Anesthesia and analgesia
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Anesthesia and analgesia · May 2003
Differing incidences of relevant hypotension with combined spinal-epidural anesthesia and spinal anesthesia.
In this investigation we assessed whether patients receiving spinal anesthesia (SPA) as part of combined spinal-epidural anesthesia (CSE) more often experience relevant hypotension than patients receiving SPA alone. From January 1, 1997, until August 5, 2000, electronic anesthesia records from 1596 patients having received SPA and 1023 patients having received CSE for elective surgery were collected by using a computerized anesthesia record-keeping system. Relevant hypotension was defined as a decrease of mean arterial blood pressure of more than 30% within a 10-min interval and a therapeutic action of the attending anesthesiologist within 20 min after onset. Electronic patient charts were reviewed by using logistic regression with a forward stepwise algorithm to identify independent risk factors that were associated with an increased incidence of hypotension after CSE. Univariate analysis was performed to assess differences in biometric data and relevant risk factors for hypotension between the two procedures. The incidence of relevant hypotension was more frequent with CSE than with SPA alone (10.9% versus 5.0%; P < 0.001). In the multivariate analysis, arterial hypertension (odds ratio, 1.83; 95% confidence interval, 1.21-2.78) and sensory block height >T6 (odds ratio, 2.81; 95% confidence interval, 1.88-4.22) were found to be factors associated with hypotension in the CSE group. Compared with patients receiving SPA alone, patients undergoing CSE had a significantly more frequent prevalence of arterial hypertension and higher sensory block levels (P < 0.01) despite smaller amounts of local anesthetics. In this study, patients receiving CSE had an increased risk for relevant hypotension as compared with patients with SPA alone. Part of this effect seems to be due to the procedure alone and not only because this population is at higher risk. ⋯ This study, based on a large number of patients with a retrospective design by using on-line recorded data, suggests that spinal anesthesia as part of combined spinal-epidural anesthesia may more often lead to relevant hypotension than spinal anesthesia alone. Preexisting arterial hypertension and a sensory block height exceeding T6 are major risk factors for the development of this complication.
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Anesthesia and analgesia · May 2003
The influence of hemorrhagic shock on etomidate: a pharmacokinetic and pharmacodynamic analysis.
We studied the influence of hemorrhagic shock on the pharmacology of etomidate in swine. Sixteen swine were randomly assigned to control and shock groups. The shock group was bled to a mean arterial blood pressure of 50 mm Hg and held there until 30 mL/kg blood was removed. Etomidate 300 micro g x kg(-1) x min(-1) was infused for 10 min to both groups. Fifteen arterial samples were collected until 180 min after the infusion began to determine drug concentration. Pharmacokinetic variables for each group were estimated by using a three-compartment model. The bispectral index scale was used as a measure of drug effect. The pharmacodynamics were characterized by using a sigmoid inhibitory maximal effect model. The raw data revealed a 25% increase in the plasma etomidate concentration at the end of the 10-min infusion which resolved after termination of the infusion in the shock group. The pharmacokinetic analysis revealed subtle changes in the variable estimates between groups. The etomidate infusion produced a similar Bispectral Index Scale change in both groups. These results demonstrated that, unlike the influence of hemorrhagic shock on other sedative hypnotics and opioids, moderate hemorrhagic shock produced minimal changes in the pharmacokinetics and no change in the pharmacodynamics of etomidate. ⋯ Hemorrhagic shock produced minimal changes in the pharmacokinetics and no change in the pharmacodynamics of etomidate in swine. These results suggest that, unlike other sedative hypnotics and opioids, minimal adjustment in the dose of etomidate is required to achieve the same drug effect during hemorrhagic shock.
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Anesthesia and analgesia · May 2003
Randomized Controlled Trial Comparative Study Clinical TrialThe influence of local active warming on pain relief of patients with cholelithiasis during rescue transport.
