Anesthesia Breathing Systems

The ventrolateral medulla (VLM) has been reported to be important as a source of tonic facilitation of dorsal respiratory neurons and as a site critical for respiratory rhythmogenesis. We investigated these theories in awake and anesthetized goats (n = 13) by using chronically implanted thermodes to create reversible neuronal dysfunction at superficial VLM sites between the first hypoglossal rootlet and the pontomedullary junction (area M (rostral) and area S). During halothane anesthesia (arterial PCO2 = 57.4 +/- 4.5 Torr), bilateral cooling (thermode temperature = 20 degrees C) of 60–100% of areas M and S for 30 s produced a sustained apnea (46 +/- 4 s) that lasted beyond the period of cooling. While the animals were awake (arterial PCO2 = 36.0 +/- 1.9 Torr), cooling the identical region in the same goats resulted in a decrease (approximately 50%) in pulmonary ventilation, with a brief apnea seen only in one goat. Reductions in both tidal volume and frequency were observed. Qualitatively similar responses were obtained when cooling caudal area M-rostral area S and rostral area M, but the responses were less pronounced. Minimal effects were seen in response to cooling caudal area S. During anesthesia, breathing is critically dependent on superficial VLM neurons, whereas in the awake state these neurons are not essential for the maintenance of respiratory rhythm. Our data are consistent with these superficial VLM neuronal regions providing tonic facilitation to more dorsal respiratory neurons in both the anesthetized and awake states.

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Inside Anesthesia Breathing Circuits

Anesthesia & Analgesia ◽

10.1213/ane.0b013e318257570f ◽

2012 ◽

Vol 115 (2) ◽

pp. 310-314 ◽

Cited By ~ 11

Author(s):

Delphine Kern ◽

Claire Larcher ◽

Bertrand Basset ◽

Xavier Alacoque ◽

Rose Fesseau ◽

...

Keyword(s):

Anesthesia Breathing

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Hyperventilation of the lungs as a preventive measure against pneumonia

Kazan medical journal ◽

10.17816/kazmj80523 ◽

2021 ◽

Vol 25 (11) ◽

pp. 1234-1234

Author(s):

N. Kramov

Keyword(s):

Carbon Dioxide ◽

Infectious Diseases ◽

Effective Means ◽

Preventive Measure ◽

Postoperative Pneumonia ◽

Deep Breathing ◽

Anesthesia Breathing

Based on the works of Corullos and Birnbaum, Scott and Cutler that postoperative pneumonia develops in atelectasized areas of the lungs, Henderson (A. M. A. 1929, 9 II) recommends inhalation of carbon dioxide in oxygen (5,0-100,0), as the most effective means of preventing pneumonia both in postoperative cases and in asphyxia and infectious diseases. As a result of anesthesia, breathing becomes shallow, the sections of the lungs are not ventilated and atelectasis appears, and the infection of these sections easily causes pneumonia; stretching these unventilated collapsed areas by deep breathing as a result of inhalation of carbon dioxide prevents atelectasis and prevents the development of pneumonia.

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