Retrobulbar versus subconjunctival anesthesia for cataract surgery.

OBJECTIVES: To compare the effectiveness, in terms of pain relief and akinesia of retrobulbar and subconjunctival an aesthesia during cataract surgery and also to compare the degree of postoperative ptosis associated with each technique. MATERIALS AND METHODS: Consecutive adult patients undergoing cataract surgery between March and June 2008 at the Guinness Eye Center Onitsha, were randomized into retrobulbar and subconjunctival an aesthesia by simple random sampling. Patients' subjective perception of pain was graded into none, mild, moderate and severe; eyeball movement during surgery was graded into none, slight, moderate excessive. Two weeks after surgery, the palpebral fissure width was measured with the metre rule to determine the degree of post-operative ptosis. RESULTS: Of the 90 patients studied, 55 (61.1%) patients had subconjunctival an anesthesia while 35(38.9%) had retrobulbar injection. In the retrobulbar injection group 25 (71.4%) patients had none or mild pains compared to 44 (80.0%) in the subconjunctival injection group; while 10 (28.6%) patients in the retrobulbar group experienced moderate to severe pains, 11 (20%) patients in the subconjunctival group had moderate pains and none experienced severe pains. But the difference in the degree of pain perception between the 2 groups is not statistically significant (χ2 = 0.01; df - 1; P>0.05 ). In the retrobulbar injection group, there was none or slight movement of the globe in 30 (85.7%) patients compared to 49 (89.1%) patients in the subconjunctival group. While 5 (14.3%) patients in the retrobulbar injection group had moderate globe movement, no patient in this group had excessive movement. In the subconjunctival injection group, 5 (9.1%) patients had moderate movement and 1 (1.8%) patient had excessive eyeball movement. The difference in the movement of the eyeball between the retrobulbar and the subconjunctival injections group was not significant (χ2 = 0.004; df - 1; P>0.05 ). In the retrobulbar injection group, the palpebral fissure width was within ≥ 10mm in 18 (51.0%) patients compared with 29 (53.0%) patients in the subconjunctival group. This difference was not statistically significant (χ2 = 0.0006; df - 1; P>0.05 ). CONCLUSIONS: Both retrobulbar and subconjunctival an aesthetic techniques are effective and safe for cataract surgery although the pain experience may be slightly more for patients being operated upon under retrobulbar anaesthesia.

A study of fatal injuries in Nigerian factories.

A study of the pattern of occupational injury mortality rates by industry and cause of death was undertaken to indicate the high-risk types of industry and the major causes of death, which could subsequently be used in developing cost-effective strategies for prevention. This is the first such study of accidental mortality factors in Nigerian factories. This paper reports the outcome of the study of mortality in Nigerian factories over a 10 year period (1987-1996). Between 1987 and 1996, a total of 3183 injuries were reported, of which 71 (2.2%) were fatal. The annual case fatality rate ranged from 0.94 per 100 injured workers in 1990 to 5.41 in 1994, with an overall fatality rate of 2.23 per 100 injured workers. Of the 71 deaths, 12 (16.9%) were associated with power-driven machinery. Ten (14.1%) deaths were associated with explosions, while people falling accounted for nine (12.6%) of the deaths. Eleven deaths (15.4%) occurred in the chemical/pharmaceuticals industry, nine (12.6%) occurred in the basic metal industry and seven (9.8%) occurred in the food, beverage and tobacco industry. There were seven (9.8%) deaths in the textile manufacturing industry. The highest case fatality rate per injured worker (16.6%) occurred in the coal-petroleum industry, followed by 5.9% in the wood and wood products industry. A rate of 5.8% occurred in the non-metallic manufacturing industry. The case fatality rates in Nigerian factories are compared with those of other predominantly African countries. Accident prevention programmes tailored to the work activities and specific causal factors in the high-risk types of industries are recommended following a detailed study of work situations and risk factors in these types of industries. Accident prevention programmes, including the use of protective equipment, safety education, machine guarding, a work permit system, effective supervision at work sites and the enforcement of factory laws and regulations, are recommended to improve accidental injury and death in the factories.

Management of technological risks in Nigeria.

Assessment of the risks associated with technological development in Nigeria called for an evaluation of the counter measures. The Government, affected organisations, and insurance companies are the three main bodies concerned with risk management. Legislative control by Government is hardly enforced due to a limited number of enforcement agents and resources. The laws do not keep pace with increasing technological risks and are reactive rather than proactive. The industries tend to insure all identified risks mainly due to the lack of competent safety personnel and the low level of corporate awareness of the importance of risk management. Risk reduction is marginally practised and the legal requirements are hardly attained. Risk transfer of a non-insurance nature from lesser to lessee is quite common. There are hardly any advisory or supervisory services by the insurance companies. The insurance industry hardly creates awareness or promotes risk reduction practices. The paper prescribes the roles of various groups in improving risk management in Nigeria including the establishment of a commission which among other functions will promote co-operation and co-ordinate the risk management efforts of the various organisations.

Studies of risks associated with technological development in Nigeria.

This paper attempts to assess the magnitude of the risks associated with industrial and transportation technologies in Nigeria using data from various governmental agencies and private organisations. The minimum annual averages of injured persons and data from accidents associated with technological risks in Nigeria were as follows: factories-402.4 injured persons and 5.8 deaths; petroleum industry - 106.5 injured and 45.3 deaths; road traffic accidents - 25,262 injured persons and 9,117 deaths; and railways 170.5 injured persons and 43.2 deaths. Of the eleven plane crashes reported between 1978 and 1991 the nine crashes for which information was disclosed claimed 352 lives. The highest technological risk is from road traffic accidents. The annual average death from road traffic accidents (9,117) was 1.05 times the annual average death (8,662) from communicable diseases and 1.2 times the number of deaths (7,711) from cholera epidemics in 1991. Between 1988 and 1991 there were 855 reported cases of occupational diseases with an annual average of 214 cases. Conjunctivitis, dermatitis, chronic bronchitis and bronchial asthma accounted for 91% of the 855 reported cases. The observations reflect the technological risk situation in Nigeria, and the need for improvements in both reducing risks and increasing the recording of risk statistics.