Biomedical subjects

S Sapsed

Publications and source records attributed to S Sapsed.

3 recordsLinked to original sources

PubMed1984

Effect of frequency of ventilation, positive end-expiratory pressure, PaO2 and PaCO2 on phrenic nerve activity. A study using a new valveless all-purpose ventilator.

The effect of changing the frequency of ventilation from 12 b.p.m. (NFV) to 80 b.p.m. (HFV) and applying PEEP on phrenic nerve activity (PNA) has been examined in anaesthetized dogs. HFV did not cause a greater decrease in PNA than the application of 0.5 kPa of PEEP. When the PEEP generated by HFV was removed by applying NEEP, PNA returned to control values. At a low normal PaCO2 (less than 5.3 kPa) and high PaO2 (greater than 30 kPa), HFV and PEEP (0.5 kPa) totally abolished PNA in some preparations. With a high normal PaCO2 (greater than 6.0 kPa) and high PaO2 (greater than 30 kPa), HFV and PEEP (0.5 kPa) decreased PNA by a mean of only 30%. When PaO2 was decreased to physiological values (less than 13.3 kPa), with a low normal PaCO2 (less than 5.3 kPa), the decrease in PNA by HFV and PEEP (0.5 kPa) was decreased to 25%. It was concluded that the frequency of ventilation per se has little or no effect on PNA in the range of frequencies studied.

Animals↗

PubMed1984

Effect of halothane on lymph flow.

The thoracic lymph duct was cannulated at the root of the neck in seven anaesthetized, artificially ventilated dogs. The mean control lymph flow was 1.51 ml kg-1 h-1 (SD +/- 0.35). The administration of 1% halothane caused a 59% decrease in mean lymph flow (to 0.62 ml kg-1 h-1) within 20 min, which returned to control values 30 min after the discontinuation of the administration of halothane.

Animals↗

PubMed1983

Dissociation between the effects of fentanyl and alfentanil on spontaneous and reflexly evoked cardiovascular responses in the dog.

Observations were made for 3 h in 10 anaesthetized dogs on the effects of alfentanil 500 micrograms kg-1 and fentanyl 100 micrograms kg-1 on resting heart rate (HR) and mean arterial pressure (MAP), and on the changes evoked in heart rate and mean arterial pressure (delta HR and delta MAP) by stimulation of a cutaneous nerve. Both drugs caused similar decreases in the resting HR (43-44%) and MAP (28-31%), which returned to baseline within 180 min following alfentanil but not fentanyl. Fentanyl decreased the somato-cardiovascular reflexes by 73% and 82% compared with a significantly smaller reduction of 54% and 55% (P less than 0.05) with alfentanil. Following alfentanil, delta MAP had recovered by 15 min and delta HR by 70 min compared with 70 and 90 min respectively for fentanyl. In conclusion, there was a dissociation between the maximum effect of alfentanil and fentanyl on the resting circulation and on the evoked cardiovascular reflexes. With both drugs a dissociation was observed between the durations of their effect on the resting cardiovascular system and on the evoked cardiovascular responses.

Alfentanil↗