Articles: intubation.
-
Comparative Study
The oesophageal obturator airway: A study of cadaver lund ventilation through obturator airways and tracheal tubes.
Ventilation of cadaver lungs using a Pneupac ventilator through oesophageal obturator airways (EOA), oesophageal gastric tube airways (EGTA), and tracheal tubes was studied in 23 subjects. The mean tidal volume obtained through tracheal tubes was 381 ml compared with a mean tidal volume of 156 ml obtained through the EOA and a mean tidal volume of 237 ml through the EGTA. ⋯ This represents adequate ventilation in these very stiff lungs. Subject to modification of the device and prevention of leakage the oesophageal gastric tube airway is a useful alternative to tracheal intubation in certain adverse conditions.
-
End-expiratory pressure is often used to improve arterial oxygenation and prevent atelectasis in intubated spontaneously breathing patients. To compare the effect of extubation from low levels of expiratory positive airway pressure (EPAP) of extubation from ambient airway pressure, functional residual capacity (FRC) and arterial blood oxygen tension (Pao2) were measured in 12 spontaneously breathing patients during three conditions in the peri-extubation period: 1) intubated at 5 cm H2O EPAP (EPAP 5); 2) intubated at ambient airway pressure (EPAP 0); and 3) within one hour after extubation. ⋯ The magnitude of increase in FRC and Pao2 on extubation from EPAP 0 varied inversely with the patient's lung thorax compliance (r = -0.84, P less than 0.005). It was concluded that a period of EPAP 0 is not necessary in the weaning period, and that it may be deleterious in patients with compromised lung thorax mechanics.
-
The general relationships between the pressure inside an endotracheal tube cuff, the pressure exerted by that cuff on the tracheal wall and the airway pressure have been re-examined in a model system. In relatively recent literature, the tracheal wall pressure at a given cuff volume has been calculated as the difference between intracuff pressures at that volume when the cuff is inflated inside the trachea and when it is inflated whilst suspended freely in air. This has been used as a general relationship, as an alternative to direct measurement in real and model tracheas. In this study, the directly measured pressure was not generally equal to the pressure as calculated above.