Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Clinical TrialTranexamic acid and aprotinin reduce postoperative bleeding and transfusions during primary coronary revascularization.
We evaluated the blood conservation effects of tranexamic acid (TA) or aprotinin administered before and during cardiopulmonary bypass (CPB) in a prospective, randomized, double-blind study of 150 adult patients undergoing primary coronary artery bypass grafting surgery. Patients received either TA (2 g) or large-dose aprotinin (7 million KIU). Thirty additional untreated patients otherwise managed in a similar fashion were included from a recently completed study for comparison of outcomes. Demographic, medical, surgical, laboratory, mediastinal chest tube drainage (MCTD), transfusion, and outcome data were collected. Allogeneic blood product administration was tightly controlled. The demographic, medical, and surgical characteristics did not significantly differ between the two therapy groups. The median postoperative MCTD loss in the TA group did not significantly differ from that in the aprotinin-treated group (708 vs 600 mL). The percentage of patients that received no allogeneic blood products was 25% for the TA group and 27% for the aprotinin group (P = not significant). The median number of allogeneic blood products administered to the TA group (0 U) did not significantly differ from that administered to the aprotinin group (0 U). The percentage of patients with excessive MCTD (>1000 mL/24 h) did not significantly differ between groups (19% and 17%, respectively). In comparison, the control group had a significantly greater (P < 0.05) median MCTD (1020 mL), median allogeneic blood product exposure (4.5 U), and incidence of excessive MCTD (66%) and transfusion therapy (66%). These data help to support the use of pharmacologic methods to improve clinically relevant indicators of blood conservation for primary CPB procedures. Furthermore, the data show that TA is equivalent to aprotinin for blood conservation in patients at risk of excessive post-CPB bleeding and transfusion therapy. ⋯ In a randomized, blind trial, we evaluated the effects of tranexamic acid or aprotinin on blood conservation after primary cardiopulmonary bypass surgery. Both drugs were equally effective in reducing blood loss, the incidence of transfusion, and the amount of blood products transfused compared with placebon.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Clinical TrialAnalgesic effect of bupivacaine on extraperitoneal laparoscopic hernia repair.
Local anesthetics decrease postoperative pain when placed at the surgical site. Patients benefit from laparoscopic extraperitoneal hernia repair because this allows earlier mobilization than the more classical open surgical approach. The purpose of this study was to determine the pain-sparing efficacy of local anesthetics placed in the preperitoneal fascial plane during extraperitoneal laparoscopic inguinal hernia surgery. Forty-two outpatients were included in a double-blind, randomized, placebo-controlled, institutional review board-approved study. At the conclusion of a standardized general anesthetic, 21 patients received 60 mL of 0.125% bupivacaine into the preperitoneal fascial plane before incisional closure, whereas the other 21 patients received 60 mL of the isotonic sodium chloride solution placebo. Postoperative pain was assessed 1, 4, 8, 24, and 72 h postoperatively. In addition, postoperative fentanyl and outpatient acetaminophen 500 mg/hydrocodone 5 mg requirements were recorded. All hernia repairs were performed by the same surgeon. Appropriate statistical analyses were used. There were no significant differences between the bupivacaine and isotonic sodium chloride solution groups with regard to postoperative pain scores, length of postanesthesia care unit stay, or analgesic requirements. Furthermore, neither unilateral versus bilateral repair nor operative time affected the measured parameters. The addition of 60 mL of 0.125% bupivacaine into the preperitoneal fascial plane during extraperitoneal laparoscopic hernia repair did not significantly alter pain scores, supplementary analgesic requirements, or recovery room length of stay. ⋯ The placement of 60 mL of 0.125% bupivacaine into the preperitoneal fascial plane during extraperitoneal laparoscopic hernia repair did not significantly alter pain scores, supplementary analgesic requirements, or recovery room length of stay.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Clinical TrialThe efficacy of intrathecal neostigmine, intrathecal morphine, and their combination for post-cesarean section analgesia.
