Leonidas G. Koniaris

Background: Moderate (conscious) sedation is required to perform endoscopic procedures. Capnography provides a means for continuous, real-time monitoring of ventilation and may also decrease the incidence of oversedation. Methods: A retrospective examination of all endoscopic procedures performed from January through December 2001 at our institution was undertaken to determine the potential benefits of capnographic monitoring. Results: In 4,846 endoscopic procedures performed without capnography, adverse outcomes related to moderate sedation were noted in 14 cases (0.29%). A subset of patients at higher risk for moderate sedation was identified. There were no cases of oversedation in 600 cases monitored with capnography. The complication rates were not significantly different for the two groups (p = 0.30, NS). Conclusion: The addition of capnography during moderate sedation endoscopy does not appear to significantly lower anesthesia-related morbidity. However, in cases requiring moderate sedation for prolonged procedures, in older patients with comorbidities, or in instances where respiratory excursion of the patient is obscured from view, practitioners should nonetheless consider capnography.

IFN-inducible protein-10 (IP-10/CXCL10) is a CXC chemokine that targets both T cells and NK cells. Elevation of IP-10 expression has been demonstrated in a number of human diseases, including chronic cirrhosis and biliary atresia. Cytokine-responsive gene-2 (Crg-2), the murine ortholog of IP-10, was induced following CCl₄ treatment of the hepatocyte-like cell line AML-12. Crg-2 expression was noted in vivo in multiple models of hepatic and bile duct injury, including bile duct ligation and CCl₄, d-galactosamine, and methylene dianiline toxic liver injuries. Induction of Crg-2 was also examined following two-thirds hepatectomy, a model that minimally injures the remaining liver, but that requires a large hepatic regenerative response. Crg-2 was induced in a biphasic fashion after two-thirds hepatectomy, preceding each known peak of hepatocyte DNA synthesis. Induction of Crg-2 was also observed in the kidney, gut, thymus, and spleen within 1 h of two-thirds hepatectomy. Characteristic of an immediate early gene, pretreatment of mice with the protein synthesis inhibitor cycloheximide before either two-thirds hepatectomy or CCl₄ injection led to Crg-2 superinduction. rIP-10 was demonstrated to have hepatocyte growth factor-inducing activity in vitro, but alone had no direct mitogenic effect on hepatocytes. Our data demonstrate that induction of Crg-2 occurs in several distinct models of liver injury and regeneration, and suggest a role for CRG-2/IP-10 in these processes.