The influence of hemorrhagic shock on ventilation through needle cricothyroidotomy in pigs.

BACKGROUND: The aim of this study was to examine the effects of controlled hemorrhage and shock on oxygenation and ventilation using needle cricothyroidotomy and jet ventilation in an animal model. METHODS: Twenty-four male pigs were randomly allocated into 4 groups: SHOCK (animals in hemorrhagic shock only), CRICH (animals that underwent needle cricothyroidotomy only), SHOCK+CRICH (animals in hemorrhagic shock + needle cricothyroidotomy), and SHAM (anesthetized animals submitted to surgical preparation only). All animals were surgically prepared and were observed for a period of 40 minutes (T0 - T40). Hemodynamic and blood gas variables were compared using analysis of variance and Bonferroni post hoc testing at a level of significance of 95%. RESULTS: CRICH and SHOCK+CRICH developed respiratory acidosis, with a progressive decrease of arterial pH after T20, and they presented a significant increase of PaCO(2) levels after T10, when compared with SHAM and SHOCK (P < .001). When SHOCK+CRICH was compared with CRICH, it presented a larger increase of PaCO(2) after T10 (P = .036) and an even more significant increase after T20 (P = .009). CONCLUSION: Hemorrhagic shock anticipated and intensified the retention of carbon dioxide and respiratory acidosis during manual jet ventilation through needle cricothyroidotomy in comparison with animals with jet ventilation but without shock. The results found in this work should be considered in future protocols for the assistance of victims of trauma in prehospital settings.

Evaluation of renal defect healing, hemostasis, and urinary fistula after laparoscopic partial nephrectomy with oxidized cellulose.

BACKGROUND AND PURPOSE: Laparoscopic partial nephrectomy (LPN) has been performed at several institutions using oxidized cellulose (OC) as a means of bleeding and urinary fistula (UF) prevention. However, a foreign-body reaction mimicking either abscess or tumor recurrence has been associated with the use of OC. We evaluated renal-defect healing after LPN with and without OC. MATERIALS AND METHODS: Sixteen female Landrace pigs underwent lower-pole excision; all the collecting systems were entered and then closed with absorbable running suture. In group 1, hemostatic U-shaped stitches were the only method of hemostasis. In group 2, a bolster of OC was added to the renal defect. The pigs were sacrificed at 1, 4, 7, or 21 days, and gross findings such as perirenal collection were observed. A catheter was advanced up to the kidney, and methylene blue was injected with collecting system pressure observation; burst pressure was defined as the appearance of extravasation. High risk for UF was defined as burst pressure <10 mm Hg. RESULTS: Neither hemorrhage nor urinoma was observed during sacrifice. One pig from group 2 had a burst pressure of 4 mm Hg At 7 days (high risk for UF). At 21 days in group 2, the tissue was grossly solid, apparently a granuloma. Suppuration tended to be greater in group 2. The foreign-body reaction was more intense in group 2 and was strongly present at 4, 7, and 21 days. CONCLUSIONS: The use of OC is associated with higher scores of suppuration and foreign-body reaction. After LPN with OC, postoperative day 7 might be a critical time for the development of urinary leakage.