The Effect of Antiemetics and Antihistamines on the QTc Interval in Emergent Dialysis Patients With Baseline QTc Prolongation.

BACKGROUND: Unfunded patients with end-stage renal disease (ESRD) who do not have routinely scheduled hemodialysis often receive medications known to prolong the QTc interval for their uremic symptoms even though they may have pre-existing QTc prolongation. OBJECTIVES: The purpose of this study was to determine the effects of these medications on the QTc interval in these patients. METHODS: Unfunded patients with ESRD presenting to the emergency department (ED) for emergent hemodialysis (HD) with QTc prolongation on their initial electrocardiogram (ECG) were recruited. Approximately 2 hours after receiving an antihistamine or antiemetic, a second ECG was ordered and the QTc was measured. The patients were followed-up 1 week later. RESULTS: Twenty-nine percent (44/152) of the unfunded patients with ESRD presenting for HD at a county hospital had QT prolongation and were included with 107 total ED visits during the 4-week study period. The mean QTc was 483.7 msec on presentation to the ED, and the mean QTc measured 2 hours after receiving an antihistamine or antiemetic was 483.8 msec. None of the patients were admitted for life-threatening dysrhythmias. Thirty-six percent (16/44) of the recruited patients had QTc intervals >500 msec with a combined total of 31 patient visits, of which only 25.8% (8/31) had an increase in the QTc interval after an antihistamine or antiemetic medication was given. None of these patients had adverse outcomes, such a dysrhythmia or death, at 1-week follow-up. CONCLUSION: This study shows that medications known to cause QTc prolongation are safe to use in therapeutic doses in patients with ESRD who have pre-existing QT prolongation. Few patients in this cohort had significantly prolonged QTc intervals at baseline.

Comparison of procedural sedation for the reduction of dislocated total hip arthroplasty.

INTRODUCTION: Various types of sedation can be used for the reduction of a dislocated total hip arthroplasty. Traditionally, an opiate/benzodiazepine combination has been employed. The use of other pharmacologic agents, such as etomidate and propofol, have more recently gained popularity. Currently no studies directly comparing these sedation agents have been carried out. The purpose of this study is to compare differences in reduction and sedation outcomes, including recovery times, of these 3 sedation agents. METHODS: We performed a retrospective chart review examining 198 patients who presented with dislocated total hip arthroplasty at 2 academic affiliated medical centers. The patients were grouped according to the type of sedation agent. We calculated percentages of reduction and sedation complications along with recovery times. Reduction complications included fracture, skin or neurovascular injury, and failure of reduction requiring general anesthesia. Sedation complications included use of bag-valve mask and artificial airway, intubation, prolonged recovery, use of a reversal agent, and inability to achieve sedation. We then compared the data for each sedation agent. RESULTS: We found reduction complications rates of 8.7% in the propofol, 24.7% in the etomidate, and 28.9% in the opiate/benzodiazepine groups. The propofol group was significantly different from the other 2agents (p ≤ 0.01). Sedation complications were found 7.3% of the time in the propofol , 11.7% in the etomidate , and 21.3% in the opiate/benzodiazepine group, (p=0.02 propofol vs. others) . Average recovery times were 25.2 minutes for propofol, 30.8 minutes for etomidate, and 44.4 minutes for opiate/benzodiazepine (p = 0.05 for propofol vs. other agents). CONCLUSION: For reduction of dislocated total hip arthroplasty under procedural sedation, propofol appears to have fewer complications and a trend toward more rapid recovery than both etomidate and opiate/benzodiazepine. These data support the use of propofol as first line agent for procedural sedation of dislocated total hip arthroplasty, with fewer complications and a shorter recovery period.

Early response of heat shock proteins to functional overload of the soleus and plantaris in rats and mice.

Heat shock proteins (HSPs) are important factors in the response of skeletal muscles to chronic increases or decreases in activation and loading. The purpose of this study was to compare species-, time- and muscle-dependent changes in protein expression of Hsp20, Hsp25, αB-crystallin, Hsp72 and Hsp90 in response to functional overload (FO) in rats and mice. We compared protein levels of Hsp20, Hsp25, αB-crystallin, Hsp72 and Hsp90 in soleus and plantaris in baseline conditions and following 0.5, 1, 2, 3 and 7 days (rats) or 3 and 7 days (mice) of FO. Baseline levels of all HSPs were higher in rat soleus than plantaris, whereas only baseline expression of Hsp20 was higher in mouse soleus than plantaris. Levels of Hsp72 and Hsp90 were higher in plantaris and soleus of FO than control mice and rats after 3 and 7 days of FO. Protein levels and phosphorylation of Hsp25 in mouse plantaris and soleus were higher than control levels after 3 and 7 days of FO, except for soleus at 3 days. αB-crystallin levels were higher in plantaris of FO than control mice after 3 and 7 days of FO and in FO than control rats after 7 days of FO. Heat shock protein 20 was the least responsive, increasing only in 7 day FO rat plantaris compared with control rats. Overall, the results demonstrate that levels of both large and small HSPs increase with FO, suggesting a contributory role during the compensatory hypertrophy response.