulation (3% vs 16%, P < .001) products in the ESC group compared to the open group. Median blood donor exposure (0 vs 1), anesthesia (168 vs 248 minutes) and surgical duration (70 vs 130 minutes), days in ICU (0 vs 2), and hospital length of stay (2 vs 4) were all significantly lower in the ESC group (all P < .001). Median volume of red blood cell administered was significantly lower in ESC (19.6 vs 26.9 mL/kg, P = .035), with a difference of approximately 7 mL/kg less for the ESC (95% confidence interval for the difference, 3-12 mL/kg), whereas the median volume of coagulation products was not significantly different between the 2 groups (21.2 vs 24.6 mL/kg, P = .73). Incidence of complications including hypotension requiring treatment with vasoactive agents (3% vs 4%), venous air embolism (1%), and hypothermia, defined as <35°C (22% vs 26%), was similar between the 2 groups, whereas postoperative intubation was significantly higher in the open group (2% vs 10%, P < .001). CONCLUSIONS: This multicenter study of ESC versus open craniosynostosis repair represents the largest comparison to date. It demonstrates striking advantages of ESC for young infants that may result in improved clinical outcomes, as well as increased safety.

Point-of-care ultrasound in pediatric anesthesiology and critical care medicine.

Ultrasound has increasingly become a clinical asset in the hands of the anesthesiologist and intensivist who cares for children. Though many applications for ultrasound parallel adult modalities, children as always are not simply small adults and benefit from the application of ultrasound to their management in various ways. Body composition and size are important factors that affect ultrasound performance in the child, as are the pathologies that may uniquely afflict children and aspects of procedures unique to this patient population. Ultrasound simplifies vascular access and other procedures by visualizing structures smaller than those in adults. Maturation of the thoracic cage presents challenges for the clinician performing pulmonary ultrasound though a greater proportion of the thorax can be seen. Moreover, ultrasound may provide unique solutions to sizing the airway and assessing it for cricothyroidotomy. Though cardiac ultrasound and neurosonology have historically been performed by well-developed diagnostic imaging services, emerging literature stresses the utility of clinician ultrasound in screening for pathology and providing serial observations for monitoring clinical status. Use of ultrasound is growing in clinical areas where time and diagnostic accuracy are crucial. Implementation of ultrasound at the bedside will require institutional support of education and credentialing. It is only natural that the pediatric anesthesiologist and intensivist will lead the incorporation of ultrasound in the future practice of these specialties.

Perioperative outcomes and management in midface advancement surgery: a multicenter observational descriptive study from the Pediatric Craniofacial Collaborative Group.

BACKGROUND/AIMS: The evolution of Le Fort III and Monobloc procedures with utilization of distraction devices has resulted in shortened surgical times, greater facial advancements, and decreased transfusion requirements. The aim of this observational study was to utilize data from the multicenter Pediatric Craniofacial Surgery Perioperative Registry to present and compare patient characteristics and outcomes in children undergoing midface advancement with distraction osteogenesis. METHODS: We queried the Pediatric Craniofacial Surgery Perioperative Registry for children undergoing midface advancement involving distractor application from June 2012 to September 2016. Data extracted included demographics, perioperative management, complications, fluid and transfusion volumes, and length of stay. The extracted patient characteristics and perioperative variables were summarized and compared. RESULTS: The query yielded 72 cases from 11 institutions: 49 children undergoing Le Fort III and 23 undergoing Monobloc procedures. Monobloc patients were younger, weighed less, and more likely to have tracheostomies along with elevated intracranial pressure. Greater transfusion was observed in the Monobloc group for nearly all of the transfusion outcomes evaluated. Median ICU and hospital length of stay were 2 and 3 days longer, respectively, in the Monobloc group. Perioperative complications were not uncommon, occurring in 18% of patients in the Le Fort III group and 30% in the Monobloc group. CONCLUSION: Monobloc procedures were associated with greater transfusion and longer ICU and hospital length of stay. Perioperative complications were more prevalent in the Monobloc group.

Perioperative Outcomes and Management in Pediatric Complex Cranial Vault Reconstruction: A Multicenter Study from the Pediatric Craniofacial Collaborative Group.

