Use of clonidine as a component of the peribulbar block in patients undergoing cataract surgery.

BACKGROUND AND OBJECTIVES: This study was designed to determine whether administration of clonidine as a component of a peribulbar block enhanced analgesia increased sedation, improved akinesia, or decreased intraocular pressure. METHODS: A randomized, double-blinded study was undertaken at a University-affiliated tertiary care hospital. Forty outpatients undergoing unilateral cataract surgery by a single surgeon (J.P.) under peribulbar blockade were evaluated. Patients received either 100 microg (1 mL) clonidine or 1 mL preservative-free normal saline mixed with the local anesthetic (7 mL 1% preservative-free lidocaine). A Honan adapter was applied for 10 minutes after block placement. The outcome measures included sedation scores, intraocular pressure (IOP) before and after peribulbar block, need for supplemental block, 24-hour analgesic requirement, and patient satisfaction. RESULTS: There were no differences between groups with respect to pain, sedation, or satisfaction scores. There was no difference with respect to onset of akinesia. This study revealed no significant difference in baseline IOP and postperibulbar IOP. CONCLUSIONS: Clonidine did not alter, in any appreciable way, the perioperative course for patients undergoing cataract operations. We do not recommend clonidine as a component of a peribulbar block in patients undergoing cataract extraction operations.

Use of clonidine in hernia patients: intramuscular versus surgical site.

BACKGROUND AND OBJECTIVES: This study was designed to determine if administration of clonidine in hernia patients enhances analgesia. It was also designed to determine whether administration directly in the surgical site further improves the analgesia. METHODS: A randomized, double-blinded study was undertaken at a tertiary care hospital. Forty-five outpatients undergoing unilateral inguinal hernia repair by one of two surgeons (D.P. or M.A.) under local anesthesia with monitored anesthesia care were evaluated. Patients were invited to participate in this investigation at the time of the preoperative surgical visit. Patients who had a contraindication to the use of clonidine or who refused repair under local anesthesia with sedation were excluded. Patients were randomized to one of three groups: (a) clonidine 0.5 microg/kg intramuscularly and saline in the surgical site (mixed with the local anesthetic); (b) clonidine 0.5 microg/kg in the surgical site and saline intramuscularly; or (c) saline in both the surgical site and intramuscularly. The outcome measures included visual analog pain scores twice in the hospital, pain scores at rest and with movement 24 hours postoperatively, the time to first analgesic, and total analgesic requirement. RESULTS: The pain scores were lower in both clonidine groups at 2 hours postoperatively than in the control group (P < .03). No difference was observed with respect to the time to first analgesic, 24-hour analgesic use, or 24-hour pain scores among the groups. CONCLUSIONS: When clonidine is administered to patients undergoing hernia repair, the 2-hour pain scores are lowered. No difference was exhibited when clonidine was administered intramuscularly or directly into the hernia site.

Discomfort associated with regional anesthetic placement in obstetrics: does alkalinization help?

Lidocaine is commonly used prior to intravenous catheter insertion as well as before instituting a regional anesthetic[ but it often causes a burning discomfort during injection. We undertook this study to determine if the addition of bicarbonate to lidocaine would decrease the discomfort associated with the initiation of regional anesthesia in obstetrics. Forty patients who were scheduled for elective cesarean section or who were in active labor were selected. Lidocaine was prepared before infiltration using 9 ml of preservative-free 1% lidocaine with either 1 ml of preservative-free normal saline or 1 ml of sodium bicarbonate (1 mEq.ml(-1)). A skin wheal was raised with 0.5 ml of the solution; the remainder (1.5 ml) was injected into the deep tissues. Pain was assessed using visual analog scales on three occasions, immediately after lidocaine placement, following introducer needle insertion (in the spinal group) or following epidural needle insertion (in the epidural group), and following the successful placement of the local anesthetic (in the spinal group) or the epidural catheter (in the epidural group). There was no difference in the visual analog scale scores at any of the assessment periods. We found no benefit from adding sodium bicarbonate to lidocaine used for infiltration before needle placement when initiating an obstetrical regional anesthetic.

