Anaesthetic management of the child with co-existing pulmonary disease

Perioperative Care of the Pediatric Patient and an Algorithm for the Treatment of Intraoperative Bronchospasm

Asthma remains a common comorbid condition in patients presenting for anesthetic care. As a chronic inflammatory disease of the airway, asthma is known to increase the risk of intraoperative bronchospasm. As the incidence and severity of asthma and other chronic respiratory conditions that alter airway reactivity is increasing, a greater number of patients at risk for perioperative bronchospasm are presenting for anesthetic care. As bronchospasm remains one of the more common intraoperative adverse events, recognizing and mitigating preoperative risk factors and having a pre-determined treatment algorithm for acute events are essential to ensuring effective resolution of this intraoperative emergency. The following article reviews the perioperative care of pediatric patients with asthma, discusses modifiable risk factors for intraoperative bronchospasm, and outlines the differential diagnosis of intraoperative wheezing. Additionally, a treatment algorithm for intraoperative bronchospasm is suggested.

Effect of General Anesthesia Maintenance with Propofol or Sevoflurane on Fractional Exhaled Nitric Oxide and Eosinophil Blood Count: A Prospective, Single Blind, Randomized, Clinical Study on Patients Undergoing Thyroidectomy

Background: Nitric oxide (NO) is considered a means of detecting airway hyperresponsiveness, since even non-asthmatic patients experiencing bronchospasm intraoperatively or postoperatively display higher levels of exhaled NO. It can also be used as a non-invasive biomarker of lung inflammation and injury. This prospective, single-blind, randomized study aimed to evaluate the impact of two different anesthesia maintenance techniques on fractional exhaled nitric oxide (FeΝO) in patients without respiratory disease undergoing total thyroidectomy under general anesthesia. Methods: Sixty patients without respiratory disease, atopy or known allergies undergoing total thyroidectomy were randomly allocated to receive either inhalational anesthesia maintenance with sevoflurane at a concentration that maintained Bispectral Index (BIS) values between 40 and 50 intraoperatively or intravenous anesthesia maintenance with propofol 1% targeting the same BIS values. FeΝO was measured immediately preoperatively (baseline), postoperatively in the Postanesthesia Care Unit and at 24 h post-extubation with a portable device. Other variables measured were eosinophil blood count preoperatively and postoperatively and respiratory parameters intraoperatively. Results: Patients in both groups presented lower than baseline values of FeΝO measurements postoperatively, which returned to baseline measurements at 24 h post-extubation. In the peripheral blood, a decrease in the percentage of eosinophils was demonstrated, which was significant only in the propofol group. Respiratory lung mechanics were better maintained in the propofol group as compared to the sevoflurane group. None of the patients suffered intraoperative bronchospasm. Conclusions: Both propofol and sevoflurane lead to the temporary inhibition of NO exhalation. They also seem to attenuate systemic hypersensitivity response by reducing the eosinophil count in the peripheral blood, with propofol displaying a more pronounced effect and ensuring a more favorable mechanical ventilation profile as compared to sevoflurane. The attenuation of NO exhalation by both agents may be one of the underlying mechanisms in the reduction in airway hyperreactivity. The clinical significance of this fluctuation remains to be studied in patients with respiratory disease.

Preoperative cardiopulmonary evaluation in specific neonatal surgery

Preoperative assessment of surgical neonates often relates to issues of prematurity, low birth weight, or associated malformations. This review explores the preoperative cardiopulmonary evaluation in specific newborn surgical populations, the role of echocardiography in congenital diaphragmatic hernia perioperative management, the impact of bronchopulmonary dysplasia in the ex-preterm surgical neonate and a brief discussion on the risk of general anesthesia and specific anesthetic considerations for any surgical neonate. Newborns with congenital anomalies requiring early general surgical intervention should have an assessment for congenital heart disease. In the asymptomatic neonate, a thorough physical exam may be sufficient preoperatively. Neonates born with esophageal atresia or anorectal malformations should have a full evaluation for VACTERL associations. Initial echocardiography in congenital diaphragmatic hernia is used to evaluate anatomy, but there is emerging evidence to suggest the use of echocardiography in the ongoing surveillance of CDH to influence the timing of surgical intervention. Bronchopulmonary dysplasia is present in up to 40% of ex-premature neonates and increases the risk of postoperative apneas and need for ventilatory support. However, all surgical neonates have an increased risk of post-operative apneas, and the need for surgical intervention should be balanced with the risk of general anesthesia.

