The Cardiorespiratory Effects of Thoracic Epidural Anaesthesia

Abstract

The cardio-respiratory effects of a thoracic epidural anaesthetic as is given for pain relief following upper abdominal surgery were examined in thirteen surgical patients studied in the immediate pre-operative period.following an overnight fast and without premedication.The focus of interest was on its effects on FRC and on gas exchange (measured as A-aD02 and OS/OT%), waich have not been previously reported. AlI subjects were given 10 ml/Kg glucose in saline I.V. during the pre-epidural periode Lidocaine 1.5% was used in aIl cases, plain lidocaine for the first eight and lidocaine with epinephrine 1/200,.000 in the other five subjects. This agent was given to achieve a sensory block to both pin-prick and ice up to T4. Neither FRC nor gas exchange showed any consistent changes following the epidural anaesthetic. These findings are in keeping with what was anticipated from a consideration of the basic physiology and pharmacology concerned and with a review of the pertinent literature. following an overnight fast and without premedication.The focus of interest was on its effects on FRC and on gas exChange (measured as A-aD02 and OS/OT%), which have not been previously reported. All subjects were given 10 ml/Kg glucose in saline I.V. during the ~re-epidural periode Lidocaine 1.5%was used in all cases, plain lidocaine for the first eight and lidocaine with epinephrine 1/200~OOO in the other five subjects. This agent was given to achieve a sensory block to both pin-prick and ice up to T4. Neither FRC nor gas exchange showed any consistent Changes following the epidural anaesthetic. These findings are in keeping with what was anticipated from a consideration of the basic physiology and pharmacology concerned and with a rev~ew of the pertinentliterature.w. MELEIKA~WAHBA' M.Sc. Exp. Red.

Ventilation‐Perfusion Relationships During Epidural Analgesia

“…The reason for this difference is not known. Studies of functional residual capacity during epidural block have not shown any significant changes from that of the control state (6,18). In our study, as in the study by McCarthy (6), no significant changes were seen in F R C or in closing capacity.…”

Effect of obesity and thoracic epidural analgesia on perioperative spirometry

“…20 In contrast with the latter results, and in line with our study, others have not found that EDA has any influence on spirometry or lung dynamics. [21][22][23][24] During forced expiration (e.g. spirometry), the principal expiratory muscles are those of the abdominal wall and, to a lesser extent, the internal intercostal muscles.…”

The effect of caudal block on functional residual capacity and ventilation homogeneity in healthy children*

“…This is the first study in children examining the impact of a neuroaxial blockade on FRC. Only studies performed in adults are available to compare our findings on the effect of epidural anaesthesia on FRC [17][18][19][20][21]. While some of the adult studies found no effect of lumbar or thoracic epidural anaesthesia [18][19][20], others showed a decrease [21] or an increase in FRC [17].…”