The prevalence of cognitive dysfunction after conventional and computer-assisted total knee replacement.

Post operative cognitive dysfunction (POCD) is common following lower limb arthroplasty. The prevalence varies from 41-75% at 7 days to 18-45% at 3 months post operatively. The wide range of prevalence is due to inconsistencies in defining and quantifying POCD. The aim of this study is to ascertain an accurate prevalence of POCD in patients who had either conventional TKR (n=31) or computer-assisted TKR (n=30). Cognition was assessed pre-operatively, 6 days and at 6 months post-operatively by a battery of 11 validated neuropsychological tests. We found the mean prevalence of POCD to be 72% at 6 days and 30% at 6 months post-operatively. When comparing the prevalence of POCD between the two groups, we found no statistically significant difference at 6 days or at 6 months post-operatively. The only statistically significant factor between the two groups was the mean procedure time which was longer in the computer-assisted TKR group (p=< 0.001). We found a correlation between procedure time and the prevalence of POCD at 6 days (p=0.02) but not 6 months (p=0.26). POCD occurs in approximately one-third of TKR patients at 6 months post-operatively. The cause is undoubtedly multi-factorial; however we have demonstrated that procedure time may be a contributing factor. Our results suggest that using an intra-medullary femoral jig has no effect on POCD. Further research into the cognitive effects following TKR with and without a tourniquet would be of benefit.

Aetiology, risk factors and immediate outcome of bacteriologically confirmed neonatal septicaemia in Mulago hospital, Uganda.

BACKGROUND: Neonatal septicaemia remains a major cause of morbidity and mortality. The aetiology, risk factors and outcome of this problem need to understood. OBJECTIVE: To determine the aetiology, risk factors and immediate outcome of bacteriologically confirmed neonatal septicaemia in Mulago hospital. METHODS: Blood cultures were aseptically obtained from neonates presenting with clinical sepsis by WHO criteria to Mulago during a five month period between July and November 2002. Blood was placed in Brain Heart Infusion media and incubated within 30 minutes. Subcultures were plated daily up to 7 days on blood, chocolate and MacConkey agar and incubated in aerobic and 5% carbon dioxide conditions. Pure colonies were identified by Gram stain and biochemical tests and antibiotic sensitivities were obtained. RESULTS: Gram positive organisms were predominant (69.2%) followed by E. coli (17%) and Group B Streptococci (GBS) (7%). Staphylococcus aureus and E. coli dominated isolates in early and late onset sepsis. S. aureus was more sensitive to gentamicin than to cloxacillin. The sensitivity of E. coli to ceftriaxone was 94.1%. Factors significantly associated with neonatal septicaemia were male sex, history of convulsions, hypoglycaemia, lack of antenatal care, late onset sepsis and umbilical pus discharge. Mortality in sepsis cases was 18.1%, and 84% of deaths occurred in the first 2 days of admission. Hypoglycaemia was significantly associated with death (p < 0.01). CONCLUSION: S. aureus predominates the aetiology of neonatal septicaemia followed by E.coli. Most deaths occur in the first 48 hours of admission and hypoglycaemia is significantly associated with death.

Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies.

OBJECTIVE: To determine the risk of lung cancer associated with exposure at home to the radioactive disintegration products of naturally occurring radon gas. DESIGN: Collaborative analysis of individual data from 13 case-control studies of residential radon and lung cancer. SETTING: Nine European countries. SUBJECTS: 7148 cases of lung cancer and 14,208 controls. MAIN OUTCOME MEASURES: Relative risks of lung cancer and radon gas concentrations in homes inhabited during the previous 5-34 years measured in becquerels (radon disintegrations per second) per cubic metre (Bq/m3) of household air. RESULTS: The mean measured radon concentration in homes of people in the control group was 97 Bq/m3, with 11% measuring > 200 and 4% measuring > 400 Bq/m3. For cases of lung cancer the mean concentration was 104 Bq/m3. The risk of lung cancer increased by 8.4% (95% confidence interval 3.0% to 15.8%) per 100 Bq/m3 increase in measured radon (P = 0.0007). This corresponds to an increase of 16% (5% to 31%) per 100 Bq/m3 increase in usual radon--that is, after correction for the dilution caused by random uncertainties in measuring radon concentrations. The dose-response relation seemed to be linear with no threshold and remained significant (P = 0.04) in analyses limited to individuals from homes with measured radon < 200 Bq/m3. The proportionate excess risk did not differ significantly with study, age, sex, or smoking. In the absence of other causes of death, the absolute risks of lung cancer by age 75 years at usual radon concentrations of 0, 100, and 400 Bq/m3 would be about 0.4%, 0.5%, and 0.7%, respectively, for lifelong non-smokers, and about 25 times greater (10%, 12%, and 16%) for cigarette smokers. CONCLUSIONS: Collectively, though not separately, these studies show appreciable hazards from residential radon, particularly for smokers and recent ex-smokers, and indicate that it is responsible for about 2% of all deaths from cancer in Europe.

