Anaesthesia for paediatric radiotherapy: A narrative review

INTRODUCTION

Radiotherapy is currently used in approximately one-third of children with cancer. Treatments are typically received as weekday outpatient appointments over 3-6 weeks. The treatment is painless but requires a still, co-operative patient who can lie alone in set positions, facilitated by the use of immobilisation devices, for up to 1 h.

METHODS

We conducted a literature search to identify relevant articles relating to radiotherapy treatment. Key search terms included: 'radiotherapy'; 'proton beam'; 'photon'; 'sedation'; 'anaesthesia'; and 'paediatric'. The abstracts of identified articles were assessed for relevance and their references reviewed for further relevant publications.

RESULTS

The requirement for anaesthesia is almost exclusively limited to younger children, who are committed to daily anaesthetics over the duration of their treatment course. Centres tend to adopt a primary anaesthetic technique of either general anaesthesia using a supraglottic airway device or deep sedation, with spontaneous ventilation maintained. A full variety of anaesthetic drugs has been used with insufficient evidence to support a standardised primary approach but an apparent global trend towards propofol by infusion for sedation. Children may become acutely unwell during their treatment course and systems for escalation of clinical care in this event are vital. Distance from the patient for staff radiation shielding, patient positioning for treatment delivery and the use of immobilisation devices may provide additional access challenges in the event of an emergency.

DISCUSSION

The requirement for anaesthesia for paediatric radiotherapy is typically confined to younger children. Patients may be unwell, with several specific considerations related to their cancer diagnosis and the impact of various treatments including surgery and chemotherapy, in addition to the radiotherapy. A multidisciplinary team approach to all aspects of care is imperative in this group of high-risk patients.

Anesthetic-sparing effect of dexmedetomidine during total intravenous anesthesia for children undergoing dental surgery: A randomized controlled trial

BACKGROUND

Dexmedetomidine, an α2-adrenergic agonist, reduces propofol and remifentanil requirements when used as an adjunct to total intravenous anesthesia in adults, but studies in a pediatric population are sparse. This study investigates the magnitude of dose-sparing effects of a postinduction dexmedetomidine bolus on propofol and remifentanil requirements during pediatric surgery.

METHODS

In this randomized, double-blind, controlled trial, children aged 2-10 years undergoing elective dental surgery were assigned to one of four groups: placebo, 0.25 mcg/kg dexmedetomidine, 0.5 mcg/kg dexmedetomidine, and 1 mcg/kg dexmedetomidine. Maintenance with fixed-ratio propofol and remifentanil total intravenous anesthesia followed a bispectral index (BIS)-guided algorithm designed to maintain a stable depth of anesthesia. The primary outcomes were time-averaged maintenance infusion rates of propofol and remifentanil. Secondary outcomes in the postanesthetic care unit included sedation scores, pain scores, and time to discharge.

RESULTS

Data from 67 patients were available for analysis. The median [interquartile range] propofol infusion rate was lower in the 1 mcg/kg dexmedetomidine group (180 [164-185] mcg/kg/min) versus placebo (200 [178-220] mcg/kg/min): percent change -10.0%; 95% CI -2.4 to -19.8; p = 0.013. The remifentanil infusion rate was also lower in the 1 mcg/kg dexmedetomidine group (0.089 [0.080, 0.095] mcg/kg/min) versus placebo (0.103 [0.095, 0.106] mcg/kg/min): percent change, -13.7%; 95% CI -5.47 to -21.0; p = .022. However, neither propofol nor remifentanil infusion rates were significantly different in the 0.25 or 0.5 mcg/kg dexmedetomidine groups. In the postanesthesia care unit, there were no differences in pain or sedation scores, and time to discharge was not significantly prolonged in any dexmedetomidine group.

CONCLUSION

Dexmedetomidine 1 mcg/kg reduced the propofol and remifentanil requirements during maintenance of anesthesia in children when administered as a postinduction bolus.

TRIALS REGISTRATION

ClinicalTrials.gov: NCT03422978, date of registration 2018-02-06.

