Use of neuromuscular blockade for neck dissection and association with iatrogenic nerve injury.

BACKGROUND: Cranial nerve injury is an uncommon but significant complication of neck dissection. We examined the association between the use of intraoperative neuromuscular blockade and iatrogenic cranial nerve injury during neck dissection. METHODS: This was a single-center, retrospective, electronic health record review. Study inclusion criteria stipulated patients > 18 years who had ≥ 2 neck lymphatic levels dissected for malignancy under general anesthesia with a surgery date between 2008 - 2018. Use of neuromuscular blockade during neck dissection was the primary independent variable. This was defined as any use of rocuronium, cisatracurium, or vecuronium upon anesthesia induction without reversal with sugammadex prior to surgical incision. Univariate tests were used to compare variables between those patients with, and those without, iatrogenic cranial nerve injury. Multivariable logistic regression determined predictors of cranial nerve injury and was performed incorporating Firth's estimation given low prevalence of the primary outcome. RESULTS: Our cohort consisted of 925 distinct neck dissections performed in 897 patients. Neuromuscular blockade was used during 285 (30.8%) neck dissections. Fourteen instances (1.5% of surgical cases) of nerve injury were identified. On univariate logistic regression, use of neuromuscular blockade was not associated with iatrogenic cranial nerve injury (OR: 1.73, 95% CI: 0.62 - 4.86, p = 0.30). There remained no significant association on multivariable logistic regression controlling for patient age, sex, weight, ASA class, paralytic dose, history of diabetes, stroke, coronary artery disease, carotid atherosclerosis, myocardial infarction, and cardiac arrythmia (OR: 1.87, 95% CI: 0.63 - 5.51, p = 0.26). CONCLUSIONS: In this study, use of neuromuscular blockade intraoperatively during neck dissection was not associated with increased rates of iatrogenic cranial nerve injury. While this investigation provides early support for safe use of neuromuscular blockade during neck dissection, future investigation with greater power remains necessary.

Electroencephalographic Biomarkers, Cerebral Oximetry, and Postoperative Cognitive Function in Adult Noncardiac Surgical Patients: A Prospective Cohort Study.

BACKGROUND: Perioperative neurocognitive disorders are a major public health issue, although there are no validated neurophysiologic biomarkers that predict cognitive function after surgery. This study tested the hypothesis that preoperative posterior electroencephalographic alpha power, alpha frontal-parietal connectivity, and cerebral oximetry would each correlate with postoperative neurocognitive function. METHODS: This was a single-center, prospective, observational study of adult (older than 18 yr) male and female noncardiac surgery patients. Whole-scalp, 16-channel electroencephalography and cerebral oximetry were recorded in the preoperative, intraoperative, and immediate postoperative settings. The primary outcome was the mean postoperative T-score of three National Institutes of Health Toolbox Cognition tests-Flanker Inhibitory Control and Attention, List Sorting Working Memory, and Pattern Comparison Processing Speed. These tests were obtained at preoperative baseline and on the first two postoperative mornings. The lowest average score from the first two postoperative days was used for the primary analysis. Delirium was a secondary outcome (via 3-min Confusion Assessment Method) measured in the postanesthesia care unit and twice daily for the first 3 postoperative days. Last, patient-reported outcomes related to cognition and overall well-being were collected 3 months postdischarge. RESULTS: Sixty-four participants were recruited with a median (interquartile range) age of 59 (48 to 66) yr. After adjustment for baseline cognitive function scores, no significant partial correlation (ρ) was detected between postoperative cognition scores and preoperative relative posterior alpha power (%; ρ = -0.03, P = 0.854), alpha frontal-parietal connectivity (via weight phase lag index; ρ = -0.10, P = 0.570, respectively), or preoperative cerebral oximetry (%; ρ = 0.21, P = 0.246). Only intraoperative frontal-parietal theta connectivity was associated with postoperative delirium (F[1,6,291] = 4.53, P = 0.034). No electroencephalographic or oximetry biomarkers were associated with cognitive or functional outcomes 3 months postdischarge. CONCLUSIONS: Preoperative posterior alpha power, frontal-parietal connectivity, and cerebral oximetry were not associated with cognitive function after noncardiac surgery.

