Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2001
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of ropivacaine and bupivacaine for cervical plexus block.
We compared bupivacaine 0.5% and ropivacaine 0.75% for cervical plexus block (CB). Forty patients scheduled for carotid artery surgery were allocated randomly to undergo superficial and deep CB with 30 mL of one of the two anesthetic solutions. We evaluated the onset of anesthetic block; the requirement for supplementation during the surgery; the patients' satisfaction; postoperative pain on a visual analog scale at 1, 2, and 3 h; and the use of paracetamol as a rescue analgesic medication. Arterial blood was sampled immediately and 1, 3, 5, 10, 15, 30, 45, and 60 min after CB for measurements of bupivacaine or ropivacaine concentrations. Patients in both groups had equivalent onset of CB, local infiltration with lidocaine during surgery, and satisfaction scores. In the Bupivacaine group, visual analog scale scores were lower at 2 and 3 h, and the delay before paracetamol administration was prolonged. Observed peak concentrations were larger in the Ropivacaine group (4.25 [2.07-6.59 mg/L] vs 3.02 [0.98-5.82 mg/L]), but time to reach peak concentrations was comparable (5 [1-15 min] vs 5 [0-45 min] in the Ropivacaine and Bupivacaine groups, respectively). We conclude that ropivacaine has no advantage over bupivacaine for CB. ⋯ Compared with bupivacaine (150 mg), a larger dose of ropivacaine (225 mg) produces comparable features of cervical plexus block but less postoperative analgesia and larger plasma concentrations. There is no reason to favor ropivacaine in such a case.
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Anesthesia and analgesia · Mar 2001
Randomized Controlled Trial Comparative Study Clinical TrialThe release of antidiuretic hormone is appropriate in response to hypovolemia and/or sodium administration in children with severe head injury: a trial of lactated Ringer's solution versus hypertonic saline.
We conducted an open, randomized, and prospective study to determine the effect of hypertonic saline on the secretion of antidiuretic hormone (ADH) and aldosterone in children with severe head injury (Glasgow coma scale <8). Thirty-one consecutive patients at a level III pediatric intensive care unit at a children's hospital received either lactated Ringer's solution (Ringer's group, n = 16) or hypertonic saline (Hypertonic Saline group, n = 15) over a 3-day period. Serum ADH levels were significantly larger in the Hypertonic Saline group as compared with the Ringer's group (P = 0.001; analysis of variance) and were correlated to sodium intake (Ringer's group: r = 0.39, R(2) = 0.15, P = 0.02; Hypertonic Saline group: r = 0.42, R(2) = 0.18, P = 0.02) and volume of fluids given IV (Ringer's group: r = 0.38, R(2) = 0.15, P = 0.02; Hypertonic Saline group: r = 0.32, R(2) = 0.1, P = not significant). Correlation of ADH to plasma osmolality was significant if plasma osmolality was >280 mOsm/kg (r = 0.5, R(2) = 0.25, P = 0.06), indicating an osmotic threshold for ADH release. Serum aldosterone levels were larger on the first day than during Days 2 and 3 in both groups and inversely correlated to serum sodium levels only in the Ringer's group (r = -0.55, R(2) = 0.3, P < 0.001). This group received a significantly larger fluid volume on Day 1 (P = 0.05, Mann-Whitney U-test) than did patients in the Hypertonic Saline group, indicating hypovolemia during the first day. Head-injured children have appropriate levels of ADH. They may be hypovolemic during the first day of treatment, especially if they receive lactated Ringer's solution. ⋯ In head-injured patients, we recommend fluid restriction to avoid inappropriate secretion of antidiuretic hormone. In a prospective, randomized, and controlled study in 31 children, we were able to show that the antidiuretic hormone levels are appropriate in response to hypovolemia, sodium load, or both.
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Anesthesia and analgesia · Mar 2001
Randomized Controlled Trial Comparative Study Clinical TrialThe influence of intravascular volume therapy with a new hydroxyethyl starch preparation (6% HES 130/0.4) on coagulation in patients undergoing major abdominal surgery.
