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Biomedical subjects

R Greengrass

Publications and source records attributed to R Greengrass.

10 recordsLinked to original sources
PubMed2001

Patient satisfaction and effectiveness of lumbar plexus and sciatic nerve block for total knee arthroplasty.

The purpose of this study was to evaluate the efficacy of combined lumbar plexus block techniques for total knee arthroplasty. Long-acting local anesthetics were used to ensure adequate intraoperative and postoperative anesthesia and analgesia. All patients undergoing total knee arthroplasty at our institution were offered lumbar plexus block after obtaining informed consent. Patients for study were a continuous group of 87 patients over a 1-year period. A subset of 40 patients was studied for postoperative analgesia effect. All patients were contacted by phone for a satisfaction survey. There were 87 patients who received initial lumbar plexus and sciatic nerve blocks, 78% (68 of 87) of whom had adequate initial blocks. Sixteen patients (22%) required conversion to general anesthesia intraoperatively because of inadequate anesthesia. A subset of patients studied for postoperative analgesia revealed an average time of 13 hours before the first request for supplemental narcotics. There were no complications related to the lumbar plexus block in our study group of patients. There was a 92% overall satisfaction rate with the anesthesia provided by the lumbar plexus block. Lumbar plexus block can be used successfully for total knee arthroplasty. Lumbar plexus block appears to have advantages for early postoperative analgesia, leading to increased patient comfort and satisfaction.

Aged↗
PubMed1999

Sameridine is safe and effective for spinal anesthesia: a comparative dose-ranging study with lidocaine for inguinal hernia repair.

UNLABELLED: Sameridine is a new compound with local anesthetic and analgesic properties when injected intrathecally. We studied the anesthetic and analgesic efficacy of three doses of isobaric sameridine (15, 20, and 23 mg) compared with 100 mg of hyperbaric lidocaine for spinal anesthesia in 140 healthy male patients undergoing inguinal hernia repair. Patients received spinal anesthesia with 4 mL of the study drug injected at the L2-3 or L3-4 interspace in the lateral decubitus position. All three doses of sameridine provided spinal anesthesia similar to lidocaine, with a slightly longer time to reach peak block height. The failure rate was highest in the 15-mg sameridine group, and accrual was discontinued in that group after 35 patients. The duration of blockade was shorter with lidocaine, but the time to voiding and ambulation was similar in all groups. Patients receiving sameridine were less likely to request morphine for postoperative analgesia and were less likely to request any analgesia in the first 4 h after injection of the drug. Use of oral analgesics (hydrocodone and acetaminophen) was similar in all groups after the first 4 h of the 24-h observation. We conclude that, in the three doses studied, sameridine provided spinal anesthesia similar to lidocaine, but with residual analgesia after drug injection that reduced the need for systemic analgesics in the first 4 h postoperatively. IMPLICATIONS: In this clinical trial, we show the potential efficacy of a class of drugs that can produce both spinal anesthesia and postoperative analgesia when used for hernia repair.

Adolescent↗
PubMed1998

Use of paravertebral block anesthesia in the surgical management of breast cancer: experience in 156 cases.

OBJECTIVE: To assess safety and efficacy of the regional anesthetic technique paravertebral block for operative treatment of breast cancer, and to compare postoperative pain, nausea, vomiting, and length of hospital stay in patients undergoing breast surgery using paravertebral block and general anesthesia. BACKGROUND: General anesthesia is currently the standard technique used for surgical treatment of breast cancer. Increasing hospital costs have focused attention on reducing the length of hospital stay for these patients. However, the side effects and complications of general anesthesia preclude ambulatory surgery for most patients undergoing breast surgery. In April 1994, the authors initiated the use of paravertebral block anesthesia for patients undergoing primary breast cancer surgery. A review of our early experience revealed that this regional anesthetic technique enables effective anesthesia for operative procedures of the breast and axilla, reduces postoperative nausea and vomiting, and provides prolonged postoperative sensory block that minimizes narcotic requirements. METHODS: A retrospective analysis of 145 consecutive patients undergoing 156 breast cancer operations using paravertebral block and 100 patients undergoing general anesthesia during a 2-year period was performed. Anesthetic effectiveness and complications, inpatient experience with postoperative pain, nausea, vomiting, and length of stay were measured. RESULTS: Surgery was successfully completed in 85% of the cases attempted by using paravertebral block alone, and in 91% of the cases, surgery was completed by using paravertebral block supplemented with local anesthetic. There was a 2.6% incidence of complications associated with block placement. Twenty percent of patients in the paravertebral group required medication for nausea and vomiting during their hospital stay compared with 39% in the general anesthesia group. Narcotic analgesia was required in 98% of general anesthesia patients, as opposed to 25% of patients undergoing paravertebral block. Ninety-six percent of patients having paravertebral block anesthesia were discharged within the day of surgery, compared with 76% of patients who had a general anesthetic. CONCLUSIONS: Paravertebral block can be used to perform major operations for breast cancer with minimal complications and a low rate of conversion to general anesthesia. Paravertebral block markedly improves the quality of recovery after breast cancer surgery and provides the patient with the option of ambulatory discharge.

