Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2000
Clinical TrialPredictors of recommendation and acceptance of intrapartum epidural analgesia.
We conducted this prospective study to characterize the obstetric and sociodemographic variables that predict physicians' recommendations and patients' acceptance of intrapartum epidural analgesia. The study population consisted of 447 consecutive, low-risk parturients in early active labor. Epidural analgesia was recommended to 393 patients (87.9%), however only 164 (41.7%) consented to receive it. A multiple logistic regression analysis demonstrated that the severity of pain, as assessed by the medical staff (odds ratio [OR] = 1.5, 95% confidence interval [CI] 1.13, 1.93), low parity (OR = 0.57, 95% CI 0.44, 0.74), and low maternal age (OR = 0.89, 95% CI 0.79, 0.99) were significant factors affecting recommendations of epidural analgesia. In a multivariate analysis, severity of subjective pain (OR = 1.39, 95% CI 1.16, 1.68), low parity (OR = 0.80, 95% CI 0.73, 0.99), high education (OR = 90.09, 95% CI 27.02,257.06), and the patients' being secular compared with religious (OR = 2.14, 95% CI 1.08,4.21) were found to be independent predictors of acceptance of epidural analgesia. There are differences between patients offered and those not offered epidural analgesia and between parturients who accept and those who do not accept this analgesia. ⋯ We studied the factors that influence the recommendation of epidural analgesia by obstetricians, as well as its acceptance by the laboring patients at a university hospital in Israel. Epidural analgesia was recommended more often to low parity, younger women exhibiting more pain. Parturients who perceived greater pain were more secular, had low parity, and had a higher level of education were more likely to accept it.
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Anesthesia and analgesia · Jan 2000
Spinal coadministration of ketamine reduces the development of tolerance to visceral as well as somatic antinociception during spinal morphine infusion.
This study was designed to investigate the effects of ketamine, an N-methyl-D-aspartate receptor antagonist, on the development of tolerance to morphine and morphine antinociception during intrathecal infusion. Two intrathecal catheters were implanted in the subarachnoid space in male rats under pentobarbital anesthesia. One catheter was used for the intrathecal infusion with the following solutions: morphine 1 microg x kg(-1) x hr(-1)(M1) and 5 microg x kg(-1) x hr(-1) (M5);ketamine 250 microg x kg(-1) x hr(-1) (K250); morphine plus ketamine, 1 microg x kg(-1) x hr(-1) plus 250 microg x kg(-1) x hr(-1) (M1 + K250) and 5 microg x kg(-1) x hr(-1) + 250 microg x kg(-1) x hr(-1) (M5 + K250); or saline. The other catheter was used for morphine challenge tests. The responses to noxious somatic and visceral stimuli were measured by tail flick (TF) and colorectal distension (CD) tests, respectively. Measurements were performed once a day for 7 days. Challenge tests with intrathecal morphine were performed to assess the magnitude of tolerance on Day 5 and Day 7. The antinociceptive effect was evaluated by using the percent of maximal possible effect (%MPE). Morphine infusion produced significant increases in %MPEs in TF and CD tests, while the saline and K250 infusions did not show any changes. The M1 + K250 infusion significantly increased the %MPEs in TF and CD tests, although the M1 and K250 infusions alone showed no changes. M5 + K250 enhanced the increases of %MPEs in TF and CD tests compared with the M5 infusion alone. In the challenge tests, the M1 + K250 infusion showed no significant decrease in %MPEs and TF and CD tests. The M5 + K250 infusion significantly inhibited those decreases in %MPEs, although the M5 infusion showed significant decreases in TF and CD tests. We concluded that ketamine attenuated the development of morphine tolerance to antinociceptive effects and increased the somatic and visceral antinociception of morphine. ⋯ Intrathecally coinfused ketamine attenuated morphine tolerance to somatic and visceral antinociception and increased morphine antinociception at the spinal level. These results suggest that a combination of morphine with ketamine may have an advantage in long-term use of opioids for controlling visceral as well as somatic pain.
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Anesthesia and analgesia · Jan 2000
Letter Case ReportsDual-plateau capnogram caused by cracked sample filter.
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Anesthesia and analgesia · Jan 2000
Sevoflurane and isoflurane do not enhance the pre- and postischemic eicosanoid production in guinea pig hearts.
Eicosanoids and volatile anesthetics can influence cardiac reperfusion injury. Accordingly, we analyzed the effects of sevoflurane and isoflurane applied in clinically relevant concentrations on the myocardial production of prostacyclin and thromboxane A2 (TxA2) and on heart function. Isolated guinea pig hearts, perfused with crystalloid buffer, performed pressure-volume work. Between two working phases, hearts were subjected to 15 min of global ischemia followed by reperfusion. The hearts received no anesthetic, 1 minimum alveolar anesthetic concentration (MAC) isoflurane (1.2 vol%), or 0.5 and 1 MAC sevoflurane (1 vol% and 2 vol%), either only preischemically or pre- and postischemically. In additional groups, cyclooxygenase function was examined by an infusion of 1 microM arachidonic acid (AA) in the absence and presence of sevoflurane. The variables measured included the myocardial production of prostacyclin, TxA2 and lactate, consumption of pyruvate, coronary perfusion pressure, and the tissue level of isoprostane 8-iso-PGF2alpha. External heart work, determined pre- and postischemically, served to assess recovery of heart function. Volatile anesthetics had no impact on postischemic recovery of myocardial function (50%-60% recovery), perfusion pressure, lactate production, or isoprostane content. Release of prostacyclin and TxA2 was increased in the early reperfusion phase 5-8- and 2-4-fold, respectively, indicating enhanced AA liberation. Isoflurane and sevoflurane did not augment the eicosanoid release. Only 2 vol% sevoflurane applied during reperfusion prevented the increased eicosanoid formation in this phase. Infusion of AA increased prostacyclin production approximately 200-fold under all conditions, decreased pyruvate consumption irreversibly, and markedly attenuated postischemic heart work (25% recovery). None of these effects were mitigated by 2 vol% sevoflurane. In conclusion, only sevoflurane at 2 vol% attenuated the increased liberation of AA during reperfusion. Decreased eicosanoid formation had no effect on myocardial recovery in our experimental setting while excess AA was deleterious. Because eicosanoids influence intravascular platelet and leukocyte adhesion and activation, sevoflurane may have effects in reperfused tissues beyond those of isoflurane. ⋯ In an isolated guinea pig heart model, myocardial eicosanoid release was not increased by isoflurane or sevoflurane, either before or after ischemia. Sevoflurane (2 vol%) but not isoflurane attenuated the increased release of eicosanoids during reperfusion.
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Anesthesia and analgesia · Jan 2000
Biography Historical ArticleErnst Trier Mørch: inventor, medical pioneer, heroic freedom fighter.