November 2024

Anesthesiology

Submitted November 2024 by Dr Eamonn Upperton

Read by 121 Journal Watch subscribers

Overview:
This retrospective study looks at the risk of developing a neurobehavioural diagnosis in two parallel groups of children aged between 3 and 15 years:
- Those who underwent appendicectomy
- Those admitted to hospital for a medical condition (pneumonia, cellulitis, and gastroenteritis)

The diagnoses in question were:
- Behavioural disorders (conduct, impulse control, oppositional defiant, attention-deficit hyperactivity disorder)
- Mood or anxiety disorders (depression, anxiety, or bipolar disorder)

The finding was that both groups showed an increased risk of being diagnosed with one of these disorders compared with their matched controls; the medical group moreso than the appendicectomy group.

Exposure to anaesthesia occurred in 100% of the appendicectomy group, and only 8% of the medical group. In the absence of an excess in the primary outcome in the group with higher anaesthesia exposure, this study supports the conclusion that a neurobehavioural diagnosis after hospital admission is likely due to factors other than anaesthesia.

Study design:
Medicaid data from across the United States of America was extracted to include patients between age 3 to 15, between 2001 to 2013. ICD codes were used to determine the diagnoses of interest.

The groups were:
- 134,388 healthy children who underwent appendicectomy; matched with healthy controls 1:5 (671,940 controls)
- 154,887 healthy children admitted for pneumonia, cellulitis or gastroenteritis; matched with healthy controls 1:5 (774,435 controls)

Each cohort was analysed for the primary outcome compared with its matched controls.

Interpretation:
This is a data-driven study, where some of its limitations are partially overcome by the sheer number of participants. This helps it achieve its impressive P values, which indicates that the appendicectomy and medical groups are likely to be truly different from the matched controls in terms of neurobehavioural diagnoses. While many confounders may give rise to this difference, this paper does not need to exclude these – it only aims to show that the cohorts’ dissimilarity in exposure to anaesthesia is not matched by a dissimilarity in primary outcome.

Interestingly, both appendicectomy and medical groups showed higher rates of dental or ophthalmology care compared with their matched controls. These outcomes were intentionally chosen to have no plausible link to anaesthesia, and the result suggests that some other factor (perhaps a propensity to higher healthcare utilisation) is responsible for the observed increased risk of neurobehavioural diagnosis for both cohorts.

Take-home message:
This study uses an enormous dataset to demonstrate that if anaesthesia exposure does influence neurobehavioural outcomes, its impact is far overshadowed by other factors – such as hospital admission.

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Pediatric Anesthesia

Submitted November 2024 by Dr Elizabeth Dalton

Read by 90 Journal Watch subscribers

This was a single-centre retrospective study aimed at determining whether intravenous lignocaine infusion therapy during posterior spinal instrumentation and fusion (PSIF) for adolescent idiopathic scoliosis impacts the reliability of intraoperative neurophysiological monitoring.

Study overview:
Data from charts and archived intraoperative neurophysiological records were collected. Patients aged 10–19 years, classified as ASA 1-3, who underwent single-stage PSIF with or without traction were included. Patients who received intraoperative lignocaine infusions were compared to those who did not. Data was retrieved from medical records from 2012 to 2021. Eighty-one patients were included, of whom 39 received lignocaine and 42 did not.

Neurophysiological data collected included the amplitude of motor evoked potentials (MEP) and the amplitude and latency of somatosensory evoked potentials (SSEPs). Significant intraoperative neuromonitoring events were identified by reviewing data for changes that met clinical alert criteria. All patients who received lignocaine infusions were consistently administered a 1 mg/kg bolus followed by an infusion of 2 mg/kg/hr for the duration of the operation. Demographic variables between the two groups were evaluated.

Results:
The study found no evidence that lignocaine infusion had a harmful effect on the measured changes from baseline for MEP/SSEP amplitudes in either the upper or lower limbs. Additionally, there was no difference in the time to the first neurophysiological event.

