Oxycodone vs. fentanyl in the treatment of early post-operative pain after laparoscopic cholecystectomy: a randomised double-blind study.

BACKGROUND: It has been suggested that oxycodone is superior to other opioids in the treatment of visceral pain. We therefore compared the effect of intravenous (i.v.) oxycodone and i.v. fentanyl on post-operative abdominal (visceral) pain after outpatient laparoscopic cholecystectomy. METHODS: Seventy-eight patients were randomised to intra- and post-operative pain treatment with either oxycodone (n=39) or fentanyl (n=39). The patients received 10 mg oxycodone/100 microg fentanyl at the end of anaesthesia. In the post-anaesthetic care unit (PACU), 5 mg oxycodone/50 microg fentanyl was administered to patients with moderate pain [3-5 on a numeric rating scale (NRS)], and 10 mg oxycodone/100 microg fentanyl was administered to patients with severe pain (>5 on an NRS). The following measures were recorded: intensity of pain at arrival, after 30, 60 and 90 min and at discharge from the PACU; total consumption of oxycodone/fentanyl; nausea; vomiting; sedation and pressure tolerance thresholds. RESULTS: The median intra- and post-operative consumption of oxycodone was 15 mg (range: 10-40 mg) and the consumption of fentanyl was 200 microg (range: 100-500 microg). The intensity of abdominal pain was significantly lower in the oxycodone group at arrival (P<0.05), after 30, 60 and 90 min, and at discharge from the PACU (P<0.01). There was a strong tendency towards more side effects with oxycodone. CONCLUSIONS: Oxycodone provided better analgesia but also more side effects, suggesting that the doses used in the present study may not be equipotent.

Scrutinizing incident reporting in anaesthesia: why is an incident perceived as critical?

BACKGROUND: The purpose of the present study was to measure the incidence and type of incidents that occurred in relation to anaesthesia and surgery during a 1-year period in six Danish hospitals. Furthermore, we wanted to identify risk factors for incidents, as well as risk factors for incidents being deemed critical. METHODS: A four-page questionnaire describing patient data, type of anaesthesia and surgery, and occurrence of incidents was filled in for all anaesthesias in the period, and subsequently processed. The incident reporting form incorporated 59 predefined adverse events. The occurrence of one or more of these events described the incident. When the reporting anaesthetist deemed that an incident had harmed the patient, that incident was defined as critical. RESULTS: A total of 64,312 anaesthesias were reported, and in 7754 of them one or more incidents occurred. A total of 8510 incidents occurred, 4077 of them were solely related to the anaesthetic procedure, 3702 described events related to physiological alterations in the patient (physiological incidents). Three hundred and twenty-three of the incidents were deemed critical. High ASA score, high age, abdominal surgery, urgent surgery, and complex anaesthetic procedure were significant risk factors for physiological incidents and critical incidents. We could not identify a simple subset of adverse events that could adequately be used to describe the critical incidents. However, complex incidents, i.e. incidents involving more than one adverse event, were more likely to be deemed critical than simple incidents. CONCLUSION: The incidence of incidents was 12.1%, and the incidence of critical incidents was 0.5%. Incidents were more likely to be deemed critical in patients with an ASA score of III and above undergoing urgent surgery.

Cost consciousness among anaesthetic staff.

BACKGROUND: Anaesthetists, like all other specialists, need to be aware of the costs of drugs, fluids and disposables commonly used in their clinical practice so that excessive costs and waste can be minimized without compromising patient care or safety. The present study describes cost consciousness among 120 anaesthetic staff members in two Danish anaesthetic departments. METHOD: A prospective study questioning 120 anaesthetic staff members (69 anaesthetic nurses, 35 senior anaesthetists and 16 junior anaesthetists) about the costs of 29 drugs, fluids and disposable used in routine anaesthetic practice. RESULTS: After the study period 107 questionnaires (90%) were available for analysis. Thirty-eight percent of all estimated costs were within 50% of the actual costs and 85% were within 100%. The costs of relatively expensive items such as isoflurane, enflurane, sevoflurane and hydroxyethyl starch were consistently underestimated, whereas cheaper items such as narcotic drugs, endotracheal tubes, intravenous tubing, plastic syringes and Quincke spinal needle were consistently overestimated. In general, the anaesthetic staff overestimated the costs by 69% (range -24% to 270%). The anaesthetic nursing group overestimated the costs by 49% (range -24% to 270%), junior anaesthetists by 94% (range 25% to 226%) and senior anaesthetists by 72% (range -14% to 135%). CONCLUSION: This study shows that the overall consciousness of the costs of anaesthetic drugs, fluids and disposables has to be improved in order to permit the staff to optimize resources.

