Risk of early recurrent stroke in symptomatic carotid stenosis after best medical therapy and before endarterectomy.

BACKGROUND: The early recurrence of neurological symptoms (NR) after urgent aggressive best medical therapy (BMT) in symptomatic carotid stenosis is not well documented. AIMS: To investigate the risk of ipsilateral NR after urgent aggressive BMT in patients with symptomatic (50-99%) carotid stenosis up to carotid endarterectomy (CEA), with emphasis on the first 14 days after index-event. METHODS: Prospective population based study, covering a period of 4½ years. NR rate was determined after initiation of urgent aggressive BMT and until CEA and compared to NR up to 90 days prior to index-event. Urgent BMT consisted of loading dose aspirin and clopidogrel thereafter therapy with aspirin and clopidogrel together with a statin. RESULTS: Of 8200 symptomatic patients (ischemic stroke, transient ischemic attack and ocular events), 250 (3%) patients underwent CEA, 47% within 14 days of the index-event and 99% within 14 days of surgical referral. The overall NR from index-event to CEA in symptomatic patients was significantly lower 1.6% (95% CI 0.5-4%) after BMT when compared with NR in the 90 days prior to referral to a stroke clinic 25% (95% CI 20-30%, p < 0.00001). Peri-operative bleeding 5% (95% CI 3-8%) was comparable with other studies. CONCLUSION: Urgent aggressive BMT after index-event is associated with a significant reduction in the risk of early NR in CEA candidates. The early risk of recurrent stroke in patients with symptomatic significant carotid stenosis is dramatically reduced after urgent aggressive BMT in specialised stroke clinics.

Accidental hypothermia with cardiac arrest: complete recovery after prolonged resuscitation and rewarming by extracorporeal circulation.

A 51-year-old male remained immersed in sea water (6 degrees C) for 40 min. Brought ashore, the ECG showed asystole. Advanced life support was immediately commenced. On arrival in hospital his rectal temperature was 27 degrees C, but continued to fall to 24 degrees C. The ECG remained isoelectric. Cardiopulmonary resuscitation was continued until extracorporeal circulation was established 190 min after rescue. Upon rewarming ventricular fibrillation occurred which was converted to sinus rhythm with a bolus of lignocaine followed by D.C. conversion at 31.5 degrees C. When rewarming was complete after 60 min, signs of severe heart failure became evident. Sternotomy and pericardiotomy were performed to exclude cardiac tamponade. After 60 min of re-perfusion the patient was be weaned from bypass supported by a high-dose vasopressor infusion and nitroglycerine. He was discharged after 13 days with no evidence of any permanent organ damage. Given the advantage of providing circulatory support, extracorporeal circulation may be useful when rewarming hypothermic victims with cardiac arrest.

[Anesthesia and porphyria]. / Anaestesi og porfyri.

The porphyrias are a group of disorders of haem metabolism. A knowledge of which anaesthetic can precipitate an acute attack of porphyria is important, since an accumulation of metabolites can result in life threatening symptoms, such as abdominal pain, vomiting, photophobia, neuropathy, bulbar paresis and respiratory failure. Treatment consists primarily of adequate calorie intake e.g. glucose, but is otherwise symptomatic. Anaesthetic drug recommendations are based both on animal experiments and patient experience, primarily case histories. An array of local anaesthetics, hypnotics, sedatives, neuroleptics, analgesics, muscle relaxants, inhalation anaesthetics and some antibiotics are reviewed. Patients with a history of porphyria should be in an optimal condition and maintain a high calorie intake perioperatively. The pre-operative fast should be a minimum and iv-glucose is advisable while fasting. There are anaesthetic agents that are safe for both regional and general anaesthesia.

[Exchange transfusion in cases of falciparum malaria]. / Utskiftningstransfusion ved alvorlig falciparum-malaria.