BACKGROUND: The Pediatric Craniofacial Collaborative Group established the Pediatric Craniofacial Surgery Perioperative Registry to elucidate practices and outcomes in children with craniosynostosis undergoing complex cranial vault reconstruction and inform quality improvement efforts. The aim of this study is to determine perioperative management, outcomes, and complications in children undergoing complex cranial vault reconstruction across North America and to delineate salient features of current practices. METHODS: Thirty-one institutions contributed data from June 2012 to September 2015. Data extracted included demographics, perioperative management, length of stay, laboratory results, and blood management techniques employed. Complications and outlier events were described. Outcomes analyzed included total blood donor exposures, intraoperative and perioperative transfusion volumes, and length of stay outcomes. RESULTS: One thousand two hundred twenty-three cases were analyzed: 935 children aged less than or equal to 24 months and 288 children aged more than 24 months. Ninety-five percent of children aged less than or equal to 24 months and 79% of children aged more than 24 months received at least one transfusion. There were no deaths. Notable complications included cardiac arrest, postoperative seizures, unplanned postoperative mechanical ventilation, large-volume transfusion, and unplanned second surgeries. Utilization of blood conservation techniques was highly variable. CONCLUSIONS: The authors present a comprehensive description of perioperative management, outcomes, and complications from a large group of North American children undergoing complex cranial vault reconstruction. Transfusion remains the rule for the vast majority of patients. The occurrence of numerous significant complications together with large variability in perioperative management and outcomes suggest targets for improvement.

Videolaryngoscopy versus Fiber-optic Intubation through a Supraglottic Airway in Children with a Difficult Airway: An Analysis from the Multicenter Pediatric Difficult Intubation Registry.

BACKGROUND: The success rates and related complications of various techniques for intubation in children with difficult airways remain unknown. The primary aim of this study is to compare the success rates of fiber-optic intubation via supraglottic airway to videolaryngoscopy in children with difficult airways. Our secondary aim is to compare the complication rates of these techniques. METHODS: Observational data were collected from 14 sites after management of difficult pediatric airways. Patient age, intubation technique, success per attempt, use of continuous ventilation, and complications were recorded for each case. First-attempt success and complications were compared in subjects managed with fiber-optic intubation via supraglottic airway and videolaryngoscopy. RESULTS: Fiber-optic intubation via supraglottic airway and videolaryngoscopy had similar first-attempt success rates (67 of 114, 59% vs. 404 of 786, 51%; odds ratio 1.35; 95% CI, 0.91 to 2.00; P = 0.16). In subjects less than 1 yr old, fiber-optic intubation via supraglottic airway was more successful on the first attempt than videolaryngoscopy (19 of 35, 54% vs. 79 of 220, 36%; odds ratio, 2.12; 95% CI, 1.04 to 4.31; P = 0.042). Complication rates were similar in the two groups (20 vs. 13%; P = 0.096). The incidence of hypoxemia was lower when continuous ventilation through the supraglottic airway was used throughout the fiber-optic intubation attempt. CONCLUSIONS: In this nonrandomized study, first-attempt success rates were similar for fiber-optic intubation via supraglottic airway and videolaryngoscopy. Fiber-optic intubation via supraglottic airway is associated with higher first-attempt success than videolaryngoscopy in infants with difficult airways. Continuous ventilation through the supraglottic airway during fiber-optic intubation attempts may lower the incidence of hypoxemia.

Effects of Obesity and Leptin Deficiency on Morphine Pharmacokinetics in a Mouse Model.