Upper abdominal pain, a frequent symptom of the presence of gallstone disease, is the cause of 6% of the emergency calls of the Austrian emergency system. Pain resulting from cholelithiasis is characteristically severe. Recent data show that active warming during emergency transport of trauma victims is effective in reducing pain. Therefore, we hypothesized that local active warming of the abdomen would be an effective pain treatment for patients with acute cholelithiasis and could be provided by paramedics. Sixty patients (>19 yr) consented to participate in this study. They were divided into two groups: Group 1, who received active warming of the upper abdomen with a carbon-fiber warming blanket (42 degrees C), and Group 2, who received no warming of the abdomen. Neither group received any drug-based pain care. Patients were asked to rate their pain and anxiety by using visual analog scales (VAS). Statistical evaluation was performed with Student's t-test; P < 0.05 was considered significant. In Group 1, a significant (P < 0.01) pain reduction was recorded in all cases on a visual analog scale (VAS), from 86.8 +/- 5.5 mm to 41.2 +/- 16.2 mm. In Group 2, the patients' pain scores remained comparable, from 88.3 +/- 9.9 mm to 88.1 +/- 10.0 mm on a VAS. In comparing Group 1 with Group 2 on arrival at the hospital, pain scores showed a significant difference (P < 0.01). In Group 1, the VAS score changes for anxiety were significantly reduced (P < 0.01), from 82.7 +/- 10.8 mm before treatment to 39.0 +/- 14.0 mm after treatment. In Group 2, a nonsignificant change of this score was noted, from 84.5 +/- 14.6 mm to 83.5 +/- 8.4 mm. Comparing Group 1 with Group 2 on arrival at the hospital showed a significant difference in anxiety scores (P < 0.01). We conclude that local active warming is an effective and easy-to-learn treatment for pain resulting from acute cholelithiasis in emergency care. ⋯ Active local warming of the upper abdomen is an effective treatment for patients with cholelithiasis being transported to the hospital by paramedics who are not permitted to provide any drug-based pain care. We observed no negative side effects of this treatment.
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Anesthesia and analgesia · May 2003
Meta AnalysisEpidural ropivacaine versus bupivacaine for labor: a meta-analysis.
Numerous studies have compared ropivacaine with bupivacaine for labor analgesia. Early studies suggested that obstetrical and some neonatal outcomes were improved when ropivacaine was used. We systematically reviewed and combined the results of the randomized controlled trials that compared ropivacaine with bupivacaine to determine whether or not there was a difference in these outcomes. We searched electronic databases and journals for randomized controlled trials composed of laboring parturients. The primary outcome was the incidence of spontaneous vaginal delivery. We examined other obstetrical, neonatal, and analgesic outcomes. Where possible, these were combined by using metaanalytic techniques and random effects modeling. We found 23 randomized controlled trials composed of 1043 patients receiving ropivacaine and 1031 receiving bupivacaine. There was no significant difference in the incidence of spontaneous vaginal delivery (odds ratio, 1.17; 95% confidence interval, 0.98-1.41; P = 0.12) or any of the other outcomes. Although more studies reported a more frequent incidence of motor block with bupivacaine, the results were heterogeneous and therefore not combined. We conclude that there is no statistically significant difference between the two drugs in the incidence of any obstetrical or neonatal outcome. Further studies using clinically appropriate concentrations of drugs are required to determine whether or not there is a difference in the incidence of motor block. ⋯ This metaanalysis of 23 randomized controlled trials shows that both ropivacaine and bupivacaine provide excellent labor analgesia. There was no significant difference between the two drugs in mode of delivery, maternal satisfaction, or neonatal outcomes. Whether or not there is a difference in motor block at clinically relevant doses is unresolved.
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Anesthesia and analgesia · May 2003
Randomized Controlled Trial Clinical TrialRepetitive large-dose infusion of the novel hydroxyethyl starch 130/0.4 in patients with severe head injury.
In this prospective, controlled, randomized, single-center study, we investigated the safety of repetitive large-dose infusion of a novel hydroxyethyl starch solution (6% HES 130/0.4) in cranio-cerebral trauma patients. Patients were randomized to receive either HES 130/0.4 (n = 16) at repetitive doses of up to 70 mL x kg(-1) x d(-1) (which is the largest HES dose reported in the literature) or the control HES 200/0.5 (n = 15) up to its approved dose limit of 33 mL x kg(-1) x d(-1) followed by human albumin up to a total dose (HES 200/0.5 + albumin) of 70 mL x kg(-1) x d(-1). We found no differences between groups in mortality, renal function, bleeding complications, and use of blood products. There were also no major differences in coagulation variables. However, at some time points, factor VIII, von Willebrand factor, and ristocetin cofactor were higher in the HES 130/0.4 group despite the large HES doses administered. We conclude that HES 130/0.4 can safely be used in critically ill head trauma patients over several days at doses of up to 70 mL x kg(-1) x d(-1). ⋯ There are concerns that infusion of certain hydroxyethyl starch (HES) types for plasma volume expansion may influence coagulation and renal function. We investigated the safety of the novel HES 130/0.4 in patients with severe cranio-cerebral trauma. The repetitive HES doses administered in this study are the largest reported in the literature.