The present study evaluated the effect of coactivation of tongue protrusors and retractors on pharyngeal patency in patients with obstructive sleep apnea. The effect of genioglossus (GG), hyoglossus (HG), and coactivation of both on nasal pressure (Pn):flow relationships was evaluated in a sleep study (SlS, n = 7) and during a propofol anesthesia study (AnS, n = 7). GG was stimulated with sublingual surface electrodes in SlS and with intramuscular electrodes in AnS, while HG was stimulated with surface electrodes in both groups. In the AnS, the cross-sectional area (CSA):Pn relationships was measured with a pharyngoscope to estimate velopharyngeal compliance . In the SlS, surface stimulation of GG had no effect on the critical pressure (Pcrit), HG increased Pcrit from 2.8 +/- 1.7 to 3.7 +/- 1.6 cmH(2)O, but coactivation lowered Pcrit to 0.2 +/- 1.9 cmH(2)O (P < 0.01 for both). In the AnS, intramuscular stimulation of GG lowered Pcrit from 2.6 +/- 1.3 to 1.0 +/- 2.8 cmH(2)O, HG increased Pcrit to 6.2 +/- 2.5 cmH(2)O (P < 0.01), and coactivation had a similar effect to that of GG (Pcrit = 1.2 +/- 2.4 cmH(2)O, P < 0.05). None of the interventions affected significantly velopharyngeal compliance. We conclude that the beneficial effect of coactivation depends on the pattern of GG fiber recruitment: although surface stimulation of GG failed to protrude the tongue, it prevented the occlusive effect of the retractor, thereby improving pharyngeal patency during coactivation. Stimulation of deeper GG fibers with intramuscular electrodes enlarged the pharynx, and coactivation had no additive effect.

Download full-text PDF

Source
http://dx.doi.org/10.1152/japplphysiol.00620.2007DOI Listing

Publication Analysis

Top Keywords

pcrit +/-
20
+/- cmh2o
20
coactivation
8
coactivation tongue
8
sleep apnea
8
pharyngeal patency
8
ans stimulated
8
surface electrodes
8
intramuscular electrodes
8
velopharyngeal compliance
8

Similar Publications

Prebypass Critical Closing Pressure Predicts Acute Kidney Injury After Cardiopulmonary Bypass.

J Cardiothorac Vasc Anesth

November 2024

Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA; Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA. Electronic address:

Objectives: Optimal blood pressure goals during cardiopulmonary bypass (CPB) remain uncertain and new metrics to individualize perfusion targets are needed. Critical closing pressure (Pcrit) is a fundamental property of the arterial circulation related to vascular tone and represents the outflow pressure impacting flow across the systemic circulation. We examined Pcrit as a prognostic marker of acute kidney injury (AKI).

View Article and Find Full Text PDF

Effects of elevated CO on the critical oxygen tension (P) and aerobic metabolism of two oxygen minimum zone (OMZ) hypoxia tolerant squat lobster species.

Sci Total Environ

December 2024

Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Chile; Instituto Milenio de Oceanografía (IMO), Universidad de Concepción, PO Box 1313, Concepción, Chile. Electronic address:

Marine invertebrates living in oxygen minimum zones (OMZ), where low pO and high pCO conditions co-occur, display physiological mechanisms allowing them to deal with these coupled stressors. We measured aerobic metabolic rate (MR) and the critical oxygen tension (P), and calculated the oxygen supply capacity (α) of both the red (Grimothea monodon) and yellow (Grimothea johni) squat lobsters, under two pCO scenarios (~414 and 1400 μatm). We also measured haemolymph pH, haemocyanin oxygen binding affinity (p), and haemolymph lactate content in both species under normoxia, low pCO hypoxia and high pCO hypoxia.

View Article and Find Full Text PDF

Oxygen availability is central to the energetic budget of aquatic animals and may vary naturally and/or in response to anthropogenic activities. Yet, we know little about how oxygen availability is linked to fundamental processes such as ion transport in aquatic insects. We hypothesized and observed that ion (22Na and 35SO4) uptake would be significantly decreased at O2 partial pressures below the mean critical level (Pcrit, 5.

View Article and Find Full Text PDF

Comparison of awake respiratory control versus sleep obstructive sleep apnea endotypes.

J Appl Physiol (1985)

December 2024

Neuroscience Research Australia (2nd arm work performed), School of Medical Sciences, University of New South Wales, Randwick, New South Wales, Australia.

Article Synopsis
  • Most research on precision medicine for obstructive sleep apnea (OSA) focuses on sleep parameters, but this study highlights the importance of wakefulness physiology measures for predicting OSA therapies.
  • The study investigated the relationship between awake ventilatory control and OSA endotypes, analyzing data from a trial comparing morphine and placebo effects on OSA severity.
  • Findings showed that awake chemosensitivity correlates with critical airway pressures and can predict changes in OSA severity when administered morphine, suggesting awake measures could enhance understanding of OSA physiology.
View Article and Find Full Text PDF

Whether hypoxia tolerance improved after short-term fasting is closely related to phylogeny but not to foraging mode in freshwater fish species.

J Comp Physiol B

December 2024

Laboratory of Evolutionary Physiology and Behavior, Chongqing Key Laboratory of Conservation and Utilization of Freshwater Fishes, Animal Biology Key Laboratory of Chongqing Education Commission of China, Chongqing Normal University, Chongqing, 401331, China.

The combined stresses of fasting and hypoxia are common events during the life history of freshwater fish species. Hypoxia tolerance is vital for survival in aquatic environments, which requires organisms to down-regulate their maintenance energetic expenditure while simultaneously preserving physiological features such as oxygen supply capacity under conditions of food deprivation. Generally, infrequent-feeding species who commonly experience food shortages might evolve more adaptive strategies to cope with food deprivation than frequent-feeding species.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!