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The Respiratory Response to Carbon Dioxide in Humans with Unilateral and Bilateral Resections of the Carotid Bodies
Author(s) -
Fatemian Marzieh,
Nieuwenhuijs Diederik J. F.,
Teppema Luc J.,
Meinesz Sietske,
Mey Andel G. L.,
Dahan Albert,
Robbins Peter A.
Publication year - 2003
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2003.042259
Subject(s) - carotid body , peripheral , peripheral chemoreceptors , ventilation (architecture) , medicine , respiration , anesthesia , hypoxia (environmental) , respiratory system , chemistry , anatomy , electrophysiology , oxygen , organic chemistry , mechanical engineering , engineering
The acute hypercapnic ventilatory response (AHCVR) arises from both peripheral and central chemoreflexes. In humans, one technique for identifying the separate contributions of these chemoreflexes to AHCVR has been to associate the rapid component of AHCVR with the peripheral chemoreflex and the slow component with the central chemoreflex. Our first aim was to validate this technique further by determining whether a single slow component was sufficient to describe AHCVR in patients with bilateral carotid body resections (BR) for glomus cell tumours. Our second aim was to determine whether the slow component of AHCVR was diminished following carotid body resection as has been suggested by studies in experimental animals. Seven BR subjects were studied together with seven subjects with unilateral resections (UR) and seven healthy controls. A multifrequency binary sequence in end‐tidal P CO2 was employed to stimulate ventilation dynamically under conditions of both euoxia and mild hypoxia. Both two‐ and one‐compartment models of AHCVR were fitted to the data. For BR subjects, the two‐compartment model fitted significantly better on 1 out of 13 occasions compared with 22 out of 28 occasions for the other subjects. Average values for the chemoreflex sensitivity of the slow component of AHCVR differed significantly ( P < 0.05 ) between the groups and were 0.95, 1.38 and 1.50 l min −1 Torr −1 for BR, UR and control subjects, respectively. We conclude that, without the peripheral chemoreflex, AHCVR is adequately described by a single slow component and that BR subjects have sensitivities for the slow component that are lower than those of control subjects.