This paper compares and describes the tidal volume (Vt) used in mechanically ventilated dogs under a range of clinical conditions. Twenty-eight dogs requiring mechanical ventilation (MV) were classified into 3 groups: healthy dogs mechanically ventilated during surgery (group I, n = 10), dogs requiring MV due to extra-pulmonary reasons (group II, n = 7), and dogs that required MV due to pulmonary pathologies (group III, n = 11). The median Vt used in each group was 16 mL/kg (interquartile range [IQR], 15.14–21) for group I, 12.59 mL/kg (IQR, 9–14.25) for group II, and 12.59 mL/kg (IQR, 10.15–14.96) for group III. The Vt used was significantly lower in group III than in group I (p = 0.016). The thoraco-pulmonary compliance was significantly higher in group I than in groups II and III (p = 0.011 and p = 0.006, respectively). The median driving pressure was similar among the groups with a median of 9, 11, and 10 cmH2O in groups I, II, and III, respectively (p = 0.260). Critically-ill dogs requiring MV due to the primary pulmonary pathology received a significantly lower Vt than healthy dogs but with a range of values that were markedly higher than those recommended by human guidelines.
Animals ; Compliance ; Dogs ; Humans ; Pathology ; Respiration, Artificial ; Tidal Volume ; Ventilator-Induced Lung Injury

OBJECTIVES: The effectiveness of the active humidification systems (AHS) in patients already weaned from mechanical ventilation and with an artificial airway has not been very well described. The objective of this study was to evaluate the performance of an AHS in chronically tracheostomized and spontaneously breathing patients. METHODS: Measurements were quantified at three levels of temperature (Tdegrees) of the AHS: level I, low; level II, middle; and level III, high and at different flow levels (20 to 60 L/minute). Statistical analysis of repeated measurements was performed using analysis of variance and significance was set at a P<0.05. RESULTS: While the lowest temperature setting (level I) did not condition gas to the minimum recommended values for any of the flows that were used, the medium temperature setting (level II) only conditioned gas with flows of 20 and 30 L/minute. Finally, at the highest temperature setting (level III), every flow reached the minimum absolute humidity (AH) recommended of 30 mg/L. CONCLUSION: According to our results, to obtain appropiate relative humidity, AH and Tdegrees of gas one should have a device that maintains water Tdegrees at least at 53degrees C for flows between 20 and 30 L/m, or at Tdegrees of 61degrees C at any flow rate.
Humans ; Humidity ; Oxygen Inhalation Therapy ; Patient Care ; Respiration ; Respiration, Artificial ; Respiratory Therapy ; Tracheostomy ; Ventilator Weaning ; Water