We designed this study to evaluate the postoperative analgesic efficacy and safety of intrathecal (i.t.) neostigmine, i.t. morphine, and their combination in patients undergoing cesarean section under spinal anesthesia. Seventy-nine term parturients were randomly divided into four groups to receive isotonic sodium chloride solution 0.2 mL, neostigmine 25 microg, morphine 100 microg, or the combination of i.t. neostigmine 12.5 microg and morphine 50 microg with i.t. 0.5% hyperbaric bupivacaine 12 mg. There were no significant differences among the four groups with regard to spinal anesthesia, maternal blood pressure and heart rate, or fetal status. Postoperative analgesia was provided by i.v. patient-controlled analgesia (PCA) using fentanyl and ketorolac. Compared with the saline group, the time to first PCA use was significantly longer in the neostigmine group (P < 0.001), with lower 24-h analgesic consumption (P < 0.001). Nausea and vomiting were the most common side effects of i.t. neostigmine (73.7%). Analgesic effectiveness was similar between the neostigmine and morphine groups. Compared with the neostigmine group, the combination group had significantly prolonged analgesic effect and reduced 24-h PCA consumption (P < 0.05) with less severity of nausea and vomiting (P = 0.058). Compared with the morphine group, the combination group tended to have prolonged times to first PCA use (P = 0.054) with a lower incidence of pruritus (P < 0.03). ⋯ Intrathecal (i.t.) neostigmine 25 microg produced postoperative analgesia for cesarean section similar to that of i.t. morphine 100 microg, but with a high incidence of nausea and vomiting. The combination of i.t. neostigmine 12.5 microg and i.t. morphine 50 microg may produce better postoperative analgesia with fewer side effects than i.t. neostigmine 25 microg or i.t. morphine 100 microg alone.
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Anesthesia and analgesia · Aug 1998
The effect of thoracic paravertebral blockade on intercostal somatosensory evoked potentials.
The paravertebral nerve blocks used in upper abdominal or thoracic surgery provide excellent pain relief and can inhibit some aspects of the neuroendocrine stress response to surgical trauma, which suggests that a very high-quality afferent block can be effected. To confirm this, we evaluated intercostal somatosensory evoked potentials (SSEPs) in 10 patients undergoing paravertebral nerve blocks as a treatment for chronic pain. SSEPs were recorded before and after ipsilateral thoracic paravertebral deposition of 1.5 mg/kg bupivacaine 0.5%. Sensory loss to temperature was demonstrated in all patients at the level of injection and had a mean superior spread of 1.4 (range 0-4) dermatomes and a mean inferior spread of 2.8 (range 0-7) dermatomes. SSEPs were abolished (the normal waveform was rendered unrecognizable with unmeasurable latencies and a mean amplitude of zero) in all patients at the level of injection. In addition, a two-dermatome SSEP abolition was found in four patients and a three-dermatome abolition was found in two patients. SSEPs were modified, but not significantly, at all other test points. We conclude that cortical responses to thoracic dermatomal stimulation can be abolished at the block level and adjacent dermatomes by thoracic paravertebral nerve blockade. Equivalent results have not been demonstrated with more central forms of afferent blockade, which suggests that thoracic paravertebral nerve blocks may be uniquely effective. ⋯ To improve outcomes after major surgery, as much nociceptive information as possible should be prevented from entering the central nervous and neuroendocrine systems. We have shown that local anesthetics alongside the vertebral column can abolish the usual brain recordings that follow intercostal nerve stimulation, which suggests that paravertebral nerve blocks may be uniquely effective.
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Anesthesia and analgesia · Aug 1998
Valuing the work performed by anesthesiology residents and the financial impact on teaching hospitals in the United States of a reduced anesthesia residency program size.
We performed a financial analysis at a large university tertiary care hospital to determine the incremental cost of replacing its anesthesiology residents with alternative dependent providers (i.e., certified registered nurse anesthetists in the operating room, advanced practice nurses and physician assistants outside the operating room). The annual average net cost of an anesthesiology resident during a 3-yr residency is approximately $38,000, and residents performed an average of $89,000 of essential clinical work annually based on replacement costs. The incremental cost (replacement labor cost minus net resident cost) to replace all essential clinical duties performed by an anesthesiology resident at Duke University Medical Center and affiliated hospitals is approximately $153,000 throughout 3 yr of clinical anesthesiology training. If this approach were applied nationwide, incremental costs of substitution would range from $36,000,000 to $93,000,000 per year. We conclude that maintaining clinical service in the face of anesthesiology residency reductions can have a marked impact on the overall cost of providing anesthesiology services in teaching hospitals. Simply replacing residents with alternate nonphysician providers is a very expensive option. ⋯ We sought to calculate the financial burden resulting from a decreased number of anesthesiology residents. Replacing each resident's essential clinical work with similarly skilled healthcare providers would cost hospitals approximately $153,000 over the course of a 3-yr residency. Varying projections yield future nationwide costs of $36,000,000 to $93,000,000 per year. Simply replacing residents with alternate nonphysician providers is a very expensive option.