Anesthesia and analgesia
-
The purpose of this study was to examine the extent and evolution of pain after common major surgical procedures and to establish correlates of three types of pain: pain at rest, pain with movement, and maximum pain over the previous 24 h. Patients completed a preoperative questionnaire to obtain data on age, gender, narcotic use, baseline level of pain, chronicity of pain, and level of anxiety. Patients were then interviewed on Postoperative Days 1, 2, and 3 to assess their pain on a scale of 0 (none) to 10 (worst imaginable). ⋯ Preoperative narcotic use and high baseline preoperative pain, defined as a score > or = 4, were significantly (P < 0.05) associated with increased pain at rest, pain with movement, and maximum pain. Epidural analgesia was the only mode of analgesia significantly associated with both decreased postoperative pain at rest and decreased pain with movement (P < 0.05). These relatively high pain scores and minimum decreases in pain from Postoperative Days 1 to 3 emphasizes the need for more effective pain management continuing into the postoperative period to facilitate mobilization and recovery.
-
Anesthesia and analgesia · Jul 1997
Comparative StudyNoninvasive monitoring of carbon dioxide during respiratory failure in toddlers and infants: end-tidal versus transcutaneous carbon dioxide.
We prospectively compared the accuracy of two noninvasive monitors of arterial CO2 (end-tidal and transcutaneous) in mechanically ventilated infants and toddlers with respiratory failure. The study included infants and toddlers less than 48 mo of age who required tracheal intubation and mechanical ventilation for respiratory failure. In each patient, both ETCO2 and transcutaneous CO2 (TC-CO2) were simultaneously monitored and compared with PaCO2 when an arterial blood gas analysis was performed. ⋯ The absolute difference of the TC-CO2 and PaCO2 was 4 mm Hg or less in 96 of the 100 values, while the ETCO2 to PaCO2 difference was 4 mm Hg or less in 38 of the 100 values (P < 0.0001). Bland-Altman analysis revealed a bias of -0.68 with a precision of +/-2.35 when comparing the TC-CO2 and the PaCO2 and a bias of -6.68 with a precision of +/-5.01 when comparing ETCO2 with PaCO2. In neonates and infants with respiratory failure, TC-CO2 monitoring provided a more accurate estimation of PaCO2 than ETCO2 monitoring.
-
Anesthesia and analgesia · Jul 1997
Comparative StudyComparative pharmacokinetics of ropivacaine and bupivacaine in nonpregnant and pregnant ewes.
We determined the pharmacokinetics and protein binding of ropivacaine and bupivacaine after intravenous administration to nonpregnant and pregnant sheep. All animals were in good condition throughout the study. The highest mean total serum drug concentrations were found at the end of infusion. ⋯ In conclusion, the pharmacokinetics of ropivacaine and bupivacaine are altered by ovine pregnancy in a similar way. If these data are applicable to humans, an unintended intravascular injection of either drug could be expected to result in higher total serum concentrations in the pregnant than in the nonpregnant patient, but drug levels would decline at similar rates in both groups of individuals. However, differences between the two drugs, particularly in T(1/2)beta and MRT, may make ropivacaine preferable for use in obstetric anesthesia.
-
Anesthesia and analgesia · Jul 1997
Comparative StudyMaturation decreases ethanol minimum alveolar anesthetic concentration in mice as previously demonstrated in rats: there is no species difference.
The potency of conventional inhaled anesthetics increases with maturation: the 50% effective dose (minimum alveolar anesthetic concentration [MAC]) for conventional inhaled anesthetics in the neonatal rat or human exceeds MAC in the young adult. This increase also applies to ethanol in rats tested using MAC as the measure of anesthesia. However, the converse appears to be true for studies in mice assessed with the righting reflex; that is, adult mice are six times more resistant than neonates to the effects of ethanol. ⋯ Accordingly, we investigated whether maturation decreased ethanol potency in mice, using MAC as the measure of anesthesia. Applying standard techniques, we tested MAC for ethanol in 15 CF-1 mice aged 10 days (6-8.5 g) and in 13 mice aged 77-84 days (34-39 g). MAC decreased with maturation, and the decrease was indistinguishable from that found in our previous studies of rats.
-
Anesthesia and analgesia · Jul 1997
Laryngeal mask airway and the incidence of regurgitation during gynecological laparoscopies.
We studied the incidence of regurgitation in 100 patients undergoing elective gynecological laparoscopies under general anesthesia with intermittent positive pressure ventilation using a laryngeal mask airway (LMA). Patients ingested methylene blue capsules 10-15 min before induction of anesthesia. After induction and insertion of an LMA using the recommended insertion technique, a fiberoptic examination of the larynx was made for traces of dye and to site a pH probe in the bowl of the LMA for continuous monitoring. ⋯ The 95% confidence limit for a true probability of regurgitation in this study is 0.041 or a true rate of regurgitation of less than 4.1%. A larger study would be required to possibly demonstrate a lower incidence of regurgitation. This study confirms the clinical impression that the incidence of regurgitation during laparoscopies with a LMA is extremely low.