Anesthesia, General↗
PubMed1996

Paravertebral block for breast cancer surgery.

PURPOSE: Major breast cancer surgery is associated with a high incidence of postoperative nausea, vomiting and pain. Regional anaesthesia, with intraoperative sedation, would seem an ideal alternative to general anaesthesia for this type of surgery. We report our initial experience using paravertebral blocks (PVB) to provide anaesthesia for major breast surgery. METHODS: Twenty-five patients agreeing to have surgery performed under paravertebral blocks were studied. Procedures performed varied from simple lumpectomy with axillary dissection to modified radical mastectomy with axillary dissection. During monitored sedation, blocks opposite spinous processes of C7-T6 were performed using bupivacaine 0.5% with epinephrine, 3-4 ml per segment. Patients were evaluated for 72 hr and were requested to document: (i) when sensation returned (ii) incidence and frequency of nausea or vomiting (iii) degree of discomfort and medication taken. RESULTS: Twenty patients had blocks that required no supplementation. Five patients had blocks that were incomplete. No complications were attributed to the blocks. Post-operatively, patients with successful blocks had minimal nausea, vomiting and pain. No patients found the procedure unsatisfactory. Patients with successful blocks were all very satisfied. CONCLUSION: Our initial results show that PVB for breast cancer surgery can be successfully performed in a majority of patients with few side effects. All patients with successful blocks were returned to the ambulatory care unit, bypassing the recovery room. That breast cancer surgery under regional anaesthesia can be safely performed as an ambulatory procedure has the potential for accomplishing major cost-saving.

Adult↗
PubMed1996

Epinephrine decreases postoperative requirements for continuous thoracic epidural fentanyl infusions.

Epidural thoracic fentanyl infusions provide effective preoperative analgesia after thoracotomy; however, side effects can limit the effectiveness of this technique. This study evaluates epinephrine as an adjunct to continuous thoracic epidural fentanyl infusions after thoracotomy. Thirty-eight patients were studied in a prospective, randomized, double-blind trial comparing fentanyl alone to fentanyl with epinephrine 1:300,000. Epidural infusion rates were titrated to equivalent pain relief using a visual analog scale. With the addition of epinephrine, there was a significant reduction in fentanyl requirements (0.82 +/- 0.07 vs 1.19 +/- 0.11 micrograms.kg-1.h-1, P = 0.005, repeated-measures analysis of variance) and in plasma fentanyl concentrations (steady state: 0.91 +/- 0.13 vs 1.65 +/- 0.23 ng/mL, P = 0.007, repeated-measures analysis of variance). There were no differences in pain scores, side effects, spirometry, patient satisfaction scores, or hemodynamic variables. This study demonstrates that adding epinephrine 1:300,000 to continuous thoracic epidural infusions decreases fentanyl requirements titrated for effective analgesia. The reduction in fentanyl requirements was associated with reduced fentanyl plasma concentrations.

Analgesia, Epidural↗
PubMed1993

Thoracic versus lumbar epidural fentanyl for postthoracotomy pain.

