Injection-induced sciatic nerve injury in Ugandan children

Introduction

Every year an estimated 12 billion injections are administered worldwide. ¹

Approximately each person in the developing countries receives two injections per year, of which 75% are unnecessary. ^1,2 The most common site of intramuscular injection is the gluteal region.

In the developing countries, sciatic nerve injury following gluteal intramuscular (IM) injection is persistent, despite the widespread teaching that the upper outer quadrant of the gluteal region should be the site for the injection or that alternative sites should be used in children. ¹

In the Mulago Hospital, a marked increase has been noticed in the number of children presenting with injection-induced sciatic nerve injury.

Materials and methods

A cross-sectional descriptive study was conducted at the Mulago Hospital – Uganda's national referral and teaching hospital – during October 2006 to March 2007. The research committee of the Mulago Hospital approved the study and informed consent was obtained and data collected using a structured, pretested questionnaire. A thorough clinical evaluation was made and relevant laboratory tests were done.

In this study, acute flaccid paralysis (AFP) is defined as the sudden onset of asymmetrical lower limb weakness and injection-induced injury of the sciatic nerve is defined as a case in which there is flaccid paralysis of one limb and a definite history of injection in that limb less than 24h before the onset of paralysis. ³

The data were analysed using SPSS version 10.0. A P value of less than 0.05 was considered to be statistically significant.

Results

A total of 135 cases of AFP were diagnosed; two were excluded due to a failure to give consent. The study involved 133 cases of AFP, of which 124 cases were due to injection-induced injury. The percentage of patients with AFP due to injection-induced sciatic nerve injury was 93.2%. Two cases of Guillain-Barré syndrome were diagnosed (Table 1). Stool culture for polio virus was carried out in 47 cases and all were negative.

The age range was 4 months to 12 years with a peak at 1 year and mean of 3.7 years: 81 males (60.9%) and 52 (39.1%) females. Malaria was the reason for most patients (65.3%) receiving gluteal intramuscular injections that resulted in injection injury of the sciatic nerve (Table 2). Private clinics accounted for about two-thirds (66.1%) of the facilities where injections resulting in injury of the sciatic nerve were administered. The majority of the intramuscular injections resulting in injury of the sciatic nerve were given by nurses (77; 62.1%). The identity of the drug in 79 cases (59.4%) was quinine; other drugs included antibiotics (9.0%), antipyretics (6.8%) and chloroquine (4.5%).

In the univariate analysis, quinine was found to be the drug statistically more likely to cause injection-induced injury of the sciatic nerve (P value = 0.005, odds ratio = 12.02, confidence interval = 1.43–100.82).

Discussion

A large percentage of AFP cases in children in the Mulago Hospital was as a result of injection-induced injury of the sciatic nerve. The high percentage observed in this study could be due to the hospital being a national referral hospital. ^4,5

The problem of injection-induced injury of the sciatic nerve was noted to be particularly common in children aged less than 5 years (76.7%), as a result of having a smaller and less developed gluteal region. ^6,7 Males were more affected than females (1.6:1) due to the greater priority for health care given to boys. ⁸ The majority of injections were administered in a private health facility (75%) and, for most of the guardians, senior school had been their highest level of education and they had unskilled jobs (65.3%) – they were, therefore, more likely to have a low socioeconomic status.

Malaria is endemic in Uganda, and so it was the leading indication for the administration of the injection that resulted in injury of the sciatic nerve in 81 cases (65.3%). ^9,10

The majority of the intramuscular injections resulting in injury of the sciatic nerve were given by nurses (62.1%). In over half of the cases (59.4%), quinine was the drug used. Studies have revealed that quinine is notorious for causing injury of the sciatic nerve when administered by intramuscular gluteal injection. ^5,9 There was a statistical significance between quinine and injection-induced sciatic nerve injury (P value = 0.005).

Conclusion

Injection-induced injury of the sciatic nerve is the leading cause of AFP in children presenting to the Mulago Hospital. There was a statistical significant association between quinine and the occurrence of injection-induced injury of the sciatic nerve in children presenting with AFP. It is recommended that the gluteal region should not be used as an intramuscular injection site in children.

Appropriate health education about injections should be given to the health workers and the public.