Discussion:
PSIF is associated with significant postoperative pain. There is emerging evidence in the paediatric population to suggest safety and efficacy of intraoperative intravenous lignocaine as an opioid-sparing analgesic technique. Identifying whether lignocaine infusion negatively impacts intraoperative neuromonitoring would help justify its use in spinal surgery.

It is challenging to draw firm conclusions based on this study due to its single-centre design and small sample size. This limits the power to detect significant differences and the authors acknowledge they had to use wider confidence intervals to do so. The anaesthetic regimen was not standardized, patient risk factors were not matched, and there was variability in reporting neurophysiological parameters due to advancing technology over the period of the study. While this initial research shows promise, further prospective studies are essential to draw safe conclusions regarding the utilisation of lignocaine infusions in this population.

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The New England Journal of Medicine

Submitted November 2024 by Dr Siak Lee

Read by 95 Journal Watch subscribers

Study Overview:
This study compares first pass intubation success using video vs. direct laryngoscopy in neonates.

Methods:
Single centre, randomised, prospective trial of 214 patients at a tertiary centre in Dublin Ireland.
Two intervention arms:
- Videolaryngoscope (VL)
- Direct laryngoscope (DL)

The majority of proceduralists were paediatric and neonatal registrars who were allowed a maximum 3 attempts. The most senior clinician in attendance made the decision to intubate. Neonatologists could intervene at any time.

Eligibility:
Inclusion
• Neonates of any gestational age intubated in the Delivery Room (DR) or NICU
• Patients included only once
• Neonates transferred from other hospitals included if intubated at author institute
Excluded
• Neonates with upper airway abnormalities

Findings:
Significant increase in first pass intubation success with videolaryngoscope compared to direct laryngoscopy (74% vs. 45%, P < 0.001)
Secondary outcomes, none statistically significant:
- Median number of successful attempts 1 vs. 2 (VL vs. DL)
- Median duration of time to successful intubation on first attempt 61 vs. 51 secs (VL vs. DL)
- Lowest median SpO2 74% vs. 68% (VL vs. DL)
- Lower median HR 153 vs. 148 bpm (VL vs. DL)
- Oral trauma 0% vs. 1% (VL vs. DL)
- ETT tip in correct position of chest radiograph 53% vs. 50% (VL vs. DL)
- Crossover 3% vs 29% (VL vs DL)

Take Home Messages and Commentary
1) Does the study address a relevant and / or important question?
For junior operators with little to no experience intubating neonates, there was a significantly higher first pass urgent intubation success rate with video laryngoscopy compared to direct laryngoscopy (74% vs. 45% VL vs. DL). Overall, higher intubation was successfully completed with videolaryngoscope (96% vs. 69% VL vs. DL, Supplementary). However, time to successful intubation was longer when using video laryngoscopy (61 vs. 51 seconds VL vs. DL).

2) Is there any recent research, evidence, or study on a similar question?
In critically ill adult populations in USA, video laryngoscopy increased first pass intubation success compared to direct laryngoscopy (Silverberg 2015). The data in paediatric and neonatal populations are conflicting. In an updated Cochrane review, ‘low certainty’ was given to VL and its ability to increase first attempt success in neonatal intubation. In addition this Cochrane review was not confident that the introduction of VL in the neonatal population would lead to fewer intubation attempts and may not reduce time required for successful intubation. However it was moderately certain that there was decreased airway trauma with neonatal VL (Lingappan et al 2023).

3) What are the strengths of the study?
• Single centre – standardisation of practise
• Tertiary centre – high complexity
• Attempts to minimise bias
• Randomisation
• Very similar medications given
• Independent data collectors
• Clinically meaningful data with statistical significance

4) What are the limitations of the study?
• Non-blinded
• Not necessarily applicable to LMIC or regional/remote centre due to high cost of purchasing video laryngoscopy
• Only one type of Video laryngoscopy was used – Miller blade
• No collection of data on
• Specific previous experience of practitioners
• Grade of laryngeal view
• Reasons for discontinuing attempts
• This study did not include neonates with upper airway abnormalities

5) Is the study applicable to our practice or to our population?
Yes
• Majority of first operators were junior clinicians
• English speaking, Western, European – similar cohort to Australia

