Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1999
Comparative StudyPercutaneous tracheostomy: a clinical comparison of dilatational (Ciaglia) and translaryngeal (Fantoni) techniques.
A number of percutaneous procedures for tracheostomy have been established within the last few years, among them a new technique by Fantoni using a translaryngeal approach for cannula placement. To compare the new translaryngeal tracheostomy (TLT) to the common percutaneous dilatational technique (PDT), we prospectively studied 90 patients who required elective tracheostomy. Tracheostomy was performed according to either the Ciaglia or the Fantoni technique in 45 patients at bedside. The overall complication rate was 11.1% (n = 5) in PDT, including aspiration of blood (n = 4) and severe bleeding requiring surgical intervention (n = 1). During TLT, there were technical difficulties involving guidewire placement in 31.1% (n = 14), and one patient required conversion to PDT. No other complications were noted in TLT. Regardless of the technique used, the postoperative PaO2/FIO2 ratio was slightly lower than preoperatively (P was not significant). When PDT and TLT were compared, the postoperative PaO2/FIO2 ratio was significantly lower in PDT than in TLT (P < 0.05), whereas the preoperative levels did not vary significantly between PDT and TLT. During TLT, the PaCO2 increased significantly, whereas it remained stable throughout PDT. No infection of the tracheostoma was noted in either the PDT or the TLT. We therefore consider both the PDT and the TLT equally safe and attractive techniques for establishing long-term airway access in critically ill patients. ⋯ Elective tracheostomy is a widely accepted procedure for gaining long-term airway access. Two techniques for percutaneous tracheostomy-the established Ciaglia method and the new translaryngeal Fantoni technique-were prospectively studied for perioperative complications and practicability in 90 critically ill-patients.
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Anesthesia and analgesia · Oct 1999
The continuous assessment of cerebrovascular reactivity: a validation of the method in healthy volunteers.
Using transcranial Doppler ultrasonography, we investigated the moving correlation between slow waves in arterial blood pressure (ABP) and blood flow velocity (FV) at different levels of cerebrovascular vasodilation provoked by changing PETCO2. Fourteen healthy volunteers were examined. The FV in middle cerebral arteries, PETCO2, and ABP were recorded during normocapnia, hypercapnia, and hypocapnia. The moving correlation coefficients between ABP and mean FV (FVm) or systolic FV (FVs) during spontaneous fluctuations in ABP were calculated for 3-min epochs and averaged for each investigation, thus yielding the mean index (Mx) and systolic index (Sx). As a reference method, Aaslid's cuff tests were performed to obtain the rate of regulation (RoR). RoR, Mx, and Sx significantly depended on PETCO2 (analysis of variance, P < 0.00001). At high PETCO2, cerebrovascular reactivity was disturbed as reflected in RoR values of < 0.17/s for all volunteers and increased values of Mx (> 0.4 in 86% of volunteers) and Sx (> 0.2 in 79% of volunteers). Overall, there was a reasonably good correlation of both Mx and Sx with RoR (R2 = 0.65 and 0.58, respectively). ⋯ Indices derived from the correlation between spontaneous fluctuations of blood flow velocity wave form and arterial blood pressure may be used for the noninvasive continuous monitoring of cerebrovascular reactivity.
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Anesthesia and analgesia · Oct 1999
Intraoperative hemodynamic predictors of mortality, stroke, and myocardial infarction after coronary artery bypass surgery.