Retrospective comparison between MRI examinations during radiographer-administered intranasal sedation or general anesthesia

INTRODUCTION

In order for young children to be able to undergo a Magnetic Resonance Imaging (MRI) examination, general anesthesia is often required. The aim of this study was to compare the image quality, times, and costs of the examinations of infant brains performed with MRI either during sedation with dexmedetomidine administered by radiographers or anesthesia with propofol administered by anesthesia staff.

METHODS

This study was a quantitative retrospective study of 27 consecutive standard brain examinations performed under sedation or anesthesia, involving 15 children under sedation and 12 under anesthesia. The age of the children was from 0.5 to five years old. The image quality was evaluated by three radiologists experienced in pediatric MRI examinations. Information such as examination time and the expense of the examination was also collected.

RESULTS

There was no statistically significant difference in the general image quality, but one image series was assessed to have significantly better image quality under sedation than under anesthesia, but all images had very high quality. However, it emerged that children under anesthesia were at the hospital on average 55 min longer and the scanner room was occupied 20 min longer on average. The anesthesia examinations were three times more expensive.

CONCLUSION

This study demonstrated equivalent image quality between sedation and anesthesia. In addition, sedation was less time-consuming and had a lower price, partly because no extra anesthetic staff were required. The use of intranasal sedation offers a possibility to expand the competence area for radiographers.

IMPLICATIONS FOR PRACTICE

If radiographers learn to perform intranasal sedation, examinations can be performed in less time, at a third of the staff costs while maintaining image quality.

Techniques and Complications of Anesthesia in Pediatric Radiotherapy: A Retrospective Cohort Study

BACKGROUND

Anesthesia during pediatric external beam radiation therapy poses a challenge, as radiotherapy rooms are not designed for the administration of anesthesia.

AIMS

We conducted a retrospective cohort study of children who underwent radiation therapy to describe the anesthetic approach and assess anesthetic-related complications.

MATERIALS AND METHODS

Data of all, who underwent radiation therapy under general anesthesia between November 2019 and January 2021, were recorded. Data were obtained from medical records, including demographic characteristics and information, regarding the anesthetic procedure and its associated complications. We describe our protocols for preoperative assessment, anesthetic procedures, and postanesthetic discharge evaluation.

RESULTS

Over the reporting period, 739 sessions of general anesthesia were performed. The mean number of radiation therapy rounds per patient was 23.5 sessions. Anesthetic induction was accomplished by sevoflurane inhalation in 639 sessions (86.4%) and intravenous propofol in the remaining 13.6%. General anesthesia was maintained with sevoflurane in all cases. Anesthesia-related complications occurred in 118 sessions (15.7%). The most frequent was nausea in 48 (6.4%) cases, followed by hypotension in 38 (5.1%). Airway-related complications occurred at a low frequency (2.3%), and all were resolved successfully with positive pressure ventilation. No patient hospitalizations were required because of any anesthetic complications.

CONCLUSIONS

Inhalation anesthesia is reliable and safe for pediatric patients undergoing radiation therapy.

Survey of Anesthesia, Sedation, and Non-sedation Practices for Children Undergoing Repetitive Cranial or Craniospinal Radiotherapy

Background

Children undergoing cranial or craniospinal radiotherapy may require over 30 treatments within a six-week period. Facilitating these many treatments with the patient under anesthesia presents a significant challenge, and the most preferred anesthetic methods remain unknown. The primary goal of this study was to determine the most preferred anesthetic methods and agents for children undergoing daily cranial or craniospinal radiotherapy.

Methods

An 83-item web-based survey was developed. An introductory email was sent to 505 physicians and child-life specialists with expertise in pediatric anesthesia and/or affiliated with pediatric radiation oncology departments.

