Adverse cardiac manifestations following dextropropoxyphene overdose: can naloxone be helpful?

Dextropropoxyphene overdose may be complicated by serious cardiovascular manifestations, including conduction abnormalities and collapse. We report two patients in whom cardiac toxicity developed. Cardiovascular depression seemed to be improved after naloxone infusion in these two cases. Possible mechanisms are briefly discussed.

Hemodynamic effects and safety of sotalol in the prevention of supraventricular arrhythmias after coronary artery bypass surgery.

Sotalol is a beta-adrenergic blocking drug with the additional property of lengthening the cardiac action potential. These electrophysiologic properties render the drug attractive for use in the prevention of postoperative supraventricular arrhythmias (SVA), and previous studies have suggested that it was indeed effective. The hemodynamic response to sotalol and its safety early after coronary artery bypass graft (CABG) surgery were therefore studied. Forty-two patients undergoing CABG were randomly assigned either to receive sotalol to prevent postoperative SVA (25 patients) or to serve as controls (17 patients). Sotalol was started 6 hours after surgery if patients had a cardiac index > 2.8 L/min/m2 with a pulmonary capillary wedge pressure < 15 mmHg, and if they had no contraindications to the use of beta-blockers. The drug was given as a loading infusion of 1 mg/kg over 2 hours, followed by a maintenance infusion of 0.15 mg/kg/h for 24 hours. Three hours later, patients received the first oral dose of 80 mg to be repeated every 8 or 12 hours. Adverse effects necessitating discontinuation of the drug (bradycardia < 50 beats/min, systolic blood pressure < 90 mmHg, or cardiac index < 2.2 L/min/m2) occurred in six patients (24%) and were mainly related to the loading infusion. The hemodynamic data for patients who completed the study were characterized by a significant fall of the cardiac index caused by a lower heart rate without significant change of the stroke volume index. The incidence of supraventricular arrhythmias was not significantly different in the two groups (3/19 in the sotalol group, 5/17 in the control group).(ABSTRACT TRUNCATED AT 250 WORDS)

Use of ketanserin in the treatment of hypertension following coronary artery surgery.

Ketanserin, a selective S2-serotonin receptor blocker with alpha 1-adrenergic blocking effects, may be a suitable antihypertensive medication after coronary artery surgery and lacks side effects seen with other vasodilators. Fifty patients with systolic blood pressures greater than 150 mmHg after coronary artery surgery were given, in a randomized double-blind fashion, either ketanserin (K) or saline (S). Each patient received six successive boluses of 1 mL of S or 1 mL of K (5 mg) at 2-minute intervals. After the last injection, sodium nitroprusside was started whenever the systolic blood pressure exceeded 150 mmHg. In the K group, the following significant (P < 0.05) changes occurred: systolic and diastolic arterial pressure -12% and -11%, respectively; heart rate -3%; systolic and diastolic pulmonary artery pressure -5% and -6%; central venous pressure -5%; pulmonary capillary wedge pressure -5%; systemic vascular resistance -16%; pulmonary vascular resistance -8%; stroke index +6%. None of these parameters changed significantly in the S group. There was no change in pulmonary shunt fraction in either group. In the K group, five patients did not require any further antihypertensive therapy during the 120 minutes following the last bolus injection. Twenty patients needed sodium nitroprusside during this period. This occurred 37 minutes (+/- 17 min) after the last bolus. In conclusion, after coronary artery bypass surgery, K is an effective antihypertensive medication, which does not cause reflex tachycardia or an increase in pulmonary shunt fraction. Exceeding the recommended dose of 10 (or 20) mg, as done in this study, does not seem to improve effectiveness or prolong the duration of action.

[Patient-controlled epidural analgesia after major urologic surgery]. / Usage de l'analgesie épidurale contrôlée par le patient aprés chirurgie urologique majeure.

Postoperative pain is an important issue after major urological surgery. Efficient analgesia is mandatory. The administration of i.m. narcotics is considered routine. This technique, however, has some disadvantages due to the pharmacology and pharmacokinetics of the drugs used. In our institution, we recently introduced a new technique: the patient controlled epidural analgesia. A computerized pump administers a continuous infusion of a mixture local anaesthetic/narcotic through a peroperatively placed epidural catheter. This pump also allows patients to administer themselves additional boluses according to their needs. Sixty-two urological patients used this system to their own satisfaction and the satisfaction of the nursing and medical staff. This new approach of postoperative pain relief is discussed.

Cardiac conduction abnormalities during carbamazepine therapy for neuralgia following Guillain-Barré syndrome.

A 61-year-old man without previous medical history was admitted for Guillain-Barré syndrome (GBS). Carbamazepine was prescribed on day 72 for dysesthesia occurring at the time of recovery. Subsequently, severe cardiac conduction disturbances (asystole, atrioventricular block) were observed and a permanent pacemaker had to be inserted. The possible relationship between carbamazepine therapy and cardiac side effects is discussed in this condition, as GBS itself is often complicated by cardiac arrhythmias.

Interscalenic approach to the cervico-brachial plexus.

The concept of a closed peri-neurovascular space surrounding the cervicobrachial plexus, introduced by A. Winnie, allows the blockade of the cervical and brachial plexuses by means of a single puncture technique. The single puncture has positive advantages: 1. The rapidity of the blockade; 2. The simplicity of the blockade; 3. Comfort for the patient. The landmarks are easy to make. As with epidural blockade, the injection level and the volume of local anesthetic determine the quality and extent of the block. The traditional indication is surgery of the shoulder and of the supraclavicular area. A new indication seems to be the implantation of a cardiac pacemaker. Complications often quoted in literature are Horner syndrome-a minor complication-and blockade of the ascending branches of the recurrent laryngeal nerve and of the phrenic nerve. The risk of a pneumothorax is almost nil.