Journal Watch Search
Journal Watch Search
260 Articles Found
Comparison of intravenous and inhalation anesthesia on postoperative behavior changes in children undergoing ambulatory endoscopic procedures: A randomized clinical trialAugust 8, 2023
This randomized, parallel, double-blinded clinical trial performed in an outpatient endoscopic clinic between October 2018 and December 2021 was designed to determine if intravenous anaesthesia was effective at reducing post operative behavioural changes in children undergoing ambulatory endoscopic procedures when compared to inhalational anaesthesia.
164 children between the ages of 1-12 yrs , ASA I -III, undergoing endoscopic day surgery procedures, were included and analysed in the study and randomised to receive either inhalational or intravenous maintenance of anaesthesia post induction. All children received inhalational induction with sevoflurane. The intravenous group was then maintained with propofol post placement of a peripheral intravenous cannula.
All children were assessed using a modified Yale Preoperative Anxiety Scale (mYPAS) and the parental anxiety preoperatively assessed using a 100mm Visual analog scale (VAS-anx). Post procedure emergence delirium was assessed using Paediatric Anaesthesia Emergence Delirium (PAED) scale whilst pain was assessed using FLACC scale. Severe emergence delirium (ED) was treated with a bolus of propofol (1mg/kg) and severe pain was treated with fentanyl (1ug/kg).
On days 1,7 and 14 post procedure, the parents were contacted by telephone, and the child’s behaviour was evaluated using the Post Hospitalisation Behaviour Questionnaire for Ambulatory Surgery (PHBQ-AS). The PHBQ-AS is a slightly abbreviated version of the PHBQ with 11 items including anxiety, regression, sleep and eating disorders, aggression and apathy.
They recorded a 19% incidence of ED in the intravenous group and 41% in the inhalational group in the first minute post wake up. This difference did not persist to the 5th and 10th minute post wake up with FLACC pain scores being comparable. There were no differences of note in the preoperative children’s or parental anxiety scores. They did not find any differences in the adverse behavioural outcome between the inhalational and intravenous group post procedure on day one, seven and fourteen as per the PHBQ-AS questionnaire. They did find a moderate co-relation between the occurrence of emergence delirium and the number of negative postoperative behaviours on day 7 but this was across both groups.
Take home message: ED and prolonged negative behavioural changes post procedure is a topic of much interest in the paediatric anaesthetic world and data to date suggests that the cause is multifactorial, with no magical single intervention to prevent their occurrence. Several studies have looked into the effect of the two anaesthetic techniques on post operative delirium and found that there may be benefits in the incidence of emergence delirium with intravenous techniques but the effects on prolonged post operative behavioural changes is less clear. This study found an early reduction in ED with the intravenous technique but no differences between inhalational and intravenous maintenance techniques for negative behaviours in the days following.
The did note that many of their patients were “frequent flyers” and may have exhibited less preoperative anxiety but the co-relation between ED and post procedural negative behaviour was reinforced regardless of technique.
Extrapolation of the findings in this study to the general “anxious” paediatric population undergoing painful procedures must be carefully made.
Reviewed by Dr Priya Sreedharan
Intranasal dexmedetomidine sedation for paediatric MRI by radiology personnel: A retrospective observational studyAugust 8, 2023
This Scandinavian study adds to the evidence base around needle-free sedation techniques for paediatric imaging, itself the subject of a recent systematic review (https://www.bjanaesthesia.org/article/S0007-0912(22)00517-7/fulltext), summarised elegantly by Dr Burton in the January-February edition of this forum (Needle-free pharmacological sedation techniques in paediatric patients for imaging procedures: a systematic review and meta-analysis – SPANZA).
The authors identify access to paediatric anaesthetic services as a common rate-limiting step for the timely provision of paediatric MRI, and moreover suggest an alternative model that is both largely needle- and anaesthetist-free.
Over a period of 4 years, 1091 appropriately-triaged children of mean age 34 months and ASA 1 or 2 received nasal dexmedetomidine alone as sedation for MRI scans of predicted duration less than one hour, administered by radiology staff in the absence of an anaesthetist. The initial dose was of 4mcg/kg, with a subsequent 2mcg/kg if the child was deemed ‘not sedated enough’.
