Does the prophylactic administration of magnesium sulphate to patients undergoing thoracotomy prevent postoperative supraventricular arrhythmias? A randomized controlled trial.

BACKGROUND: Supraventricular arrhythmias (SVA) are common after thoracic surgery and are associated with increased morbidity and mortality. This prospective, randomized, double-blind, placebo-controlled trial examined the effects of perioperative magnesium on the development of postoperative SVA. METHODS: Two hundred patients undergoing thoracotomy for lobectomy, bi-lobectomy, pneumonectomy, or oesophagectomy were recruited and randomly allocated into two groups. The treatment group received magnesium (5 g daily) intraoperatively, and on days 1 and 2 after operation, the control group received placebo. The primary outcome of the study was the development of SVA within the first 5 days after operation. RESULTS: There were 100 patients in each arm of the study, with one withdrawal and three lost to follow-up in the treatment group and four withdrawals in the control group. Ninety-six patients received magnesium and 96 received placebo. There was no difference in the incidence of SVA between the treatment and control groups, 16.7% (16/96) vs 25% (24/96), P=0.16. In the predefined subgroup analysis, patients at highest risk of arrhythmias (those undergoing pneumonectomy) had a significant reduction in the frequency of SVA, 11.1% (2/18) vs 52.9% (9/17), P=0.008. There were no differences in hospital length of stay or mortality. Patients receiving i.v. magnesium experienced a higher frequency of minor side-effects (stinging at injection site). The treatment was otherwise well tolerated. CONCLUSIONS: Overall, prophylactic magnesium did not reduce the incidence of SVA in patients undergoing thoracotomy. However, it reduced the incidence of SVA in the high-risk cohort of patients undergoing pneumonectomy. (ISRCTN22028180.).

Evaluation of extensions of sinonasal mass lesions by computerized tomography scan.

INTRODUCTION: Cross-sectional imaging has had a significant impact on the management of the sinonasal malignancy. Staging of these lesions has been closely monitored by dependence on computerized tomography (CT) scan and now in small proportion with MRI. The objective of the study was to evaluate the reliability of CT scan in assessing the extensions of the sinonasal mass lesions and their impact on tumor staging. MATERIALS AND METHODS: All cases of sinonasal lesions were reviewed retrospectively from June 2001 to May 2006 (five years) at KMIO, Bangalore. Only those cases that had CT scan reports and Histopatholgy Examination (HPE) reports were included in the study. All the cases, which were subjected to radiotherapy prior to surgery, were excluded from the study. There were a total of 38 cases with slight male preponderance. Tumor staging was done according to the sixth edition of TNM classification of malignant tumors. Two observers evaluated all the cases (Blinded Study) and sensitivity, specificity, positive predictive value, negative predictive value and predictive accuracy were estimated. RESULTS: The relation between the CT scan findings and HPE reports was high. Though false positivity was noted more in the ethmoid sinuses, significant impact on tumor staging was noted with false positivity of the nasopharynx. Also, false positivity was noted with orbital wall/content extensions, resulting in unnecessary exenterations of the orbit. However, CT scan reliably predicted infratemporal fossa extension in the absence of trismus. False negativity was noted more often in soft palate, indicating the need of using MRI for delineation of tumor extension. Thus, we conclude that judicious use of CT scan in all cases and MRI in selected cases will translate into better tumor-free resections and improves survival.

Significance of free radical injury in laryngeal and hypopharyngeal cancers.

BACKGROUND AND OBJECTIVES: Laryngeal and hypopharyngeal cancer is a multifactorial disease caused by various carcinogens such as tobacco, alcohol and viruses. Likewise, oxidative stress is known to cause aberrations in the cell membrane and DNA, leading to cancer. We conducted this prospective study in order to evaluate the level of oxidative stress in laryngeal and hypopharyngeal cancer patients. METHODS: Fifty patients with laryngeal and hypopharyngeal cancer and 40 control subjects were selected. Serum malondialdehyde concentrations and ferric reducing antioxidant power were assessed, in order to evaluate oxidative stress. Results were analysed by Student's t-test. RESULTS: Malondialdehyde levels were significantly higher and ferric reducing antioxidant power lower in the cancer patients, compared with the controls, indicating higher oxidative stress in the former. There was no statistically significant difference in malondialdehyde concentration or ferric reducing antioxidant power, comparing patients with versus without neck secondaries, and patients with early stage versus late stage tumours. CONCLUSION: Oxidative stress may have a role to play in the initiation of laryngeal and hypopharyngeal cancers, especially in patients with other risk factors such as tobacco and alcohol use.

Acalculous gallbladder distension in a young child due to HAV infection: Diagnostic dilemma.

Gall bladder distension with acute viral acalculous cholecystitis is a rare event in pediatric cases with a high incidence of perforation, gallbladder necrosis and mortality. We report a two and a half year old female child presenting with fever, vomiting, pain abdomen, mild hepatosplenomegaly and tenderness in right hypochondrium. Laboratory investigations revealed hyperbilirubinemia and elevated alkaline phosphatase, but there was no evidence of bacterial or parasitic infection. Serology for viral hepatitis suggested acute Hepatitis A infection. Ultrasonographically, distended inflamed gallbladder without calculous was observed. Finally acute acalculous cholecystitis due to Hepatitis A virus was diagnosed and the child responded to the conservative management.