Wilson T. Chimbira

How do pediatric anesthesiologists define intraoperative hypotension

Introduction:  Although blood pressure (BP) monitoring is a recommended standard of care by the ASA, and pediatric anesthesiologists routinely monitor the BP of their patients and when appropriate treat deviations from ‘normal’, there is no robust definition of hypotension in any of the pediatric anesthesia texts or journals. Consequently, what constitutes hypotension in pediatric anesthesia is currently unknown. We designed a questionnaire‐based survey of pediatric anesthesiologists to determine the BP ranges and thresholds used to define intraoperative hypotension (IOH).

Does an objective system-based approach improve assessment of perioperative risk in children? A preliminary evaluation of the ‘NARCO’

BACKGROUND This study evaluated whether an objective tool would provide a more reliable and valid assessment of perioperative risk compared with the ASA-physical status (ASA-PS) in children. METHODS A system-based risk assessment tool was developed using these categories: Neurological, Airway, Respiratory, Cardiovascular, and Other (NARCO) with a subcomponent grading surgical severity (SS). Anaesthesiologists reviewed the preoperative assessments and assigned NARCO, SS, and ASA-PS scores independently. Perioperative outcomes were recorded by trained observers. Validity and reliability of the tools were evaluated. RESULTS NARCO correlated with ASA-PS (ρ=0.664; P<0.01) supporting its criterion validity. Inter-rater reliability of the measures was supported (intraclass correlation coefficients 0.71-0.96; κ 0.43-0.87) except for the Airway category. Measures of exact agreement were slightly better for NARCO compared with ASA-PS. NARCO, SS, and ASA-PS scores correlated significantly with perioperative escalation of care, adverse events (AE), hospital length of stay, and admission status. Correlations between NARCO and ASA-PS and outcomes improved when SS was factored into their coding. There were significant, but low, correlations between all measures and mortality. The odds of having escalation of care, AE, and mortality were 5-47 times greater among children with higher risk scores. CONCLUSIONS Findings suggest that all measures of outcome have acceptable to excellent reliability with a slight improvement in agreement for the NARCO compared with the ASA-PS. This study supports the validity of both the NARCO and the ASA-PS in predicting perioperative risk in children with a slight improvement in correlations when combined with the SS score.

Does High BMI Influence Hospital Charges in Children Undergoing Adenotonsillectomy

Background: Obesity is a highly prevalent chronic problem with health and fiscal consequences. Data from adults and nonsurgical pediatric patients suggest that obesity has serious implications for the US economy.

Prevalence of habitual snoring in children and occurrence of peri-operative adverse events.

Objective To describe the prevalence of habitual snoring and examine its association with peri-operative adverse events in children undergoing elective non-cardiac surgery – a relationship that has not been previously characterised. Methods Using a prospective observational design, we studied children aged 6–18 years undergoing elective non-cardiac surgeries at our institution. Trained research assistants collected clinical (including peri-operative adverse events) and anthropometric data on all individuals. Patients were stratified into two classes, habitual snorers and non-snorers. Subsequently, univariate factors associated with snoring were explored and then odds ratios for the occurrence of peri-operative adverse events were calculated from logistic regression after controlling for clinically relevant cofactors. Results Among 1102 patients, the prevalence of habitual snoring was 27.3% (28.2% for boys vs. 26.3% for girls). All the measured anthropometric parameters (BMI, waist circumference and neck circumference) were significantly higher in habitual snorers compared with non-snorers. The overall respiratory complication rate was 11.1%. Respiratory adverse events were more frequent in habitual snorers compared with non-snorers (16.9 vs. 8.9%; P < 0.001). Additionally, habitual snoring was associated with longer post-anaesthesia care unit (PACU) stay (114.0 ± 49.6 vs. 103.6 ± 48.9 min; P = 0.002) even after controlling for the occurrence of adverse respiratory events. Conclusion The prevalence of habitual snoring was high in this cohort of paediatric surgical patients. Habitual snoring was associated with some peri-operative adverse events and prolonged PACU stay and should be considered an important symptom in the pre-operative review of children.

Association of childhood high body mass index and sleep disordered breathing with perioperative laryngospasm.

