To evaluate a safety protocol to reduce Epidural Anaesthesia related complications in patients posted for knee replacement surgeries: A Randomized Trial

Epidural anaesthesia and analgesia has emerged as the gold standard regional anaesthetic technique for lower limb surgeries, particularly joint replacement procedures and major abdominal surgeries. With recent advances in anaesthetic practice, epidural anaesthesia has become a key modality for perioperative analgesia, offering superior pain control, reduced opioid requirements, enhanced patient tolerance, early mobilization, and cost-effectiveness compared to conventional approaches.

However, epidural catheter placement is not without complications. The most frequently encountered complications include hypotension, paresthesias, inadvertent vascular or subarachnoid cannulation, catheter insertion failure, post-dural puncture

headaches, non-uniform drug distribution, epidural hematomas, and vasovagal reactions. Among these, vasovagal attacks represent a particularly concerning complication that can manifest as sudden cardiovascular collapse with profound bradycardia and hypotension.

Vasovagal reactions during epidural procedures occur with an incidence ranging from 0-4% in general populations, with higher rates of 3.5% reported for epidural steroid injections specifically (Malave & Vrooman, 2022). These episodes can present with a

spectrum of symptoms including diaphoresis, nausea, vomiting, dizziness, palpitations, visual disturbances, and in severe cases, sudden cardiac arrest.

Three types of vasovagal responses have been described in the literature: a cardio inhibitory form (HR < 40 bpm), vasodepressor form (SBP < 80 mmHg or decrease by >30% without significant HR reduction), or mixed form (HR < 40 bpm and SBP < 80 mmHg or decrease by >30%) .

The literature shows that preloading of crystalloids prevents hypotension induced by spinal /epidural anesthesia,may help to prevent vasovagal reaction.

There are studies that tested that pre distending the epidural space with saline 5ml before epidural catheter  insertion can help to prevent intravascular placement by pushing blood vessels and other anatomical structures away from the catheter path, potentially ease in insertion of epidural catheter and reducing its intravascular placement.

The drug glycopyrrolate a quaternary ammonium compound, another antimuscarinic drug, has similar pharmacological effect like atropine but more prolonged action with minimal CNS side effects (as it does not crosses the Blood Brain Barrier).