Critical care medicine
-
Critical care medicine · Sep 1984
Case ReportsHigh-frequency jet ventilation for differential lung ventilation.
High-frequency jet ventilation using a jet injector located at the right mainstem bronchus was superimposed on standard mechanical ventilation to ventilate the injured lung of a patient with unilateral massive atelectasis secondary to pulmonary hemorrhage. This technique of differential ventilation markedly improved arterial oxygenation in this patient and may prove to be a simpler modality of respiratory support in patients who have respiratory failure from unilateral lung disease.
-
Critical care medicine · Sep 1984
Comparative StudyClinical factors influencing the selection of high-frequency jet ventilators.
Criteria for selection of high-frequency ventilators, and in particular high-frequency jet ventilators are not significantly different from those for conventional mechanical ventilators. Selection is based upon the design principles and performance characteristics of the ventilator and successful clinical applications that establish clearly its safety and efficacy. The final choice is also influenced by the physical status of the patient, potential physiologic advantages and disadvantages, the necessary requirements of the clinical situation, and the capability of providing adequate oxygenation and ventilation.
-
Critical care medicine · Sep 1984
Comparative StudyHemodynamic effects of continuous positive-pressure ventilation and high-frequency jet ventilation with positive end-expiratory pressure in normal dogs.
The hemodynamic effects of high-frequency jet ventilation (HFJV) at 60, 120, 240, and 480 breath/min, and conventional ventilation at 15 breath/min were compared in 6 anesthetized, paralyzed dogs, at 0, 10, and 20 cm H2O of positive end-expiratory pressure (PEEP). On HFJV at the same inspired oxygen, PaCO2, and PEEP levels, hemodynamic function improved significantly. ⋯ When PEEP was applied, hemodynamic function improved even when mean airway pressure was maintained constant. The findings suggest that lung volume was smaller during HFJV, and/or that lung volume changes during each respiratory cycle contributed to differences in venous return and ventricular function.
-
As the treatment of respiratory failure becomes more sophisticated and technical, the critical care nurse is faced with many challenges. High-frequency ventilation is a modality of respiratory support employing principles different from those of conventional ventilation. For these reasons, the nurse must be familiar with the indications for its use and the practical management of the ventilated patient. This paper addresses those aspects of respiratory support which have the greatest impact on nursing care.
-
Critical care medicine · Sep 1984
Comparative StudyGas exchange during conventional and high-frequency pulse ventilation in the surfactant-deficient lung: influence of positive end-expiratory pressure.
High-frequency pulse ventilation (HFPV) was compared to conventional ventilation (CV) in a model of severe respiratory failure induced by serial lung lavages with warm saline in 8 mongrel dogs. Before the lavage, during HFPV at 4 Hz with a pulse volume (PV) of 125 ml, mean PaO2 was 107 torr and mean PaCO2 was 34 torr. After the last lavage, during CV at an inspired oxygen fraction FIO2 of 1.0 and a tidal volume (VT) of 535 ml, the PaO2 averaged 60 torr and PaCO2 was 45 torr. ⋯ The corresponding mean airway pressure (Paw) was about 20 cm H2O. Thus, application of PEEP during HFPV at low PV did not improve PaO2 even when measured Paw approximated 20 cm H2O. This suggests that HFPV with high PV is more effective than either CV with PEEP, or HFPV with low PV and PEEP.