The Central African journal of medicine最新文献

Background: Acid base alterations occur during laparoscopy with carbon dioxide insufflation. The purpose of this study was to investigate the effects of low tidal volume ventilation on acid base status during pneumoperitonium.

Materials and methods: 30 patients undergoing laparoscopic surgery under General Anaesthesia were ventilated with tidal volume of 6 ml/kg and respiratory rate of 12 breaths/minute. Arterial blood gas analysis was done before, during and after C02 pneumoperitoneum. Arterial haemoglobin oxygen saturation by pulse oximetry (SPO2) and EtC02 were monitored continuously throughout the laparoscopy. Respiratory adjustments were done for EtCO2 levels above 60mmHg or SPO2 below 92% or adverse haemodynamic changes.

Results: low tidal volume ventilation during pneumoperitoneum resulted in a significant elevation in PaCO2 (p<0.001) and a fall of pH (p <0.001), ion bicarbonate (HCO3-) (p = 0.011), and base excess (ABE) (p <0.001). A correlation was found between the EtCO2 and PaCO2 during pneumoperitoneum. Oxygenation was well maintained during pneumoperitoneum. No ventilatory adjustments were instituted on any of the patients as they maintained EtCO2 below 60mmHg throughout pneumoperitoneum.

Conclusion: Ventilation with low tidal volume during pneumoperitoneum causes a mixed respiratory and metabolic acidosis. EtCO2 is still a good non-invasive monitor for estimation of PaCO2 during low tidal volume ventilation during pneumoperitoneum.

Postpartum Haemorrhage (PPH) is the most common cause of maternal mortality globally, leading to a woman's death every seven minutes. In Zimbabwe, there has been a 300% increase in the Maternal Mortality Ratio (MMR) between 1994 and 2010 and the MMR was estimated at 960 maternal deaths per 100,000 live births in 2012.2-3 Overall, 14% of all maternal deaths in Zimbabwe are due to PPH. Ensuring prompt access to high-quality prevention and treatment of PPH for all women who deliver is an essential strategy to combat PPH-related morbidity and mortality and to make progress toward reaching Millennium Development Goal 5, the reduction of maternal mortality by three-quarters by 2015.

Phenytoin toxicity masquerading as deterioration of neurological symptoms caused by interaction with chloramphenicol is a very rare but real risk. To the authors’ knowledge only one such case occurring in humans has been reported in the English literature. No case of clinical phenytoin toxicity occurring at less than double the serum phenytoin therapeutic levels, occurring as a result of chlorampenicol interaction has been documented, hence our report.A 17 year old man, whose frontal subdural empyema had been drained, had his seizures well controlled on phenytoin. Shortly after, he had a parasagital subdural empyema which was also drained. He was put on chloramphenicol. He improved tremendously until he then developed cerebellar symptoms. Phenytoin levels were noted to be almost twice the maximum therapeutic value. On stopping chloramphenicol, phenytoin levels normalized and symptoms resolved.Possibility of phenytoin toxicity should always be entertained in patients who are also taking chlorampenicol, presenting with new or worsening neurological symptoms.

Background: High negative appendicectomy rates are no longer acceptable with improvements in imaging techniques and clinical prediction rules. The use of ultrasound and CT scan in addition to clinical assessment and blood investigations has greatly reduced the negative appendicectomy rate to less than 10%.

Objectives: The aim of the study was to determine the negative appendicectomy rate at the two major teaching hospitals in Harare and to evaluate the accuracy of the Alvarado score and ultrasound scan in diagnosing acute appendicitis.

Design: Prospective observational, cross sectional study.

Setting: Parirenyatwa Group of Hospitals and Harare Central Hospital, in Zimbabwe.

Materials and methods: A total of 206 patients undergoing appendicectomy at the two major teaching hospitals in Harare were included in this study between June 2012 and May 2013. Information recorded included: age, sex, clinical features, investigations and treatment. Alvarado score was calculated from the data in the case notes and ultrasound scan results were also captured. All appendices removed at operation were sent for histopathological examination. Appendicitis was confirmed at histology. The positive predictive value of Alvarado score and sensitivity and specificity of ultrasound scan were calculated.

