From the Guidelines
The most common complication of epidural analgesia is hypotension (option A). When local anesthetics are administered into the epidural space, they block sympathetic nerve fibers that maintain vascular tone, leading to vasodilation and decreased peripheral vascular resistance. This vasodilation causes blood pressure to drop, sometimes significantly. The incidence of hypotension varies but can occur in 10-80% of patients receiving epidural analgesia, depending on factors such as the dose and type of local anesthetic used, patient positioning, volume status, and concurrent medications.
Key Points to Consider
- Hypotension typically develops within 20-30 minutes after administration and can be managed by intravenous fluid administration, positioning the patient (often in left lateral position for pregnant women), and occasionally vasopressors like ephedrine or phenylephrine if severe 1.
- According to the study by 1, after ensuring the patient is normovolemic, hypotensive patients receiving epidural analgesia should be treated with vasopressors rather than indiscriminate fluid boluses.
- While nausea, respiratory depression, and deep vein thrombosis can occur with epidural analgesia, they are less common than hypotension, which remains the predominant side effect that clinicians must monitor for and manage.
Management of Hypotension
- The aim should be to remove the epidural 48-72 h postoperatively by the time the patient has had a bowel movement, as stated in the study by 1.
- Using low-dose concentrations of local anaesthetic combined with a short-acting opiate appears to offer the best combination of analgesia while minimising the risk of motor block and hypotension due to sympathetic blockade 1.
- Several meta-analyses have shown improved outcomes with TEA compared with opioid-based analgesia, including pain, complications, PONV and insulin resistance 1.
From the FDA Drug Label
Ephedrine may decrease the efficacy of epidural blockade by hastening the regression of sensory analgesia. The most common complication of epidural analgesia is not directly stated in the provided drug label. However, hypotension is a known complication of epidural analgesia, and ephedrine is indicated for the treatment of clinically important hypotension occurring in the setting of anesthesia 2. Therefore, it can be inferred that hypotension is a common complication of epidural analgesia.
From the Research
Complications of Epidural Analgesia
The most common complication of epidural analgesia is hypotension, which occurs due to sympathetic nerve blockade. This can lead to decreased blood pressure, potentially causing myocardial and cerebral ischemia, as well as neonatal acidaemia in obstetric practice 3.
Factors Associated with Hypotension
Several factors can increase the probability of hypotension after epidural blockade, including:
- Administration of epidural fentanyl 4
- Body weight and spread of epidural analgesia 4
- Use of certain local anesthetics, such as carbonated lidocaine 4
Management of Hypotension
Hypotension can be managed using vasopressor agents, such as ephedrine, which is often used as a first-line agent in obstetric anesthesia 3. Other agents, such as methoxamine or phenylephrine, may be considered in non-obstetric cases 3.
Other Complications
While hypotension is the most common complication, other potential risks of epidural anesthesia include:
- Infection
- Hematoma
- Intravascular or subdural injections of medication
- Direct nerve trauma
- Air embolism
- Entry into a disc space
- Urinary retention
- Radiation exposure
- Hypersensitivity reactions 5
Answer to the Question
Based on the available evidence, the correct answer is: A. Hypotension
This is supported by studies that consistently show hypotension as a common complication of epidural analgesia 3, 4, 6.