Difference Between Spinal and Epidural Anesthesia

Anesthesia is a way of controlling pain during a surgery by using some special medicines called ‘anesthetics’. It supports mainly to control breathing, blood pressure, blood flow, and heart rate and rhythm during surgeries. Anesthetics are mainly used to relax the body, block the pain, and make ourselves unconscious and drowsy. Anesthesia can be classified into two main techniques; general anesthesia and regional anesthesia. Anesthesiologists use the term ‘regional anesthesia’ to describe both epidural and spinal anesthesia, as these techniques are confined to a particular region of the body. The regional anesthesia techniques can be used as complete anesthetics for a wide variety of surgical procedures on the lower abdomen or lower extremities. However, when it comes to surgeries of the lower abdomen, general techniques may also require supplementing the regional techniques.

What is Spinal Anesthesia?

The spinal anesthesia is a single-shot technique that mainly involves injecting a set of local anesthetics into the subarachnoid space. Normally, for spinal anesthesia, low volumes of local anesthetic drugs are used. This technique uses a fine hollow needle with a diameter only slightly larger than horsehair. Less diameter of the needle makes penetration process easier. Once the anesthetics are deposited into the spinal fluid, there is a fixed amount of hours (around 2 to 3 hours) that it will work. The advantages of spinal anesthesia over epidural anesthesia include its low cost, low usage of drugs, reliability, lack of need for catheter care or pumps, and its simplicity.

What is Epidural Anesthesia?

The epidural anesthesia techniques can be carried out either as a single shot or usually as a continuous technique that allows infusion of anesthetics into the epidural space. Here, either local or narcotic medications can be used depending on the surgery type or surgical procedures. Normally, the duration of anesthesia is around 3 to 5 hours, but there is no fixed time as the spinal anesthesia.

What is the difference between Spinal and Epidural Anesthesia?

• Spinal anesthesia is simple, rapid and reliable, whereas epidural anesthesia is more complex.

• Epidural anesthesia has longer onset of time than spinal anesthesia. Normally the onset of spinal epidural is 2 to 5 minutes, while that of epidural anesthesia is 20 to 30 minutes.

• Spinal technique needs around 2.5ml to 4ml drug volume, while epidural technique needs around 20ml to 30ml. In general, spinal anesthesia needs less anesthetic amount than epidural anesthesia.

• Epidural technique provides anesthesia for longer duration (3- 5 hours) than spinal anesthesia (2 – 3 hours).

• Spinal anesthesia has a higher incidence of hypotension, whereas epidural anesthesia has lesser incidence of hypotension.

• For spinal anesthesia, a specialized fine, hollow needle (a diameter only slightly larger than horsehair) is required. In contrast, for epidural anesthesia, a larger hollow needle (larger than an adult intravenous needle) is required.

• During spinal anesthesia, local anesthetics are injected into the subarachnoid space. In contrast, during epidural anesthesia, local anesthetics are inserted into the epidural space.

• Spinal anesthesia is a single-shot technique, whereas epidural anesthesia can be either single shot or continuous technique.