Nalmefene or naloxone for preventing intrathecal opioid mediated side effects in cesarean delivery patients.

This study was designed to evaluate the efficacy of nalmefene vs. naloxone in preventing side effects resulting from intrathecal opioids, in patients undergoing cesarean delivery. Eighty patients who were scheduled for elective cesarean delivery under spinal anesthesia were included in a double-blind, placebo-controlled study. Patients were randomized into four groups: saline; intravenous nalmefene 0.25 micro.kg(-1) every 12 h x 2; intravenous nalmefene 0.5 microg.kg(-1) every 12 h x 2; and naloxone infusion 48 microg.h(-1) (1.2 microg.ml(-1)). There were no significant differences among the groups with respect to pain, sedation, satisfaction, or the occurrence or treatment of pruritus or nausea. There was a significant difference among the groups with respect to the occurrence of vomiting (P < 0.03): both nalmefene groups had a higher rate of vomiting than did the control group; the 0.25 microg.kg(-1) nalmefene group had a higher rate than did the naloxone group. The use of narcotic antagonists does not result in improved comfort in obstetrical patients receiving intrathecal morphine and fentanyl.

Pregnancy and delivery in a patient with recent peripartum cardiomyopathy.

We present a case of successful pregnancy and delivery in a patient with peripartum cardiomyopathy who conceived only 3 months after a vaginal delivery complicated by peripartum cardiomyopathy. Following the onset of labor, an arterial pressure catheter and pulmonary artery catheter were placed. A combined epidural spinal technique was performed without difficulty for labor analgesia. After a few hours of labor, the fetal heart rate tracing revealed repetitive variable decelerations, and a decision was made to proceed with operative delivery. The mother's hemodynamic changes are presented, and the specifics of the anesthetic care are outlined.

Effect of epidural clonidine added to epidural sufentanil for labor pain management.

Labor analgesia with intrathecal sufentanil has been shown to be prolonged by the addition of intrathecal clonidine. The current study was designed to determine if epidural clonidine would prolong labor analgesia provided by epidural sufentanil. Forty laboring primiparous women at less than 5 cm cervical dilation requesting epidural analgesia were enrolled. Following a 3 mL test dose of lidocaine with epinephrine, patients were randomized to receive 10 mL of either sufentanil 20 microg (S) or sufentanil 20 microg with clonidine 75 microg (SC). After administration of the analgesic, pain scores and side-effects were recorded for each patient at 5, 10, 15, 20 and 30 min, and every 30 min thereafter, by an observer blinded to the technique used. There were no demographic differences between the two groups. Pain relief was rapid for all patients. The mean duration of analgesia was similar between the S group (153 +/- 78 min) and the SC group (178 +/- 55 min). Side-effects were similar between the two groups. There was no difference between the two groups in time from sufentanil administration to delivery, incidence of operative or assisted delivery, or cervical dilation at the time of redose. For early laboring patients, epidural sufentanil 20 microg after a lidocaine test dose provides analgesia comparable to that of sufentanil 20 microg with clonidine 75 microg; there was no significant difference in analgesic duration between the two groups.

Intraoperative hypotension due to unrecognized bleeding from a continuous spinal catheter site.

We recently cared for a patient who had a rare complication from a continuous spinal catheter: extensive bleeding around the catheter insertion site. This complication went unrecognized intraoperatively because the bleeding was hidden from view. The possible etiologies for this bleeding are discussed, as well as methods to recognize this complication before significant bleeding occurs.

A comparison of the Bullard laryngoscope versus the flexible fiberoptic bronchoscope during intubation in patients afforded inline stabilization.

