PURPOSE: This study was conducted to compare effects of open and closed suctioning methods on lung dynamics (dynamic compliance, tidal volume, and airway resistance) and hypoxemia (oxygen saturation and heart rate) in mechanically ventilated patients. METHODS: This study was a cross-over repeated design. Participants were 21 adult patients being treated with endotracheal intubation using a pressure-controlled ventilator below Fraction of Inspired Oxygen (FiO2) 60% and PEEP 8 cmH2O. Data were collected at baseline and 1, 2, 3, 4, 5, and 10 minutes after suctioning. Data were analyzed using two-factor ANOVA with repeated measures on time and suctioning type. RESULTS: Effects of the interaction between suction type and time were significant for oxygen saturation and heart rate but not significant for dynamic compliance, tidal volume, or airway resistance. Prior to performance of suctioning, tidal volume and oxygen saturation were significantly lower, but airway pressure and heart rate were significantly higher using the closed suctioning method as compared with the open suctioning method. CONCLUSION: For patients on ventilator therapy below FiO2 60% and PEEP 8cmH2O, open suctioning performed after delivery of 100% FiO2 using a mechanical ventilator may not have as much negative impact on lung dynamics and hypoxemia as closed suctioning.
APACHE ; Adult ; Aged ; Aged, 80 and over ; Anoxia/*physiopathology/therapy ; Female ; Heart Rate/physiology ; Humans ; Intubation, Intratracheal ; Lung/*physiopathology ; Male ; Middle Aged ; Oxygen Consumption/physiology ; Respiration, Artificial/*instrumentation ; Suction

Contribution of histamine H1- and H2-receptors to the effect of compound 48/80, a potent histamine releaser, upon asphyxiation and body temperature in mice was investigated in the present experiments. Compound 48/80 showed an apparent protective potency against hypoxia and significantly prolonged the latencies for convulsions and death in a dose-dependent manner. Compound 48/80 also decreased the body temperature, which was in relation with the antihypoxic effect. Both the H1-receptor antagonist, dimethindene, and the H2-receptor antagonist, ranitidine, attenuated the hypothermic effect of compound 48/80, indicating the involvement of central histamine through both the H1- and H2-receptors. Ranitidine had no effect on the protective effect of compound 48/80 against hypoxia-induced lethality, whereas dimethindene completely antagonized it. These results suggest that the protective effect of compound 48/80 against hypoxia is mediated through histamine H1-receptors and is not related to its ability to induce hypothermia.
Animal ; Anoxia/*drug therapy/physiopathology ; Body Temperature/*drug effects ; Convulsions/prevention & control ; Male ; Mice ; Mice, Inbred BALB C ; Receptors, Histamine H1/*physiology ; Receptors, Histamine H2/*physiology ; p-Methoxy-N-methylphenethylamine/*pharmacology