Nasopharyngeal tubes in pediatric anesthesia: Is the flow-dependent pressure drop across the tube suitable for calculating oropharyngeal pressure?
Rohrer's equation
anesthesia
nasopharyngeal tube
oropharyngeal pressure
pediatrics
pressure drop
Journal
Paediatric anaesthesia
ISSN: 1460-9592
Titre abrégé: Paediatr Anaesth
Pays: France
ID NLM: 9206575
Informations de publication
Date de publication:
07 2021
07 2021
Historique:
revised:
06
04
2021
received:
08
06
2020
accepted:
07
04
2021
pubmed:
15
4
2021
medline:
5
8
2021
entrez:
14
4
2021
Statut:
ppublish
Résumé
Nasopharyngeal tubes are useful in pediatric anesthesia for insufflating oxygen and anesthetics. During nasopharyngeal tube-anesthesia, gas insufflation provides some positive oropharyngeal pressure that differs from the proximal airway pressure owing to the flow-dependent pressure drop across the nasopharyngeal tube (ΔP This study aimed to investigate whether ΔP In a physical model of nasopharyngeal tube-anesthesia, using Rohrer's equation, we calculated ΔP When we tested small-diameter nasopharyngeal tubes at high-flow or high-peak inspiratory pressure, proximal airway pressure measurements markedly overestimated oropharyngeal pressure. Comparing measured and calculated maximum and minimum oropharyngeal pressure couples yielded root mean square deviations less than 0.5 cmH During nasopharyngeal tube-assisted anesthesia, proximal airway pressure readings on the anesthetic monitoring machine overestimate oropharyngeal pressure especially for smaller-diameter nasopharyngeal tubes and higher flow, and to a lesser extent for large leaks. Given the importance of calculating oropharyngeal pressure in guiding nasopharyngeal tube ventilation in clinical practice, we propose an accurate calculation using Rohrer's equation method, or approximating oropharyngeal pressure from flow and pressure readings on the anesthetic machine using the ΔP
Sections du résumé
BACKGROUND
Nasopharyngeal tubes are useful in pediatric anesthesia for insufflating oxygen and anesthetics. During nasopharyngeal tube-anesthesia, gas insufflation provides some positive oropharyngeal pressure that differs from the proximal airway pressure owing to the flow-dependent pressure drop across the nasopharyngeal tube (ΔP
AIMS
This study aimed to investigate whether ΔP
METHODS
In a physical model of nasopharyngeal tube-anesthesia, using Rohrer's equation, we calculated ΔP
RESULTS
When we tested small-diameter nasopharyngeal tubes at high-flow or high-peak inspiratory pressure, proximal airway pressure measurements markedly overestimated oropharyngeal pressure. Comparing measured and calculated maximum and minimum oropharyngeal pressure couples yielded root mean square deviations less than 0.5 cmH
CONCLUSION
During nasopharyngeal tube-assisted anesthesia, proximal airway pressure readings on the anesthetic monitoring machine overestimate oropharyngeal pressure especially for smaller-diameter nasopharyngeal tubes and higher flow, and to a lesser extent for large leaks. Given the importance of calculating oropharyngeal pressure in guiding nasopharyngeal tube ventilation in clinical practice, we propose an accurate calculation using Rohrer's equation method, or approximating oropharyngeal pressure from flow and pressure readings on the anesthetic machine using the ΔP
Identifiants
pubmed: 33853203
doi: 10.1111/pan.14194
pmc: PMC8252547
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
809-819Informations de copyright
© 2021 The Authors. Pediatric Anesthesia published by John Wiley & Sons Ltd.
Références
Anesthesiology. 1993 Sep;79(3):503-13
pubmed: 8363076
Anesth Analg. 2002 Feb;94(2):467-9, table of contents
pubmed: 11812720
Crit Care Med. 2000 Apr;28(4):1018-26
pubmed: 10809276
Crit Care Med. 1980 Jan;8(1):38-40
pubmed: 7349947
Br J Anaesth. 2001 Oct;87(4):602-7
pubmed: 11878731
Br J Anaesth. 2003 Mar;90(3):388-91
pubmed: 12594157
Pediatr Pulmonol. 1995 May;19(5):269-74
pubmed: 7567201
Paediatr Anaesth. 2015 Apr;25(4):413-20
pubmed: 25491944
Paediatr Anaesth. 2005 Oct;15(10):839-45
pubmed: 16176311
Physiol Meas. 2011 Sep;32(9):1439-51
pubmed: 21799238
Med Eng Phys. 2018 Apr;54:32-43
pubmed: 29487038
Crit Care Med. 2007 May;35(5):1383-9
pubmed: 17414085
Respirology. 2006 Jul;11(4):471-6
pubmed: 16771919
Crit Care Med. 2000 May;28(5):1595-8
pubmed: 10834718
Br J Anaesth. 2016 Aug;117(2):151-63
pubmed: 27440626
Am Rev Respir Dis. 1989 Jul;140(1):10-6
pubmed: 2751156
J Appl Physiol (1985). 1999 Jul;87(1):36-46
pubmed: 10409556