STUDY OBJECTIVE: To compare the Bullard laryngoscope (BL) with the flexible fiberoptic bronchoscope (FFB) in a cervical spine injury model, using inline stabilization. DESIGN: Randomized clinical trial. SETTING: Main operating room of a tertiary care hospital. PATIENTS: 50 adult, ASA physical status I, II, and III patients undergoing an elective general anesthetic. INTERVENTIONS: Each patient's trachea was intubated with both techniques. Cricoid pressure was applied to half of the study patients. MEASUREMENTS: The time for laryngoscopic view and the time to intubation were recorded for each technique. The effects of cricoid pressure on laryngoscopic view and intubation time were determined. MAIN RESULTS: The times for laryngoscopy and intubation were longer in the FFB group than in the BL group (p < 0.004). There was a significantly lower success rate of laryngoscopy view in the FFB group in the presence of cricoid pressure (15 of 25 patients, or 60%) than either of the BL groups or the FFB no-cricoid pressure group. CONCLUSIONS: The BL is more reliable, quicker, and more resistant to the effects of cricoid pressure than is the FFB.

An evaluation of the cuffed oropharyngeal airway for elective pediatric anesthesia.

STUDY OBJECTIVE: To evaluate the usefulness in pediatric patients of the cuffed oropharyngeal airway (COPA), an airway device with an inflatable cuff around its distal portion, and which provides airway patency in the majority of anesthetized adult patients. DESIGN: Prospective evaluation. SETTING: Pediatric operating room of a tertiary-care medical center. PATIENTS: 50 anesthetized ASA physical status I pediatric patients, under 6 yr of age undergoing elective surgery. INTERVENTIONS: Patients were fitted with a size 7 COPA placed following anesthetic induction. If an adequate airway was not obtained, a size 8 COPA was placed. If an adequate airway was not obtained despite repositioning the size 8, the COPA was considered failed. MEASUREMENTS AND MAIN RESULTS: The ease of insertion and ability to manage the airways were evaluated. Complications were evaluated on insertion, during maintenance, and upon awakening. The ability to positive pressure ventilate via the COPA was assessed. The size 7 COPA obtained an initial fit in 38 (76%) of the patients. Nine patients were managed with a size 8 COPA. The COPA was unsuccessful in 3 (6%) patients. Laryngospasm occurred in three patients. Blood was not visible on any of the COPAs. Positive pressure ventilation was achieved with 30 +/- 7 cm H(2)O pressure. CONCLUSIONS: The results using the COPA in pediatric patients seem to parallel the experience of using larger sizes in adult patients.

Use of single-dose epidural morphine in a patient undergoing an abdominal aortic aneurysm resection.

To avoid possible trauma to the epidural venous plexus in a 56-year-old male who presented for abdominal aortic aneurysm resection, the authors preoperatively injected a single dose of epidural morphine rather than inserting an indwelling epidural catheter. The patient's intraoperative anesthetic requirements appeared to have been decreased, he was extubated shortly after the end of the procedure, and he experienced good postoperative analgesia. No untoward neurologic sequelae occurred. The authors feel that a single dose of epidural morphine, compared to epidural catheter placement when systemic heparinization is planned, decreases intraoperative anesthetic requirements, provides good postoperative analgesia, and may have the benefit of decreasing the possibility of epidural hematoma formation.

Temporal correlation of succinylcholine-induced fasciculations to loss of twitch response at different stimulating frequencies.

