[Hemodynamic side effects of high-frequency jet ventilation as a function of lung volume. Impedance spirometric studies]. / Hämodynamische Nebenwirkungen der High-Frequency Jet Ventilation (HFJV) als Funktion des Lungenvolumens. Impedanzspirometrische Untersuchungen.
Anaesthesist
; 35(1): 24-9, 1986 Jan.
Article
em De
| MEDLINE
| ID: mdl-3516001
ABSTRACT
In five patients with acute respiratory insufficiency the changes in tracheal pressure (P), lung volume (V) and transthoracic electric impedance TEI (Z) were measured during delayed expiration all over the inspiratory capacity (IC) from TLC to FRC. The quasi-static V/Z- and Z/P-curves were two-dimensionally displayed, and the Z/P-curve was volume-calibrated on the Y-axis (Z) using the linear V/Z-relationship. During high-frequency jet ventilation (HFJV, 200/min), the Z- and P-excursions were displayed on the "frozen" Z/P-curve as flat discs. By well-aimed increase in driving pressure and I/E-ratio the unknown FRC was enhanced in 4 stages (I-IV) by 0.33 IC, 0.5 IC, 0.66 IC and 0.75 IC, to measure haemodynamic reactions 10 minutes later (Swan-Ganz catheter). The pulmonary vascular resistance remained unchanged between stage I and II. It changed moderately in stage III (+14%) and was found to be markedly increased in stage IV (+45%). The increase in PVR was well parabolically correlated (r = 0.88) to the fraction of IC by which FRC was expanded. In a previous study a very similar function could be documented by us for the end-inspiratory lung volume during conventional PEEP ventilation. Concomitant to the increase in PVR the CI fell linearilly (r = 0.95). We conclude from our results:
1. TEI may be of value in monitoring HFJV. It offers the possibility to measure the increase in lung volume ("PEEP effect") and to titrate it deliberately within the usable volume range IC. 2.(ABSTRACT TRUNCATED AT 250 WORDS)
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Base de dados:
MEDLINE
Assunto principal:
Insuficiência Respiratória
/
Respiração com Pressão Positiva
/
Medidas de Volume Pulmonar
Limite:
Humans
Idioma:
De
Revista:
Anaesthesist
Ano de publicação:
1986
Tipo de documento:
Article