Control of the Respiratory Cycle in Conscious Humans

Acute effects of fentanyl on breathing pattern in anaesthetized subjects

“…6) in our patients was the same as noted in conscious man. 25 In conclusion, we have shown that small doses of opioid have a discernible primary effect on respiratory timing. Consequently, investigation of agents that offset these actions may be of value in mitigating some of the depression caused by opioids.…”

Nonrandom Variability of Respiration During Sleep in Healthy Humans

“…These data reflect that central control of respiratory drive is intact during REM sleep and confirm our results of a strongly metabolically influenced control of respiratory drive not only during NREM sleep, but also during REM sleep. The lack of STC for respiratory timing during NREM and REM sleep shows that regulation of respiratory timing and drive are different and assumes that, as in wakefulness, the control of respiratory drive is more automatically influenced by reflex mechanisms ensuring metabolic homeostasis 23 than is control of respiratory timing.…”

“…22 Investigations on respiration in conscious humans have shown that respiratory timing can easily be influenced by cortical factors, whereas the control of respiratory drive prevents a reduction in tidal volume (V T ) below a required level, ensuring metabolic homeostasis. 23 During wakefulness, consciousness might affect breathing by will, which underlines the importance of an investigation during sleep where external stimuli are absent or at least reduced. Furthermore, results of a diminished hypercapnic ventilatory response during REM sleep compared to wakefulness and NREM sleep suggest a changed or possibly disturbed metabolic control of ventilatory drive during REM sleep.…”

Modulation of the corticospinal control of ventilation by changes in reflex respiratory drive

“…Similarly, if voluntary ventilation is reduced to a level below that present during eupnea, we would expect an increased error associated with tracking during eucapnia. It is, however, not clear what components of the overall level of ventilation (i.e., timing, VT, or airflow) might be important in this regard; Rafferty and Gardner (22) propose that maintenance of VT may be more important than other aspects of respiratory pattern for, in the steady state, subjects are unable to voluntarily reduce VT below that determined during free breathing at rest (22). In contradiction, it is clearly possible to take voluntarily breaths smaller than a resting VT; the characteristics of the interaction between voluntary and reflex control may therefore depend on the duration of any given targeting period.…”