Haematogenous spread of pulmonary tuberculosis to a hemiarthroplasty of the hip.

Tuberculosis (TB) in a joint arthroplasty is unusual, and is usually due to reactivation from a previously infected joint or rarely from endogenous spread. We present a patient with septic loosening of a cemented Thompsons hemiarthroplasty due to Mycobacterium tuberculosis infection seven years post-operatively. At the time of surgery he had no symptoms or signs of TB. There have been no such reported cases in the English medical literature. (Hip International 2004; 14: 258-61).

N-acetyltransferase 2 and bladder cancer: an overview and consideration of the evidence for gene-environment interaction.

Genetic polymorphism of the carcinogen metabolizing enzyme N-acetyl transferase 2 (NAT2) may influence susceptibility to bladder cancers related to smoking or to occupational exposure to arylamine carcinogens. This article reviews the results of 21 published case-control studies of NAT2 polymorphism and bladder-cancer risk, with a total of 2700 cases and 3426 controls. The published evidence suggests that NAT2 slow acetylator phenotype or genotype may be associated with a small increase in bladder cancer risk. However, given the possibility of selective publication of results from studies that found an excess risk, the current evidence is not sufficient to conclude that there is a real increase in risk. Only five of the 21 studies reported results separately for the effect of NAT2 on bladder cancer risk in smokers and non-smokers. Although the results suggest that the effect may be greater in smokers than in non-smokers, the possibility of publication bias makes these results difficult to interpret. There was insufficient evidence to assess the joint effect of NAT2 and occupational exposure to arylamines on bladder cancer risk. Even if estimates of the effect of NAT2 from published data are correct, studies with around 3000-5000 cases will be needed to confirm them.

Smoking, smoking cessation, and lung cancer in the UK since 1950: combination of national statistics with two case-control studies.

OBJECTIVE AND DESIGN: To relate UK national trends since 1950 in smoking, in smoking cessation, and in lung cancer to the contrasting results from two large case-control studies centred around 1950 and 1990. SETTING: United Kingdom. PARTICIPANTS: Hospital patients under 75 years of age with and without lung cancer in 1950 and 1990, plus, in 1990, a matched sample of the local population: 1465 case-control pairs in the 1950 study, and 982 cases plus 3185 controls in the 1990 study. MAIN OUTCOME MEASURES: Smoking prevalence and lung cancer. RESULTS: For men in early middle age in the United Kingdom the prevalence of smoking halved between 1950 and 1990 but the death rate from lung cancer at ages 35-54 fell even more rapidly, indicating some reduction in the risk among continuing smokers. In contrast, women and older men who were still current smokers in 1990 were more likely than those in 1950 to have been persistent cigarette smokers throughout adult life and so had higher lung cancer rates than current smokers in 1950. The cumulative risk of death from lung cancer by age 75 (in the absence of other causes of death) rose from 6% at 1950 rates to 16% at 1990 rates in male cigarette smokers, and from 1% to 10% in female cigarette smokers. Among both men and women in 1990, however, the former smokers had only a fraction of the lung cancer rate of continuing smokers, and this fraction fell steeply with time since stopping. By 1990 cessation had almost halved the number of lung cancers that would have been expected if the former smokers had continued. For men who stopped at ages 60, 50, 40, and 30 the cumulative risks of lung cancer by age 75 were 10%, 6%, 3%, and 2%. CONCLUSIONS: People who stop smoking, even well into middle age, avoid most of their subsequent risk of lung cancer, and stopping before middle age avoids more than 90% of the risk attributable to tobacco. Mortality in the near future and throughout the first half of the 21st century could be substantially reduced by current smokers giving up the habit. In contrast, the extent to which young people henceforth become persistent smokers will affect mortality rates chiefly in the middle or second half of the 21st century.

Laparoscopic excision of the urachus.

Embryologically, the urachus represents the obliterated alantois in the form of a fibrous cord extending from the dome of the bladder to the umbilicus. Incomplete obliteration can result in the formation of an umbilical sinus, fistula, cyst, or abscess in the infraumbilical area. The traditional treatment of a residual urachus is surgical resection of the entire tract from the dome of the bladder to the umbilicus through a lower midline incision. We report the case of a 14-year-old girl who presented with an abscess below the umbilicus. After initial drainage, she developed a sinus that communicated with the navel. Surgical resection of the underlying urachus was carried out laparoscopically. The peritoneum was incised at the umbilicus, and the whole tract along with the skin sinus was excised using diathermy scissors. The lower end was ligated and the specimen retrieved. The patient was discharged the following day. One week later, her wounds had healed. Histology confirmed an epithelial-lined urachus. We believe that laparoscopic excision of a patent urachus is feasible and safe. This technique gives the surgeon good access to the area and has a cosmetically better result.