The Use of Regional Anesthesia by Anesthesiologists in Nigeria

Abstract

There is growing interest in the use of regional anesthesia worldwide. With this survey, we determined the use of regional techniques among anesthesiologists in Nigeria using a cross-sectional study design. A self-administered questionnaire was mailed to a randomly generated list of anesthesiologists in Nigeria. From 196 questionnaires, 140 anesthesiologists (71.4%) responded. Regular use of spinal, epidural, and peripheral nerve blocks was 92.9%, 15%, and 2.9%, respectively. A high percentage of respondents (47.1%) had never performed a nerve block and only 31.4% had used a nerve stimulator technique. Limited exposure to equipment and techniques accounted for their lack of use.

In Brief

Published ahead of print November 6, 2009

Regional anesthesia, particularly peripheral nerve blocks, has become an important anesthetic tool for pain and surgical management during the past century.¹ The use of regional techniques provides site-specific, complete pain relief sufficient for bone and soft tissue operations while avoiding general anesthesia and its attendant risks.² Peripheral blockade facilitates early mobilization and rehabilitation. Placement of a peripheral catheter ensures prolonged analgesia while reducing the need for systemic drugs with their side effects.³ Despite these advantages, the techniques have not been embraced as alternatives to general anesthesia in Nigerian hospitals. In this study, we documented the current practice of regional anesthesia, with a focus on peripheral techniques, among anesthesiologists in Nigeria.

METHODS

We used a cross-sectional study design. The study was based on a completed questionnaire regarding the practice of regional techniques by anesthesiologists in Nigeria. Participants were members of the Nigerian Society of Anesthesiologists with 400 members working in secondary and tertiary hospitals across the country. We estimated the required sample size using the “Stat cal” feature on a population survey⁴ with the following inputs: population size of 400, expected prevalence of use 50%, and a precision of 5%. The prevalence of 50% gave the optimum sample size required because we do not have prior information on the prevalence of use in our environment. The sample size obtained assuming a type 1 (α) error of 0.05 was 196. Using a table of random figures, a list of 196 anesthesiologists was generated from the Nigerian Society of Anesthesiologists register. A self-administered questionnaire was then mailed to each member in the randomly generated list and followed up 4 wk later with another mailing to nonrespondents. The questionnaire focused on techniques, frequency of use, barrier to use, exposure to peripheral nerve block techniques and equipment during residency training, and perceived roles of peripheral nerve block in their future practice. Responses were analyzed using the Statistical Package for the Social Sciences (SPSS, Chicago, IL) version 11.0. Data analysis included frequencies, percentages, and χ² statistical test. The chart was generated using Microsoft Excel. A P value of <0.05 was considered statistically significant.

RESULTS

One hundred forty anesthesiologists (71.4%) from 196 mailed questionnaires responded. The responders' clinical experience ranged from 1 to 29 yr in practice; of these, 29.3% were senior anesthesiologists (Consultants and Senior Registrars). Among the respondents, 92.9% indicated that they regularly used (i.e., used whenever a surgical procedure is amenable to a regional technique) spinal block in their practice. However, only 15.0% reported regular use of epidural techniques and 25.7% reported that they never performed epidural block. Regular use of peripheral nerve block was reported by only 2.9% and almost half (47.1%) had never attempted a peripheral nerve block. The majority of anesthesiologists in Nigeria reported only occasional use of epidural (59.3%) and peripheral nerve block (50%) techniques.

Peripheral nerve blocks of the upper extremity (axillary 62.1%, supraclavicular 14.3%, and interscalene 13.6%) were more frequently used compared with lower limb nerve blocks (ankle 34.3%, femoral 17.9%, sciatic 10%, and popliteal 5%) (P = 0.0001) (Fig. 1). Sixty-eight percent believed that the impediment to their use of plexus anesthesia was lack of skill; only 7% admitted they did not have suitable patients.

Figure 1.: Horizontal bars showing the percentages of anesthesiologists who reported the use of plexus techniques in their practice.

A majority of anesthesiologists (76.4%) had seen a peripheral nerve stimulator before, but only 31.4% of them used it in their practice. However, a high proportion of anesthesiologists (83.6%) believed that nerve blocks should not be performed without a peripheral nerve stimulator. Most respondents (89%) rated their exposure to peripheral nerve blocks during their residency training as poor and in need of more education with a prediction that their use of regional anesthesia would increase in the future.

DISCUSSION

Our survey showed that despite the potential benefits of regional anesthesia, the techniques are not widely used by anesthesiologists in Nigeria. In a nationwide study conducted in 1995, Hadzic et al.⁵ reported underuse of peripheral nerve blocks in the United States. In this study, we found that upper limb blocks were used frequently, especially the axillary approach to the brachial plexus, compared with lower extremity blocks. This is consistent with findings in the United States.⁵ Regional anesthesia, particularly plexus blocks, are growing in popularity in Europe and the United States, with emphasis on training during the residency program and organized anesthesia societies, such as American Society of Regional Anesthesia, promoting its use.^6,7 The underutilization of plexus blocks can be a result of lack of familiarity (and/or availability) of peripheral nerve block equipment: few of our respondents had seen or used a peripheral nerve stimulator but the majority believed that peripheral nerve blocks should not be done without one. Rudkin and Micallef⁸ reported that lack of anatomical knowledge or technique was the major barrier for performing fewer than 10 ankle blocks per annum in Australia. Limited exposure to techniques and equipment was pivotal in this survey. It is encouraging that our respondents believe that peripheral nerve blocks will assume a greater role in their future practice, which is consistent with the growing popularity of plexus blocks in Europe and the United States.^5,9

This survey shows that there is enthusiasm for regional anesthesia among anesthesiologists in Nigeria, and the availability of equipment, including peripheral nerve stimulators, may encourage more use of plexus blocks. Affiliations with American, European, and Asian societies may promote regional anesthesia through the organization of workshops and symposia, as well as assist with the development of a teaching model for training in regional blockade.