The influence of regional blocks on hypoxic pulmonary vasoconstriction during anaesthesia for thoracic surgery

L. Băilă¹ , Bencze R.² , M. Chiorean³
1. Catedra Terapie Intensivă – Urgenţe, UMF Tg.Mureş
2. Secţia ATI, Spitalul Municipal Odorheiu Secuiesc
3. Catedra Terapie Intensivă – Urgenţe, UMF Tg.Mureş

Abstract

In this study, the influence of sympaticolysis induced by high epidural anesthesia and thoracic paravertebral block on pulmonary shunt during one-lung ventilation was investigated. Two groups of patients (E - epidural and P – paravertebral) were scheduled for thoracothomy under one-lung ventilation (OLV). The patients were both studies and controls, the same patient being anesthetized in two phases – general (TIVA) and then combined (TIVA + regional). Arterial blood gas samples were analysed in the final phases of anesthesia. We observed a predictable reduction of PaO2 after the onset of one-lung ventilation, but in both groups, the PaO2 values after the onset of regional anesthesia were similar, statistically non-significant (OLV_TIVA - 132.15 mmHg vs OLV_TIVAE - 122.02mmHg, respective OLV_TIVA - 133.47 mmHg vs OLV_TIVAP - 130,52 mmHg). We conclude that high thoracic epidural anesthesia and thoracic paravertebral block has no influence on PaO2 during OLV, and is very possible that the sympathetic block has no effect on hypoxic pulmonary vasoconstriction, during relative hemodinamic stability.

Key words: one-lung ventilation, thoracic epidural anesthesia, paravertebral block, pulmonary shunt, hypoxic pulmonary vasoconstriction

STUDII CLINICE
Influenţa unor blocuri regionale asupra vasoconstricţiei pulmonare hipoxice în anestezia pentru chirurgia toracică

Jurnalul Român de Anestezie Terapie intensivă 2004 Vol.11 Nr.2, 85-91