Postsurgical compartment syndrome of the forearm diagnosed in a child receiving a continuous infra-clavicular peripheral nerve block.

Opinions diverge as to whether or not regional anaesthesia delays the diagnosis of evolving acute compartment syndrome. Withholding regional anaesthesia from patients with painful orthopaedic injuries may be ethically unacceptable, however. In this report, we describe a case of acute compartment syndrome in a 4-year old child who underwent resection of a forearm osteochondroma. Analgesia was satisfactory during the first post-operative night, but the child later complained of pain despite an effective infra-clavicular block. Motor function and sensibility were disturbed and the fingers were swollen. The forearm cast was removed as it was suspected to be causing external compression. Pain disappeared while motor function and sensation recovered. The child was discharged without any complications. Despite an effective peripheral nerve block and the young age of the patient, the diagnosis of acute compartment syndrome could be made thanks to a well-defined post-operative analgesia protocol, a high level of suspicion and careful clinical assessment when break-through pain occurred.

Functional study on TRPV1-mediated signalling in the mouse small intestine: involvement of tachykinin receptors.

Afferent nerves in the gut not only signal to the central nervous system but also provide a local efferent-like effect. This effect can modulate intestinal motility and secretion and is postulated to involve the transient receptor potential of the vanilloid type 1 (TRPV1). By using selective TRPV1 agonist and antagonists, we studied the efferent-like effect of afferent nerves in the isolated mouse jejunum. Mouse jejunal muscle strips were mounted in organ baths for isometric tension recordings. Jejunal strips contracted to the TRPV1 agonist capsaicin. Contractions to capsaicin showed rapid tachyphylaxis and were insensitive to tetrodotoxin, hexamethonium, atropine or L-nitroarginine. Capsaicin did not affect contractions to electrical stimulation of enteric motor nerves and carbachol. Tachykinin NK1, NK2 and NK3 receptor blockade by RP67580, nepadutant plus SR-142801 reduced contractions to capsaicin to a similar degree as contractions to substance P. The effect of the TRPV1 antagonists capsazepine, SB-366791, iodo-resiniferatoxin (iodo-RTX) and N-(4-tertiarybutylphenyl)-4-(3-cholorphyridin-2-yl)tetrahydropyrazine-1(2H)-carbox-amide (BCTC) was studied. Capsazepine inhibited contractions not only to capsaicin but also those to carbachol. SB-366791 reduced contractions both to capsaicin and carbachol. Iodo-RTX partially inhibited the contractions to capsaicin without affecting contractions to carbachol. BCTC concentration-dependently inhibited and at the highest concentration used, abolished the contractions to capsaicin without affecting those to carbachol. From these results, we conclude that activation of TRPV1 in the mouse intestine induces a contraction that is mediated by tachykinins most likely released from afferent nerves. The TRPV1-mediated contraction does not involve activation of intrinsic enteric motor nerves. Of the TRPV1 antagonists tested, BCTC combined strong TRPV1 antagonism with TRPV1 selectivity.