[Gabapentin--yet another antiepileptic agent for the treatment of neuropathic pain?]. / Gabapentin--endnu et antiepileptikum til behandling af neuropatiske smerter?

Gabapentin is a recently introduced anti-epileptic drug used as an adjuvant in partial and secondarily generalised tonic-clonic seizures. Its mechanism of action has not been fully elucidated, but it seems that gabapentin may regulate voltage-dependent calcium channels, presumably on a spinal level, in the nociceptive system. Two large, controlled clinical trials of painful diabetic neuropathy and postherpetic neuralgia have demonstrated its analgesic efficacy. The adverse effects associated with gabapentin treatment are relatively harmless, mild to moderate in severity, and usually transient, with tolerance developing 2-3 weeks after start of treatment. Gabapentin and tricyclic antidepressants are efficacious in the treatment of painful diabetic neuropathy and postherpetic neuralgia.

PaO2 during anaesthesia and years of smoking predict late postoperative hypoxaemia and complications after upper abdominal surgery in patients without preoperative cardiopulmonary dysfunction.

BACKGROUND: The incidence of late postoperative hypoxaemia and complications after upper abdominal surgery is 20-50% among cardiopulmonary healthy patients. Atelectasis development during anaesthesia and surgery is the main hypothesis to explain postoperative hypoxaemia. This study tested the predictive value of PaO2<19 kPa during combined general and thoracic epidural anaesthesia and the preoperative functional residual capacity (FRC) reduction in the 30 degree head tilt-down position for the development of late prolonged postoperative hypoxaemia, PaO2<8.5 kPa for a minimum of 3 out of 4 days, and other complications. Forty patients without cardiopulmonary morbidity, assessed by ECG, spirometry, FRC and diffusion capacity preoperatively, underwent upper abdominal surgery. PaO2 during anaesthesia and preoperative FRC reduction were compared to known risk factors for the development of hypoxaemia and complications: age, pack-years of smoking and duration of operation. The effect of optimizing pulmonary compliance with peroperative positive end-expiratory pressure (PEEP) on postoperative hypoxaemia and complications was evaluated in a blinded and randomized manner. RESULTS: Late prolonged postoperative hypoxaemia and other complications were found in 37% and 38% of the patients, respectively. Patients with PaO2>19 kPa during anaesthesia with F(I)O2=0.33 exhibited a risk, irrespective of PEEP status, of suffering late prolonged hypoxaemia of 0% (0;23) and patients with PaO2<19 kPa a risk of 52% (32;71), P<0.005. Having smoked more than 20 pack-years was associated with a 47% (19;75) higher incidence of postoperative complications than having smoked less than 20 pack-years, P<0.006. CONCLUSIONS: PaO2 during anaesthesia and smoked pack-years provide new tools evaluating patients undergoing upper abdominal surgery in order to predict the patients who develop late postoperative hypoxaemia and complications.

[Methadone as an analgesic]. / Methadon som analgetikum.

Methadone is a synthetic opioid agonist which has been available for more than 40 years. Although its main use has been in the maintenance therapy of opioid addicts, it has a number of unique characteristics including excellent analgesic effect, a high bioavailability, no known active metabolites, long duration of action during long-term treatment, high potency, and low cost. However, its use is limited by the complexity of the pharmacokinetics, with a risk of drug accumulation with toxic effects. Recent findings suggest that standard equianalgesic tables are unreliable, because methadone is much more potent when used for long-term treatment. Therefore methadone should be titrated carefully and increases in dosage should be performed every third or fourth day.

[Diagnosis and treatment of postoperative nerve damage. Chronic neuropathic pain]. / Diagnose og behandling af perifere nerveskader efter operationer. Kroniske neuropatiske smerter.

Neuropathic pain is caused by lesions in the peripheral and/or central nervous system. Patients with pain due to nerve damage after operations are often misinterpreted and met with suspicion of malingering. Neuropathic pain typically presents with a characteristic set of sensory disorders independent of the cause. The sensory dysfunction may manifest itself as hypo- and/or hyperesthesia to one or more modalities, increased pain to painful stimuli (hyperalgesia) and/or pain to non-painful stimuli (allodynia). Conventional analgesics such as acetaminophen, non-steroidal anti-inflammatory drugs and opioids are often ineffective. Instead, antidepressants and anticonvulsants may be tried. The pain condition is unknown to most physicians. This may result in mistreated patients having undergone several unnecessary and ineffective investigations and treatments.

