Anesthesia and analgesia
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Anesthesia and analgesia · Nov 1998
Randomized Controlled Trial Comparative Study Clinical TrialCompromised blood coagulation: an in vitro comparison of hydroxyethyl starch 130/0.4 and hydroxyethyl starch 200/0.5 using thrombelastography.
We compared the effects of progressive in vitro hemodilution (30% and 60%) on blood coagulation in 80 patients receiving one of two different 6% hydroxyethyl starch (HES) solutions using thrombelastography (TEG). The newly developed solution has a mean molecular weight of 130 kD and a degree of substitution, defined as the average number of hydroxyethyl groups per glucose moiety, of 0.4 (HES 130/0.4); the conventional solution has a mean molecular weight of 200 kD and a degree of substitution of 0.5 (HES 200/0.5). Both HES solutions significantly compromised blood coagulation, as seen by an increase in reaction time and coagulation time and a decrease in angle alpha, maximal amplitude, and coagulation index (all P < 0.05). There was no difference between HES 130/0.4 and HES 200/0.5 diluted blood (P > 0.05 for all TEG variables). When analyzing the intrinsic HES effect by taking hemodilution with 0.9% saline into account, progressive hemodilution with both HES solutions resulted in an increasing clot lysis (P < 0.05 after 60 min). Again, there was no difference between HES 130/0.4 and HES 200/0.5 diluted blood. We conclude that HES 130/ 0.4 and HES 200/0.5 compromise blood coagulation to the same degree. ⋯ Progressive in vitro hemodilution using hydroxyethyl starch (HES) compromises blood coagulation. We observed similar effects of a new HES solution with a mean molecular weight of 130 kD and a degree of substitution of 0.4 (HES 130/0.4), compared with the conventional HES 200/0.5.
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Anesthesia and analgesia · Nov 1998
Randomized Controlled Trial Clinical TrialThe peripheral effect of fentanyl on postoperative pain.
The clinical value of the analgesic effect of opioids administered peripherally (except for intraarticular administration) has not been clearly demonstrated. The aim of this study was to test the hypothesis that fentanyl, added to a local anesthetic for wound infiltration, can enhance postoperative analgesia via a peripheral mechanism. Patients with inguinal herniorrhaphy performed under spinal anesthesia were randomly assigned to one of two groups (n = 10 each). At the end of surgery, the wound was infiltrated with 10 mL of lidocaine 0.5% and fentanyl 0.001% (10 microg) in one group; in the other group, the wound was infiltrated with 10 mL of lidocaine 0.5% alone (and fentanyl 10 microg IM contralaterally). The following variables were determined in a double-blind manner: the duration of anesthesia (response to a von Frey filament), the duration of analgesia (time to mild postoperative pain), postoperative meperidine consumption, intensity visual analog scale of spontaneous and movement-associated pain 24 h after surgery, and wound pain threshold 24 h after surgery (pressure algometry). The addition of fentanyl for wound infiltration enhanced the duration of anesthesia (130+/-37 vs 197+/-27 min; P < 0.001) and decreased the intensity of spontaneous (50+/-17 vs 19+/-18 mm; P < 0.002) and movement-associated (56+/-15 vs 26+/-21 mm; P < 0.002) pain 24 h postoperatively. Differences between groups for other variables were not statistically significant. Fentanyl added to a local anesthetic for wound infiltration after spinal anesthesia can enhance postoperative analgesia by a peripheral mechanism. ⋯ Fentanyl can enhance analgesia by a peripheral mechanism. Added to a local anesthetic for wound infiltration, it may be of benefit for the relief of postoperative pain.
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Anesthesia and analgesia · Nov 1998
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of the reliability of two techniques of left double-lumen tube bronchial cuff inflation in producing water-tight seal of the left mainstem bronchus.
A double-lumen endobronchial tube (DLT) bronchial cuff inflation technique that reliably ensures effective water-tight isolation of the two lungs has not been determined. In this study, 20 patients undergoing thoracic surgery requiring a left DLT had the bronchial cuff of the DLT inflated by one of two techniques. In Group 1, the cuff was inflated to produce an air-tight seal of the left bronchus using the underwater seal technique. In Group 2, the cuff was inflated to a pressure of 25 cm H2O. After bronchial cuff inflation in both groups, water-tight bronchial seal was tested by instilling 2 mL of 0.01% methylene blue (MB) above the bronchial cuff of the DLT. Fifteen minutes later, fiberoptic bronchoscopy was performed via the bronchial lumen of the DLT to determine whether MB had seeped past the bronchial cuff. Cuff volume was 0.75+/-0.64 and 0.76+/-0.46 mL, cuff pressure was 30.1+/-27.0 and 25.0+/-0.0 cm H2O (mean+/-SD), and MB was positively identified in two and five patients in Groups 1 and 2, respectively. The difference in cuff volume and pressure and the higher MB seepage in Group 2 compared with Group 1 was not statistically significant. In both groups, MB seepage occurred only when the bronchial cuff volume was <1 mL and when the patients were positioned in the left lateral decubitus position. These findings suggest that the risk of aspiration is greatest when the DLT is positioned in the dependent lung and when the bronchial cuff volume is <1 mL. ⋯ Water-tight sealing of the left bronchus by DLT bronchial cuff was tested after cuff inflation using two different techniques. Neither air-tight bronchial seal nor cuff pressure of 25 cm H2O guaranteed protection against aspiration. The risk of aspiration was greatest when the DLT was positioned in the dependent lung and when the bronchial cuff volume was < 1 mL.