Evidence that intraoperative hemodynamic abnormalities influence outcome is limited. The purpose of this study was to determine whether intraoperative hemodynamic abnormalities were associated with mortality, stroke, or perioperative myocardial infarction (PMI) in a large cohort of patients undergoing coronary artery bypass grafting. Risk factors and outcomes were queried from a state-mandated cardiac surgery reporting system at two hospitals in New York, NY. Intraoperative hemodynamic abnormalities were derived from computerized anesthesia records by assessing the duration of exposure to moderate or severe extremes of hemodynamic variables. Multivariate logistic regression identified independent predictors of perioperative mortality, stroke, and PMI. Among 2149 patients, there were 50 mortalities, 51 strokes, and 85 PMIs. In the precardiopulmonary bypass (pre-CPB) period, pulmonary hypertension was a predictor of mortality (odds ratio [OR] 2.1, P = 0.029), and bradycardia and tachycardia were predictors of PMI (OR 2.9, P = 0.007 and OR 2.0, P = 0.028, respectively). During CPB, hypotension was a predictor of mortality (OR 1.3, P = 0.025). Post-CPB, tachycardia was a predictor of mortality (OR 3.1, P = 0.001), diastolic arterial hypertension was a predictor of stroke (OR 5.4, P = 0.012), and pulmonary hypertension was a predictor of PMI (OR 7.0, P < 0.001). Increased pulmonary arterial diastolic pressure post-CPB was a predictor of mortality (OR 1.2, P = 0.004), stroke (OR 3.9, P = 0.002), and PMI (OR 2.2, P = 0.001). Rapid intraoperative variations in blood pressure and heart rate were not independent predictors of these outcomes. These findings demonstrate the prognostic significance of intraoperative hemodynamic abnormalities, including data from pulmonary artery catheterization, to adverse postoperative outcomes. It is not known whether interventions to control these variables would improve outcome. ⋯ Intraoperative hemodynamic abnormalities, including pulmonary hypertension, hypotension during cardiopulmonary bypass, and postcardiopulmonary bypass pulmonary diastolic hypertension, were independently associated with mortality, stroke, and perioperative myocardial infarction over and above the effects of other preoperative risk factors.
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Anesthesia and analgesia · Oct 1999
Comparative StudyThe effect of a sciatic nerve block on the development of inflammation in carrageenan injected rats.
Neurogenic inflammation may participate in postoperative inflammatory pain. We evaluated, in the rat, the influence of a short and prolonged sciatic nerve block on carrageenan-induced inflammation, the time course of which may be compared to postoperative inflammation. A catheter was placed on the right sciatic nerve and injected with 0.5% bupivacaine with epinephrine (0.2 mL): one injection in the Short Block Group, and four injections performed at 90-min intervals in the Prolonged Block Group. In all groups, the two hind paws were then injected with carrageenan. The development of inflammation was evaluated in both hind paws by measurement of paw circumference (PC) before, and 1, 2, 3, 4, 6, and 24 h after carrageenan injection. Temperature of both hind paws was evaluated at the same time points. The vocalization threshold to paw pressure test (VTPP) of both hind paws was evaluated at 6, 8, 10, 12, and 24 h after carrageenan injection. The left hind paw was used for the Control Group. A Sham Group had a catheter placed on the sciatic nerve and injected with normal saline. Inflammation developed in the Control Group with a maximum increase of PC (32%) and temperature (14%) 4 h after carrageenan injection and a maximal reduction of VTPP (44%) at 6 h, reflecting mechanical allodynia. A similar evolution was observed in the Sham Group. In the Short Block Group, the nerve block did not influence the PC, the paw temperature, or the VTPP when compared with the Control Group. In the Prolonged Block Group, when compared with the Control Group, the increased PC was reduced throughout the 24 h (P < 0.0001). The maximal increase in PC at 4 h was limited to 23%, as compared with the precarrageenan value. This effect on PC did not persist at 24 h. Paw temperature was increased (P = 0.07) throughout the study in the Prolonged Block Group, as compared with the Control Group. The VTPP reduction was still limited in the Prolonged Block Group at 24 h, as compared with the Control Group (P < 0.0001). We conclude that a prolonged sciatic nerve block limits carrageenan-induced increase in PC and, subsequently, mechanical allodynia at 24 h in rats. ⋯ Our study has shown that a prolonged (6 h) but not a short sciatic nerve block (90 min) can limit edema and related pain after carrageenan-induced inflammation in rat.