Epidural Volume Extension Technique safe for high risk cardiac patients undergoing LSCS

In order to increase the height of the sensory block, epidural volume extension includes the infusion of normal saline into the epidural space immediately after an intrathecal injection. It provides an acceptable amount of anaesthesia and analgesia with minimum hemodynamic abnormalities and has a strong dose-sparing effect.

Obstetric patients with poor heart health undergoing caesarean section present special difficulties to the anaesthesiologist and may need regional anaesthesia. The selected anesthetic approach should produce minimum hemodynamic disturbances and provide the highest level of safety for both mother and fetus. Recent published case series demonstrated the efficacy of the Epidural Volume Extension Technique in cardiac patients at high risk undergoing elective lower segment caesarean surgery.

EVE method, since several publications have shown its advantages. It has a strong dose-sparing effect, offers an acceptable amount of anesthesia and analgesia with minimum haemodynamic abnormalities, and facilitates the recovery of motor function more rapidly. This method is dependable, with the added benefit of epidural anesthesia's ability to extend the period of anesthesia if necessary, and it may also be utilized for postoperative analgesia. [34] It offers benefits over general anesthesia because it avoids airway manipulation and the subsequent stress reaction, which has a negative impact on the patient's cardiovascular health.

EVE technique-

Under aseptic precautions, an 18 G epidural catheter was placed using an 18 G Tuohy needle into the L2-L3 intervertebral area. Using the loss of air resistance approach, the epidural space was detected, and a catheter was positioned such that it was 4 cm within the epidural space. Following this, a subarachnoid block was performed using 1.2 ml of 0.5% hyperbaric bupivacaine and 25 mg of fentanyl administered intrathecally into the L3-L4 intervertebral area using a 26 G Quincke Babcock spinal needle. A wedge was positioned under the right hip joint. The dermatomal level attained was evaluated 5 minutes after spinal anesthesia was administered. The epidural catheter was administered with 8 ml of normal saline 5 minutes after the subarachnoid block. The dermatomal level was measured again 3, 5, and 10 minutes after epidural saline delivery using the pinprick technique.

The primary drawback of the EVE approach is that it cannot be utilized for emergency LSCS because to its time-consuming nature and the possibility of unintentional catheter migration into the intravascular or intrathecal area, as well as a fast increase in spinal block. Before administering epidural saline, it is necessary to assess the extent of block.

To obtain the necessary degree of surgical anaesthetic in high-risk cardiac patients undergoing LSCS without generating unfavorable hemodynamic disturbances, the EVE approach may be employed safely.

Reference –

Y, Smitha,; CP, Naveen Kumar Epidural volume extension technique in high risk obstetric patients – Case series, Indian Journal of Anaesthesia: May 2022 - Volume 66 - Issue 5 - p 375-378

doi: 10.4103/ija.ija_1082_21