Racial Disparity in Residual Sleep Apnea After Adenotonsillectomy.

OBJECTIVE: Black children have a higher risk of residual obstructive sleep apnea after adenotonsillectomy than non-Black children. We analyzed Childhood Adenotonsillectomy Trial data to better understand this disparity. We hypothesized that (1) child-level factors, such as asthma, smoke exposure, obesity, sleep duration, and (2) socioeconomic factors, such as maternal education, maternal health, and neighborhood disadvantage, may confound, modify, or mediate the association between Black race and residual obstructive sleep apnea after adenotonsillectomy. STUDY DESIGN: Secondary analysis of a randomized controlled trial. SETTING: Seven tertiary care centers. METHODS: We included two hundred and twenty-four 5-to-9-year-olds with mild-to-moderate obstructive sleep apnea who underwent adenotonsillectomy. The outcome was residual obstructive sleep apnea 6 months after surgery. Data were analyzed with logistic regression and mediation analysis. RESULTS: Of 224 included children, 54% were Black. Compared with non-Black children, Black children had 2.7 times greater odds of residual sleep apnea (95% confidence interval [CI]: 1.2, 6.1; p = .01), adjusted for age, sex, and baseline Apnea Hypopnea Index. There was significant effect modification by obesity. Among obese children, there was no association between Black race and outcome. However, nonobese Black children were 4.9 times as likely to have residual sleep apnea than non-Black children (95% CI: 1.2, 20.0; p < 0.01). There was no significant mediation by any of the child-level or socioeconomic factors tested. CONCLUSION: There was substantial effect modification by obesity on the association between Black race and residual sleep apnea after adenotonsillectomy for mild-to-moderate sleep apnea. Black race was associated with poorer outcome among nonobese but not obese children.

Preoperative Predictors of Severe Respiratory Events After Tonsillectomy: Consideration for Pediatric Intensive Care Admission.

OBJECTIVE: Few data are available to guide postadenotonsillectomy (AT) pediatric intensive care (PICU) admission. The aim of this study of children with a preoperative polysomnogram (PSG) was to assess whether preoperative information may predict severe respiratory events (SRE) after AT. STUDY DESIGN: Retrospective cohort study. SETTING: Single tertiary center. METHODS: Children aged 6 months to 17 years who underwent AT with preoperative polysomnography (2012-2018) were identified by billing codes. Data were extracted from medical records. SRE were defined as any 1 or more of desaturations <80% requiring intervention; newly initiated positive airway pressure; postoperative intubation; pneumonia/pneumonitis; respiratory code, cardiac arrest, or death. We hypothesized that SRE would be associated with age <24 months, major medical comorbidity, obesity (>95th percentile), apnea-hypopnea index (AHI) ≥ 30, and O2 nadir <70% on PSG. Analysis was performed with multivariable logistic regression. RESULTS: Of 1774 subjects, 28 (1.7%) experienced SRE. Compared to those without, children with SRE were on average younger (3 vs 5 years, p < .01) with a greater probability of medical comorbidities (59% vs 18%, p < .001). After adjustment for sex, black race, obesity, and age <24 months, children with major medical comorbidity were more likely than other children to have SRE (odds ratio [OR]: 14.2; 95% confidence interval [CI]: [5.7, 35.2]), as were children with AHI ≥ 30 (OR: 7.7 [3.0, 19.9]), or O2 nadir <70% (OR 6.1 [2.1, 17.9]). Age, obesity, sex, and black race did not independently predict SRE. CONCLUSION: PICU admission may be most prudent for children with complex medical co-morbidities, high AHI (>30), and/or low O2 nadir (<70%).

Neurophysiologic Complexity in Children Increases with Developmental Age and Is Reduced by General Anesthesia.

