Cardiovascular aspects of glossopharyngeal insufflation and exsufflation. Undersea Hyperb Med 2007;34(6):415-23
Date
02/07/2008Pubmed ID
18251438Scopus ID
2-s2.0-38949116346 (requires institutional sign-in at Scopus site) 25 CitationsAbstract
Breath-hold divers use glossopharyngeal breathing to inhale above total lung capacity (glossopharyngeal insufflation, GI) or exhale below residual volume (glossopharyngeal exsufflation, GE). In these maneuvers, air is moved using glossopharyngeal rather than respiratory muscle activity. Four competitive divers performed several GI and GE maneuvers in sitting or standing position, while cardiovascular parameters were measured with a photoplethysmographic method; echocardiography was also performed during GE. During GI, the divers showed a 48% drop in mean arterial pressure (MAP) to 50 mmHg, with a 88% decrease in pulse pressure (PP), while heart rate (HR) increased by 36% to 103 beats/min and cardiac output (CO) dropped by 79% to 1.3 l/min. The increase in intrathoracic pressure during GI, measured in separate experiments, is probably responsible for these hemodynamic changes, by impeding venous return into the chest. Associated with the drop in MAP during GI were various neurological signs and symptoms, including dizziness, tunnel vision, involuntary twitching of facial muscles and one brief episode of loss of consciousness. During GE, initially MAP and PP increased by 36% and 61%, to 149 and 95 mmHg respectively; later HR decreased by 37% to 45 beats/min and CO dropped by 37% to 4.3 l/min. The early cardiovascular changes of GE may be related to a decrease in intrathoracic pressure, enhancing venous return, as shown by a 6 to 15% increase in end-diastolic diameter; later changes are similar to the responses to apnea at low lung volumes. Because of their hemodynamic effects, these breathing maneuvers should be performed with caution, particularly in the case of GI.
Author List
Novalija J, Lindholm P, Loring SH, Diaz E, Fox JA, Ferrigno MAuthor
Jutta Novalija MD, PhD Professor in the Anesthesiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdultBlood Pressure
Cardiac Output
Diving
Echocardiography
Exhalation
Female
Heart Rate
Humans
Inhalation
Male
Pharyngeal Muscles
Tongue