Results

The response rate was 128/505 (25%) and included specialists from Africa (5, 4%), Asia (18, 14%), Australia/Oceania (5, 4%), Europe (45, 35%), North America (50, 39%), and South America (5, 4%). The 128 respondents included 91 anesthesiologists (71%), 20 physicians who were not anesthesiologists (16%), 14 child life/social education specialists (11%), one radiotherapist, one pediatric radiation nurse, and one non-specified medical professional (all = 2%). Of the 128 respondents, 95 (74%) used anesthesia or sedation to facilitate repetitive cranial or craniospinal radiotherapy. Overall, total intravenous anesthesia without intubation was preferred by 67 of 95 (71%) specialists during one or more forms of radiotherapy. During photon-based radiotherapy, total intravenous anesthesia without intubation was the preferred anesthetic method with the patient in the supine (57/84, 68%) and prone positions (25/40, 63%). Propofol was the most used anesthetic agent for both supine (73/84, 87%) and prone positions (38/40, 95%). For proton radiotherapy, total intravenous anesthesia without intubation was the most preferred anesthetic method for the supine (32/42, 76%) and prone treatment positions (11/18, 61%), and propofol was the most used anesthetic (supine: 40/43, 93%; prone: 16/18, 89%).

Conclusions

In this survey of 95 specialists responsible for anesthesia or sedation of children undergoing repetitive cranial or craniospinal radiotherapy, propofol-based total intravenous anesthesia without intubation was the preferred anesthetic technique.

Propofol Protects against Cerebral Ischemia/Reperfusion Injury by Down-Regulating Long Noncoding RNA SNHG14

Cerebral ischemia-reperfusion (CI/R) injury is a serious central nervous system disease. Propofol (PPF) exerts a neuroprotective effect in CI/R injury; the underlying cause is still unclear. Here, we cultured mouse hippocampal neuron (HT22 cells) in oxygen-glucose deprivation/reoxygenation (OGD/R) conditions to mimic CI/R injury in vitro. PPF treatment promoted cell viability and reduced apoptotic cells in the OGD/R-treated HT22 cells, which was effectively abrogated by SNHG14 overexpression. Moreover, we constructed a CI/R injury mouse model on C57BL/6J mice by middle cerebral artery occlusion/reperfusion (MCAO/R), followed by administration of PPF. PPF reduced neuronal damage and loss, enhanced glial cell hyperplasia, and ameliorated cerebral cortex tissue damage and brain infarct in MCAO/R-induced mice. SNHG14 overexpression aggravated MCAO/R-induced CI/R injury in mice. Furthermore, SNHG14 promoted the expression of Atg5 and Beclin 1 via competitively binding miR-30b-5p, which contributed to activate autophagy and apoptosis in HT22 cells. In addition, the levels of p-p38 and p-SP1 were reduced in the OGD/R-treated HT22 cells in the presence of PPF. SP1 interacted with the promoter of SNHG14 and elevated the expression of SNHG14. PPF treatment inhibited the SP1-mediated up-regulation of SNHG14. In conclusion, this work demonstrates that PPF inhibits SNHG14 expression though the p38 MAPK signaling pathway. SNHG14 promotes Atg5 and Beclin 1 expression by sponging miR-30b-5p and thus activates autophagy and aggravates CI/R injury.

Anesthetic management of precise radiotherapy under apnea-like condition

Objective

To study the safety and feasibility of implementation of precise radiotherapy with inducement of an apnea-like condition.

Methods

Two patients with lung tumors underwent precise radiotherapy under an apnea-like condition. The apnea-like condition was induced 11 times between the two patients for tumor localization and treatment. The changes in the blood oxygen saturation, blood pressure, heart rate, and end-tidal carbon dioxide during the apnea-like periods were observed, and the incidence of adverse reactions was recorded.

Results

The average apnea-like time was 6.2 minutes (range, 3–9 minutes), and the average radiotherapy time was 4.6 minutes (range, 1–7 minutes). The lowest blood oxygen saturation level was 97%, with a change of <1%. The heart rate and average arterial blood pressure increased during the apnea-like periods. Contact sores appeared on the patients’ posterior pharyngeal wall after the first apnea-like period; no other adverse events occurred.

Conclusion

Precise radiotherapy under an apnea-like condition is safe and feasible for patients with lung tumors.