BACKGROUND: Neurophysiologic complexity in the cortex has been shown to reflect changes in the level of consciousness in adults but remains incompletely understood in the developing brain. This study aimed to address changes in cortical complexity related to age and anesthetic state transitions. This study tested the hypotheses that cortical complexity would (1) increase with developmental age and (2) decrease during general anesthesia. METHODS: This was a single-center, prospective, cross-sectional study of healthy (American Society of Anesthesiologists physical status I or II) children (n = 50) of age 8 to 16 undergoing surgery with general anesthesia at Michigan Medicine. This age range was chosen because it reflects a period of substantial brain network maturation. Whole scalp (16-channel), wireless electroencephalographic data were collected from the preoperative period through the recovery of consciousness. Cortical complexity was measured using the Lempel-Ziv algorithm and analyzed during the baseline, premedication, maintenance of general anesthesia, and clinical recovery periods. The effect of spectral power on Lempel-Ziv complexity was analyzed by comparing the original complexity value with those of surrogate time series generated through phase randomization that preserves power spectrum. RESULTS: Baseline spatiotemporal Lempel-Ziv complexity increased with age (yr; slope [95% CI], 0.010 [0.004, 0.016]; P < 0.001); when normalized to account for spectral power, there was no significant age effect on cortical complexity (0.001 [-0.004, 0.005]; P = 0.737). General anesthesia was associated with a significant decrease in spatiotemporal complexity (median [25th, 75th]; baseline, 0.660 [0.620, 0.690] vs. maintenance, 0.459 [0.402, 0.527]; P < 0.001), and spatiotemporal complexity exceeded baseline levels during postoperative recovery (0.704 [0.642, 0.745]; P = 0.009). When normalized, there was a similar reduction in complexity during general anesthesia (baseline, 0.913 [0.887, 0.923] vs. maintenance 0.851 [0.823, 0.877]; P < 0.001), but complexity remained significantly reduced during recovery (0.873 [0.840, 0.902], P < 0.001). CONCLUSIONS: Cortical complexity increased with developmental age and decreased during general anesthesia. This association remained significant when controlling for spectral changes during anesthetic-induced perturbations in consciousness but not with developmental age.

Weight gain in children after adenotonsillectomy: undesirable weight gain or catch-up growth?

OBJECTIVE/BACKGROUND: Obesity and obstructive sleep apnea (OSA) are consequential conditions with significant overlap in the pediatric population. Early studies documented catch-up growth in underweight children after adenotonsillectomy, but more recent studies suggested that normal and even overweight children may experience excess weight gain after adenotonsillectomy. We performed a secondary analysis of Childhood Adenotonsillectomy Trial (CHAT) data to test whether there was an effect of early adenotonsillectomy on undesirable weight gain, defined as an increase in body mass index (BMI) Z score in an already overweight or obese child or a change from baseline normal or underweight to a follow up BMI Z score classified as overweight. PATIENTS/METHODS: We included 398 children with moderate OSA and complete anthropomorphic data randomized to adenotonsillectomy versus watchful waiting with supportive care. Pearson's χ2 and independent t tests were used to compare demographic, activity, sleep and anthropomorphic characteristics between children who did and did not experience undesirable weight gain over seven months. Logistic regression was used to test for an association between adenotonsillectomy and undesirable weight gain, both unadjusted and adjusted for age, sex, Black race, average parent-reported weekly activity level, mother's body mass index, average nightly sleep duration and either baseline or follow up AHI (in separate models). RESULTS: Forty three percent (n = 172) experienced undesirable weight gain. A similar percentage of children in both arms experienced undesirable weight gain (45% adenotonsillectomy vs 41% watchful waiting). Neither unadjusted nor adjusted regression analysis demonstrated a significant effect of adenotonsillectomy on undesirable weight gain. CONCLUSION: Adenotonsillectomy may not be an independent risk factor for undesirable weight gain in children.

The Effects of Intraoperative Caffeine on Postoperative Opioid Consumption and Related Outcomes After Laparoscopic Surgery: A Randomized Controlled Trial.

