B. Adelhøj

Influence of cigarette smoking on the risk of acid pulmonary aspiration

Twenty‐five non‐smokers and 35 smokers who had abstained overnight from cigarette smoking and were undergoing minor elective orthopaedic surgery were studied in order to compare gastric volume and pH. There was no significant difference in aspirated volume and pH both just after intubation and prior to extubation between the two groups, thus indicating that habitual smokers undergoing elective surgery in general anaesthesia do not have increased risk of acid pulmonary aspiration compared with non‐smokers.

Buprenorphine Delays Drug Absorption and Gastric Emptying in Man

The aim of the present study was to investigate the effects of buprenorphine on drug absorption and gastric emptying in man, using paracetamol absorption as an index of gastric emptying rate. Paracetamol was given to eight healthy volunteers p. o. together with or without a single i. v. dose of buprenorphine 4 μg kg‐1 body weight. Nausea occurred in five of the subjects, four subjects vomited and one was excluded due to vomiting during the study period. The mean peak serum paracetamol concentration (Cmax) was significantly (P< 0.0002) lowered by a factor 3 by buprenorphine, the mean time from administration of paracetamol to its peak concentration (Tmax) was significantly (P<0.03) prolonged by a factor 6, and the area under the plasma concentration‐time curve from 0 to 120 min was significantly (P<0.00006) reduced by a factor 3. This demonstrates a marked inhibition of the rate of paracetamol absorption, indicating a clinically important reduction of gastric emptying following administration of buprenorphine.

Refraining from cigarette smoking before premedication does not decrease the risk of acid pulmonary aspiration during anaesthesia

Seventy-four habitual smokers who had refrained overnight from cigarette smoking and were undergoing elective orthopedic surgery were allocated randomly to two groups in order to investigate the effect of smoking two cigarettes before premedication on volume and pH of gastric contents. The smoking group was allowed to smoke two cigarettes while the non-smoking group was not allowed to smoke. There was no significant difference in volume or pH between the groups, either just after intubation or prior to extubation, thus indicating no decreased risk of acid pulmonary aspiration because of refraining acutely from cigarette smoking.RésuméSoixante-quatorze fumeurs qui s’étaient abstenus de fumer la veille d’une opération élective en orthopédie ont été divisés au hasard en deux groupes afin d’étudier les effets de deux cigarettes avant prémédication sur le volume et le pH gastrique. Le groupe des fumeurs a été permis de fumer deux cigarettes alors que le groupe de non fumeurs n’etait pas permis de fumer. II n’y a eu aucune différence significative dans le volume ou le pH entre les deux groupes soil immédiatement après intubation ou avant l’extubation. Ainsi le risque d’aspiration n’est pas diminué si on s’abstient de fumer la cigarette pour une phase aiguë.

The effect of spinal analgesia and surgery on peroperative drug absorption and gastric emptying in man

Paracetamol 20 mg kg‐1 dissolved in 200 ml of water was given by mouth to seven patients undergoing minor orthopedic surgery in spinal analgesia, and again 2 weeks later. The rate of paracetamol absorption was significantly delayed by spinal analgesia and surgery, indicating an inhibition of peroperative drug absorption and gastric emptying. The effect of spinal analgesia on gastric emptying was not able to normalize the delayed peroperative gastric emptying produced by surgery, and suggests that surgery is an important factor in peroperatively delayed gastric emptying.

Effect of chlorpromazine on drug absorption and gastric emptying in man

In a double-blind study the effect of a single IV dose (25 mg) of chlorpromazine on gastric emptying, as determined by the rate of paracetamol absorption, was measured in seven healthy volunteers. Each volunteer acted as his/her own control. There was no significant difference between the maximum paracetamol concentration, the time to reach the plasma maximum concentration, and the area under the plasma concentration time curve from 0-120 minutes on the two occasions, indicating unchanged gastric emptying after administration of chlorpromazine.RésuméDans une étude à double insu, on a mesuré ľeffet ďune dose unique i. v. (25 mg) de chlorpromazine sur la vidange gastrique tel que déterminé par le taux ďabsorption de paracétamol, chez sept volontaires en santé. Chaque volontaire était son propre témoin. Les deux fois, il n’y avait pas de différence significative dans la concentration maximale de paracétamol, le temps requis pour atteindre la concentration plasmatique maximale, et la surface sous la courbe du temps de la concentration plasmatique de 0-120 minutes, ce qui démontrait une vidange gastrique inaltérée après ľdministration de chlorpromazine.