Meta-analysis of the efficacy of extradural clonidine to relieve postoperative pain: an impossible task.

Clonidine, an alpha2 adrenoceptor agonist, has anti-hypertensive and anti-nociceptive effects. It is commonly used in association with local anaesthetics and opioids to enhance the quality and duration of extradural analgesia in the postoperative period, and to decrease the incidence of side effects. As a sole analgesic, it has seldom been used to relieve postoperative pain. The dose of extradural clonidine to achieve good pain relief without deleterious side effects remains undetermined. In order to address this problem, we performed a computer search via two well-known databases, Medline and Excerpta Medica, covering the period from 1985 to September 1997. One hundred and fifty-nine articles were retrieved of which 38 dealt with extradural clonidine and postoperative pain. All but 16 studies suffered from serious design flaws, such as lack of controls and/or randomization, or inadequate statistical analysis. The data from these studies were difficult to interpret because of the tremendous variation in variables, especially dose of clonidine, level of extradural injection, time of administration, type of anaesthesia, type of surgery, and reference and rescue drugs. The simultaneous extradural use of local anaesthetics and opioids further hindered data interpretation, and precluded any meta-analysis. Proposals for a standard study design are made to help comparison between studies involving extradural clonidine and postoperative pain.

[A retrospective evaluation of venous thrombosis prevention in regulated orthopedic surgery (1986-1989) at the Saint-Germain-en-Laye hospital center]. / Examen rétrospectif de la prévention des thromboses veineuses en chirurgie orthopédique réglée (1986-1989) au Centre hospitalier de Saint-Germain-en-Laye.

The first, from the beginning of 1986 to September 1987 prescribing subcutaneous Heparin; the second from October 1987 to the end of 1988, prescribing a low molecular weight Heparin. There was a 2.6% incidence of pulmonary embolism and a 5.2% incidence of phlebitis in the first group (77 cases). In the second group there was a 1.54% incidence of PE and 3.08% incidence of phlebitis (65 cases). Other techniques know for decreasing the risk of thromboembolic complications were in both groups: hemodilution--locoregional anesthesia--early rising--post-op respiratory and functional physiotherapy.