BACKGROUND: Surgical patients are vulnerable to opioid dependency and related risks. Clinical-translational data suggest that caffeine may enhance postoperative analgesia. This trial tested the hypothesis that intraoperative caffeine would reduce postoperative opioid consumption. The secondary objective was to assess whether caffeine improves neuropsychological recovery postoperatively. METHODS: This was a single-center, randomized, placebo-controlled trial. Participants, clinicians, research teams, and data analysts were all blinded to the intervention. Adult (≥18 years old) surgical patients (n = 65) presenting for laparoscopic colorectal and gastrointestinal surgery were randomized to an intravenous caffeine citrate infusion (200 mg) or dextrose 5% in water (40 mL) during surgical closure. The primary outcome was cumulative opioid consumption through postoperative day 3. Secondary outcomes included subjective pain reporting, observer-reported pain, delirium, Trail Making Test performance, depression and anxiety screens, and affect scores. Adverse events were reported, and hemodynamic profiles were also compared between the groups. RESULTS: Sixty patients were included in the final analysis, with 30 randomized to each group. The median (interquartile range) cumulative opioid consumption (oral morphine equivalents, milligrams) was 77 mg (33-182 mg) for caffeine and 51 mg (15-117 mg) for placebo (estimated difference, 55 mg; 95% confidence interval [CI], -9 to 118; P = .092). After post hoc adjustment for baseline imbalances, caffeine was associated with increased opioid consumption (87 mg; 95% CI, 26-148; P = .005). There were otherwise no differences in prespecified pain or neuropsychological outcomes between the groups. No major adverse events were reported in relation to caffeine, and no major hemodynamic perturbations were observed with caffeine administration. CONCLUSIONS: Caffeine appears unlikely to reduce early postoperative opioid consumption. Caffeine otherwise appears well tolerated during anesthetic emergence.

A Lower Tidal Volume Regimen during One-lung Ventilation for Lung Resection Surgery Is Not Associated with Reduced Postoperative Pulmonary Complications.

BACKGROUND: Protective ventilation may improve outcomes after major surgery. However, in the context of one-lung ventilation, such a strategy is incompletely defined. The authors hypothesized that a putative one-lung protective ventilation regimen would be independently associated with decreased odds of pulmonary complications after thoracic surgery. METHODS: The authors merged Society of Thoracic Surgeons Database and Multicenter Perioperative Outcomes Group intraoperative data for lung resection procedures using one-lung ventilation across five institutions from 2012 to 2016. They defined one-lung protective ventilation as the combination of both median tidal volume 5 ml/kg or lower predicted body weight and positive end-expiratory pressure 5 cm H2O or greater. The primary outcome was a composite of 30-day major postoperative pulmonary complications. RESULTS: A total of 3,232 cases were available for analysis. Tidal volumes decreased modestly during the study period (6.7 to 6.0 ml/kg; P < 0.001), and positive end-expiratory pressure increased from 4 to 5 cm H2O (P < 0.001). Despite increasing adoption of a "protective ventilation" strategy (5.7% in 2012 vs. 17.9% in 2016), the prevalence of pulmonary complications did not change significantly (11.4 to 15.7%; P = 0.147). In a propensity score matched cohort (381 matched pairs), protective ventilation (mean tidal volume 6.4 vs. 4.4 ml/kg) was not associated with a reduction in pulmonary complications (adjusted odds ratio, 0.86; 95% CI, 0.56 to 1.32). In an unmatched cohort, the authors were unable to define a specific alternative combination of positive end-expiratory pressure and tidal volume that was associated with decreased risk of pulmonary complications. CONCLUSIONS: In this multicenter retrospective observational analysis of patients undergoing one-lung ventilation during thoracic surgery, the authors did not detect an independent association between a low tidal volume lung-protective ventilation regimen and a composite of postoperative pulmonary complications.

Propofol versus dexmedetomidine during drug-induced sleep endoscopy (DISE) for pediatric obstructive sleep apnea.

PURPOSE: To test for differences in DISE findings in children sedated with propofol versus dexmedetomidine. We hypothesized that the frequency of ≥ 50% obstruction would be higher for the propofol than dexmedetomidine group at the dynamic levels of the airway (velum, lateral walls, tongue base, and supraglottis) but not at the more static adenoid level. METHODS: A single-center retrospective review was performed on children age 1-18 years with a diagnosis of sleep disordered breathing or obstructive sleep apnea (OSA) who underwent DISE from July 2014 to Feb 2019 scored by the Chan-Parikh scale sedated with either propofol or dexmedetomidine (with or without ketamine). Logistic regression was used to test for a difference in the odds of ≥ 50% obstruction (Chan-Parikh score ≥ 2) at each airway level with the use of dexmedetomidine vs. propofol, adjusted for age, sex, previous tonsillectomy, surgeon, positional OSA, and ketamine co-administration. RESULTS: Of 117 subjects, 57% were sedated with propofol and 43% with dexmedetomidine. Subjects were 60% male, 66% Caucasian, 31% obese, 38% syndromic, and on average 6.5 years old. Thirty-three percent had severe OSA and 41% had previous tonsillectomy. There was no statistically significant difference in the odds of ≥ 50% obstruction between the two anesthetic groups at any level of the airway with or without adjustment for potential confounders. CONCLUSION: We did not find a significant difference in the degree of upper airway obstruction on DISE in children sedated with propofol versus dexmedetomidine. Prospective, randomized studies would be an important next step to confirm these findings.