[Severely traumatized patients admitted to Aarhus Community Hospital 1994-1995]. / Svaert tilskadekomne patienter indbragt til Arhus Kommunehospital 1994-1995.

In Denmark, only few studies have addressed the problem of severe trauma. In relation to establishing a trauma manual at our hospital we studied trauma patients requiring immediate anaesthesiological assistance. Patients from the preceeding years, 1994-1995 were identified. The injuries were scored according to the Abbreviated Injury Scale (AIS), and Injury Severity Scores (ISS) were calculated. Two hundred and fifty-eight trauma patients were identified, 132 of these were severely injured, defined as having ISS > or = 15. Of these, 75 patients were multitraumatised, defined as AIS > or = 3 in at least two regions. None of the patients with ISS < or = 15 died. Mortality was 49% among severely injured but not multitraumatised patients, while mortality was 56% among the multitraumatised patients. Head injuries were the most frequently found severe injury (AIS > or = 3), followed by injuries to the thorax and extremities. The anaesthesiologist and the orthopaedic surgeon were involved in initial diagnosis and treatment in all patients, and beyond these a variety of medical specialties were involved. In the light of this study we have revised our procedures and registration concerning severe trauma patients.

Increased urinary loss of uric acid in adults with acute respiratory failure requiring mechanical ventilation.

INTRODUCTION: The purpose of this study was to test a hypothesis of increased urinary excretion of uric acid as an indicator of adenosine triphosphate (ATP) degradation in adult patients with acute respiratory failure, and to look for a correlation to the clinical outcome. STUDY DESIGN: Prospectively 31 patients with acute respiratory failure were studied. The patients were divided into two groups according to the clinical outcome: the need for solely supplemental oxygen (group 1), death or mechanical ventilation (group 2). METHODS: Uric acid was determined by spectrophotometry. RESULTS: Mean uric acid excretion was 39 mumol/kg (range, 7 to 92 mumol/kg) body weight/per 24 h in group 1 (16 patients) compared with 65 mumol/kg/24 h (range, 8 to 253 mumol/kg/24 h) in group 2 (13 patients were mechanically ventilated, and two patients died). The difference was highly significant (p less than 0.0001). CONCLUSION: Increased amount of urinary uric acid was related to the severity of acute respiratory failure in adults.

[Continuous positive airway pressure (CPAP)--does the equipment live up to its name?]. / Continuous positive airway pressure (CPAP)--lever apparaturet op til navnet?

The purpose of this study was to evaluate the in- and expiratory pressures achieved by the use of different continuous positive airway pressure (CPAP) delivery systems. The study was performed on ten healthy adults breathing spontaneously with: 1) "simple CPAP", consisting of a fresh gas flow around 40 l/min and reservoir balloons of 2, 6 and 10 l and expiration against a water column, 2) a high-flow system CR60 CPAP, designed for home treatment and 3) another high-flow system Down's CPAP. Both high-flow systems used a venturi device (Downs Flow Generator, Vital Signs) giving flows around 90 and 170 l/min in our set-up, and the same PEEP valves (Vital signs) were used. All systems were tested with expiratory pressures set at 5, 10 and 20 cm H2O. Individual responses were found, but in general the simple CPAP with a 10 l latex balloon reservoir gave optimal CPAP. The high-flow systems were not found to provide better CPAP, however, CR60 CPAP was found also to be optimal with 5 and 10 cm H2O. Down's CPAP provided 3-5 cm higher expiratory pressure than the intended CPAP level. We recommend measurement of the pressure during the CPAP treatment to ensure that the intended CPAP is achieved.

Variation in spinal analgesia with plain bupivacaine 0.5% when repeated in the same patient.

