Techniques d'analgésie conventionnelle: morphiniques et non morphiniques. Indications,effets indésirables et surveillance

Morphine dosage must be carefully adapted in patients with renal failure or severe liver failure. The IV route is used for morphine titration in the post anaesthesia care unit (PACU), or for analgesia in children. Systematic (not on demand) intramuscular or subcutaneous morphine must be administered at intervals not longer than 4 hours. Dosage is best determined after IV titration in the PACU. Codeine, administered orally, is metabolised into morphine. Codeine has almost no effect in 7% of Caucasians and at least 15% of Asians. Nalbuphine, which has a sedative effect and a short half-life, is mainly used in children. Paracetamol (acetaminophen) is used orally or rectally, most often in combination with codeine. Paracetamol dosage is 60–90 mg · kg⁻¹· d⁻¹, including a 20 mg (orally), or 40 mg (rectally) loading dose. Its therapeutic ratio is low, with a potential hepatic toxicity. Dosage must be lowered in alcoholics or in patients under isoniazide therapy. Non-steroidal anti-inflammatory drugs are powerful antinociceptive agents. Their use must be restricted to the first 5 postoperative days. Their major contraindications are kidney failure, risk of gastrointestinal bleeding, coagulation disorders, allergy. They also have a marked morphine sparing effect and reduce therefore the respiratory depression induced by morphine.     

De la nosologie floue des polyarthrites rhumatoïdes débutantes et des spondylarthropathies débutantes : classifications carrées par raisonnement circulaire ?

Although rheumatoid arthritis (RA) and spondyloarthropathy (SP) are useful concepts in practice, it remains unclear whether they are diseases. Most experts believe they are syndromes. RA and SP may stem from a common root of undifferentiated inflammatory joint disease, perhaps related to an at least transient impairment in exogenous antigen clearance followed by an inappropriate immune response to persistence of the excess antigens. Whether the undifferentiated joint disease evolves into RA or into SP may depend on a number of patient-related factors, most notably genes, of which some may be common to RA and SP. Differences in the number of these factors may explain the considerable variations in disease severity across patients subjected to similar triggering insults. Mountains intertwined at their base may be an apt illustration of this hypothesis of a role for multiple and partly shared pathogenic factors in chronic inflammatory joint diseases. Binary classifications of early arthritis into early RA or early SP are often arbitrary and/or based on circular reasoning. The same is true of the cutoffs considered suggestive of these “diagnoses”. The controversy in recent publications on this issue and the limited efficacy of existing criteria in diagnosing early RA and SP bear witness to these shortcomings.     

Analgésie postopératoire par voie locorégionale chez l'adulte: techniques perimédullaires et périphériques. Indications,effets indésirables et surveillance

Regional analgesia is a very effective way to treat postoperative pain. Lumbar and thoracic epidural analgesia are well adapted to major abdominal and thoracic surgery. Nevertheless, respiratory side effects induced by opioids are potentially severe and an adequate monitoring is essential. In orthopaedic surgery, perineural blocks are the best technique to manage postoperative pain and perineural catheters may be used. The importance of intra-articular analgesia, simple and safe, is not fully understood. The association of a local anaesthetic inducing a minor motor block and a strong sensitive block (bupivacaine, ropivacaine), with an opioid seems to be the best pharmacologic choice regarding quality of analgesia and safety. Benefits of postoperative regional analgesia on mortality and morbidity are not demonstrated. Medical and nursing staff and specialized units should improve quality of postoperative regional analgesia as well. General guidelines for the practice of regional anaesthesia must be closely followed.     

Dégénérescence discale et hernie discale : rôle des contraintes mécaniques

Experimental studies on the role for mechanical stresses in the genesis of disk degeneration and herniation are reviewed. Simple mechanical stimulations of functional vertebral segments cannot cause a disk herniation: a complex mechanical stimulation combining forward and lateral bending of the spine followed by violent compression is needed to produce posterior herniation of the disk. Intervertebral disk degeneration seems to influence the development of posterior disk herniation or foraminal disk protrusion. Furthermore, direct mechanical stimulation of the disk tissue or cells generates complex metabolic and cellular responses that lead to qualitative and quantitative modulation of disk matrix proteins. Thus, it is becoming increasingly likely that physical and metabolic factors act in concert to produce disk herniation.     

Devenir des mono-arthrites chroniques indéterminées : étude rétrospective de 46 cas

Objective. – To determine the natural history of undifferentiated monoarthritis of more than 3 months’ duration and to evaluate the usefulness of classic diagnostic tools for identifying factors associated with outcomes.Method. – Retrospective study of 46 patients with undifferentiated monoarthritis of more than 3 months’ duration.Results. – Full resolution was the outcome in 50% of cases. Rheumatoid arthritis and spondyloarthropathy were the most common diagnoses in the remaining patients. HLA-B27 status was the only significant predictor of outcome: progression to spondyloarthropathy was significantly more common (P = 0.05) among HLA-B27-positive patients. Mean time to full recovery was significantly shorter than mean time to disease progression (12 vs. 45 months, P = 0.0015). Intraarticular glucocorticoid injections were effective in over 50% of patients. Arthritis relief during the month following the injection was associated with self-limited disease. The role for magnetic resonance imaging in managing patients with undifferentiated monoarthritis remains unclear.Conclusion. – In patients with undifferentiated monoarthritis, the likelihood of a full recovery is 50%. The only significant predictor of outcome was positive HLA-B27 status, which was associated with progression to spondyloarthropathy.     

Lithiase rénale : des mécanismes au traitement médical préventif

Renal lithiasis is a frequent pathology (prevalence ranging from 10 to 12% in France) and a recurrent condition. It is associated with chronic kidney disease and is responsible for 2 to 3% of cases of end-stage renal disease, especially if it is associated with nephrocalcinosis and/or is part of a monogenic disease (1.6% of lithiasis in adults, including 1% of cystinuria). In order to understand the pathophysiology of the nephrolithiasis, the analysis of stones (morphological and by infrared spectrophotometry) as well as a minimal biological evaluation including crystalluria must be carried out. Calcium nephrolithiasis is the most common form (more than 80%). Its preventive medical treatment relies on simple hygienic dietetics: non-alkaline hyperdiuresis greater than 2 liters/day, normalization of calcium intakes (1 g/day to be distributed over the three meals), restriction of sodium intakes (6 g/day) and of protein intakes (0.8–1 g/kg of theoretical weight/day), and avoidance of foods rich in oxalate. If there is a hypercalciuria (greater than 0.1 mmol/kg of theoretical weight/day with normal calcium intakes), its mechanism should be explored with an oral calcium load test. In the absence of primary hyperparathyroidism, thiazide diuretics can be prescribed, taking care to prevent hypokalemia and iatrogenic hypocitraturia. The treatment of uric acid lithiasis includes alkaline hyperdiuresis (urinary pH 6.2 to 6.8). Allopurinol is only justified if the urinary excretion of uric acid exceeds 4 mmol/day. With a well-managed medical treatment, more than 80% of recurrent lithiasis can be stopped, making nephrolithiasis one of the kidney diseases the more accessible to the preventive medical treatment.