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Low flow oxygen delivery via nasal cannula to neonates
Author(s) -
Finer Neil N.,
Bates Rosanne,
Tomat Paula
Publication year - 1996
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/(sici)1099-0496(199601)21:1<48::aid-ppul8>3.0.co;2-m
Subject(s) - nasal cannula , medicine , anesthesia , cannula , tidal volume , ventilation (architecture) , flow measurement , oxygen , oxygen delivery , respiratory minute volume , respiratory system , surgery , chemistry , mechanical engineering , physics , engineering , organic chemistry , thermodynamics
Neonates with chronic lung disease often require oxygen in the neonatal intensive care unit. The purpose of this study was to determine (1) the actual inspired oxygen concentration (F 1 O 2 ) delivered to neonates when using a low‐flow flowmeter and a nasal cannula, and (2) the accuracy with which F 1 O 2 could be estimated using a formula that we developed. We studied two groups of infants: 18 infants less than 1,500 g and 13 infants greater than 1,500 g. We measured pharyngeal oxygen levels by sampling pharyngeal gas in infants receiving 100% humidified oxygen by nasal cannula from a low range flow flowmeter. The oxygen flow was increased by 25 mL/min increments from 25 to 200 mL/min. The measured F 1 O 2 was compared with the calculated F 1 O 2 using the formula: F 1 O 2 measured = oxygen flow (mL/min × 0.79) + (0.21 × V E )/V E × 100, Where minute ventilation (V E ) equals the minute ventilation in mL/min (V E = V T × respiratory rate). For both groups of infants, increments of 25 mL/min of flow produced distinctive changes in F 1 O 2 at all levels ( P < 0.001). The calculated F 1 O 2 did not significantly differ from the actual F 1 O 2 at any flow. The calculated F 1 O 2 was most predictive when using an assumed tidal volume of 5.5 mL/kg. We conclude that an accurate flowmeter connected to 100% humidified oxygen can produce a wide range of predictable F 1 O 2 s for neonates, especially those with birthweights of less than 1,500 g. The proposed formula allows useful estimation of the infant's F 1 O 2 when we assume a tidal volume of 5.5 mL/kg. Pediatr Pulmonol. 1996; 21:48–51. © 1996 Wiley‐Liss, Inc.