Practices surrounding pulmonary hypertension and bronchopulmonary dysplasia amongst neonatologists caring for premature infants

OBJECTIVE

Pulmonary hypertension (PH) is associated with bronchopulmonary dysplasia (BPD). Screening strategies, a thorough investigation of co-morbidities, and multidisciplinary involvement prior to anti-PH medications have been advocated by recent guidelines. We sought to evaluate current practices of neonatologists caring for premature infants with PH.

DESIGN

Electronic survey of American Academy of Pediatrics neonatology members.

RESULTS

Among 306 neonatologist respondents, 38% had an institutional screening protocol for patients with BPD; 83% screened at 36 weeks for premature neonates on oxygen/mechanical ventilation. In those practicing more than 5 years, 54% noted increasing numbers of premature infants diagnosed with PH. Evaluation for PH in BPD patients included evaluations for micro-aspiration (41%), airways anomalies (29%), and catheterization (10%). Some degree of acquired pulmonary vein stenosis was encountered in 47%. A majority (90%) utilized anti-PH medications during the neonatal hospitalization.

CONCLUSIONS

Screening for PH in BPD, and subsequent evaluation and management is highly variable.

A case in which a capnometer was useful for diagnosing laryngospasm following administration of sugammadex

Background

Sugammadex has been reported to cause upper-airway obstruction, such as laryngospasm or bronchospasm. These two conditions are treated using different approaches, but the differential diagnosis is difficult.

Case presentation

We describe a case in which general anesthesia was administered via endotracheal intubation, in combination with brachial-plexus block, for arthroscopic surgical treatment of a rotator-cuff tear caused by recurrent shoulder dislocation. The total dose of rocuronium administered was 90 mg, and the last dose of 10 mg was given 15 min before the end of the surgery. Sugammadex was intravenously administered at 100 mg to reverse the effect of rocuronium after the operation ended. After extubation in this case, we placed a mask firmly around the patient's mouth, and thus, there was no air leakage around the mask. We detected upper-airway obstruction that was presumably attributable to administration of sugammadex. The end-tidal carbon dioxide (EtCO₂) concentration was undetectable on a capnometer. Although 100% oxygen was administered at 10 L/min via a facemask, oxygen saturation (SpO₂) decreased to approximately 70%. With suspected onset of laryngospasm, continuous positive airway pressure with 100% oxygen at 10 L/min was started at 30 cm H₂O. The patient's airway obstruction resolved after a short time.

Conclusion

The use of a capnometer facilitated the diagnosis of laryngospasm and allowed us to administer appropriate treatment after administration of sugammadex.

Variability in anesthesiologists' approach to the preoperative management of asthmatic children

OBJECTIVE

No consensus guidelines exist for the preoperative treatment of asthmatic children referred for elective surgery. We investigated the attitude of pediatric anesthesiologists to this issue.

DESIGN

A questionnaire survey was conducted.

SETTING

National survey.

SUBJECTS

Certified Israeli pediatric anesthesiologists from all 24 general hospitals in Israel.

MEASUREMENT

Twenty-one questions regarding the approach to preoperative management of asthmatic children including 6 case scenarios with a variety of clinical situations and treatments of asthmatic children. The results were compared with the attitude of pediatric pulmonologists recently published using a similar methodology.

MAIN RESULTS

Forty-four pediatric anesthesiologists from all 24 general hospitals in Israel responded. Twenty-five percent of pediatric anesthesiologists answered that, in addition to pediatric anesthesiologists, the primary pediatrician should be consulted, and 70% believed that a pediatric pulmonologists should also be consulted. Overall, results showed a wide variability between responders especially for preschool children and unstable school-aged asthmatic children for both disciplines. The variability referred to the use of any treatment, bronchodilators, inhaled corticosteroids and their combination, addition of systemic corticosteroids, and the length of preoperative treatment. Compared with pediatric pulmonologists, a better within-discipline agreement was observed by the pediatric anesthesiologists for stable school-aged asthmatic children with a lower inclination to augment preoperative treatment (P< .001). No difference was observed for the preschool children with asthma and for the unstable school-aged asthmatic child.