References:
1. Silverberg MJ, N L, So A, Pd K. Comparison of video laryngoscopy versus direct laryngoscopy during urgent endotracheal intubation: a randomized controlled trial. Critical care medicine. 2015;43(3). doi:10.1097/CCM.0000000000000751
2. Lingappan K, Neveln N, Arnold JL, Fernandes CJ, Pammi M. Videolaryngoscopy versus direct laryngoscopy for tracheal intubation in neonates - Lingappan, K - 2023 | Cochrane Library. Accessed October 16, 2024. https://www.cochranelibrary.com/cdsr/doi/10.1
002/14651858.CD009975.pub4/full

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Pediatric Anesthesia

Submitted November 2024 by Dr Su May Koh

Read by 74 Journal Watch subscribers

This prospective observational study involved 200 paediatric surgical patients and assessed the reliability of fasting with ultrasound (US) imaging and suction in paediatric patients presenting for single long-bone fracture repair after appropriate fasting intervals.

Methods
The authors appropriately excluded multi-trauma patients and patients who had gastric motility issues. All patients were fasted appropriately, even excessively by some standards; 8 hours for solid foods, 6 hours for milk/juice, 4 hours for breastmilk, and 2 hours for clear liquids. Certainly, many paediatric centres these days allow more liberal nil by mouth recommendations.
The authors used two techniques (imaging and suction) to evaluate gastric contents during surgery. US imaging was performed pre-induction with 2 views (supine and right lateral decubitus). A stomach with no visible contents in either supine or right lateral decubitus (RLD) positions was recorded as Grade 0, one with contents identified in RLD only was Grade 1, and cases with gastric contents visible in both positions were Grade 2. If gastric contents were identified with US, the patients then underwent a rapid sequence induction (RSI) and intubation. The authors placed an orogastric tube to suction gastric contents after induction and intubation for all patients and recorded the volume and pH of the suctioned gastric contents. The duration of fasting was also recorded for all food types as well as preoperative opioid analgesic use, age and BMI.

Results
Despite meeting typical fasting standards (median 14 hour fasting), many patients retained non-trivial quantities of gastric contents at surgery. Even with fasting, this study showed 27% with US Grade 0, 48% US Grade 1, and 26% US Grade 2. Concerningly over 70% of patients had gastric contents seen on ultrasound despite a prolonged fast. Interestingly, suctioned volume did correspond well to US grading in this study as well.

The median fasting interval was over 14 hours which is surprisingly long, and the median interval between accident and surgery presentation was almost 20 hours. However, even though many patients retained non-trivial quantities of gastric contents at surgery, there were no regurgitation or aspiration events. This is likely because in this study all patients were intubated.
The authors commented that the highest observed retained gastric contents were associated with relatively low opioid administration suggesting that opioids are not a primary driving factor in these results.

All patients with very large (>4 mL/kg) suctionable gastric contents presented as US Grade 2, and all of the US Grade 0 patients presented with low or very low quantities (<1ml/kg).

Conclusion
The authors conclude that fasting status is less predictive of gastric contents at time of surgery in patients with a fracture than previously assumed. However, bedside US screening may provide more useful information for the planning of airway management.

Take home messages
This study is interesting as it informs us that paediatric patients with long bone fractures are still likely to have persistent gastric contents despite prolonged fasting. It also suggests that in appropriately skilled hands, gastric ultrasound may be a useful tool in eliciting residual gastric content and helping the anaesthetist decide on appropriate airway management.

This study supports a flurry of recent studies in promoting the utility of gastric ultrasound in assessing paediatric patients perioperatively (Sever et al, 2024)(Sander et al, 2023). However, whilst the previous studies have all focussed on elective patients with minimal gastric contents, one of the strengths of this study is that it specifically assessed emergency patients and reinforces that we need to be cautious with this group of patients.

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The Lancet Respiratory Medicine

Submitted November 2024 by Dr Richard Barnes

Read by 133 Journal Watch subscribers

This prospective randomised trial was conducted in five tertiary Australian paediatric centres. The trial compared two techniques of oxygen delivery during tubeless ENT airway surgery in children aged 0-16 years: standard care with oxygen flows of up to 6l/min by oral or nasal catheter; or trial care with nasal high-flow oxygen at 2L/kg/min in younger children, up to a maximum of 50L/min in older patients.