Risk Factors for Intraoperative Hypoglycemia in Children: A Multicenter Retrospective Cohort Study.

BACKGROUND: Intraoperative hypoglycemia can result in devastating neurologic injury if not promptly diagnosed and treated. Few studies have defined risk factors for intraoperative hypoglycemia. The authors sought to characterize children with intraoperative hypoglycemia and determine independent risk factors in a multicenter cohort. METHODS: This retrospective multicenter study included all patients <18 years undergoing an anesthetic from January 1, 2012, to December 31, 2016, at 12 institutions participating in the Multicenter Perioperative Outcomes Group (MPOG). The primary outcome was blood glucose <60 mg/dL (3.3 mmol/L). Data collected included patient characteristics, comorbidities, and intraoperative factors. A multivariable logistic regression model was used to identify independent predictors of intraoperative hypoglycemia. RESULTS: Blood glucose was measured in 26,142 of 394,231 (6.6%) cases. Of these, 1017 (3.9%) had a glucose <60 mg/dL (3.3 mmol/L). Independent predictors for intraoperative hypoglycemia identified were age <30 days (estimated adjusted odds ratio [AOR] vs ≥5 years 4.2; 95% confidence interval [CI], 3.4-5.3), age 30 days to <5 years (estimated AOR vs ≥5 years 2.7; 95% CI, 2.3-3.2), weight for age <5th percentile (estimated AOR, 1.6; 95% CI, 1.4-1.9), American Society of Anesthesiologists (ASA) status ≥III (estimated AOR, 1.3; 95% CI, 1.1-1.6), presence of a gastric or jejunal tube (estimated AOR, 1.3; 95% CI, 1.1-1.6), poor feeding (estimated AOR, 1.5; 95% CI, 1.2-1.7), and abdominal surgery (estimated AOR, 1.4; 95% CI, 1.1-1.7). Eighty percent of hypoglycemia occurred in children <5 years of age and in children <20 kg. CONCLUSIONS: Young age, weight for age <5th percentile, ASA status ≥III, having a gastric or jejunal tube, poor feeding, and abdominal surgery were risk factors for intraoperative hypoglycemia in children. Monitoring of blood glucose is recommended in these subsets of children.

Risk factors for intraoperative hypoglycemia in children: a retrospective observational cohort study.

PURPOSE: Intraoperative hypoglycemia can result in devastating neurologic injury if not promptly diagnosed and treated. Few studies have defined risk factors for intraoperative hypoglycemia. The authors sought to characterize children with intraoperative hypoglycemia and determine independent risk factors. METHODS: This retrospective observational single-institution study included all patients < 18 yr of age undergoing an anesthetic from January 1 2012 to December 31 2016. The primary outcome was blood glucose < 3.3 mmol·L-1 (60 mg·dl-1). Data collected included patient characteristics, comorbidities, and intraoperative factors. A multivariable logistic regression model was used to identify independent predictors of intraoperative hypoglycemia. RESULTS: Blood glucose was measured in 7,715 of 73,592 cases with 271 (3.5%) having a glucose < 3.3 mmol·L-1 (60 mg·dl-1). Young age, weight for age < 5th percentile, developmental delay, presence of a gastric or jejunal tube, and abdominal surgery were identified as independent predictors for intraoperative hypoglycemia. Eighty percent of hypoglycemia cases occurred in children < three years of age and in children < 15 kg. CONCLUSION: Young age, weight for age < 5th percentile, developmental delay, having a gastric or jejunal tube, and abdominal surgery were independent risk factors for intraoperative hypoglycemia in children. Frequent monitoring of blood glucose and judicious isotonic dextrose administration may be warranted in these children.