Maternal Haemodynamic Changes during Caesarean Section: A Comparison of Epidural and General Anaesthesia

Abstract

Haemodynamic measurements were performed on 20 healthy women before and during elective caesarean section under epidural (10 women) or general anaesthesia (10 women). The influence of the two anaesthetic techniques on the haemodynamic changes associated with operative delivery was compared. The following haemodynamic variables were studied: cardiac output (CO), stroke volume (SV) determined non-invasively with impedance cardiography, heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP), pulse pressure, mean arterial pressure (MAP) and total peripheral vascular resistance (TPR). During epidural anaesthesia, SV was largely unchanged before delivery but increased (P less than 0.05) following delivery. However, CO increased (P less than 0.05) prior to delivery due to an increase (P less than 0.01) in HR. A further increase (P less than 0.05) in CO was recorded following delivery. SBP, DBP, MAP and TPR decreased (P less than 0.01) during epidural anaesthesia. In the patients undergoing general anaesthesia, SV decreased (P less than 0.05) prior to delivery. However, CO remained largely unchanged due to an increase (P less than 0.01) in HR. Following delivery, CO (P less than 0.05) and SV (P less than 0.01) increased whereas HR decreased (P less than 0.01). SBP, DBP and MAP increased (P less than 0.01) prior to delivery, returning to the same level as prior to induction of anaesthesia following delivery. TPR was largely unchanged prior to delivery but decreased (P less than 0.01) following delivery.

Changes in cardiac output during epidural anaesthesia for Caesarean section

“…The elevation in central venous pressure after infusion of 2 litres of crystalloid solution and establishment of epidural block lends support to this. 3 A decrease in systolic arterial blood pressure of greater than 20% occurred in 25% of subjects after epidural blockade. Previous studies, which have used a similar definition, have reported hypotension in 2 5 4 5 % of subjectsZ'i5'16 Lewis et d 3 suggested that the incidence of hypotension was related to the volume of preload administered.…”

The Management of a Caesarean Section in a Patient with an Intracranial Arteriovenous Malformation

“…8 The preference for epidural anaesthesia in this case was influenced by the desire to avoid the hypertensive response to tracheal intubation and the narcotics necessary to modify this. 8 The preference for epidural anaesthesia in this case was influenced by the desire to avoid the hypertensive response to tracheal intubation and the narcotics necessary to modify this.…”

The management of Caesarean section in a patient with an intracranial arteriovenous malformation

“…8 The preference for epidural anaesthesia in this case was influenced by the desire to avoid the hypertensive response to tracheal intubation and the narcotics necessary to modify this. Epidural anaesthesia, utilising small increments of local anaesthetic to give the gradual onset of sympathetic blockade accompanied by adequate circulatory preload, and the use of small doses of ephedrine as required provides the necessary cardiovascular stability.…”