Abstract
Respiratory muscles such as the diaphragm are active across a range of behaviors including ventilation and higher-force behaviors necessary for maintenance of airway patency, and minimal information is available regarding anesthetic effects on the capacity of respiratory muscles to generate higher forces. The purpose of the present study was to determine whether diaphragm EMG activity during lower-force behaviors, such as eupnea and hypoxia-hypercapnia, is differentially affected compared with higher-force behaviors, such as a sigh, in lightly anesthetized animals. In adult male rats, chronically implanted diaphragm EMG electrodes were used to measure the effects of low-dose ketamine (30 mg/kg) and xylazine (3 mg/kg) on root mean square (RMS) EMG amplitude across a range of motor behaviors. A mixed linear model was used to evaluate the effects of ketamine-xylazine anesthesia on peak RMS EMG and ventilatory parameters, with condition (awake vs. anesthetized), behavior (eupnea, hypoxia-hypercapnia, sigh), side (left or right hemidiaphragm), and their interactions as fixed effects and animal as a random effect. Compared with the awake recordings, there was an overall reduction of peak diaphragm RMS EMG across behaviors during anesthesia, but this reduction was more pronounced during spontaneous sighs (which require 60% of maximal diaphragm force). Respiratory rates and duty cycle during eupnea and hypoxiahypercapnia were higher in awake compared with anesthetized conditions. These results highlight the importance of identifying anesthetic effects on a range of respiratory motor behaviors, including sighs necessary for maintaining airway patency. NEW & NOTEWORTHY Respiratory muscles accomplish a range of motor behaviors, with forces generated for ventilatory behaviors comprising only a small fraction of their maximal force generating capacity. Induction of anesthesia exerts more robust effects on the higher-force diaphragm motor behaviors such as sighs compared with eupnea. This novel information on effects of low, sedative doses of a commonly used anesthetic combination (ketamine-xylazine) highlights the importance of identifying anesthetic effects on a range of respiratory motor behaviors.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 915-922 |
| Number of pages | 8 |
| Journal | Journal of Applied Physiology |
| Volume | 124 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1 2018 |
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Keywords
- Anesthesia
- Diaphragm muscle
- Electromyography
- Force
- Ketamine
ASJC Scopus subject areas
- Physiology
- Physiology (medical)
Cite this
Diaphragm muscle activity across respiratory motor behaviors in awake and lightly anesthetized rats. / Jimenez-Ruiz, Federico; Khurram, Obaid U.; Zhan, Wen Zhi; Gransee, Heather M.; Sieck, Gary C; Mantilla, Carlos Bernardo.
In: Journal of Applied Physiology, Vol. 124, No. 4, 01.04.2018, p. 915-922.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Diaphragm muscle activity across respiratory motor behaviors in awake and lightly anesthetized rats
AU - Jimenez-Ruiz, Federico
AU - Khurram, Obaid U.
AU - Zhan, Wen Zhi
AU - Gransee, Heather M.
AU - Sieck, Gary C
AU - Mantilla, Carlos Bernardo
PY - 2018/4/1
Y1 - 2018/4/1
N2 - Respiratory muscles such as the diaphragm are active across a range of behaviors including ventilation and higher-force behaviors necessary for maintenance of airway patency, and minimal information is available regarding anesthetic effects on the capacity of respiratory muscles to generate higher forces. The purpose of the present study was to determine whether diaphragm EMG activity during lower-force behaviors, such as eupnea and hypoxia-hypercapnia, is differentially affected compared with higher-force behaviors, such as a sigh, in lightly anesthetized animals. In adult male rats, chronically implanted diaphragm EMG electrodes were used to measure the effects of low-dose ketamine (30 mg/kg) and xylazine (3 mg/kg) on root mean square (RMS) EMG amplitude across a range of motor behaviors. A mixed linear model was used to evaluate the effects of ketamine-xylazine anesthesia on peak RMS EMG and ventilatory parameters, with condition (awake vs. anesthetized), behavior (eupnea, hypoxia-hypercapnia, sigh), side (left or right hemidiaphragm), and their interactions as fixed effects and animal as a random effect. Compared with the awake recordings, there was an overall reduction of peak diaphragm RMS EMG across behaviors during anesthesia, but this reduction was more pronounced during spontaneous sighs (which require 60% of maximal diaphragm force). Respiratory rates and duty cycle during eupnea and hypoxiahypercapnia were higher in awake compared with anesthetized conditions. These results highlight the importance of identifying anesthetic effects on a range of respiratory motor behaviors, including sighs necessary for maintaining airway patency. NEW & NOTEWORTHY Respiratory muscles accomplish a range of motor behaviors, with forces generated for ventilatory behaviors comprising only a small fraction of their maximal force generating capacity. Induction of anesthesia exerts more robust effects on the higher-force diaphragm motor behaviors such as sighs compared with eupnea. This novel information on effects of low, sedative doses of a commonly used anesthetic combination (ketamine-xylazine) highlights the importance of identifying anesthetic effects on a range of respiratory motor behaviors.
AB - Respiratory muscles such as the diaphragm are active across a range of behaviors including ventilation and higher-force behaviors necessary for maintenance of airway patency, and minimal information is available regarding anesthetic effects on the capacity of respiratory muscles to generate higher forces. The purpose of the present study was to determine whether diaphragm EMG activity during lower-force behaviors, such as eupnea and hypoxia-hypercapnia, is differentially affected compared with higher-force behaviors, such as a sigh, in lightly anesthetized animals. In adult male rats, chronically implanted diaphragm EMG electrodes were used to measure the effects of low-dose ketamine (30 mg/kg) and xylazine (3 mg/kg) on root mean square (RMS) EMG amplitude across a range of motor behaviors. A mixed linear model was used to evaluate the effects of ketamine-xylazine anesthesia on peak RMS EMG and ventilatory parameters, with condition (awake vs. anesthetized), behavior (eupnea, hypoxia-hypercapnia, sigh), side (left or right hemidiaphragm), and their interactions as fixed effects and animal as a random effect. Compared with the awake recordings, there was an overall reduction of peak diaphragm RMS EMG across behaviors during anesthesia, but this reduction was more pronounced during spontaneous sighs (which require 60% of maximal diaphragm force). Respiratory rates and duty cycle during eupnea and hypoxiahypercapnia were higher in awake compared with anesthetized conditions. These results highlight the importance of identifying anesthetic effects on a range of respiratory motor behaviors, including sighs necessary for maintaining airway patency. NEW & NOTEWORTHY Respiratory muscles accomplish a range of motor behaviors, with forces generated for ventilatory behaviors comprising only a small fraction of their maximal force generating capacity. Induction of anesthesia exerts more robust effects on the higher-force diaphragm motor behaviors such as sighs compared with eupnea. This novel information on effects of low, sedative doses of a commonly used anesthetic combination (ketamine-xylazine) highlights the importance of identifying anesthetic effects on a range of respiratory motor behaviors.
KW - Anesthesia
KW - Diaphragm muscle
KW - Electromyography
KW - Force
KW - Ketamine
UR - http://www.scopus.com/inward/record.url?scp=85047737567&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85047737567&partnerID=8YFLogxK
U2 - 10.1152/japplphysiol.01004.2017
DO - 10.1152/japplphysiol.01004.2017
M3 - Article
C2 - 29357493
AN - SCOPUS:85047737567
VL - 124
SP - 915
EP - 922
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 4
ER -