Anesthesia and analgesia
-
Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialRopivacaine 0.075% and bupivacaine 0.075% with fentanyl 2 microg/mL are equivalent for labor epidural analgesia.
Fifty percent effective dose estimates for ropivacaine and bupivacaine suggest that ropivacaine is 40% less potent than bupivacaine to initiate labor analgesia. At clinically used concentrations, however, the drugs seem indistinguishable for initiating and maintaining labor analgesia. We designed this study to evaluate a concentration near the reported 50% effective dose values for ropivacaine and bupivacaine in an attempt to detect differences between the drugs during routine clinical use. Fifty-nine nulliparous women in labor were randomized to receive 0.075% ropivacaine or bupivacaine, each with fentanyl 2 microg/mL. After epidural placement and the administration of a lidocaine/epinephrine test dose, 20 mL of study solution was administered and a patient-controlled epidural infusion was initiated with the following settings: 6 mL/h basal rate, 5 mL bolus, 10 min lockout, and 30 mL/h limit. Breakthrough pain was treated with 10-mL boluses of study solution. By using a study design to detect a 40% difference in hourly drug use between groups, we found no statistically significant differences in the amount of local anesthetic used, verbal pain scores, sensory levels, motor blockade, labor duration, mode of delivery, side effects, or patient satisfaction. We conclude that 0.075% ropivacaine and bupivacaine, with fentanyl, are equally effective for labor analgesia using the patient-controlled epidural analgesia technique. ⋯ At small concentrations, ropivacaine and bupivacaine when combined with fentanyl are equally effective for labor analgesia. Patients self-administered similar volumes of 0.075% ropivacaine or bupivacaine solutions containing fentanyl (2 microg/mL) suggesting that at this concentration, and with the addition of fentanyl, ropivacaine and bupivacaine can be used interchangeably.
-
Anesthesia and analgesia · Jan 2002
Case ReportsHuman error: the persisting risk of blood transfusion: a report of five cases.
It is common experience that virus transmission, particularly transmission of the human immunodeficiency virus (HIV), is a principal concern of patients and physicians regarding blood transfusion (1). Many physicians are probably unaware that transfusion-transmitted HIV infection is approximately 50 to 100 times less likely to occur than transfusion error (2-4). This misconception may have been encouraged by the scarcity of reports on transfusion error relative to the tremendous public attention focused on HIV infection. We present five cases illustrating how anesthesiologists, intensivists, and emergency physicians are particularly vulnerable to the risk of administering blood to the wrong recipient. All five cases were collected during a 4-yr period. Transfused units of packed red cells totaled approximately 50,000 U during this period in our department. ⋯ Human error leading to the transfusion of blood to an unintended recipient is a major source of transfusion-related fatalities. We report five cases that highlight some specific areas in which transfusion error is likely to occur.
-
Opening of the first door of pulse photometry gave us pulse oximeter. The next door opens to multiwavelength pulse photometry. It will give us a high performance pulse oximeter, providing a wide variety of clinical information simultaneously. This next generation of pulse photometry should further improve bedside monitoring and patient care.
-
Anesthesia and analgesia · Jan 2002
Differences in pulse oximetry technology can affect detection of sleep-disorderd breathing in children.
Newer pulse oximeters have been developed to be motion resistant and thus have few false alarms. However, they have not yet been evaluated in a pediatric sleep laboratory setting. While evaluating new oximeters for use in our laboratory, we obtained simultaneous pulse oximetry data from two Masimo oximeters and from two Nellcor oximeters during nocturnal polysomnography in children referred for sleep-disordered breathing (SDB). In series 1, comprising 24 patients, comparisons were made between a Masimo oximeter with 4-second averaging time and the Nellcor N-200 oximeter set for 3 to 5 second averaging. A maximum of 20 events per patient were randomly selected for analysis, an "event" being a desaturation of > or = 4% registered by either oximeter. Interobserver agreement for event classification was 93%. Eighty-eight percent of 220 desaturation events occurring during wakefulness and 38% of 194 events occurring during sleep were classified as motion artifact on the Nellcor oximeter. Neither the Masimo oximeter nor the transcutaneous oxygen probe confirmed that the desaturation was real, in most of these cases. During sleep, there were 119 events detected by either or both oximeters: 113 (95%) by the Nellcor versus 82 (69%) by the Masimo. For these 119 events, the extent of desaturation was slightly less for the Masimo than the Nellcor oximeter, 4.5 +/- 2.4% versus 5.5 +/- 2.5%, respectively. In series 2, 22 patients were studied comparing a Masimo Radical oximeter with 2 second averaging to the Nellcor N-200 oximeter. The extent of desaturation was slightly greater for the Masimo oximeter. The Masimo oximeter detected more non-artifactual desaturation events occurring during sleep than the Nellcor oximeter, 90% versus 76% (chi2 = 9.9, p < 0.01). In series 3, comprising 128 events in 5 patients, a Nellcor N-395 oximeter detected fewer desaturations during non-movement, sleep periods and had more movement related "desaturation" events, compared to a Masimo Radical oximeter. ⋯ The Masimo oximeters register many fewer false desaturations due to motion artifact. Using 4-second averaging, a Masimo oximeter detected significantly fewer SaO2 dips than the Nellcor N-200 oximeter but using 2-second averaging, the Masimo oximeter detected more SaO2 dips than the Nellcor N-200 oximeter. The sensitivity and motion artifact rejection characteristics of the Nellcor N-395 oximeter are not adequate for a pediatric sleep laboratory setting. These findings suggest that in a pediatric sleep laboratory, use of a Masimo oximeter with very short averaging time could significantly reduce workload and improve reliability of desaturation detection.
-
Anesthesia and analgesia · Jan 2002
Comment Letter Case ReportsAnother cause of epidural catheter breakage?