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The oxygram: an unappreciated technique for assessing hypoventilation in paediatric anaesthesia
Author(s) -
Jr JOHN E. MORRISON,
FRIESEN ROBERT H.,
KOYLE MARTIN A.
Publication year - 1994
Publication title -
pediatric anesthesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.704
H-Index - 82
eISSN - 1460-9592
pISSN - 1155-5645
DOI - 10.1111/j.1460-9592.1994.tb00120.x
Subject(s) - medicine , anesthesia , hypoventilation , halothane , pulse oximetry , ventilation (architecture) , respiratory rate , spirometer , heart rate , fresh gas flow , respiratory minute volume , intubation , sevoflurane , respiratory system , blood pressure , airway , mechanical engineering , exhaled nitric oxide , engineering , bronchoconstriction
Summary This study assessed the use of the oxygram, specifically the difference between inspired and end tidal oxygen concentrations, F 1 ‐eto 2 , to detect hypoventilation in a paediatric population. Ten healthy unpremedicated children, aged 1‐5 years, scheduled for elective minor urologic surgery were studied. A Modulus® II Plus Anesthesia System was used, with Rascal® II Anesthesia Gas Monitor for analysis of anaesthetic and respiratory gases with a Wright spirometer to monitor minute ventilation. Following inhalational induction, intubation, and caudal anaesthetic administration, the children breathed end‐tidal halothane concentrations of 0.5%, 2%, 1.5%, 1.0%, and again 0.5% with measurements of inspired and end‐tidal oxygen and halothane concentrations, end tidal CO 2 ( P etco 2 ), minute ventilation (VE), respiratory rate (f), pulse oximetry saturations ( S po 2 ), heart rate (HR), and mean blood pressure (BP). F I‐ETO 2 increased proportionately with hypoventilation at 2%, 1.5%, and 1% halothane concentrations compared to the 0.5% halothane group ( P < 0.0001, 0.0008, and 0.0013 respectively), associated with corresponding increases of P etco 2 and decreases of minute ventilation (VE). We conclude the oxygram was effective in monitoring hypoventilation in paediatric patients within the format of the protocol studied