M. Ibsen

Onset and duration of action of rocuronium – from tracheal intubation, through intense block to complete recovery

Background: The primary objective of this study was to establish the relation between the post tetanic count (PTC) and the time to reappearance of the first response (T1) in train‐of‐four (TOF) nerve stimulation following rocuronium 0.6 mg/kg, 0.9 mg/kg, and 1.2 mg/kg. The secondary objective was to evaluate the intubation conditions after 1 min.

Preoperative infiltration of the surgical area enhances postoperative analgesia of a combined low–dose epidural bupivacaine and morphine regimen after upper abdominal surgery

In a randomized, blinded trial we assessed the value of adding preoperative infiltration of the surgical area with bupivacaine to a low dose epidural regimen for postoperative pain treatment. Forty–nine patients scheduled for major upper abdominal surgery during combined thoracic epidural (bupivacaine + morphine) and general anaesthesia were studied. Postoperative analgesia was epidural bupivacaine 10 mg hr‐1 + morphine 0.2 mg hr‐1 for 72 h. The patients randomly received preoperative infiltration of the surgical area with bupivacaine 0.25%, 40 ml (group I); or no infiltration (group II). Pain was evaluated at rest, during cough and during mobilization six and eight h after start of surgery, and at 8 a.m. and 4 p.m. on the following days until 72 h after start of surgery. The sensory level of analgesia was evaluated by pin prick. We found no difference between the two groups during rest and cough. However, during mobilization group I had lower pain scores compared to group II (P < 0.05). There was a significant reduction in the need for supplemental intramuscular morphine in the treatment group compared to the control group (P <0.05). Thus an enhanced analgesic effect was demonstrated by adding preoperative infiltration of the surgical area with local anaesthetic to a low dose epidural bupivacaine/morphine regimen after upper abdominal surgery.

Low‐flow isoflurane‐nitrous oxide anaesthesia offers substantial economic advantages over high‐and medium‐flow isoflurane‐nitrous oxide anaesthesia

Isoflurane consumption was studied for three different fresh gas flows in patients scheduled for major elective abdominal, urological or gynaecological surgery under general anaesthesia with an expected duration of 2 h or more. Thirty patients were randomly assigned to either high‐flow anaesthesia using a partial rebreathing system without carbon dioxide absorption (Mapleson D) or medium‐ or low‐flow anaesthesia using a circle system with carbon dioxide absorption. Patients were anaesthetised with isoflurane in 40% oxygen and 60% nitrous oxide. The amount of isoflurane consumed was measured with a precision scale. The total consumption of liquid isoflurane (mean ± s.d.) during the first 2 h was 40.8± 12.2 ml in the high‐flow group, 18.5 ± 5.4 ml in the medium‐flow group and 7.9 ± 2.2 ml in the low‐flow group. The corresponding cost of isoflurane for the three groups was 214 Danish kroner (DKK) (±19.5), 97 DKK (±8.8) and 42 DKK (±3.8), respectively. The calculated total cost of anaesthetics was 286 DKK(±26), 155 DKK (±14.1) and 91 DKK (±8.3), respectively. In conclusion, low‐flow isoflurane‐nitrous oxide anaesthesia offers substantial economic advantages over high‐ and medium‐flow isoflurane‐nitrous oxide anaesthesia.

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.

Plasma cholinesterase activity and duration of action of mivacurium in phenotypically normal patients

Background: The short duration of action of mivacurium is due to its rapid hydrolysis by plasma cholinesterase (pChe). In patients with normal phenotype, low pChe activity because of, for instance, disease or intake of drugs may prolong the duration of action of mivacurium. The purpose of this study was to evaluate the relationship between pChe activity and the duration of action of mivacurium 0.2 mg/kg in phenotypically normal patients.

Effects of endotoxaemia on markers of permeability, metabolism and inflammation in the large bowel of healthy subjects

Background:  Increased permeability and increased luminal concentrations of l‐lactate have previously been shown in the large bowel in septic patients. To advance these observations, a human model of colorectal barrier failure in sepsis is desirable. Therefore, we assessed the effects of endotoxaemia on markers of permeability, metabolism and inflammation in the large bowel in healthy subjects.

Psychomimetic reactions after neurolept and propofol anaesthesia

The purpose of this study was to compare the frequency of psychomimetic reactions after 24 h and 3 months following total intravenous anaesthesia with propofol and neurolept anaesthesia. Forty otherwise healthy female patients were randomly divided into two groups. All were undergoing elective gynaecological laparotomy for non‐malignant disease. Nineteen patients were anaesthetized with droperidol, fentanyl, pancuronium, N2O/O2. Twenty patients received total intravenous anaesthesia with propofol, fentanyl and pancuronium. Twenty‐four hours after the anaesthesia the patients were interviewed about their subjective experiences of anaesthesia and recovery. Three months after the operation the patients were sent a questionnaire concerning ability to work, sleep and memory disorders. After 24 h the anaesthesia was judged as good by 18 patients receiving propofol and 13 patients receiving NLA (n.s.). The recovery was judged as good by 16 patients in the propofol group and six patients in the NLA group (P<0.05). Locked‐in feelings were reported by one patient in the propofol group and ten patients in the NLA group (P<0.01). Impairment of memory was reported by one patient in the propofol group and seven patients in the NLA group (P<0.01). A questionnaire used after 3 months was answered by 18 patients in the propofol group and 17 patients in the NLA group. There were few complaints, and no differences were found between the two groups. In conclusion, total intravenous anaesthesia with propofol seems more acceptable than anaesthesia with neurolept as judged by the patients 24 h after anaesthesia. There were no differences between the two groups concerning psychomimetic reactions 3 months after anaesthesia.

Lactate concentrations in the rectal lumen in patients in early septic shock.

Background: Previously, we observed that rectal luminal lactate was higher in non‐survivors compared with survivors of severe sepsis or septic shock persisting >24 h. The present study was initiated to further investigate this tentative association between rectal luminal lactate and mortality in a larger population of patients in early septic shock.

Norepinephrine in low to moderate doses may not increase luminal concentrations of L-lactate in the gut in patients with septic shock.

Aim:  To investigate the effect of different doses of norepinephrine (noradrenaline) on luminal concentrations of l‐lactate in the rectum and stomach in patients with fluid‐resuscitated septic shock.

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.