Avoiding failed spinal anesthesia: "Advik technique".

Sir,

Spinal anesthesia refers to a technique whereby local anesthetics are administered in the cerebrospinal fluid (CSF) in the subarachnoid space. Apart from avoiding the complications of general anesthesia, it is a simple, reliable, and quick procedure, but sometimes we come across partial or complete failure of spinal anesthesia, failure rates of 0.72%–16.0% have been reported.[12] After proper positioning, the top of iliac crests is identified. After injecting local anesthesia, spinal needle is inserted; an increased resistance is felt as the needle enters the ligamentum flavum, followed by a loss of resistance as the epidural space is entered. As the needle goes through the dura mater, a “pop” is felt; at this time, stylet should be removed to check for CSF flow that the needle tip is in the correct space.[3] Many times, we are unable to get a point at which CSF flows “freely” in the hub. At this point, after the initial appearance of CSF, rotating the needle clockwise or anticlockwise through 90° has been advocated to know the free flow of CSF, but that method also can fail at times, and some might have to repeat spinal anesthesia in the same patient or convert it into general anesthesia.[4] We deduced “Advik technique,” in which we use “1 ml syringe” which is inserted firmly into the hub of spinal needle to know exactly where the CSF flows best and that is the point where it is desirable to give the drug. We use 1 ml syringe as flow is best assessed in the narrowest syringe whereas in two or five ml syringe (usually used to give drug), flow can sometimes be difficult to assess. Suppose CSF does not flow freely in 1 ml syringe [Figure 1], we rotate it clockwise/anticlockwise by 90° each time until 360° and see the point at which it comes freely, and it is desirable to give drug at the point where CSF flows freely [Figure 2]. Hence, we keep the hub of spinal needle steady between the thumb and index finger of the left hand, remove 1 ml syringe, and attach the syringe containing spinal drug which is injected at the rate of 0.2 ml/s.

Figure 1

Advik technique – Note that cerebrospinal fluid flow is inadequate in 1 ml syringe although cerebrospinal fluid was present till the hub of spinal needle

Figure 2

Advik technique – one may see “free flow” of cerebrospinal fluid and it is desirable to give spinal drug

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