The primary outcome was the need to interrupt surgery for rescue oxygenation. Secondary outcomes most importantly included degree and duration of any hypoxaemia. Data for 528 children were analysed. The recruitment number was calculated according to a power analysis based on a halving of the rate of the primary outcome with high-flow.

The primary outcome – surgical care without need for interruption – occurred in 88% of patients in both groups. There were no significant differences in any of the secondary outcomes. The statistics were not designed to look for a true “no difference”, but the numbers strongly suggest this to be the case.

This study represents a great deal of work by a large group of investigators. It is also, as Engelhardt and Disma put it in an accompanying editorial, a “testament to the clinical skills and expertise of the participating Australian tertiary paediatric centres, which are able to provide care with either technique in these patients with frequently complex and challenging conditions.” Interestingly, the 12% incidence of the need to interrupt surgery observed in both group is half what had been anticipated based on a preliminary pilot study of 78 children. One wonders whether the research brought about a Hawthorne effect.

The study shows conclusively that nasal high-flow oxygen delivery confers no advantage over standard care for the challenging field of paediatric tubeless ENT airway surgery. In my opinion, standard care continues to offer certain advantages: the ability to deliver sevoflurane (which was chosen either alone or in combination with intravenous anaesthesia in half the standard care cases); and the ability to deliver positive pressure without surgical interruption. From the resource point of view, standard care is simpler and less costly.

Nasal high-flow oxygen has swept across the anaesthetic world over the past decade, for both adult and paediatric patients, in a variety of settings involving both apnoea and spontaneous ventilation. This study adds to the accumulating data-bank of situations in which the technique’s promise does not match the reality.

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Pediatric Anesthesia

Submitted November 2024 by Dr Meghan Cooney

Read by 110 Journal Watch subscribers

This article provides excellent context for starting to understand health inequity among First Nations and Māori children and young people in Australia and New Zealand. It is essential reading as we endeavour to improve our comprehension of the peri-operative journey and provide better cultural safety when we work with patients and families from First Nations and Māori communities.

Notably, the authors consulted with First Nations people from the Northern Territory and Dr Dash Newington, an Arrernte woman from the Central Australian Desert Country, Paediatric Anaesthetist. Author, Dr Jane Thomas, also identifies as Ngāti Porou, Ngāti Kahungungu.

The geographical challenges for access to care are described clearly in this paper. The implications for First Nations and Māori patients and families of being in healthcare settings so far away from home and community could have been further explored, though this may reflect the lack of literature available to cover this. The authors have taken care to use strong language in reference to the lasting intergenerational effects of colonisation, as it continues to have a devastating impact on health outcomes for these populations.

The article provides a detailed exploration of paediatric anaesthesia in Australia and New Zealand including training and professional organisations such as SPANZA. They highlight that both ANZCA and SPANZA support efforts working towards health equity. The NZ Māori Anesthetists Netwrok Aotearoa (MANA) and Pasifika Anesthetists in Aotearoa (PAiA) have been established to ensure Māori and Pacific trainees and fellows are supported and ensure future growth of the Māori and Pacific anaesthetic workforce.

Some notable facts from the article include:
- The University of Auckland Anaesthesiology Dept has established a committee that reviews all research proposals through a Māori perspective.
- There is a relative paucity of literature looking at ethnic differences in peri-operative outcomes and inequities for Māori and Pacific children in New Zealand, as well as First Nations children in Australia.
- First Nations and Māori people are underrepresented in the healthcare workforce.

It is evident that there is urgent need for more research further examining the perioperative journey for patients and families with First Nations or Māori background; to review factors that drive health inequity, and to determine how to improve their care in anaesthesia and pain management. This article artfully “highlights the importance of clinicians having an appreciation of First Nations peoples’ and Māori history and culture, language, family-centered care and cultural safety.”

This topic can be further explored through the ANZCA library guide https://libguides.anzca.edu.au/indigenous

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