CONCLUSIONS

A wide variability exists in pediatric anesthesiologists' approach to the preoperative management of asthmatic children for most common case scenarios. This is probably explained by the heterogeneity of asthma, the type of surgery, the lack of guidelines, and the paucity of data. Similarities as well as differences exist between pediatric anesthesiologists and pulmonologists. Further studies and implementation of consensus guidelines are needed.

Usability of dexmedetomidine for deep sedation in infants and small children with respiratory morbidities

BACKGROUND

Children with respiratory morbidities are at increased risk of developing adverse respiratory events while undergoing deep sedation. Dexmedetomidine possesses sedative properties with minimal respiratory depression. This report aimed to determine the usability of dexmedetomidine in children with significant respiratory morbidities who require deep sedation.

METHODS

Medical records of children with ASA classification III who had at least three characteristics of respiratory morbidities and who received dexmedetomidine sedation for magnetic resonance imaging (MRI) between January 2014 and May 2015 were retrospectively reviewed. Dexmedetomidine was administered as a bolus of 1 μg/kg over 10 min followed by 1 μg/kg/h infusion. If necessary, an additional bolus dose was given and the infusion rate was increased to 2 μg/kg/h. Respiratory morbidities, haemodynamic parameters, total dexmedetomidine dose, adverse cardiorespiratory events and sedation characteristics were analysed.

RESULTS

Nineteen out of 642 children who underwent MRI were eligible for evaluation. Seventeen children (89%) had at least four characteristics of respiratory morbidities. The median [IQR] age was 9 months [3.5-14]. All patients completed MRI scans while breathing spontaneously via the native airway. No episodes of adverse respiratory events or haemodynamic instability were observed. Children who were administered a lower dexmedetomidine dose and had a shorter sedation time were more likely to be younger than 1 year of age.

CONCLUSION

These data demonstrate that dexmedetomidine deep sedation was well-tolerated in children with significant respiratory morbidities. Moreover, children younger than 1 year of age were administered lower dexmedetomidine dose than children older than 1 year of age for the same sedation level.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02555605.

Anaesthesia for children with bronchial asthma and respiratory infections

Asthma represents one of the most common chronic diseases in children with an increasing incidence reported worldwide. The key to successful anaesthetic outcome involves thorough pre-operative assessment and optimisation of the child's pulmonary status. Judicious application of proper anti-inflammatory and bronchodilatory regimes should be instituted as part of pre-operative preparation. Bronchospasm triggering agents should be carefully probed and meticulously avoided. A calm and properly sedated child at the time of induction is ideal, so also is extubation in a deep plane with an unobstructed airway. Wherever possible, regional anaesthesia should be employed. This will avoid airway manipulations, with additional benefit of excellent peri-operative analgesia. Agents with a potential for histamine release and techniques that can increase airway resistance should be diligently avoided. Emphasis must be given to proper post-operative care including respiratory monitoring, analgesia and breathing exercises.

Pediatric pulmonologists approach to the pre-operative management of the asthmatic child

OBJECTIVE

No consensus guidelines exist for the respiratory treatment of asthmatic children referred for elective surgery. The aim of this study was to evaluate the attitude of pediatric pulmonologists regarding the pre-operative management of these children.

METHODS

A survey of pre-operative management of asthmatic children was conducted. All 48 certified pediatric pulmonologists in Israel completed a questionnaire that comprised 20 questions regarding their approach to pre-operative management including six case scenarios with a variety of clinical situations and treatments of children with asthma.

RESULTS

Response rate was 100%. All believed that pre-operative treatment should be considered in all asthmatic children. Almost 50% suggested that a pediatric pulmonologist should be consulted in all pre-operative assessments. 50% recommended consultation only in individual cases. Overall, results showed a very wide variability between responders especially in pre-school and poorly controlled school children. The variability referred to the use of bronchodilators, inhaled corticosteroids and their combination during the pre-operative days, the addition of systemic CS and the length of pre-operative treatment. Almost all participants suggested either the initiation or augmentation of pre-operative treatment in high risk situations.

CONCLUSIONS

This data demonstrate an important variability among pediatric pulmonologists in Israel regarding the practice of pre-operative treatment of infants and children with asthma especially for the less controlled and high risk children. This is most probably explained by the paucity of evidence-based data and the lack of established guidelines. Consensus guidelines for the pre-operative management of asthmatic children are needed.