Thirty patients were prospectively randomized to receive either thoracic or lumbar epidural fentanyl infusion for postthoracotomy pain. Epidural catheters were inserted, and placement was confirmed with local anesthetic testing before operation. General anesthesia consisted of nitrous oxide, oxygen, isoflurane, intravenous fentanyl citrate (5 micrograms/kg), and vecuronium bromide. Pain was measured by a visual analogue scale (0 = no pain to 10 = worst pain ever). Postoperatively, patients received epidural fentanyl in titrated doses every 15 minutes until the visual analogue scale score was less than 4 or until a maximum fentanyl dose of 150 micrograms by bolus and an infusion rate of 150 micrograms/h was reached. The visual analogue scale score of patients who received thoracic infusion decreased from 8.8 +/- 0.5 to 5.5 +/- 0.7 (p < or = 0.05) by 15 minutes and to 3.5 +/- 0.4 (p < or = 0.05) by 45 minutes. The corresponding values in the lumbar group were 8.8 +/- 0.6 to 7.8 +/- 0.7 at 15 minutes and 5.3 +/- 0.9 at 45 minutes (p < or = 0.05). The infusion rate needed to maintain a visual analogue scale score of less than 4 was lower in the thoracic group (1.55 +/- 0.13 micrograms.kg-1 x h-1) than in the lumbar group (2.06 +/- 0.19 microgram.kg-1 x h-1) during the first 4 hours after operation (p < or = 0.05). The epidural fentanyl infusion rates could be reduced at 4, 24, and 48 hours after operation without compromising pain relief. Four patients in the lumbar group required naloxone hydrochloride intravenously.(ABSTRACT TRUNCATED AT 250 WORDS)

Analgesia, Epidural↗
PubMed1993

Diagnostic algorithm for acute superior vena caval obstruction (SVCO).

Acute SVCO presents a serious diagnostic and therapeutic dilemma to the thoracic surgeon. It is highly desirable to obtain a definitive tissue diagnosis but this requirement must be balanced against the risks inherent in invasive diagnostic procedures in these oft-times critically ill patients. In the past 5 years we have developed an algorithm that has been used successfully in 18 patients presenting with acute SVCO. The decision tree consists of scalene node biopsy, bronchoscopy and mediastinoscopy with categorization into low and high risk groups in the latter. The gender distribution of the 18 patients was 12 male and 6 female with the ages being 58.3 +/- 16.3 and 64.2 +/- 11.2 years respectively. The duration of symptoms range from 1.5 to 12 weeks and averaged 4.5 +/- 3.2 weeks. Two patients had palpable scalene nodes which were positive at biopsy. Bronchoscopy was positive in 5 out of 11 examinations. In 5 instances it was not done. Twelve patients underwent various forms of mediastinal biopsy and one underwent sternotomy. Seven patients requiring mediastinoscopy were judged to be high risk as defined by severe airway and vascular obstruction. Perioperative difficulties occurred in two patients due to cardiorespiratory factors associated with the obstruction. Both patients were undergoing cervical mediastinoscopy under general anesthesia and no difficulties were encountered in high risk patients when local anesthesia was used to perform anterior mediastinotomy. Five patients that were considered low risk all underwent uncomplicated procedures under general anesthesia. Thirteen patients proved to have bronchogenic carcinoma and a specific tissue diagnosis was obtained in 12. The undetermined diagnosis was in a patient who had prior radiotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1986

Acidemia impairs autoregulation of cerebral blood flow in newborn lambs.

Cerebral blood flow (CBF) and autoregulation of cerebral blood flow were assessed in newborn lambs before and after inducing metabolic acidemia. CBF was measured by xenon washout and autoregulation by the change in CBF after increasing mean arterial pressure (MAP) 30 per cent with 0.02 per cent phenylephrine hydrochloride. After surgical preparation, stabilization, and demonstration of the presence of autoregulation, six lambs received 10 mg X kg-1 of lactic acid intravenously over 30 minutes. Arterial pH decreased from 7.35 +/- 0.01 (mean +/- SEM) during the control period to 6.96 +/- 0.02 (p less than 0.01) at the end of the lactic acid infusion. Arterial blood gases, MAP's, and heart rates did not change. Prior to lactic acid infusion, CBF before and after raising MAP were 53 +/- 3 ml/100 g/min and 56 +/- 4 ml/100 g/min respectively. After lactic acid infusion, CBF increased from 54 +/- 2 ml/100 g/min to 62 +/- 3 ml/100 g/min (p less than 0.05) following phenylephrine induced rise in MAP. Five control lambs showed no significant change in any of these variables, including CBF, over the same time periods. These data indicate that metabolic acidosis per se does not alter CBF, but that metabolic acidosis impairs cerebral vascular autoregulation in hyperoxic lambs. Similar changes in human neonates might result in intracranial haemorrhage.

Acidosis↗