Results: The overall negative appendicectomy rate was 16.5%. The negative appendicectomy rate for men was 13.3% and that for females was 24.4%. The negative appendicectomy rate for Parirenyatwa Group of Hospitals was 19.0% and that for Harare Central Hospital was 12.1%. The mean age was 28 years (SD 12.8). Appendicitis was diagnosed commonly in the second and third decades of life. Sensitivity of ultrasound scan in diagnosing acute appendicitis was 89.5% with a positive predictive value of 77.2%. Females were 2.6 times more likely to have an ultrasound scan done to diagnose appendicitis than males. Alvarado score had a sensitivity of 95.3% with a positive predictive value of 90.3%.

Conclusion: The negative appendicectomy rate (16.5%) at the two University Teaching Hospitals in Harare is relatively high when compared with modern trends. Alvarado score had a high sensitivity (95.3%) and predictive value (90.3%). Ultrasound scan had a high sensitivity (89.5%) and a relatively low predictive value (77.2%) in diagnosing acute appendicitis. Regular use of these assessment modalities should contribute substantially to reduction in the negative appendicectomy rate in our practice.

Background: Among HIV-infected children ear infections are recurrent and chronic, which may lead to hearing loss.

Objective: To determine the prevalence, cause and severity of hearing impairment among HIV-infected children aged 5-17 years attending for HIV care in Harare.

Design and setting: An analytical cross-sectional survey conducted at Newlands Clinic, an opportunistic infections clinic in Harare.

Materials and methods: Participants underwent a standardised otoscopic examination of the ear and Pure Tone Audiometry (PTA). Factors associated with hearing impairment were investigated using multivariate logistic regression.

Results: Three hundred and eighty (380) participants (55% female and mean age 11 years (SD: 3.3 years)) were consecutively recruited. The vast majority of participants (n=338; 89% were taking antiretroviral therapy (ART) for a median of 3 (IQR: 2-5) years at recruitment, and the most recent median CD4 Count (i.e. CD4 count measured within 6 months of the study recruitment) was 725 (IQR: 497-1000) cells/µL, with no difference by ART status. 61% (n= 231) of participants had an abnormal ear examination. Of the 359 participants who underwent audiometry, the prevalence of hearing impairment was 32.3% (95%CI: 27.5%-37.4%) based on a PTA threshold ≥26Db. Hearing impairment was associated with a recent CD4 count <350cell/µL (OR 2.1, P<0.037).

Conclusion: There is a high prevalence of hearing impairment among HIV-infected children and adolescents. Low CD4 count remains a risk factor even among those who are on ART. We recommend that HIV infected children and adolescents, particularly those with low CD4 counts, should have routine evaluation of hearing as part of HIV care.

Background: The establishment of a credible, defensible and acceptable “formal competency based ophthalmology training curriculum for undergraduate medical and dental students” is fundamental to program recognition, monitoring and evaluation. The University of Zimbabwe College of Health Sciences (UZ-CHS) has never had a formal ophthalmology training curriculum for medical graduates since its inception. This has cast doubts on the quality of medical graduates produced with regards to delivery of basic primary eye care in the community.

Objective: The aim of this project was to develop a formal “competency based ophthalmology training curriculum” (CBOTC) for medical graduates in Zimbabwe.

Design: Institution based (University of Zimbabwe College of Health Sciences and Parirenyatwa Group of Hospitals), cross-sectional analytic study.

Methodology: A review of undergraduate medical training curriculum and literature was done to identify gaps in the ophthalmology training curriculum. A local needs assessment was conducted through interviews of major stake holders in the University of Zimbabwe College of Health Sciences and Parirenyatwa Group of Hospitals.

Results: This project confirmed the lack of a formal ophthalmology training curriculum for medical graduates at the UZCHS, ad-hoc training of undergraduate ophthalmology and inconsistent student assessment in knowledge of and care of eye complaints. Cataract, glaucoma, refractive errors, ocular tumours, conjunctivitis, eye infection and eye injuries were suggested as priority conditions every student should learn during the rotation. A formal CBOTC for medical graduates based on identified needs and priority eye diseases has been developed in response.

Conclusion: A CBOTC based on identified needs and focused on targeted diseases has been proposed geared towards producing medical graduates with the basic knowledge, skills and attitudes to deliver adequate primary eye care.