A new hydroxyethyl starch (HES) preparation with a mean molecular weight of 130,000 daltons and a degree of substitution of 0.4 shows favorable pharmacokinetic properties. We conducted a study of the influence of the new HES specification on coagulation and compared it with another colloidal intravascular volume replacement regimen using gelatin. According to a prospective, random sequence, 42 patients undergoing major abdominal surgery received either HES 130/0.4 (n = 21) or gelatin (n = 21) until the first postoperative day (POD) to keep central venous pressure between 10 and 14 mm Hg. From arterial blood samples, standard coagulation variables were measured, and modified thrombelastogram (TEG) measurements using different activators were performed. A total of 2830 +/- 350 mL of gelatin and 2430 +/- 310 mL of HES 130/0.4 were administered until the morning of the first POD. The use of allogeneic blood/blood products and standard coagulation variables did not differ significantly between the two groups. After induction of anesthesia, all TEG data for both groups were within normal range. Coagulation time and maximum clot firmness did not change significantly in any TEG measurements during the study period. The kinetics of clot formation (clot formation time) significantly increased immediately after surgery, but without showing significant group differences. On the morning of the first POD, the clot formation time returned to almost normal levels, except for aprotinin-activated TEG(R). We conclude that administration of moderate doses of the new HES 130/0.4 preparation in patients undergoing major abdominal surgery results in similar coagulation alterations as those after using an established gelatin-based volume-replacement regimen. ⋯ We compared the effects of infusion of a new hydroxyethyl starch preparation (6% hydroxyethyl starch; mean molecular weight 130,000 daltons; degree of substitution 0.4) on coagulation with a gelatin-based intravascular volume replacement regimen in patients undergoing major abdominal surgery. After moderate doses of hydroxyethyl starch (2430 +/- 310 mL until the morning of the first postoperative day), coagulation monitoring, including modified thrombelastography, did not show impaired hemostasis.
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Anesthesia and analgesia · Mar 2001
Randomized Controlled Trial Clinical TrialThe addition of morphine prolongs fentanyl-bupivacaine spinal analgesia for the relief of labor pain.
The combination intrathecal fentanyl (25 microg) and bupivacaine (2.5 mg) provides effective labor analgesia for approximately 90 minutes. The purpose of this prospective, randomized, double-blinded investigation was to determine if the addition of morphine (150 microg) to the intrathecal combination of fentanyl (25 microg) and bupivacaine (2.5 mg) would prolong labor analgesia. By using the combined spinal epidural technique, 95 healthy primiparous laboring women in early labor received 2 mL of one of the two intrathecal study solutions, either FB (n = 48): fentanyl (25 microg) and bupivacaine (2.5 mg); or FBM (n = 47): fentanyl (25 microg) and bupivacaine (2.5 mg) plus morphine (150 microg). The mean duration of labor analgesia was significantly longer in the FBM group than in the FB group (252 +/- 63 min vs 148 +/- 44 min, P < 0.01). There were no significant differences between the two groups regarding the sensory levels, the incidence of nausea, vomiting, pruritus, hypotension, or operative delivery. In conclusion, the addition of 150 microg of morphine to the intrathecal combination of fentanyl plus bupivacaine prolonged the duration of labor analgesia duration without increasing adverse effects. ⋯ The addition of morphine (150 microg) to intrathecal fentanyl (25 microg) and bupivacaine (2.5 mg) prolongs the duration of labor analgesia duration without increasing adverse effects.
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Anesthesia and analgesia · Mar 2001
Randomized Controlled Trial Clinical TrialDexamethasone for preventing nausea and vomiting associated with epidural morphine: a dose-ranging study.
We conducted a dose-ranging study of dexamethasone for preventing nausea and vomiting within the first 24 h after the administration of epidural morphine. Two hundred twenty-five women (n = 45 in each of the five groups) undergoing simple abdominal total hysterectomy under epidural anesthesia were enrolled in this randomized, double-blind, placebo-controlled study. When the incision closure was completed, patients received IV dexamethasone, 10 mg, 5 mg, or 2.5 mg; IV droperidol 1.25 mg; or saline 2 mL. All patients received epidural morphine 3 mg for postoperative analgesia. We found that patients who received dexamethasone 5 mg or 10 mg or droperidol 1.25 mg were significantly different from those who received saline alone in the following variables: the total incidence of nausea and vomiting, the incidence of more than four vomiting episodes, the number of patients requiring rescue antiemetics, the total number of patients with no vomiting and/or no antiemetic medication (P < 0.05 to P < 0.01). The differences among dexamethasone 10 mg and 5 mg and droperidol 1.25 mg were not significant. Dexamethasone 2.5 mg was ineffective. In conclusion, because dexamethasone 5 mg was as effective as 10 mg as an antiemetic, we recommend the smaller dose for preventing nausea and vomiting associated with epidural morphine. ⋯ We conducted a dose-ranging study of dexamethasone for preventing nausea and vomiting within the first 24 h after the administration of epidural morphine. We found that dexamethasone 5 mg was as effective as 10 mg. We recommend the smaller dose for this purpose.