In order to estimate the incidence and significance of aspiration during anaesthesia, a study of cases in which this complication had occurred was made at the Karolinska Hospital. With the aid of the anaesthetic recordkeeping system of the Department of Anaesthesia and the computer-based register of diagnoses of in-patients at the hospital, all cases in which aspiration was recorded were retrieved. Eighty-three cases of aspiration were retrieved from the file of anaesthetic records and four from the in-patient register. This constitutes an incidence of 4.7 aspirations in 10 000 anaesthetics, or 1 in 2131. The patients most often affected were children and the elderly. In 83% of the cases there were one or more preoperative factors indicating an increased risk for aspiration, such as emergency operation (38 cases, 43%), upper abdominal or emergency abdominal surgery (14 cases, 16%), a history indicating delayed gastric emptying (e.g. peptic ulcer/gastritis, pregnancy, obesity, unusual stress or pain, elevated intracranial pressure, 54 cases, 61%). In 29 cases (33%) there was a history indicating an increased risk of regurgitation, e.g. nasogastric tube, oesophageal disease or pregnancy. In 15 cases of elective surgery, no history of increased risk for aspiration could be found. In 67% of those cases the aspiration was preceded by difficulties involving the airways or intubation. The incidence of aspiration was more than sixfold higher during the night than during regular daytime working hours. In 41 cases (47%) the aspiration led to aspiration pneumonitis confirmed by x-ray. Fifteen patients (17%) needed mechanical ventilation, and four died.(ABSTRACT TRUNCATED AT 250 WORDS)

With the aid of a computerized anaesthetic record-keeping system, the incidence of laryngospasm during anaesthesia was studied, in order to quantify the risk of this complication. 136,929 patients given 156,064 anaesthetics were studied. There were 1,232 cases of laryngospasm recorded in 1,197 patients. The incidence of laryngospasm was calculated in subgroups characterized by age, sex, preanaesthetic conditions, premedication, anaesthetic technique, type of surgery and concomitant complication. An incidence exceeding 50 laryngospasms in 1,000 patients was observed when giving anaesthesia to children with bronchial asthma, with airway infection, in those who had a previous anaesthetic complication, during oesophagoscopy and when correction of hypospadias was performed. Extirpation of skin tumours and scars in males 50-59 years old was also accompanied by a similarly high incidence. Figures exceeding 25 laryngospasms in 1,000 patients were seen in the age group 1-3 months and in children undergoing appendicectomy, oral endoscopy and plastic surgery, when tracheal intubation had been performed and when a gastrointestinal tube was used. In the age group 50-59 years, an incidence exceeding 25 in 1,000 patients was seen when there had been preoperative airway obstruction and in females when the anaesthetic technique included spontaneous breathing and face mask, or apneic oxygenation. Dilatation of the anal sphincter and mediastinoscopy in males were also associated with an increased incidence of laryngospasm.

With the aid of a computer-based anaesthetic record-keeping system, anaesthetics complicated by bronchospasm during anaesthesia at the Karolinska Hospital were retrieved. The incidence of bronchospasm was calculated in groups characterized by various variables. In total, 246 cases of bronchospasm in 156,064 anaesthetics were retrieved. This corresponds to one case in 634 anaesthetics or 1.7 per 1000 patients. High incidence figures were seen in the age group 0-9 years (4.0/1000) when the patients showed a respiratory infection (41.1/1000), a pathological preoperative ECG (24.3/1000), an obstructive lung disease (21.9/1000), were classified as belonging to ASA class III (23.8/1000), if a tracheal intubation was performed (9.1/1000) or a rectal anaesthesia (35.7/1000) was given. In the age group 50-69 years (1.8/1000), high incidence figures were seen when there was an airway obstruction (8.8/1000), an obstructive lung disease (7.7/1000), a previous myocardial infarction (5.4/1000), a bronchoscopy (7.6/1000) or a mediastinoscopy (7.8/1000) was performed. Most of the cases had no history of allergy or asthma recorded in the anaesthetic form. In this series the triggering factor more often seemed to be of mechanical origin. There were no intraoperative deaths.

We studied the pharmacokinetics after caudal block of ropivacaine (2 mg ml-1, 1 ml kg-1) performed in 20 children aged 1-8 yr undergoing subumbilical surgery, in this open, non-comparative, multicentre study. Venous blood samples were collected up to 12-36 h. The mean (SD) peak plasma concentration, 0.47 (0.16) mg litre-1, was achieved after 12-249 min. The free fraction was 5% and the highest individual peak plasma concentration of free ropivacaine was 0.04 mg litre-1. Clearance was 7.4 (1.9) ml min-1 kg-1 and the terminal half-life 3.2 (0.8) h. Thus, the free plasma concentrations of ropivacaine were well below those associated with toxic symptoms in adults and the capacity to eliminate ropivacaine seems to be well developed in this age group. In this open study of 20 patients, ropivacaine was well tolerated and provided satisfactory postoperative pain relief without observable motor block.

With the aid of a computer-based anaesthetic record-keeping system, all cardiac arrests during anaesthesia at the Karolinska Hospital between July 1967 and December 1984 were retrieved. There were a total of 170 cardiac arrests and 250,543 anaesthetics in the data file, which gives an incidence of 6.8 cardiac arrests per 10,000 anaesthetics. Sixty patients died, constituting a mortality of 2.4 per 10,000 anaesthetics: 42 were considered as inevitable deaths (rupture of aortic or cerebral aneurysm, multitrauma, etc.); 13 cases of cardiac arrest were considered as non-anaesthetic, i.e. complications due to surgery and other procedures. Nine of these patients died. 115 cases of cardiac arrest were considered as caused by the anaesthetic and nine of these patients died. Thus mortality caused by anaesthesia was 0.3 per 10,000 anaesthetics. The most common cause of cardiac arrest due to anaesthesia was hypoxia because of ventilatory problems (27 patients), postsuccinylcholine asystole (23 patients) and post-induction hypotension (14 patients). The highest mortality was seen when spinal or epidural anaesthetics were given to patients with impaired physical status including hypovolaemia. The incidence of cardiac arrest has declined considerably during the period studied, and this coincides with an increasing number of qualified anaesthetists employed in the department during the same period.