Spinal anaesthesia outdoes epidural anaesthesia in reducing CS-associated pain
The administration of spinal anaesthesia (SA) rather than epidural surgical anaesthesia (ESA) after epidural labour analgesia (ELA) resulted in better pain reduction during intrapartum Caesarean section (CS), according to a Korean study.
“[SA] can provide a denser sensory block than ESA … [which] may be more effective at suppressing intraoperative pain than ESA during intrapartum CS,” said the researchers.
A total of 350 patients were randomized to receive ESA (n=169, 17 mL of 2 percent lidocaine mixed with 100 μg fentanyl, 1:200,000 epinephrine, and 2 mEq bicarbonate) or SA (n=168, 10 mg of 0.5 percent hyperbaric bupivacaine and 15 μg fentanyl). Of these, 163 ESA and 160 SA recipients were included in the final evaluation.
Participants in both arms were administered continuous epidural infusions for labour pain (10 mL/h, 0.1 percent ropivacaine with 1.5 μg/mL of fentanyl). [Korean J Anesthesiol 2017;70:412-419]
Patients given SA after ELA were more likely to achieve pain-free surgery compared with those who received ESA after ELA (failure rate, 2.5 percent vs 15.3 percent; p<0.001).
The rate of analgesic supplementation was also significantly lower in the SA vs ESA arm (1.3 percent vs. 12.9 percent; p<0.001), with 21 patients in the ESA arm eventually receiving 100 μg fentanyl due to poor anaesthesia quality.
Compared with the ESA arm, patients in the SA arm had a significantly shorter interval between injection and skin incision (12 vs 18 min) and time for sensory block to reach the T5 dermatome (coldness [6 vs 12 min] and pinprick [7 vs 13.5 min]; p<0.001 for all).
Despite the shorter interval between drug administration and surgery initiation in the SA arm, the findings are limited to patients with urgency classification category 3, ie, those who require early delivery but without maternal or foetal compromise, noted the researchers.
It is important to include patients in higher urgency categories in further studies, they said. “[In this case], the decision to delivery interval could be more critical for maternal and neonatal outcomes … [E]ffective anaesthesia without delaying the decision to delivery interval is recommended.”
The increased anaesthetic demand in patients undergoing intrapartum CS could be attributed to increased anxiety levels which, in turn, could worsen intraoperative pain. [Anesth Prog 2004;51:46-51; Anesth Analg 1999;89:1346-51] “[T]issue injury and pain experienced as labour progresses could [also] decrease the threshold of pain perception,” said the researchers, hence the need for a denser sensory block that may be achieved through SA.