Malaria is diagnosed in 50-70 patients each year in Norway. Severe malarial infection with cerebral involvement as well as hypoglycaemia, circulatory collapse and renal failure is often difficult to diagnose since the condition is only rarely seen in Scandinavia. This report describes a 49 year old seaman, who was admitted to hospital with a clinical picture of sepsis with multiorgan involvement including cerebral affection. Subsequently, it turned out that the patient had a severe infection with Plasmodium falciparum, involving more than 50 per cent of the red blood cells. Despite being comatose for one week with repeated attacks of grand mal type, and requiring 11 days mechanical ventilation plus dialysis for 4 weeks, he recovered uneventfully and was dismissed from hospital with only minor neurological sequelae. Even severe malaria with cerebral involvement can result in full restitution if the diagnosis is made early and exchange transfusion plus treatment with relevant drugs are instituted promptly.

Micro-drop size and intravenous administration of sedative-anaesthetic solutions.

The variation in micro-drop size was studied for a series of sedative-anaesthetic solutions administered via a standard paediatric infusion set in combination with an infusion pump and drop counter. Of the solutions tested, only Diazemuls 20 mg% failed to alter micro-drop size. Solutions containing Ketalar, Apozepam, Hypnomidate and Althesin all caused a decrease in drop size and therefore in administered volume. The largest error (37%) occurred with a solution containing althesin 20% (v/v).

The effect of intranasally administered nitroglycerin on the blood pressure response to laryngoscopy and intubation in patients undergoing coronary artery by-pass surgery.

The effect of intranasally administered nitroglycerin (NTG) on the cardiovascular response to laryngoscopy and intubation was studied. Thirty patients scheduled to undergo coronary artery by-pass surgery under thiopentone, enflurane and pancuronium anaesthesia were randomly divided into three groups. Group I received lignocaine 1.5 mg/kg i.v. prior to laryngoscopy and intubation (control group). Group II received lignocaine 1.5 mg/kg i.v. and in addition 2 mg nitroglycerin (NTG) was given intranasally. Group III received only 2 mg NTG intranasally. In Group I laryngoscopy and intubation caused a significant increase in mean arterial pressure (MAP) (P less than 0.01), heart rate (HR) (P less than 0.01) and rate pressure product (RPP) (P less than 0.01) compared to preoxygenation values. In Group II and III MAP and RPP remained unchanged, whereas HR increased (P less than 0.01 and P less than 0.01 respectively). It can be concluded that intranasally administered NTG effectively attenuates the pressor response to laryngoscopy and intubation in patients presenting for coronary artery by-pass surgery and that it is more effective and convenient method than intravenous lignocaine.

Effect of 1 or 2 MAC isoflurane with or without ketanserin on cerebral blood flow autoregulation in man.

We have studied the effect of 1 or 2 MAC isoflurane with or without ketanserin on cerebral blood flow (CBF), cerebral oxygen metabolism (CMRO2) and CBF autoregulation in 20 adult patients undergoing lumbar disc surgery. Ten patients received ketanserin and 10 isotonic saline. CBF measurements were started after 1 h of infusion of saline or ketanserin. The patients were anaesthetized with thiopentone 5 mg kg-1 followed by isoflurane. During 1 MAC of isoflurane, baseline values were recorded and then CBF autoregulation was examined (mean arterial pressure increased by about 30% with angiotensin). The sequence was repeated with 2 MAC of isoflurane. CBF was measured by the i.v. xenon-133 technique. CMRO2 was calculated as the product of CBF and the cerebral arterio-venous oxygen content difference. Ketanserin had no effect on CBF, CMRO2 or CBF autoregulation during isoflurane anaesthesia, therefore all patients were pooled for evaluation of the effect of isoflurane. Increasing isoflurane anaesthesia from 1 to 2 MAC increased mean CBF from 41 to 49 ml/100 g min-1 (P < 0.01) and decreased mean CMRO2 from 1.5 to 1.1 ml/100 g min-1 (P < 0.001) and thus abolished the coupling between flow and metabolism. The CBF autoregulation test indicated that autoregulation was disrupted at 2 MAC, but not during 1 MAC isoflurane anaesthesia.