Within the limits of the study design, the results seem appealing; 93% of scans commenced were completed as planned with adequate image acquisition.
The mean time from first administration of dexmedetomidine to scan readiness is not clear, nor the time at which a second dose (required in 36% of children) was adjudged to be required or effective. Further, there is a poorly-defined cohort of children in whom adequate sedation was never achieved despite repeat dosing, and who do not appear in the subsequent analysis.
The safety data is confusingly presented but appears re-assuring (especially given the dexmedetomidine protocol did not mandate any pre-procedural fasting); 4 children had minor de-saturations requiring only brief supplemental oxygen, and 5 had bradycardias below the 1st centile for age, with none requiring intervention. Closer inspection however suggests that agreed indications for seeking anaesthetic input were not always followed by radiology staff, and moreover blood pressure was not measured at any point during the period of sedation.
In the discussion the authors argue their results support the safety and efficacy of nasal dexmedetomidine for paediatric MRI, thereby enabling radiology departments to take greater ownership of the process, including those previously lacking the opportunity. They go on to extrapolate that paediatric anaesthetists need not be part of the process beyond a consultative role.
Whilst no doubt an interesting study, I’m not sure their findings yet support their confidence.
Ultrasound Assessment of Gastric Fluid Volume in Children Scheduled for Elective Surgery After Clear Fluid Fasting for 1 Versus 2 Hours: A Randomized Controlled TrialJuly 27, 2023
This small randomized single-blinded controlled trial is the second such trial comparing gastric fluid volumes after a 1-hour versus a 2-hour clear fluid fast in children undergoing general anaesthesia for elective surgery. It is the first utilising ultrasound. The authors (from a major university hospital in Cairo, Egypt) postulated that a 1-hour fast would result in significantly higher gastric volumes. They did indeed demonstrate that the volumes roughly doubled, and suggest that a 1-hour fast may result in an unsafe stomach. The questions the reader is specifically interested in, however, are: Is there a gastric fluid volume at which the risk of aspiration is significantly increased? Does a 1-hour fluid fast lead to a significantly greater proportion of patients having gastric volumes above this threshold?
The former question has as yet not been clearly answered. It would require a study of 10,000-20,000 patients in order to reliably demonstrate an increase in aspiration rates above baseline levels. What we do have is attempts to define a normal distribution of gastric volumes in small (ranging 34 to 538 patients) observational studies of both adults and children with and without risk factors for regurgitation or aspiration events. These normal distributions seem to demonstrate that around 95% of children have volumes less than 1.5ml/kg and that there are always small groups of outliers with larger volumes occupying the remaining 5% who have volumes greater than this regardless of clear fluid fasts of 2, 5 or 6-hours. This study demonstrates that whether a 1 or 2-hour fast is enforced, a child’s gastric volume never lies above this 1.5ml/kg threshold. Other risk thresholds of 1.25ml/kg and 0.8ml/kg (as mentioned by the authors) seem to be based on an arbitrary grading system that has not been related to aspiration risk nor to a normal distribution of the population of interest.
Strengths of the study included a robust overall design, a fairly well powered sample size, standardisation of quantity and caloric content to a maximum of 3ml/kg and 0.42kcal/ml respectively in keeping with standard practices in many countries and international recommendations. They did not comment on exactly how successful they were at enforcing the precise 1 and 2-hour fasts. It would also have been helpful to have some more parameters reported such as mean, standard deviation and range in order to establish the nature of the normal distribution in each sample. Their reference to several difference risk thresholds (0.8ml/kg, 1.25ml/kg and 1.5ml/kg) is likely confusing for practical application.
In summary, this study shows that whilst gastric volumes are higher after a 1-hour versus a 2-hour fast, this does not seem to place patients outside of the normal distribution of what is understood to be a fasted stomach and would, contrary to the authors conclusions, support a 1-hour minimum fast given that we know that most patients who apply this rule in practice fast longer than 1 hour. It would be helpful in the future to better define the normal distribution of gastric volumes in fasted children for the sake of studies like this one since some of the statistical reporting in existing studies is not always crystal clear on this point. A multicentre study is likely necessary to generate the numbers needed to relate this to aspiration risk.
Townsville University Hospital