Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2003
Case ReportsAn indication for continuous cervical paravertebral block (posterior approach to the interscalene space).
We present a patient who required perioperative analgesia with continuous nerve block for shoulder disarticulation, for whom the only approach possible to the brachial plexus was from posterior. A 51-yr-old woman was suffering from intractable upper extremity pain and dysfunction as a result of severe lymphedema after metastatic spread of breast cancer to the axilla. Her pain was poorly controlled despite aggressive treatment with oral, systemic, and intrathecal opiates. ⋯ In order to provide optimal postoperative analgesia, continuous peripheral nerve block was selected in consultation with the patient, and due to anatomic disfigurement and tumor invasion, a continuous cervical paravertebral block was placed preoperatively and shoulder disarticulation was performed using a combined regional/general anesthesia technique. The patient had an uneventful recovery without pain for the 6 postoperative days that the catheter was in place and 0.25% bupivacaine was infused at 5 mL/h. Because of anatomic considerations, which precluded the use of all other approaches to the brachial plexus, the posterior cervical paravertebral approach provided an effective means of pain control in this difficult clinical situation.
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Anesthesia and analgesia · Sep 2003
Comparative Study Clinical TrialMeasuring cerebral oxygenation during normobaric hyperoxia: a comparison of tissue microprobes, near-infrared spectroscopy, and jugular venous oximetry in head injury.
We measured simultaneous changes in jugular venous oxygen saturation, brain tissue oxygen tension, and cerebral tissue oxygen index by using near-infrared spectroscopy during normobaric hyperoxygenation in eight severely brain-injured patients. Patients were ventilated at their baseline fraction of inspired oxygen (FIO(2)), followed by stepped changes in FIO(2) to 1.0, 0.6, and 0.02-0.05 less than baseline. There was an increase (P < 0.01) in jugular venous saturation (mean +/- SD) from a baseline value of 79% +/- 7% to 89% +/- 6% and 84% +/- 8% at an FIO(2) of 1.0 and 0.6, respectively. ⋯ There was a reduction (P < 0.05) in tissue oxygen index to 76.2% +/- 3.0% when the FIO(2) was reduced to less than baseline. The changes in the three variables followed similar patterns but varied in their degree and speed of response. During brain injury, FIO(2) affects measured variables of cerebral oxygenation.
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Anesthesia and analgesia · Sep 2003
Comparative Study Clinical TrialA comparative evaluation of transcutaneous and end-tidal measurements of CO2 in thoracic anesthesia.
We performed this study to assess the accuracy of transcutaneous CO(2) (PTCCO(2)) monitoring compared with end-tidal CO(2) (PETCO(2)) in thoracic anesthesia. Twenty-six patients undergoing pneumonectomy with thoracotomy for which a long period of one-lung ventilation (OLV) was required were studied. The lungs were mechanically ventilated in the lateral decubitus position. ⋯ All patients completed the study protocol. Bland-Altman analysis revealed a bias of -0.4 mm Hg with a precision of +/-2.5 mm Hg during OLV and 1.4 mm Hg with +/-4.3 mm Hg during TLV when PTCCO(2) and PaCO(2) were compared and revealed a bias of -5.8 mm Hg with a precision of +/-4.1 mm Hg during OLV and -7.1 mm Hg with +/-4.6 mm Hg during TLV when PETCO(2) and PaCO(2) were compared. We conclude that PTCCO(2) monitoring is accurate for evaluating CO(2) levels during thoracic anesthesia.
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Anesthesia and analgesia · Sep 2003
Clinical TrialIntravenous remifentanil produces withdrawal hyperalgesia in volunteers with capsaicin-induced hyperalgesia.
Opioids administered during surgery may be beneficial by preempting postoperative pain or detrimental by causing acute tolerance. We used a stable model of hyperalgesia in volunteers to test whether acute opioid exposure also results in such pain sensitization over a period of hours in humans. Ten healthy volunteers were studied. ⋯ Areas of hyperalgesia and allodynia continuously enlarged 4 h after remifentanil was stopped, to 180% +/- 47% and 180% +/- 86%, respectively. This study demonstrates that acute opioid exposure enhances hypersensitivity for hours after exposure. If applicable to the surgical setting, this could increase the dose of opioid required for postoperative analgesia and enhance, rather than inhibit, postoperative pain.
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Anesthesia and analgesia · Sep 2003
Clinical TrialPatient-controlled sedation using propofol for dressing changes in burn patients: a dose-finding study.
The first change of dressings after skin grafting in burn patients is a source of great anxiety because of pain anticipation and the immediate and first confrontation with the result of skin grafting. We designed this dose-finding study to determine the feasibility and safety of patient-controlled sedation (PCS) using propofol during these procedures. Twenty patients were familiarized with the PCS and asked to use PCS whenever they felt uncomfortable or anxious. ⋯ The second group of patients showed a more effective sedation, with respiratory and hemodynamic variables being not significantly different from the first group of patients. PCS with propofol is feasible in burn patients and can be used safely. To provide an optimal sedation, we suggest to initially titrate the bolus to achieve a significant decrease of BIS or a clinically effective state of sedation and to abolish the lockout interval.