Effect of piroxicam in addition to continuous thoracic epidural bupivacaine and morphine on postoperative pain and lung function after thoracotomy.

Twenty-eight patients scheduled for lung resection with lateral thoracotomy and postoperative chest drains during combined thoracic epidural bupivacaine plus morphine and general anaesthesia were studied. Postoperative pain treatment was continuous epidural infusion of bupivacaine 0.25% 5 ml h-1 plus morphine 0.2 mg h-1 for 48 h and, in addition, the patients received rectal piroxicam 40 mg randomly and double-blind 12 h and 1 h before surgery and 20 mg 24 h-1 postoperatively or placebo. Pain was evaluated at rest, during cough and mobilisation, together with pulmonary function (FEV1, FVC, PEFR) and sensory level of analgesia repeatedly for 48 h. The results showed efficient pain relief, but without differences in pain scores or need for supplementary analgesics between the two groups. Pulmonary function decreased similarly in the two groups. Thus we were unable to show enhanced analgesia by supplementing an otherwise effective low-dose epidural bupivacaine and morphine treatment with piroxicam after thoracic surgery with chest drains.

[Patients' knowledge about their own medication--does verbal information help? A blind, randomized study]. / Patienters viden om egen medicin--hjaelper mundtlig information? En blindet, randomiseret undersøgelse.

Patient's knowledge about their own medicine is often insufficient, and this is possibly a contributory factor for noncompliance. We interviewed 65 patients (median age 61 years) from an out-patient clinic with free access and 86 patients (median age 68 years) from a hospital outpatient clinic. In both groups, knowledge about the dosage and the adverse effects of the drugs was poor. Old age and polypharmacy were associated with poor knowledge; there were no differences as regards knowledge between the two out-patient clinics. The 86 patients from the hospitals out-patient clinic were randomised to either 30 minutes of extended verbal information or to the standard information of the department. At the subsequent visit eight weeks later, a repeated interview indicated, that the informed group had generally improved knowledge about their own medication, while this was not the case in the control group. A statistically significant difference between the groups was, however, only found for medication knowledge about side effects. It is concluded that out-patients knowledge about their own medication is often poor, but can be improved by verbal information.

Changes in serum electrolyte and atrial natriuretic peptide concentrations, acid-base and haemodynamic status after rapid infusion of isotonic saline and Ringer lactate solution in healthy volunteers.

Opinions differ on the use of isotonic sodium chloride and Ringer lactate solution for extracellular volume depletion. We have compared changes in serum electrolyte concentrations and acid-base and haemodynamic status after rapid infusion of 2 litre of either isotonic sodium chloride or Ringer lactate solution in healthy volunteers. Changes within groups were small and statistically insignificant. Central venous pressure changes were associated with secretion of atrial natriuretic peptide, but this response was delayed.

The systemic availability of buprenorphine administered by nasal spray.

The kinetics and systemic bioavailability of intranasally administered buprenorphine have been investigated in 9 healthy volunteers in an intranasal/intravenous cross-over study. Each subject received a nominal 0.3 mg dose of buprenorphine intranasally followed one week later by a matched dose intravenously. For the intranasal administration mean tmax and mean Cmax were 30.6 min and 1.77 ng mL-1, respectively. Mean intranasal bioavailability was 48.2 +/- 8.35% (mean +/- s.e.m.) of the intravenous value. Intranasal administration may represent a valuable new delivery route for buprenorphine.

Antiestrogen therapy in pancreatic carcinoma: a preliminary report.

Ten patients with unresected pancreatic carcinoma, treated with Nolvadex 10 mg 3 times a day were compared to a historic untreated control group. The median survival was 7 months in the treated group compared to 3 months in the untreated. In the control group all patients died within the first 9 months, in the treated group 40% of the patients were still alive after 14 months.