Anesthesia and analgesia
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The performance of a new calibrator for pulse oximeters is tested with five pulse oximeters from different manufacturers. The calibrator is based on time resolved transmission spectra of human fingers. Finger spectra with different arterial oxygen saturation can be selected to simulate real patients. ⋯ Beside accuracy tests the suitability for artifact simulation with the new device is discussed. The response of the five tested pulse oximeters is in good agreement with the response of the pulse oximeters connected to real patients. A test procedure for pulse oximeters similar to the conventional desaturation practice is possible; some of the typical artifacts pulse oximetry has to cope with can be simulated easily.
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialRemifentanil provides hemodynamic stability and faster awakening time in transsphenoidal surgery.
In this prospective study, we evaluated the effects of remifentanil in ASA I-II patients undergoing transsphenoidal surgery. After the induction of anesthesia, patients were randomly allocated to the Isoflurane (n = 22, 60% nitrous oxide, isoflurane up to 2% end-tidal) or Remifentanil group (n = 21, 60% nitrous oxide, 0.5% end-tidal isoflurane, remifentanil up to 2 microg x kg(-1) x min(-1)). If mean arterial pressure (MAP) increased >80 mm Hg during maximal dosage of isoflurane or remifentanil, labetalol was administered. At the end of anesthesia, extubation and awakening times, respiratory rate, SpO(2), MAP, heart rate, and adverse effects were recorded. Hemodynamics and bleeding (minimal, mild, moderate, severe) were not different between groups. Bleeding grade increased with MAP >80 mm Hg (P < 0.001). Labetalol was administered to 20 patients in the Isoflurane group, and 10 patients in the Remifentanil group (P < 0.01). The dose of labetalol was larger in the Isoflurane group (1.0 +/- 0.6 versus 0.5 +/- 0.7 mg/kg, P < 0.05). Time to extubation did not differ, whereas time to follow commands was shorter in Remifentanil patients (16 +/- 8 versus 10 +/- 2 min, P < 0.01). No adverse effects occurred in the early postoperative period. ⋯ In patients undergoing transsphenoidal surgery, balanced anesthesia with remifentanil (0.22 +/- 0.17 microg x kg(-1) x min(-1)) provides faster awakening time, as compared with large-dose volatile-based anesthesia, without the risk of postoperative opioid respiratory depression.
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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.
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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.
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Anesthesia and analgesia · Jan 2002
Colostrum morphine concentrations during postcesarean intravenous patient-controlled analgesia.
Patient-controlled analgesia (PCA) with morphine is a convenient method for providing postoperative analgesia. Despite the fact that it is used after cesarean delivery, data on transfer of morphine and of its active metabolite morphine-6 glucuronide (M6G) into maternal milk are scarce. It is not known whether breast-feeding during PCA with morphine has neonatal implications. We sought to measure morphine and M6G concentrations in colostrum during postpartum IV PCA and evaluate the potential for drug intake by neonates being breast-fed by these mothers. Seven informed and consenting mothers, given IV PCA with morphine, were investigated. Plasma and milk samples were obtained at titration, and at 12, 24, 36, and 48 h. Morphine and M6G were measured by high-performance liquid chromatography. In plasma, morphine concentrations ranged from <1 to 274 ng/mL, M6G ranged from <5 to 974 ng/mL. In milk, opioids were found in only 3 patients in whom morphine concentrations ranged from <1 to 48 ng/mL and M6G from <5 to 1084 ng/mL. The milk-to-plasma ratio was always <1 for morphine. In conclusion, we observed very small morphine and M6G concentrations in colostrum during PCA with morphine. Under these conditions, the amounts of drug likely to be transferred to the breast-fed neonate are negligible. ⋯ Colostrum concentrations of morphine and its active metabolite morphine-6 glucuronide were measured in mothers receiving patient-controlled analgesia with morphine after cesarean delivery. The concentrations were found to be very small, thus supporting the safety of breast-feeding in mothers receiving IV patient-controlled analgesia with morphine.