Intravenous Dexamethasone Effectiveness in Post Caesarean Section Analgesia

A a prospective randomized double-blinded controlled study including 84 parturient women, conducted at the Anesthesia and Surgical Intensive Care Department of Mongi Slim University Hospital, La Marsa Tunisia. It was performed after obtaining the approval of the Research Ethical Committee of our hospital (Ethical Committee No. 02/2020). Eligible patients were informed of the study design and their written consent was obtained.

Patients:

Inclusion criteria were Age >= 18 years, American Society of Anesthesiologists (ASA) statue II-III, a pregnancy term >= 37 weeks, elective cesarean section and Pfannenstiel incision.

Exclusion criteria were severe hypertension / preeclampsia, poorly balanced diabetes mellitus, allergy to one of the study drugs, patients with chronic pain or long-term use of opioids, and patients on long-term corticosteroid therapy.

Study protocol During the preoperative visit, all patients have had a full clinical examination and further examinations have been requested in accordance with the most recent guidelines. The informed written consent was obtained at this moment. Postoperative pain predisposition (the prediction of pain and the anxiety level) was assessed using a questionnaire.

Randomization and allocation were performed using a computer-generated sequence of randomization numbers and the envelope technique; patients were randomized into two groups:

• Dexamethasone Group (DG): receiving 8mg (2ml) of intravenous (IV) Dexamethasone after spinal anesthesia
• Placebo Group (PG): receiving 2 ml of IV Saline solution after spinal anesthesia.

Patients enrolled and the anesthesiologists in charge were both blinded to the study group. In the operating room, all patients had standard non-invasive monitoring including an electrocardiogram, non invasive blood pressure and pulse oxymetry. An 18-gauge intravenous cannula was inserted into the nondominant arm or hand and 500 ml of a saline solution (0.9 %) was infused. The prevention of postoperative nausea and vomiting (PONV) was assured to all patients by administering 4 mg of IV Ondansetron. Spinal anesthesia was performed according to our department protocol: L4-L5 or L3-L4 intervertebral space puncture using a 25 gauges needle, with injection of 0.5% hyperbaric Bupivacaine mixture (dose depending on patient height) associated with 2.5 ug Sufentanil and 100 ug Morphine. Before surgical incision, patients received either an intravenous injection of 8 mg (2 ml) Dexamethasone (DG) or 2 ml of a Saline solution (PG). During the procedure, we noted hemodynamic constants, surgical related data and APGAR score for the newborns. At the end, patients were transferred initially to the post-operative monitoring room, and then to the Gynecology Obstetric department after assessing the hemodynamic constants, the absence of bleeding, the good tone of the uterine globe and the disappearance of the motor block.

The analgesic protocol was standardized: systemic analgesia during the first 24 hours was assured by a postoperative regimen combining intravenous Paracetamol 1g*4/day and Nefopam 20 mg*3/day . The rescue analgesic is IV Tramadol 100 mg administered at the request of the patient and if the analog visual scale (AVS) was greater than 3/10, with a maximum dose of 100 mg * 3/day. Static and dynamic pain was assessed at 2 hours, 6 hours, 12 hours and 24 hours postoperatively using the analog visual scale ( values raging from 0 for no pain to 10 for a maximum pain). Time to first request and cumulative dose of Tramadol were recorded. We also noted the length of the sensory and the motor blocks, postoperative nausea and vomiting and patient satisfaction. Hospital discharge was allowed after 24 hours if there were no complications.

Follow-up at 3 months:

Patients were contacted after 3 months to complete a telephonic survey about chronic pain and postpartum depression . We excluded patients who had other surgery within 3 months of the cesarean section or any other cause of chronic pain.

Outcomes:

Our main outcome was the use of Tramadol within the first 24 hours. Secondary endpoints were static and dynamic analog visual scale at 2 hours, 6 hours,12 hours, and 24 hours, time to first request of Tramadol, cumulative Tramadol dose within the first 24 hours, length of sensory and motor block, incidence of post-operative nausea and vomiting (PONV), chronic pain at 3 months, incidence of postpartum depression, and patient satisfaction.