The 2023 American Academy of Neurology, American Academy of Pediatrics, Child Neurology Society, and Society of Critical Care Medicine Pediatric and Adult Brain Death/Death by Neurologic Criteria Determination Consensus Guidelines: What the Critical Care Team Needs to Know

Prevalence of Arginine Vasopressin Deficiency among Children and Adolescents Declared Dead by Neurologic Criteria

OBJECTIVES

To determine the prevalence of arginine vasopressin deficiency (AVP-D) in children and adolescents declared brain dead (BD)/death by neurologic criteria (DNC) and to evaluate the association between cause of brain injury and the development of AVP-D.

STUDY DESIGN

We retrospectively analyzed 53 pediatric BD/DNC patients ages 0 to 21 years from 2013 to 2023 at a single tertiary children's hospital to assess the prevalence of AVP-D and compare those patients with and without AVP-D. AVP-D frequency by injury mechanism (anoxic brain injury, traumatic brain injury [TBI], malignancy) was also analyzed.

RESULTS

Of the 53 patients declared BD/DNC, 47 (88.7%, 95% CI 77.9% to 95.3%) were diagnosed with AVP-D. The prevalence of AVP-D was similar according to the cause of brain injury (84.4%, 100.0%, and 92.3% for anoxic brain injury, TBI, and brain tumor, respectively; p = 0.410). Clinical characteristics and length of stays were similar between AVP-D and non-AVP-D groups. The estimated glomerular filtration rate (ml/min/1.73m2) was lower in children without AVP-D (78 [51-165] vs 178 [133-253]; p = 0.009).

CONCLUSIONS

The prevalence of AVP-D is high in children and adolescents declared BD/DNC, and it is not significantly different based on the cause of BD/DNC. The absence of AVP-D was associated with reduced renal function. Additional multicenter studies are needed to assess clinical characteristics and renal function with preserved neuroendocrine function in children with BD/DNC.

Diagnostic Sensitivity of the Revised Venous System in Brain Death in Children

BACKGROUND/OBJECTIVES

While ancillary tests for brain death diagnosis are not routinely recommended in guidelines, they may be necessary in specific clinical scenarios. Computed tomography angiography (CTA) is particularly advantageous in pediatric patients due to its noninvasive nature, accessibility, and rapid provision of anatomical information. This study aims to assess the diagnostic sensitivity of a revised venous system (ICV-SPV) utilizing a 4-point scoring system in children clinically diagnosed with brain death.

MATERIALS AND METHODS

A total of 43 pediatric patients clinically diagnosed with brain death who underwent CTA were retrospectively analyzed. Imaging was performed using a standardized brain death protocol. Three distinct 4-point scoring systems (A20-V60, A60-V60, ICV-SPV) were utilized to assess vessel opacification in different imaging phases. To evaluate age-dependent sensitivity, patients were categorized into three age groups: 26 days-1 year, 2-6 years, and 6-18 years. The sensitivity of each 4-point scoring system in diagnosing brain death was calculated for all age groups.

RESULTS

The revised venous scoring system (ICV-SPV) demonstrated the highest overall sensitivity in confirming brain death across all age groups, significantly outperforming the reference 4-point scoring systems. Furthermore, the ICV-SPV system exhibited the greatest sensitivity in patients with cranial defects.

CONCLUSIONS

The revised 4-point venous CTA scoring system, which relies on the absence of ICV and SPV opacification, is a reliable tool for confirming cerebral circulatory arrest in pediatric patients with clinical brain death.

Prospective Evaluation of a Modified Apnea Test in Brain Death Candidates that Does Not Require Disconnection from the Ventilator

BACKGROUND

The apnea test (AT) is an important component in the determination of brain death/death by neurologic criteria (BD/DNC) and often entails disconnecting the patient from the ventilator followed by tracheal oxygen insufflation to ensure adequate oxygenation. To rate the test as positive, most international guidelines state that a lack of spontaneous breathing must be demonstrated when the arterial partial pressure of carbon dioxide (PaCO2) ≥ 60 mm Hg. However, the loss of positive end-expiratory pressure that is associated with disconnection from the ventilator may cause rapid desaturation. This, in turn, can lead to cardiopulmonary instability (especially in patients with pulmonary impairment and diseases such as acute respiratory distress syndrome), putting patients at increased risk. Therefore, this prospective study aimed to investigate whether a modified version of the AT (mAT), in which the patient remains connected to the ventilator, is a safer yet still valid alternative.

METHODS

The mAT was performed in all 140 BD/DNC candidates registered between January 2019 and December 2022: after 10 min of preoxygenation, (1) positive end-expiratory pressure was increased by 2 mbar (1.5 mm Hg), (2) ventilation mode was switched to continuous positive airway pressure, and (3) apnea back-up mode was turned off (flow trigger 10 L/min). The mAT was considered positive when spontaneous breathing did not occur upon PaCO2 increase to ≥ 60 mm Hg (baseline 35-45 mm Hg). Clinical complications during/after mAT were documented.

RESULTS

The mAT was possible in 139/140 patients and had a median duration of 15 min (interquartile range 13-19 min). Severe complications were not evident. In 51 patients, the post-mAT arterial partial pressure of oxygen (PaO2) was lower than the pre-mAT PaO2, whereas it was the same or higher in 88 cases. In patients with pulmonary impairment, apneic oxygenation during the mAT improved PaO2. In 123 cases, there was a transient drop in blood pressure at the end of or after the mAT, whereas in 12 cases, the mean arterial pressure dropped below 60 mm Hg.

CONCLUSIONS

The mAT is a safe and protective means of identifying patients who no longer have an intact central respiratory drive, which is a critical factor in the diagnosis of BD/DNC. Clinical trial registration DRKS, DRKS00017803, retrospectively registered 23.11.2020, https://drks.de/search/de/trial/DRKS00017803.