108 research outputs found
Autonomic cardiovascular function in high-altitude Andean natives with chronic mountain sickness
No full textAutonomic cardiovascular function in high-altitude Andean natives with chronic mountain sickness.
C. KEYL, 1 A. SCHNEIDER, 1 A. GAMBOA, 2 L. SPICUZZA, 3 N. CASIRAGHI, 4 ́ N-VELARDE, 2 AND L. BERNARDI 4, A. MORI, 5 R. TAPIA RAMIREZ, 2 F. LEO
1 Department of Anesthesiology, University Medical Center, 93042 Regensburg, Germany; 2 Department of Physiological Sciences, Universidad Cayetano Heredia, Lima 700, Peru; 3 Institute of Respiratory Diseases, University of Catania, 95124 Catania, Italy; 4 Department of Internal Medicine and Institute of Hematology, and 5 Department of Pathology, University of Pavia and Istituto di Ricovero e Cura a Carattere Scientifico San Matteo, 27100 Pavia, Italy
We evaluated autonomic cardiovascular regulation in subjects with polycythemia and chronic mountain sickness (CMS) and tested the hypothesis that an increase in arterial oxygen saturation has a beneficial effect on arterial baroreflex sensitivity in these subjects. Ten Andean natives with a Hct >65% and 10 natives with a Hct 65% showed an increased incidence of CMS compared with subjects with Hct <60%. Spontaneous baroreflex sensitivity was significantly lower in subjects with high Hct compared with the control group. The effects of supplemental oxygen or modification of the breathing pattern on autonomic function were as follows: 1) heart rate decreased significantly after both maneuvers in both groups, and 2) spontaneous baroreflex sensitivity increased significantly in subjects with high Hct and did not differ from subjects with low Hct. Temporary slow-frequency breathing may provide a beneficial effect on the autonomic cardiovascular function in high-altitude natives with CMS
Sleep-related hypoxaemia and excessive erythrocytosis in Andean high-altitude natives
No full textSleep-related hypoxaemia and excessive erythrocytosis in Andean
high-altitude natives.
L. Spicuzza * , N. Casiraghi # , A. Gamboa } , C. Keyl z , A. Schneider z , A. Mori § , F. Leon-Velarde } , G.U. Di Maria * , L. Bernardi #
*Dept of Internal Medicine and Medical Specialities, University of Catania, # Dept of Internal Medicine and § Pathology, IRCCS S. Matteo and University of Pavia, Italy. } University Cayetano Heredia, Lima, Peru. z Dept of Anaesthesiology, University of Regensburg, Germany.
To determine whether nocturnal hypoxaemia contributes to the excessive erythrocytosis (EE) in Andean natives, standard polysomnographies were performed in 10 patients with EE and in 10 controls (mean haematocrit 76.6 +/- 1.3% and 5.4 +/- 0.8%, respectively) living at an altitude of 4,380 m. In addition, the effect of O2 administration for 1 h prior to sleep, and the relationship between the hypoxic/hypercapnic ventilatory response and the apnoea/hypopnoea index (AHI) during sleep were studied. Awake arterial oxygen saturation (Sa,O2) was significantly lower in patients with EE than in controls (83.7 +/- 0.3% versus 85.6 +/- 0.4%). In both groups, the mean Sa,O2 significantly decreased during sleep (to 80.0 +/- 0.8% in EE and to 82.8 +/- 0.5% in controls). The mean Sa,O2 values remained significantly lower in patients with EE than in controls at all times of the night, and patients with EE spent significantly more time than the controls with an Sa,O2 of <80%. There were no differences between the two groups in the number and duration of the apnoeas/hypopnoeas. None of these variables were affected by O2 administration. In both groups the AHI positively correlated with the hypercapnic ventilatory response. Andean natives undergo minor respiratory disorders during sleep. The reduction in oxygen saturation found in subjects with excessive erythrocytosis was small, yet consistent and potentially important, as it remained below the threshold known for the increase in erythropoietin stimulation. This may be an important factor promoting erythropoiesis, but its relevance needs to be further explored
Equipment for noninvasive mechanical ventilation.
No full textNoninvasive ventilation consists of the application of a ventilator to the patient’s airways without recourse to orotracheal intubation or tracheostomy and therefore requires a range of devices that guarantee mechanical ventilatory support to the spontaneous pulmonary breathing. Two different types of systems are defined, namely closed and opened, depending on the type of circuit and mask used. Mechanical noninvasive ventilator delivers gas flow through pressured or volumed algorithms as well as in the intensive care unit but often are easier to manage. The importance of a good ventilation is often driven by specialized teamwork by clinicians, nursery, and trained personnel. Communicating and receiving feedback from the patient who needs to undergo a NIV session, if possible, increases compliance and improves the outcome of care significantly. Technical aspects of devices with detailed references to interfaces, management, and prevention of ventilation side effects are reported
Slow breathing reduces chemoreflex response to hypoxia and hypercapnia, and increases baroreflex sensitivity
No full text
- …