STUDY OBJECTIVE: The present study was undertaken to determine the time courses of succinylcholine-induced fasciculations and adductor pollicis single-twitch responses at two stimulating frequencies. DESIGN: A prospective, randomized study. SETTING: The main operating room of a university teaching hospital. PATIENTS: Forty-four patients undergoing general anesthesia and requiring tracheal intubation. INTERVENTIONS: In 22 patients, anesthesia was induced with thiopental sodium, fentanyl, and midazolam and maintained with 70% nitrous oxide in oxygen prior to the administration of succinylcholine 1 mg/kg. In another 22 patients, end-tidal isoflurane 0.75% to 1% was included in the induction regimen. Patients in each group were randomly assigned to receive ulnar nerve stimulation at either 0.1 Hz or 1.0 Hz. MEASUREMENTS AND MAIN RESULTS: The times at which fasciculations were first noticed and no longer visible and the times to 25%, 50%, 75%, 90%, and 100% twitch depression were recorded. These times were compared for the two rates of neurostimulation. With single-twitch nerve stimulation at 1.0 Hz, 100% twitch depression occurred 6 +/- 16 seconds following the end of fasciculations, while at a stimulating frequency of 0.1 Hz, it occurred 52 +/- 32 seconds later (p less than 0.05). At the end of fasciculations, single-twitch depression of 50% or more was noted in only 19% of patients in the 0.1 Hz groups and in all patients in the 1.0 Hz groups (p less than 0.05). In the 0.1 Hz groups, 50% twitch depression occurred 19 +/- 27 seconds after the end of fasciculations, with more than three-quarters of the patients having achieved 50% twitch depression 30 seconds following the disappearance of fasciculations. The addition of isoflurane did not significantly alter any of these times. CONCLUSIONS: The data reveal that cessation of fasciculations may be an inaccurate clinical sign of the readiness for intubation and confirm that standardized methods of neurostimulation are necessary in the pharmacodynamic evaluation of neuromuscular blocking drugs. In settings where profound neuromuscular relaxation is not required, waiting at least 30 seconds beyond the disappearance of fasciculations should provide good intubating conditions.

Comparison of wire reinforced tubes with warmed standard tubes to facilitate fiberoptic intubation.

STUDY OBJECTIVE: To compare the ease of insertion of a warmed standard tracheal tube to that of a wire reinforced tracheal tube when placed over a flexible fiberoptic bronchoscope. DESIGN: Randomized controlled trial. SETTING: Tertiary care hospital. PATIENTS: 50 patients undergoing elective general anesthesia. INTERVENTIONS: Patients' tracheas were intubated with a flexible fiberoptic bronchoscope and had either a standard or wire-reinforced tracheal tube inserted. If resistance was met, the tube was withdrawn, rotated, and readvanced. This was repeated two times. If unsuccessful, the flexible fiberoptic bronchoscope was removed, and intubation was attempted with the other type of tracheal tube. MEASUREMENTS: The ability to advance the tracheal tube was determined. MAIN RESULTS: There were no demographic differences between the two groups. There was a similar ease of advancement of the two tracheal tubes. CONCLUSIONS: When performing elective flexible fiberoptic bronchoscopy for intubation, we recommend using the less expensive warmed standard tracheal tube.

Anesthetic management of the exit (ex utero intrapartum treatment) procedure.

The EXIT (ex utero intrapartum treatment) procedure is used to maintain fetal-placental circulation during partial delivery of a fetus with a potentially life-threatening upper airway obstruction. We performed the EXIT procedure on a fetus with a large intra-oral cyst. Sevoflurane was used as the anesthetic because of its rapid titratability. Sevoflurane provided excellent maternal and fetal anesthesia. Modifications to previously described monitoring techniques for the EXIT procedure were also used.

Postoperative analgesia for outpatient arthroscopic knee sugery with intraarticular bupivacaine and ketorolac.

Intraarticular (IA) local anesthetics are often used for the management and prevention of pain after arthroscopic knee surgery. Systemic ketorolac is also useful in the management of these patients. Ketorolac, a nonsteroidal antiinflammatory drug (NSAID), alters the sensitivity of peripheral nociceptors by reducing the local concentration of allogenic chemicals which are activated by peripheral tissue injury. It is interesting to speculate that placing a NSAID at the site of injury might result in more profound pain relief. However, IA ketorolac has not been evaluated in arthroscopic patients. This study thus was designed to determine which regimen would result in the most effective analgesic benefit. The four groups evaluated received ketorolac (either via the parenteral or IA route) or saline placebo with or without IA bupivacaine, as follows: Group 1 received IA bupivacaine; Group 2, intravenous ketorolac and IA bupivacaine; Group 3, IA bupivacaine with ketorolac; and Group 4, IA ketorolac. The results of this study revealed a significant difference in analgesia from the IA administration of ketorolac. The group who received a combination of IA bupivacaine and IA ketorolac had decreased postoperative pain, a decreased need for postoperative analgesics, and an increased analgesic duration. We conclude that the use of IA ketorolac improved comfort in patients undergoing knee arthroscopy.

