A Bedside Equation to Estimate Endotracheal Tube Length for Infants.

OBJECTIVE: To develop a bedside equation that can be used to estimate the ideal oral and nasal endotracheal tube (ETT) length for children younger than 1 year of age. STUDY DESIGN: Retrospective database analysis of 735 children younger than 1 year of age admitted to pediatric intensive care at Evelina London Children's Hospital from June 1, 2019, through August 31, 2021. ETT positions were determined by tube-tip superimposition over vertebral body on postintubation chest radiograph by trained medical students and pediatric radiologists with bedside assessment of ETT length at nostril or lip as recorded electronically by nursing staff. RESULTS: The position of 1176 ETTs were evaluated, of which 784 (66%) were nasal and 392 (33%) were oral. After averaging length to account for multiple intubation events per patient, 281 (39%) nasal tubes and 105 (28%) oral tubes were found to be positioned optimally at T2. Using weight was superior to age or corrected age at estimating ETT length. Regression analysis revealed that optimal (T2) positioning of oral ETTs occurs at a length of (weight2+8) cm and in nasal ETTs at (weight2+9.5) cm with a mean absolute prediction error of 5%. The formulae did not require adjustments for those with comorbidities or prematurity. CONCLUSIONS: The optimal insertion length of ETTs placed both orally and nasally in children up to 1 year of age can be estimated with appropriate accuracy by a simple bedside formula using weight as the only variable.

Oxygen saturation and haemodynamic changes prior to circulatory arrest: Implications for transplantation and resuscitation.

AIMS: To describe the progression of oxygen saturations and blood pressure observations prior to death. INTRODUCTION: The progression of physiological changes around death is unknown. This has important implications in organ donation and resuscitation. Donated organs have a maximal warm ischaemic threshold. In hypoxic cardiac arrest, an understanding of pre-cardiac arrest physiology is important in prognosticating and will allow earlier identification of terminal states. METHODS: Data were examined for all regional patients over a two-year period offering organ donation after circulatory death. Frequent observations were taken contemporaneously by the organ donation nurse at the time of and after withdrawal of intensive care. RESULTS: In all, 82 case notes were examined of patients aged 0 to 76 (median 52, 4 < 18 years). From withdrawal of intensive care to death took a mean of 28.5 min (range 4 to 185). A terminal deterioration in saturations (from an already low baseline) commenced 14 min prior to circulatory arrest, followed by a blood pressure fall commencing 8 min prior to circulatory arrest, and finally a rapid fall in heart rate commencing 4 min prior to circulatory arrest. Two patients had a warm ischaemic time of greater than 30 min; 15 patients had a warm ischaemia time of 10 min or greater; and 53 patients had a warm ischaemia time of 5 min or less. It was observed that 0/82 patients had saturations of less than 40% for more than 3 min prior to cardiac arrest and 74/82 for more than 2 min. CONCLUSIONS: There is a perimortem sequence of hypoxia, then hypotension, and then bradycardia. The heart is extremely resistant to hypoxia. A warm ischaemic time of over 30 min is rare.