Successful resuscitation of an ASA 3 patient following ropivacaine-induced cardiac arrest.

A patient with severe myocardial disease and acute-on-chronic renal failure was undergoing a brachial plexus block for formation of an arteriovenous fistula when accidental intravascular injection of ropivacaine resulted in ventricular fibrillation. Cardiopulmonary resuscitation was instituted immediately and the advanced life support algorithm was followed until the return of sinus rhythm. Although, in comparison with bupivacaine, ropivacaine appears to be a safer local anaesthetic agent in the setting of intravenous injection, the emphasis on safety should remain a priority. Awareness of the risk of central nervous system and cardiovascular toxicity and preparation for immediate commencement of resuscitation in the event of toxicity remain of paramount importance.

Regional immunosuppression in esophageal squamous cancer: evidence from functional studies with matched lymph nodes.

Although production of immunosuppressive factor(s) by esophageal squamous cancer has been demonstrated, systemic immunosuppression occurs late. Whether local immunosuppression by tumor-derived factors occurs in vivo as a potential mechanism of escape from immune surveillance is unknown. We found that lymphocytes from nodes draining distal esophageal squamous tumors in 23 consecutive patients had depressed proliferative and cytotoxic responsiveness relative to both lymphocytes from a reference node outside the field of drainage and matched PBL from the same patient. In a subset of patients in which more than one tumor-draining node was examined, a radial or zonal immunosuppression relative to the primary tumor was evident. The findings were unrelated to surgery or anatomic location because all but 2 of 26 control patients with esophagogastric adenocarcinoma had normal or enhanced lymphocyte responsiveness in the tumor-draining node. The absence of overt or even micrometastatic nodal disease, as determined by immunostaining for cytokeratin expression, coupled with the long-term survival of several of the patients, strongly suggests that the immunosuppressive effect is due to mechanisms other than metastases, and may be a premetastatic occurrence. We conclude that regional immunesuppression does exist in patients with esophageal squamous cancer when systemic immunity is still well preserved. The local immune suppression inhibits the generation of lymphokine-activated killer (LAK) cells and may be an impediment to potential immunotherapeutic strategies.

The effect of tunnelling on epidural catheter migration.

A prospective, randomised study of 82 patients having postoperative epidural analgesia was performed to determine whether the tunnelling of an epidural catheter influences its migration. Tunnelling of the catheter subcutaneously for a distance of 5 cm reduced the incidence of inward migration of 1 cm or more (p < 0.01) compared to a standard method of fixation with a transparent adhesive dressing. This effect was more marked if the epidural catheter was sited in the thoracic rather than the lumbar area. Sixty two percent (n = 26) of tunnelled catheters remained within 0.5 cm of their original position compared to 38% (n = 16) of non-tunnelled catheters, although this difference was not statistically significant. Outward catheter migration was not reduced by subcutaneous tunnelling.