The study was done to see if it was possible to predict the level of analgesia in repeated spinal blocks with our routine technique where the patient is seated during injection of plain 0.5% bupivacaine 3.5 ml at the L3-L4 interspace and placed in the lithotomy position after 0.5 min. Thirty patients with tumour of the bladder had two spinal blocks during a 13-month period. The segmental spread of sensory loss was tested with the pin-prick technique. A wide range of height of blocks was found, increasing with age. Regression analysis on maximum cephalad spread of the second spinal analgesia against the first had a slope of 0.48 (P less than 0.01 for the hypothesis that the slope is zero). A significant correlation between the time for maximal cephalad spread was found, while the correlation between duration of thoracal analgesia was non-significant.

Hypoalgesia following intrathecal morphine: a segmental dependent effect.

The onset phase of hypoalgesia, following intrathecal morphine, was assessed by experimental argon laser-induced pain. A dose of 0.4 mg morphine was injected pre-operatively at the L3-L4 level into nine patients. The thresholds to laser-induced pain and pain-evoked brain potentials were monitored for 2 h at the S1, L1, and C7 dermatomes. Hypoalgesia was detected at the S1 and L1 dermatomes after 5 and 15 min, respectively. No hypoalgesic effect was found at C7. This indicates that hypoalgesia was caused predominantly by segmental spinal mechanisms during the onset phase, and not by a general widespread effect. No latency changes (conduction delay) of the brain potentials evoked from the hypoalgesic dermatomes were found. Cutaneous pain, induced experimentally by laser stimulation, has the advantage of being quantitative and is useful to assess the onset and the segmental spread of hypoalgesia.

Subhypnotic doses of thiopentone and propofol cause analgesia to experimentally induced acute pain.

Subhypnotic doses of thiopentone are considered to have a hyperalgesic effect, while propofol has a hypoalgesic effect. We investigated the effect of these drugs on the nociceptive system by measuring the pain threshold to laser stimulation and the pain evoked potential (power and latency). Nineteen patients (ASA group I) participated. Twelve patients received thiopentone 0.5 mg kg-1 and propofol 0.25 mg kg-1 in random order separated by an interval of 14 h, and seven patients received saline. Immediately after the injection of both agents, the pain threshold was increased significantly (P less than 0.001) and the amplitude of the evoked potential was reduced significantly (P less than 0.05), while the latency of the evoked potential remained constant. It is concluded that, in subhypnotic doses, both thiopentone and propofol decrease the acute pain evoked by argon laser stimulation.

Postoperative pain treatment after open knee surgery: continuous lumbar plexus block with bupivacaine versus epidural morphine.

The anesthetic and side effects of a continuous lumbar plexus block ("3-in-1" block) were compared with that of epidurally administered morphine after open knee surgery. Twenty-two patients were randomized into two groups in this prospective, double-blind study. At the end of surgery, catheters were inserted for all the patients into both the femoral nerve sheath and the epidural space. Pain treatment was given as either bupivacaine in the femoral catheter or morphine in the epidural catheter, with saline in the other catheter. All treatments were given as a bolus dose followed by continuous infusion. If the patients had pain, they were given morphine intramuscularly on demand. The pain scores and supplemental morphine consumption were low in both groups and did not differ significantly. Lumbar plexus block produced a statistically significant a lower incidence of nausea, vomiting, pruritus and urinary retention. Although no significant differences in pain relief were shown between the two methods, we conclude that postoperative lumbar plexus block is preferable for postoperative pain relief because there is a lower frequency of side effects.

[The quality of a manual method for the identification of the lumbar vertebrae]. / Undersøgelse af kvaliteten af en manuel metode til bestemmelse af lumbalhvirvler.

In order to identify the spinous processes in the lumbar region, we employ the following rule: that "the line between the iliac crests passes through the spinous process of L4 or the intervertebral space between the 4th and 5th lumbar vertebrae". Three anaesthetists (two junior staff and one consultant) identified a spinous process marked by lead-shot in 33 patients prior to radiological examination. No significant differences were found between the estimates made by the junior staff and the consultant and none of the following factors were of significance for the estimates: height, weight, weight index, sex or age of the patients. When the patients were subdivided according to the radiographic degree of pathological findings in the lumbar spine, only 48% of the estimates were found to be correct while where no or slight changes were present, 71% of the estimates were correct. The differences were significant. It is concluded that 40% of the estimates were incorrect but never by more than one segment. The method may be employed where unreliability of one segment is acceptable.