BACKGROUND Childhood high body mass index (BMI) and sleep disordered breathing (SDB) are increasingly prevalent and both are associated with perioperative respiratory complications. Laryngospasm is one of the more serious respiratory complications with potentially devastating consequences. It is presently unclear whether high BMI and incident SDB in children significantly amplifies the risks of perioperative laryngospasm. This study examined the hypothesis that compared to controls; children with high BMI and SDB at the time of surgery have higher rates of perioperative laryngospasm. METHODS Children (6-18 yr) who underwent elective, non-cardiac operations at a tertiary care center were the subjects of this cross-sectional study. Rates of perioperative laryngospasm were compared between normal controls and children who were overweight/obese and had clinical history of SDB at the time of surgery. Stepwise logistic regression analysis was performed to identify independent predictors of perioperative laryngospasm (dependent variable) using high BMI/SDB as the primary predictor variable. RESULTS Among 642 children, those who were overweight/obese and had incident SDB (N = 197) were younger, and had higher indexes of central adiposity. Children with high BMI and SDB had 3.8 times higher unadjusted odds of developing intraoperative laryngospasm (OR = 3.8; 95% CI = 2.1-6.9, p < 0.001). After adjusting for several relevant covariates, the following factors were found to be independent predictors of perioperative laryngospasm: high BMI + SDB, male sex and increasing neck circumference. CONCLUSION High BMI and incident SDB in children is associated with increased rates of perioperative laryngospasm. The mechanism(s) underlying this propensity to laryngospasm deserve further elucidation.

Racial differences in the pain management of children recovering from anesthesia

When pain management has been studied in settings such as pediatric emergency departments, racial disparities have been clearly identified. To our knowledge, this has not been studied in the pediatric perioperative setting. We sought to determine whether there are differences based on race in the administration of analgesia to children suffering from pain in the postanesthesia care unit.

Severe Obesity and Sleep-Disordered Breathing as Risk Factors for Emergence Agitation in Pediatric Ambulatory Surgery

Purpose: Sleep‐disordered breathing (SDB) may be a critical risk factor for emergence agitation (EA). We hypothesized that SDB diagnosis is a predictor of EA in children after general anesthesia for ambulatory surgery. Design: Prospective, observational, cohort study. Methods: Children aged 4 to 17 years were assessed for the occurrence of EA. Differences in probability of EA were assessed using multivariable logistic regression analyses. Findings: Of 1,076 children, 66 (6.1%) had EA. Compared with those without EA, children with EA were younger (P < .001), more likely to have had mask induction (P < .001) and a preoperative diagnosis of SDB (P = .008). On multivariable analysis, SDB, severe obesity, decreasing age in years, increasing first arousal pain score, and intraoperative use of sevoflurane were independently associated with EA. Conclusions: SDB and severe obesity may be critical independent predictors of EA in children. Mechanisms underlying these observations deserve further elucidation.

Anaesthetic Concerns for Patients Undergoing Neurosurgical Procedures Utilising Intra-operative Magnetic Resonance Imaging

Intra-operative magnetic resonance imaging (ioMRI) is an evolving technology that offers precise intra-cranial lesion localisation and intraoperative navigation by combining the high-resolution imaging capabilities of MRI with an operative suite. Developed in the 1990s, ioMRI presents caregivers with a variety of unique challenges revolving around performing surgical procedures in an operating theatre with a high-strength magnetic field. Different types of ioMRI systems exist, differentiated by the relative mobility of the patient and magnet. As with any MRI environment, safety is of paramount concern. Published safety guidelines exist from both the American College of Radiology and the American Society of Anesthesiologists. A variety of checklists can be used to enhance the safety of the ioMRI suite. There are a variety of anaesthetic considerations when caring for patients in this environment including concerns related to the anaesthesia equipment, the patient and the general MRI environment. A multidisciplinary approach can encourage safety and efficiency in this unique operating room. The purpose of this review is to discuss the variety of topics that anaesthesiologists need to consider using this technology, including the indications, specific equipment considerations and unique safety aspects of caring for patients in the ioMRI suite. While performing surgery in a high-strength magnetic field environment carries its own special risks, each type of ioMRI suite presents its own unique challenges to patient safety. Although the challenges are significant, safe care and optimal outcomes are certainly possible with appropriate understanding of the factors unique to the ioMRI environment, good communication, a collaborative approach and proper procedural planning.

Intraoperative Bronchopleural Fistula During Thoracoscopic Lobectomy: The Role of End-Tidal CO2 Monitoring.

Video-assisted thoracoscopic surgery has become a common procedure in pediatric surgery. We present a case of accidental intraoperative bronchopleural fistula during a video-assisted thoracoscopic surgery procedure, which was first identified by the anesthesia team. We discuss differential diagnoses including the role of end-tidal carbon dioxide monitoring as an aid to prompt diagnosis.