A comparison of the end-tidal CO2 measured by portable capnometer and the arterial P CO2 in spontaneously breathing patients

AbstractAn end-tidal CO2 (ETCO2) monitor (capnometer) is used most often as a noninvasive substitute for P aCO2 in anesthesia, anesthetic recovery and intensive care. However, the utility and accuracy of the portable capnometer in spontaneously breathing patients with or without chronic pulmonary diseases has received little recognition. To determine the utility of the portable capnometer in general wards and in in-home care, we examined the correlation between ETCO2 measured by a portable capnometer and simultaneous P aCO2 measured in 41 spontaneously breathing patients. TV-ETCO2 (ETCO2 measured by tidal volume maneuver) was lower than P aCO2 by an average of 9.0 mmHg and VC-ETCO2 (ETCO2 measured by vital capacity maneuver) was lower than P aCO2 by an average of 0.5 mmHg. The mean difference between P aCO2 and VC-ETCO2 was not statistically significant. Regression analysis showed a close correlation between VC-ETCO2 and P aCO2 (r = 0.91, P < 0.0001). Thus, VC-ETCO2 was highly correlated with P aCO2. Furthermore, a close correlation between VC-ETCO2 and P aCO2 was also observed in patients with compromised pulmonary function (r = 0.88, P < 0.0001 in patients with below 70% of FEV1.0%; r = 0.89, P < 0.0001 in patients with below 80% of %VC). Our studies show that VC-ETCO2 measured by the portable capnometer gives a reliable point estimate ofP aCO2, and can be useful to evaluate the respiratory condition of spontaneously breathing patients in general wards and in in-home care

Survey of Molecular Mechanisms of Hyperbaric Oxygen in Tissue Repair

For more than six decades, hyperbaric oxygen (HBO) has been used for a variety of indications involving tissue repair. These indications comprise a wide range of diseases ranging from intoxications to ischemia-reperfusion injury, crush syndrome, central nervous injury, radiation-induced tissue damage, burn injury and chronic wounds. In a systematic review, the molecular mechanisms triggered by HBO described within the last two decades were compiled. They cover a wide range of pathways, including transcription, cell-to-cell contacts, structure, adhesion and transmigration, vascular signaling and response to oxidative stress, apoptosis, autophagy and cell death, as well as inflammatory processes. By analyzing 71 predominantly experimental publications, we established an overview of the current concepts regarding the molecular mechanisms underlying the effects of HBO. We considered both the abovementioned pathways and their role in various applications and indications

Repair of non-circumferential cervical trachea defects by three different latissimus dorsi flaps. A comparative studyin an experimental setting.

BACKGROUND: Large intrathoracic airway defects may be closed using a pedicled latissimus dorsi (LD) flap, with rewarding results. This study addresses the question of whether this holds true for extrathoracic non-circumferential tracheal defects. METHODS: A cervical segment of the trachea of 4 x 1 cm was resected in 9 white male pigs. The defect was stented with a silicone stent for 3 months and closed either by an LD flap alone (group a, n = 3), an LD flap with an attached rib segment covered by pleura (group b, n = 3), or an LD flap reinforced by a perforated polylactide (MacroPore) plate (group c, n = 3). The trachea was assessed by rigid endoscopy at 3 and 4 months and histologically at 4 months postoperatively. RESULTS: The degree of stenosis at the level of the reconstruction at 4 months was 25, 50 and 75% in group a, 15, 50 and 60% in group b, and 20, 95 and 95% in group c, respectively. The percentage of the defect covered by columnar epithelium was 100% in all animals of group a, 60, 100 and 100% in group b, and 10, 0 and 0% in group c. Resorption of the rib was seen in all animals of group b and obstructive inflammatory polyps were found in 2 animals of group c. CONCLUSION: Pedicled LD flaps provided less satisfactory results for closure of large non-circumferential extrathoracic airway defects than observed after intrathoracic reconstruction. A pedicled rib segment added to the LD flap did not improve the results obtained from LD flap repair alone, and an embedded MacroPore prosthesis may result in severe airway stenosis due to plate migration and intense inflammatory reaction protruding into the tracheal lumen