Postarthroscopic meniscus repair analgesia with intraarticular ketorolac or morphine.

Both ketorolac, a nonsteroidal antiinflammatory drug, and morphine, an opioid agonist, provide enhanced patient analgesia after arthroscopic knee surgery when administered via the intraarticular route. This study was designed to determine whether ketorolac or morphine results in better patient analgesia and whether their combination would provide superior analgesia to either drug alone. Patients undergoing arthroscopic knee meniscus repair under local anesthesia with sedation were evaluated. Each of the study groups evaluated received ketorolac (either via the parenteral or intraarticular route) and morphine (via either the parenteral or intraarticular route). This study revealed a significant benefit from the individual intraarticular administration of both morphine and ketorolac. The combination of these drugs did not result in decreased postoperative pain or need for postoperative analgesics, and it did not result in an increased analgesic duration. We conclude that the use of either intraarticular ketorolac or intraarticular morphine improves the comfort in patients undergoing arthroscopic meniscus repair and that their combination offers no advantage over either drug alone.

Postoperative analgesia for outpatient arthroscopic knee surgery with intraarticular clonidine.

UNLABELLED: Intraarticular (i.a.) local anesthetics are often used for the management and prevention of pain after arthroscopic knee surgery. Clonidine prolongs the duration of local anesthetics. We designed this study to determine whether clonidine added to an i.a. injection would result in an analgesic benefit. Fifty patients were randomly assigned to one of five groups that received clonidine (either via the subcutaneous or i.a. route) or saline placebo with or without i.a. bupivacaine, as follows: Group 1 received 30 mL of 0.25% bupivacaine i.a.; Group 2 received 30 mL of 0.25% bupivacaine with clonidine (1 microg/kg) i.a.; Group 3 received 30 mL of 0.25% bupivacaine i.a. and subcutaneous clonidine (1 microg/kg); Group 4 received 30 mL of 0.25% bupivacaine with epinephrine (5 microg/mL) i.a.; and Group 5 received clonidine (1 microg/kg) in 30 mL of saline i.a.. The results of this study revealed a significant difference in analgesia from the i.a. administration of clonidine. The group who received a combination of i.a. bupivacaine and clonidine had a significantly decreased need for oral postoperative analgesics and an increased analgesic duration (P < 0.0001). We conclude that i.a. clonidine improved comfort in patients undergoing knee arthroscopy. IMPLICATIONS: The intraarticular administration of clonidine along with bupivacaine results in a significant improvement in analgesia compared with either drug alone. There was an increased time to first analgesic request and a decreased need for postoperative analgesics.

Double lumen tube placement with the Bullard laryngoscope.

PURPOSE: Placement of double lumen tubes (DLTs) in both normal and difficult airways may be considerably more difficult than standard laryngoscopy and intubation using standard tracheal tubes. Alternative techniques to place DLTs have not been uniformly successful and alternative tracheal tubes do not provide the versatility afforded by the DLT. We intubated the tracheas of patients undergoing thoracic procedures requiring DLTs with the Bullard laryngoscope (BL) to determine its efficacy and outline its shortcomings. METHODS: Twenty nine consecutive patients scheduled for general anesthesia requiring DLT were evaluated. The laryngeal view, time to intubation and the reason for any difficulty with intubation were recorded. Any patient who required a second DLT placement had the second attempt performed via standard laryngoscopy. RESULTS: The time to laryngoscopy was 9+/-5 sec, and the time to intubation was 28+/-10 sec. All patients had Cormack scores of grade of 1 through the BL. The placement of the bronchial lumen of the DLT was found to be in the correct location (left mainstem bronchus) in 9 of 28 patients. CONCLUSION: The BL appears to be effective in the placing DLT into the trachea of patients.