An evaluation of methods for the isolation of nontuberculous mycobacteria from patients with cystic fibrosis, bronchiectasis and patients assessed for lung transplantation

BACKGROUND

RGM medium is an agar-based, selective culture medium designed for the isolation of nontuberculous mycobacteria (NTM) from the sputum of patients with cystic fibrosis (CF). We evaluated RGM medium for the detection of NTM in patients with CF (405 samples), bronchiectasis (323 samples) and other lung diseases necessitating lung transplantation (274 samples).

METHODS

In total, 1002 respiratory samples from 676 patients were included in the study. Direct culture on RGM medium, with incubation at two temperatures (30 °C and 37 °C), was compared with conventional culture of decontaminated samples for acid-fast bacilli (AFB) using both a solid medium (Löwenstein-Jensen medium) and a liquid medium (the Mycobacterial Growth Indicator Tube; MGIT).

RESULTS

For all three patient groups, significantly more isolates of NTM were recovered using RGM medium incubated at 30 °C than by any other method (sensitivity: 94.6% vs. 22.4% for conventional AFB culture; P < 0.0001). Significantly more isolates of Mycobacterium abscessus complex were isolated on RGM at 30 °C than by AFB culture (sensitivity: 96.1% vs. 58.8%; P < 0.0001). The recovery of Mycobacterium avium complex was also greater using RGM medium at 30 °C compared to AFB culture (sensitivity: 83% vs. 70.2%), although this difference was not statistically significant and a combination of methods was necessary for optimal recovery (P = 0.21).

CONCLUSIONS

In the largest study of RGM medium to date, we reaffirm its utility for isolation of NTM from patients with CF. Furthermore; we show that it also provides an effective tool for culture of respiratory samples from patients with bronchiectasis and other lung diseases.

Clinico-radiological profile of stroke in eastern Nepal: a computed tomographic study

AIM

Stroke is a frequent cause of death and disability in elderly patients. This study was carried out to establish the pattern of various types of cerebrovascular accident (CVA) in eastern Nepal and to correlate the clinical data and radiological findings in cases of stroke.

MATERIALS AND METHODS

All the patients clinically diagnosed as stroke and referred to the radiology department for Computed tomography (CT) of the brain over a period of 1 year were included.

RESULTS

There were 150 patients with stroke (104 males and 46 females), aged 7 to 91 years in which infarction (58%) was more common than haemorrhage (42%) in both group of age (< or = 40 years and > 40 years). Smoking was the commonest risk factor noted in 40.66% cases followed by hypertension (40%). Excessive meat consumption (more than 4 times a week) was seen in 69.1% cases. In early Middle Cerebral Artery (MCA) territory infarction presenting within six hours of onset, positive CT findings were seen in 40% cases among which, obscuration of the lentiform nuclei was diagnostic.

CONCLUSION

In this part of Nepal, infarction is more common than haemorrhage as the cause of stroke and in contrary to western population; hemorrhagic stroke constitutes a significantly higher proportion of stroke. Smoking is the commonest risk factor followed by hypertension and it is also seen in combination with alcohol in many cases. Excessive meat consumption could be an additional risk factor for stroke in this part of Nepal. In younger age group (< or = 40 years), haemorrhage is more common than infarction and alcohol consumption is the commonest risk factor.

The control of intra-ocular pressure during the induction of anaesthesia for emergency eye surgery. A high-dose vecuronium technique

A technique of rapid sequence induction of anaesthesia for use in patients with penetrating eye injuries is described. This utilises a three maximal breaths method of pre-oxygenation, the intravenous injection of thiopentone and high dose vecuronium (0.2 mg/kg). Using the loss of eyelash reflex as the starting point for timing, all patients were intubated after 60 seconds without coughing and bucking. No postintubation increases in intra-ocular pressure were seen in 70% of patients and in no patient did the increase in intra-ocular pressure exceed 5 mmHg. After 3 minutes of apnoea, the minimum haemoglobin oxygen saturation was 94% with a mean value of 97.6%.

Anaesthesia for extracorporeal shock wave lithotripsy

The anaesthetic considerations of patients presenting for extracorporeal shock wave lithotripsy are described. Regional anaesthesia with sedation may be preferable to general anaesthesia for patients undergoing this form of therapy. If regional anaesthesia is contra-indicated, general anaesthesia using controlled ventilation with muscle relaxation, supplemented with a narcotic and a low concentration of volatile anaesthetic has been found to be a suitable alternative. The additional epidural preparation time has to be balanced against the benefits of easier patient transfer, especially during multi-stage procedures, and better postoperative analgesia. The epidural catheter can be left in situ in patients who require multiple treatments or who may experience severe ureteric pain as the resulting 'sand mass' is passed. Epidural space localisation using a 'loss of resistance to saline' technique is recommended, in order to avoid the possible risk of damage to the spinal cord and emerging nerves (due to the presence of an air-water interface). Patients with cardiac insufficiency need special consideration, in view of the effects of immersion on right and left heart filling pressures.

Effects of general anaesthesia on the intraocular pressure in man. Trichloroethylene in nitrous oxide and oxygen

The effect of TCE on the intraocular pressure was investigated in eight patients under thiopentone nitrous oxide/oxygen anaesthesia, using a muscle relaxant (pancuronium bromide). Pulmonary ventilation was controlled and the end-tidal carbon dioxide was maintained at 5 per cent. In every patient the intraocular pressure was observed to rise as TCE was administered and then to return to the initial level when the administration of TCE ceased.