Onset phase of spinal bupivacaine analgesia assessed quantitatively by laser stimulation.

Analgesia was assessed quantitatively at various dermatomes (C7, T8, T10, T12, L1, L3, S1) for the first 30 min after subarachnoid administration of 0.5% bupivacaine 3.5 ml. Stimulation with 10 needles and laser stimulation could evoke pain in dermatomes with adequate analgesia to single needle stimulation. Analgesia was assessed by thresholds (sensory and pain) and by pain-related brain potentials (amplitude and latency) to laser stimulation. Little analgesia was found at T10, but it increased gradually towards caudal segments. The dermatome related to the site of the injection (L3) was not blocked to a greater extent than the surrounding dermatomes. Conduction time (the latency of the evoked brain potential) was increased relatively more from the S1 dermatome compared with L1.

Continuous blockade of the lumbar plexus after knee surgery: a comparison of the plasma concentrations and analgesic effect of bupivacaine 0.250% and 0.125%.

In 20 patients a continuous block of the lumbar plexus was administered after knee-joint surgery, and the analgesic effect of two different concentrations of bupivacaine was compared. The same volume of bupivacaine was given to both groups of patients: a bolus dose of 0.4 ml/kg, 0.5% or 0.25%, followed by infusion of 0.14 ml/kg/h, 0.25% or 0.125%, respectively, via a catheter placed in the neurovascular fascial sheath of the femoral nerve according to the "3-in-1 block" technique. The median morphine consumption during the first 16 h postoperatively was 6.0 mg when bupivacaine 0.5/0.25% was used and 9.5 mg when 0.25/0.125% was used. This difference is not significant. The visual analogue pain scores were also similar in the two groups (P greater than 0.05). All plasma concentrations were below 4 micrograms/ml, the highest concentration measured being 3.6 micrograms/ml. It is concluded that when used for a continuous block of the lumbar plexus after knee-joint surgery, bupivacaine in a concentration of 0.125% offers the same pain relief as a concentration of 0.25%, and the risk of toxic reactions is reduced.

[Inguinal paravascular block (3-in-1 block)]. / Den ingvinale paravaskulaere blokade ("3-i-1" blok).

The three main nerves from the lumbar plexus may be blocked by injection of local anesthetic into the facial envelope of the femoral nerve ("three-in-one block"). The femoral nerve may be localized by obtaining paresthesia, by employing a nerve stimulator or by the loss of resistance technique. We prefer the use of a nerve stimulator. The "three-in-one block" may be employed for immediately pain relief of pain and for treatment of postoperative pain from fractures in the hip, femur and knee. Introduction of a catheter into the femoral nerve sheath is recommended to provide continuous block of the lumbar plexus for relief of postoperative pain.

[Calculation of the amount of thiopental used in induction of anesthesia]. / Opgørelse af tiopentalforbruget ved anaestesi-indledning.

A retrospective investigation was undertaken of the amount of thiopental employed in induction of anaesthesia. This revealed that only three factors were of significance for the dosage employed: age, weight and cardiac disease. In patients over the age of 70 years, the dosage could be reduced by 30%. In patients of more than 10% overweight, the dosage could be reduced by 7% and in patients who were 10% underweight, the dosage was increased by 10%. In cases of heart disease the dosage was reduced by 20% in the proportion of 5 mg thiopental per kg body-weight.

[Transdermal scopolamine to prevent postoperative nausea and vomiting after uterine curettage and termination of pregnancy. A double-blind clinically controlled study with placebo]. / Transdermal skopolamin som profylakse mod postoperativ kvalme ved abrasio uteri og abortus provocatus. En dobbeltblind klinisk kontrolleret undersøgelse med placebo.

A randomized double-blind clinically controlled investigation with a placebo was undertaken to investigate the prophylactic effect of transdermal scopolamine on postoperative nausea and vomiting after dilatation and curettage and termination of pregnancy. No significant difference was found between the placebo and transdermal scopolamine. On the other hand, the patients in the scopolamine group had significantly more postoperative discomforts which were attributable to the anticholinergic effect of scopolamine. Transdermal scopolamine cannot be recommended for the prophylaxis of postoperative nausea and vomiting following uterine curettage and termination of pregnancy.