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Journal Watch Search

188 Articles Found

Hypoxemia in Young Children Undergoing One-lung Ventilation: A Retrospective Cohort Study.

April 4, 2022

One lung ventilation in children remains a specialised practice in children performed by either endobronchial intubation or use of a bronchial blocker. With low case numbers, assessment of best practice is difficult. This retrospective cohort study interrogated data from a large multicentre cohort of children (aged 2 months to 3 years) undergoing one-lung ventilation for non-cardiac procedures. Investigators analysed 306 cases across 15 sites looking at factors that influenced likelihood of hypoxaemia during one-lung ventilation, primarily the relationship between lung isolation technique and incidence of hypoxaemia.

Findings

Investigators noted hypoxemia was common, with 26% of children saturating at less than 90% for 3 min or more and 18% of children saturating at less than 90% for 5 min or more (continuous). Bronchial blocker use was found to be associated with a lower risk of hypoxemia during one-lung ventilation. Investigators also noted left-sided surgery had reduced incidence of hypoxemia, however this finding did not reach statistical significance when controlled for other factors. Hypoxemia risk had no relationship with lower tidal volume ventilation, younger age, lower preoperative saturations, or increased duration of one-lung ventilation after controlling for other factors.

Commentary

This study adds to the limited multicentre data available on one-lung ventilation in children. Most data to date derives from individual experience and single centre case series. Notably, multicentre studies have not previously looked at factors such as age, surgical side, or lower tidal volume ventilation with respect to risk stratification for the outcome of intraoperative hypoxemia during one-lung ventilation. However, limitations of this study include relatively small sample size and retrospective method. While it is of interest to paediatric anaesthetists that bronchial blocker use was associated with less hypoxemia in children undergoing one-lung ventilation in this cohort, study limitations mean this finding cannot be taken as evidence of causation.

Take Home Message

This study provides impetus for us to reconsider our choice of practice between endobronchial intubation and bronchial blocker use due to the potential benefit of less hypoxemia during one-lung ventilation with bronchial blocker use in children undergoing non-cardiac thoracic procedures. A definitive change of practice recommendation regarding choice of lung isolation technique for such patients is not recommended based on this study due to limitations outlined. Individualised risk benefit including factoring in technical expertise of the proceduralist is always the safest approach.

 

Reviewed by Chloe Heath


Risk factors for anesthetic-related complications in pediatric patients with a newly diagnosed mediastinal mass.

April 4, 2022

Study design  

Single centre, retrospective case review.

Aim

Identification of risk factors for anaesthetic-related complications in paediatric patients with any type of mediastinal mass.

Methods

CT scans of patients presenting to Children’s Mercy Hospital, Kansas City between 2008-2019 were queried for “mediastinal mass”. Cardiac and respiratory symptoms were recorded and a blinded radiologist reviewed the imaging.

The procedure, type of anaesthetic administered and choice of airway management were examined. Anaesthetic complications were classified as; desaturation <80%, blood pressure <30% of peri-operative baseline or loss of ETCO2.

Findings 

86 patients were identified. 48% of patients underwent mediastinal mass biopsy, 21% tumour resection and 11% had a lymph node biopsy. Anaesthetic type was intubation with sevoflurane (56%), IV ketamine and/or dexmedetomidine using a natural airway (35%), anxiolysis or sedation (7%) and laryngeal mask airway with sevoflurane.

Six patients experienced an anaesthetic related complication, the commonest being desaturation <80%. All were intubated and had preoperative respiratory symptoms. Five experienced a reduction in BP or loss of ETCO2. Three, already had an ETT in situ (from ICU or the radiology suite).

Commentary

Morbidity remains high for children undergoing anaesthesia for procedures directly and indirectly related to mediastinal masses. As they are uncommon, any risk scoring system to predict those at highest risk would be beneficial. More than one preoperative respiratory symptom and tracheal compression on CT imaging were factors most predictive of anaesthetic complications, similar to previous reviews. The absence of pre-procedure orthopnoea and size and location of mediastinal masses were not predictive of incidences of anaesthetic complications.

If tumour resection was not required, IV anaesthesia and a natural airway was used. No complications occurred using this technique suggesting that it is safe in this high risk group of patients. Heliox (80% helium:20% oxygen) via facemask was administered if the patient had tracheal compression. A typical recipe was:

  1. Administer IV midazolam and glycopyrrolate
  2. Apply facemask with Heliox (80:20) if airway compression is present
  3. Prior to starting case, administer
    1. Dexmedetomidine 0.5-1 mcg/kg IV over 10 minutes
    2. 5 mg/kg IV
  4. During case, administer
    1. Dexmedetomidine 1 mcg/kg/hr IV
    2. Ketamine 1 mg/kg/hr IV and additional boluses as needed

 

The retrospective design, single centre and small patient numbers are the studies main limitations. During the study period, this institution developed a multi-disciplinary mediastinal mass huddle. Procedures required for the patient were identified to ensure they are done under one anaesthetic. The need for ventilation via a rigid bronchoscope is also discussed and anaesthesia tailored to individual patients.

Reviewed by Dr Vicky Lewis 


Neonatal resuscitation: current evidence and guidelines

April 4, 2022

This article serves as a review of neonatal resuscitation guidelines which may be of interest to the obstetric anaesthetist involved in the care of newborns at the time of birth.

  • Cord management:
    • Deferred clamping for 1-2 minutes allows an increased blood volume to be transferred from the placenta to the newborn, with evidence for lower mortality rates in infants. It is therefore recommended when feasible, if no immediate resuscitation is required.
    • Timing of uterotonic drugs in relation to cord clamping has not been adequately studied, but does not appear to affect neonatal outcomes.

 

  • Initial assessment:
    • Dry newborns >32 weeks gestation, wrap newborns <32 weeks in plastic without drying
    • Gentle stimulation and warm theatre
    • Universal suctioning is not supported by evidence and may be harmful. Suction only when clearly excessive secretions present, or if mask ventilation is required and does not appear to result in effective ventilation as noted by chest rise.

 

  • Monitoring:
    • HR is the most important sign (via ECG/pulse oximetry/cord palpation/cardiac auscultation)

 

  • Positive pressure ventilation:
    • Initiate if apnoeic or gasping newborn, or HR <100, after period of drying and stimulation
    • Start with a PIP of 30 cmH20 for term newborns and 20-25 cmH20 for preterm newborns. First 5 inflations to be held for 2-3 seconds each.
    • Lower FiO2 (0.21-0.3) decreases short term mortality in term newborns. Set low then increase if HR not responding. Set at 1.0 if requiring compressions.

 

  • Compressions:
    • If HR <60 despite effective ventilation for 30 seconds.
    • Coordinated with breaths at 3:1 ratio, 2 thumb technique.

 

  • Medications:
    • Standardised adrenaline concentration to 0.1 mg/ml
    • IV or IO dose is 10-30 microg/kg (0.1-0.3 ml/kg)
    • Intra-tracheal dose is 50-100 microg/kg (0.5-1 ml/kg)

 

  • Other considerations:
    • If not responding to resuscitation efforts, consider a pneumothorax or congenital anomalies such as congenital diaphragmatic hernia.

 

 

Reviewed by Dr Natalie Akl