[Diaphragmatic strength and ventilatory control in experimental hypothermia].
In ten lightly anaesthetized dogs breathing spontaneously, we studied diaphragmatic force generation (Pdi 10, 30, 100 Hz and single twitch) and ventilatory control (P 0, 1, Vt/Ti and respiratory frequency). We found CO2 retention proportional to hypothermia (Fig. 3). The TP was not changed while VMxA and VMxD decreased (Table 1). High frequency fatigue and low frequency potentiation were found (Fig. 1, 2). These changes do not explain CO2 retention which correlated with fall in central drive (P 0, 1, Vt/Ti, Fig. 3, 4) and respiratory timing (respiratory frequency, Fig. 4).
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Instituto de Investigaciones Médicas Alfredo Lanari, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Roncoroni
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AJ
D000818:Animals; D003964:Diaphragm / Q000502:physiology*; D004285:Dogs; D004558:Electric Stimulation; D007036:Hypothermia, Induced; D010100:Oxygen / Q000502:physiology; D010791:Phrenic Nerve / Q000502:physiology; D012119:Respiration / Q000502:physiology*
D010100:Oxygen
Fuerza diafragmática y control ventilatorio en la hipotermia experimental.