The value of cardiac MRI versus echocardiography in the pre-operative assessment of patients with Duchenne muscular dystrophy.

BACKGROUND/PURPOSE: Duchenne Mmuscular Ddystrophy (DMD) related cardiomyopathy is associated with significant perioperative mortality. Cardiac MRI (CMR) has not previously been systematically evaluated as pre-operative assessment tool for heart function in DMD. Our aim was to establish whether CMR versus echocardiography contributes to pre-operative DMD assessment. METHODS: Case records were retrospectively reviewed of 35 consecutive DMD boys who underwent evaluation for surgical procedures between 2010 and 2013. RESULTS: Echocardiography revealed a median left ventricular (LV) shortening fraction (SF) of 29/% (range: 7-44). 37% of boys (13/35) had abnormal SF <25%, 66% (23/35) showed hypokinesia and 26% (9/35) had LV dilatation. CMR revealed a median left ventricular ejection fraction (LVEF) of 52% (range: 27-67%). 57% of boys (20/35) had abnormal LVEF <55%, 71% (25/35) had hypokinesia, and 82% late gadolinium enhancement. Extensive versus minimal late gadolinium enhancement was associated with reduced left ventricular ejection fraction (48% vs 58%; p = 0.003) suggesting more severe cardiomyopathy. Although echocardiography shortening fraction correlated with CMR ejection fraction (rs = 0.67; p < 0.001), three-quarter of echocardiography studies had suboptimal scanning windows and in 26% measurements significantly over- or underestimated left-ventricular function compared to CMR. CONCLUSION: Our findings clearly demonstrate the added value of CMR versus echocardiography in assessing DMD-cardiomyopathy. Particularly when echocardiographic scanning windows are suboptimal, CMR should be considered to allow accurate pre-operative cardiac assessment.

A double-blind comparison of codeine and morphine for postoperative analgesia following intracranial surgery.

Codeine and morphine were compared in a double-blind study of postoperative analgesia in 40 patients after intracranial neurosurgery. Eighteen patients received codeine phosphate 60 mg and 18 morphine sulphate 10 mg, both by intramuscular injection; 4 patients (10%) required no analgesia. Both drugs provided analgesia within 20 min of injection but morphine was more effective than codeine beyond 60 min (p = 0.01). Fewer doses of morphine than codeine were required (p = 0.003). Nine patients requested one dose of morphine and 9 two doses. Seven patients required three doses of codeine and 1 patient required four doses. Neither drug caused respiratory depression, sedation, pupillary constriction or unwanted cardiovascular effects. We conclude that, in the doses used, morphine is a safe alternative to codeine for analgesia after neurosurgery and has a more persistent action.

Air embolism during awake craniotomy.

A case of venous air embolism during awake craniotomy is described. Chest pain and electrocardiographic changes were the major presenting features. Capnography detected a decrease in end-tidal carbon dioxide and demonstrates its use as an aid in the diagnosis of air embolism in the awake patient. Following this episode persistent hypoxaemia developed secondary to acute pulmonary oedema and a pleural effusion.