Surgeon Administered Regional Anaesthetic Blocks For Hand Surgery In Resource Limited Areas
Kigera JWM1 MbChB, MMed (Orth), Schenck R2, MD, FACS Affi liation: 1-Department of Orthopaedics, Makerere University, Kampala, Uganda /Orthopaedic Surgeon, Orthopaedic Rehabilitation Unit, PCEA Kikuyu Hospital, Kikuyu Kenya 2- Department of Plastic Surgery, Rush University, Chicago, Illinois, USA Correspondence to Dr. James W M Kigera, firstname.lastname@example.org
Introduction: The axillary block was described more than sixty years ago and has since been used in a variety of scenarios. Recently it has been described with the use of ultrasound and nerve stimulators. These facilities are not available in resource limited areas.
Methods: We describe the simple, but effective, perivascular axillary block technique we have used for regional anaesthetic blocks for hand surgery. We also undertook a prospective cohort study of all patients undergoing hand surgery under this regional block technique at Mu-lago Hospital. We abstracted the drug and dosage used, delay in onset of action and duration of action data for each patient. We excluded patients younger than 12 years. All cases with attempted blocks were included.
Results: The success rate of the procedure was 77.8%. The mean delay in onset of action was 20 minutes with an average duration of action of 99 minutes. The commonest drug used was Mepivacaine with a mean dosage of 333.3mg.
Discussion and conclusion: This technique is reliable with a high success rate. It has few complications and can be used in areas without ultrasound or nerve stimulators.
The axillary approach to anaesthetising the brachial plexus has been used for over half a century(1). Since the perivascular approach was described, it has gained popularity and is used for operative anaesthesia, emer-gency room manipulations and for pain free upper limb physiotherapy(2-4). Recent techniques have been devel-oped using ultrasound and nerve stimulators to increase the accuracy of the technique(5, 6). These facilities are not widely available in resource limited settings. We de-scribe a perivascular technique that can be used in re-source limited areas. This will acquaint surgeons who have previously used only general anaesthesia for hand surgery with a technique that has served well for many years even in places without ultrasound and nerve stim-ulators. We aim to describe the technique and showcase its use in a number of hand surgical cases.
The method of achieving anaesthesia is described. The patient lies supine with the arm abducted and externally rotated to expose the axilla. The axillary artery is palpat-ed in the axilla and marked with a marker pen. The skin of the axillary area is prepared with alcohol mixed with iodine. The surgeon dons sterile gloves and palpates for the axillary artery guided by the mark previously made. A gauge 25 needle is introduced adjacent to the pulsa-tions of the artery. Vascular penetration is indicated by blood flowing back through the needle. Should this happen, the needle is repositioned as to have the needle adjacent to the artery in the axillary sheath. This will be evidenced by a pulsatile needle without any blood flow-ing back. The chosen local anaesthetic is then instilled through the needle. The surgeon aspirates every 5mls to ensure the needle is not in a vessel. Correct needle placement in the axillary sheath is confirmed by a char-acteristic resistance to the instillation of the local anaes-thetic and by back flow of local anaesthetic through the needle when the syringe is removed. A tourniquet may be used after the first 20mls have been instilled to ensure proximal flow of the anaesthetic in the sheath ensuring a more profound block. Take of the block is assessed by evaluating the motor and sensory functions of the nerves of the upper limb.
We reviewed details of nine patients who underwent hand surgery under the regional block described at the Mulago Hospital. We excluded patients under the age of 12 years. The regional block was administered by the surgeon and intraoperative monitoring by an anaesthetic officer. The delay in onset of anaesthesia was determined
as the time from instillation of anaesthetic drug to com-plete anaesthesia of the surgical site. The duration of surgery was measured from skin incision to skin closure and dressing. In cases of failure of the regional block, the patient was put under general anaesthesia by the anaesthetic officer. An axillary block was determined as successful if the entire surgery was conducted under the block without need for supplementation or conversion to either general surgery or the tumescent technique. Pa-tients in whom there was no take were operated either under general anaesthesia or the tumescent technique.
The data on age, procedure, delay and duration of sur-gery was inputted into a computer and analysis conduct-ed using Microsoft Excel software.
Six of the nine patients undergoing ten procedures were males (Table 1). The median age of the patients was 25years (Range 12-27 years). The procedures included tendon repairs, carpectomies and fixation for hand frac-tures (table 1). The block was successful in 7 patients giv-ing a success rate of 77.8%. In all cases the drug used was Mepivacaine 1% with an average dosage and volume of 333.3mg and 33.3millilitres respectively. The two cases in this study that failed were due to failure to palpate the artery in one and the use of a wide needle in the other. The average delay in onset was 20 minutes (Range 14-
while the average duration of surgery was 99 min-utes (Range 55-180)
The reported rates of success with the perivascular ax-illary block technique have varied from centre to cen-tre, although generally high (7). A study in Germany reported a success rate of 72% without the use of ul-trasound while in Croatia they were able to report suc-cessful anaesthesia in 85% of patients(8, 9) Our success rate closely matches this but we are confident that the success rate will improve with subsequent patients. Suc-cess rates as high as 98% have been described and are achievable(10).
The technique described has fewer complications than other techniques used for upper limb surgery. Of note is the risk of pneumothorax which does not occur with this technique but has been reported with the supracla-vicular approach (7). It seems that with the use of ul-trasound and nerve stimulators, this risk is somewhat
reduced(11). These facilities are however not available in resource poor settings. It is hence safer to use the peri-vascular technique.
There is a risk of intravascular injection with this peri-vascular technique and this has been touted as one of the advantages for the us