BACKGROUND: Obesity causes multiorgan dysfunction, specifically metabolic abnormalities in the liver. Obese patients are opioid-sensitive and have high rates of respiratory complications after surgery. Obesity also has been shown to cause resistance to leptin, an adipose-derived hormone that is key in regulating hunger, metabolism, and respiratory stimulation. We hypothesized that obesity and leptin deficiency impair opioid pharmacokinetics (PK) independently of one another. METHODS: Morphine PK were characterized in C57BL/6J wild-type (WT), diet-induced obese (DIO), and leptin-deficient (ob/ob) mice, and in ob/ob mice given leptin-replacement (LR) therapy. WT mice received several dosing regimens of morphine. Obese mice (30 g) received one 80 mg/kg bolus of morphine. Blood was collected at fixed times after morphine injection for quantification of plasma morphine and morphine 3-glucuronide (M3G) levels. PK parameters used to evaluate morphine metabolism included area-under the curve (AUC150), maximal morphine concentration (CMAX), and M3G-to-morphine ratio, and drug elimination was determined by clearance (Cl/F), volume of distribution, and half-life (T1/2). PK parameters were compared between mouse groups by the use of 1-way analysis of variance, with P values less than .05 considered significant. RESULTS: DIO compared with WT mice had significantly decreased morphine metabolism with lower M3G-to-morphine ratio (mean difference [MD]: -4.9; 95% confidence interval [CI]: -8.8 to -0.9) as well as a decreased Cl/F (MD: -4.0; 95% CI: -8.9 to -0.03) Ob/ob compared with WT mice had a large increase in morphine exposure with a greater AUC150 (MD: 980.4; 95% CI: 630.1-1330.6), CMAX (MD: 6.8; 95% CI: 2.7-10.9), and longer T1/2 (MD: 23.1; 95% CI: 10.5-35.6), as well as a decreased Cl/F (MD: -7.0; 95% CI: -11.6 to -2.7). Several PK parameters were significantly greater in ob/ob compared with DIO mice, including AUC150 (MD: 636.4; 95% CI: 207.4-1065.4), CMAX (MD: 5.3; 95% CI: 3.2-10.3), and T1/2 (MD: 18.3; 95% CI: 2.8-33.7). When leptin was replaced in ob/ob mice, PK parameters began to approach DIO and WT levels. LR compared with ob/ob mice had significant decreases in AUC150 (MD: -779.9; 95% CI: -1229.8 to -330), CMAX (MD: -6.1; 95% CI: -11.4 to -0.9), and T1/2 (MD: -19; 95% CI: -35.1 to -2.8). Metabolism increased with LR, with LR mice having a greater M3G-to-morphine ratio compared with DIO (MD: 5.3; 95% CI: 0.3-10.4). CONCLUSIONS: Systemic effects associated with obesity decrease morphine metabolism and excretion. A previous study from our laboratory demonstrated that obesity and leptin deficiency decrease the sensitivity of central respiratory control centers to carbon dioxide. Obesity and leptin deficiency substantially decreased morphine metabolism and clearance, and replacing leptin attenuated the PK changes associated with leptin deficiency, suggesting leptin has a direct role in morphine metabolism.

Are nocturnal hypoxemia and hypercapnia associated with desaturation immediately after adenotonsillectomy?

BACKGROUND: Children who undergo adenotonsillectomy for sleep-disordered breathing frequently have postoperative oxygen desaturations. Nocturnal hypoxia has been shown to predict postoperative respiratory complications; however, other gas exchange abnormalities detected on polysomnography (PSG) have not been evaluated. AIM: We sought to determine whether hypercapnia seen on preoperative nocturnal PSG can predict postoperative hypoxemia. METHODS: We conducted a retrospective review of 319 children who underwent polysomnography before adenotonsillectomy. Saturation levels were recorded for at least 2 h postoperatively, and the primary outcome was desaturation (<90%). RESULTS: The median patient age was 5 years (range, 5 months-17 years). Patients who desaturated postoperatively had higher median peak endtidal CO2 (EtCO2 ) levels (55.5 vs 52 mmHg; P = 0.02), lower saturation nadirs (80.5% vs 88%; P = 0.048), and were younger (2 vs 6 years; P < 0.001) than those without desaturation. Age was significantly correlated with peak EtCO2 (r = -0.16), respiratory disturbance index (RDI; r = -0.23), and oxygen saturation nadir (r = 0.25; all P < 0.01). In unadjusted analysis, age <3 years compared to ≥9 years (odds ratio [OR] = 10.09; 95% confidence interval [CI] = 2.13-96.26), peak EtCO2  > 55 mmHg (OR = 3.38; 95% CI = 1.21-9.47), and RDI ≥ 10 (OR = 2.89; 95% CI = 1.05-8.42) were associated with increased odds of desaturation. Multivariable logistic regression on age, race, sex, peak EtCO2 , RDI, opioid use, and saturation nadir showed that only age was significantly associated with postoperative desaturation. Patients 0-2 years old were 10.43 (95% CI = 1.89-110.9) times more likely to have desaturation than patients 9-17 years old. CONCLUSION: Patients <3 years of age are most likely to have postoperative hypoxemia after adenotonsillectomy. Gas exchange abnormalities did not correlate with postoperative desaturations, although age and peak EtCO2 did strongly correlate.