Benign paroxysmal positional vertigo
It is a remarkable physiologic feature that our sense of position is determined by fluid accelerations within 3 small semicircular canals deep inside the ear. Benign paroxysmal positional vertigo (BPPV) is a common condition whereby this system goes awry and, though termed benign, causes exceedingly unpleasant symptoms. Parnes and colleagues review BPPV, emphasizing the mechanism of disease and diagnostic manoeuvres, and provide a detailed description (with figures) of the particle repositioning manoeuvre. This manoeuvre takes less than 5 minutes to complete and can be a highly effective treatment for BPPV. The surgical treatment of intractable BPPV is also described.
See page 681
Antiretroviral therapy in injection drug users
Highly active antiretroviral therapy (HAART) reduces HIV replication, improves CD4 cell counts and, thus, decreases mortality. Among HIV- infected patients, Wood and colleagues compared the efficacy of HAART in injection drug users with that in patients with no history of injection drug use. At first glance it appears that the injection drug users obtained less benefit from HAART but, when the rates were adjusted for adherence to therapy, the levels of HIV-1 RNA suppression became similar for the 2 groups. These results underscore the need for interventions aimed at improving treatment adherence among injection drug users.
See page 656
Grading evidence
That evidence-based medicine can be translated into sound clinical practice is universally accepted; however, assessing all the sources of evidence (i.e., individual clinical trials) is time-consuming for clinicians. Well-performed systematic reviews address this problem by grading levels of evidence and often become the basis for practice guidelines. Unfortunately, the grading systems themselves have become puzzling combinations of letters and numbers with various definitions in the literature. In an essay, Schünemann and colleagues discuss this paradox and the factors to be considered in developing grading systems.
In a related commentary, Upshur describes the different ways in which 4 organizations currently rate levels of evidence and recommendations. Clearly, the call for both common sense and uniformity is needed.
Risk of emergency admission while awaiting elective cholecystectomy
Patients with biliary colic often wait many months before undergoing cholecystectomy. In that period, many suffer episodes of severe pain related to obstruction of the cystic duct by a gallstone. Sobolev and colleagues examine the rates of emergency cholecystectomy among patients who are on a waiting list for elective cholecystectomy. They find that the rate of emergent surgery for acute cholecystitis increases significantly after being on a waiting list more than 20 weeks. That patients should suffer with ongoing pain is impetus enough to reduce their waiting times for surgery. However, these results demonstrate that prolonged waiting is associated with a significant adverse event.
See pages 662