Comparison of the Effect of Aminophylline, Magnesium Sulphate and Placebo in Prevention of Post Dural Puncture Headache in Parturient Undergoing Caesarean Section. A Double-blind Placebo Controlled Trial.

Delivery by cesarean section (CS) is becoming more frequent and is one of the most common operative procedures performed worldwide. In the USA a CS rate of 26% for all births is reported (1). According to the data by the Central Agency for Public Mobilisation and Statistics (CAPMAS) on the Health of the Egyptian Family (HEF) in late August, C-section births increased to 72 percent in 2021. (2) The postpartum period is marked by the presence of post- dural puncture headache (PDPH) which is an unpleasant emotional and sensory experience. Therefore, any form of intervention that leads to improvement in pain/headache relief can positively impact on patients satisfaction and prevent long hospital stay.

Spinal anesthesia remains the most common analgesic and anesthetic modality in women undergoing CS. It has a worldwide acceptance; it is very reliable and safe as a form of obstetrics anesthesia. Spinal anesthesia also has a fast onset of action and its use is efficacious (3). Although, spinal anesthesia has a generally acceptable complication rate, PDPH has remained its major drawback and unpleasant complication. This complication is especially noticeable few hours after the procedure (4). Although there is no clear pathophysiologic mechanism for PDPH, many treatment options used frequently in clinical practice to prevent or treat headache have been tried but currently there is still no approach that has been shown to offer complete prevention or treatment of the PDPH. Apart from the choice of insertion technique, optimal needle size and tip (5).

The incidence of PDPH has been estimated between 1% and 40% based on the gauge and orientation of needles, the operator proficiency, etc. The incidence rate of PDPH can also be associated with the type of lumbar puncture.(6) Despite that the therapeutic mechanism of aminophylline on PDPH is not fully described yet (7), some studies suggest that it might be responsible for blocking adenosine receptors, constricting blood vessels, and blocking pain transmission. It also seems that aminophylline can increase the intracellular levels of cyclic adenosine monophosphate. Furthermore, calcium uptake by the endoplasmic reticulum of endothelial cells might be suppressed with the administration of aminophylline; this process induces CSF secretion.

Although the precise mechanism is uncertain, magnesium sulfate's ability to function as a noncompetitive antagonist of (NMDA) receptors among peripheral tissues as well as the central nervous system explains the analgesic effects. It also affects how much intracellular calcium is present (8).