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Biomedical subjects

B Ginsberg

Publications and source records attributed to B Ginsberg.

At least 37 records · Page 2Linked to original sources
PubMed1997

Determination of plasma concentrations of propofol associated with 50% reduction in postoperative nausea.

BACKGROUND: Subhypnotic doses of propofol possess direct antiemetic properties. The authors sought to determine the plasma concentration of propofol needed to effectively manage postoperative nausea and vomiting. METHODS: Patients aged 18-70 yr who were classified as American Society of Anesthesiologists physical status 1 or 2 and had surgery during general anesthesia were approached for the study. Only patients who had nausea (verbal rating score > 5 on a 0- to 10-point scale), retching, or vomiting in the postanesthetic care unit participated. Propofol was administered to these patients to achieve target plasma concentrations of 100, 200, 400, and 800 ng/ml using a computer-assisted continuous infusion device. Target concentrations were increased every 15 min until patients described at least a 50% reduction in symptoms on the verbal rating score. An arterial blood sample was obtained at each step. The measured plasma propofol concentrations were used to analyze data. Blood pressure, heart and respiratory rates, arterial blood saturation, sedation score, and overall satisfaction with treatment were recorded. RESULTS: Of the 89 patients who consented to the study, 15 patients met entry criteria and were enrolled. Five of these patients also had retching or vomiting when they entered the study. Fourteen patients responded successfully to treatment. One patient did not achieve the required response at plasma concentrations of 830 ng/ml. Hence the success rate for the treatment of postoperative nausea and vomiting was 93%. Among patients who responded, the median plasma concentration associated with an antiemetic response was 343 ng/ml. There was no difference in sedation scores from baseline and no episodes of desaturation. Hemodynamic parameters were stable during the study. CONCLUSIONS: Propofol is generally efficacious in treating postoperative nausea and vomiting at plasma concentrations that do not produce increased sedation. Simulations indicate that to achieve antiemetic plasma propofol concentrations of 343 ng/ml, a bolus dose of 10 mg followed by an infusion of approximately 10 microg x kg(-1) x min(-1) are necessary.

Adolescent↗
PubMed1997

Opioid-sparing effects of a low-dose infusion of naloxone in patient-administered morphine sulfate.

BACKGROUND: A naloxone infusion is effective in reducing epidural and intrathecal opioid-related side effects. The use of naloxone infusion concomitant with intravenous morphine patient-controlled analgesia (PCA) has not been evaluated, probably because of an expected direct antagonism of the systemic opioid effect. The authors compared the incidence of morphine-related side effects and the quality of analgesia from two small doses of naloxone infusion. METHODS: Sixty patients classified as American Society of Anesthesiologists physical status 1, 2, or 3 who were scheduled for total abdominal hysterectomies were enrolled in the study. Patients received a standardized general anesthetic. In the postanesthetic care unit, patients received morphine as a PCA. They were randomized to receive either 0.25 microg x kg(-1) x h(-1) naloxone (low dose), 1 microg x kg(-1) x h(-1) (high dose), or saline (placebo) as a continuous infusion. Verbal rating scores for pain, nausea, vomiting, and pruritus; sedation scores; requests for antiemetic; and morphine use were recorded for 24 h. Blood pressure, respiratory rate, and oxyhemoglobin saturation were also monitored. RESULTS: Sixty patients completed the study. Both naloxone doses were equally effective in reducing the incidence of nausea, vomiting, and pruritus compared with placebo (P < 0.05 by the chi-squared test). There was no difference in the verbal rating scores for pain between the groups. The cumulative morphine use was the lowest in the low-dose group (42.3 +/- 24.1 mg; means +/- SD) compared with the placebo (59.1 +/- 27.4 mg) and high-dose groups (64.7 +/- 33.0 mg) at 24 h (P < 0.05 by analysis of variance). There was no incidence of respiratory depression (<8 breaths/min) and no difference in sedation scores, antiemetic use, respiratory rate, and hemodynamic parameters among the groups. CONCLUSIONS: Naloxone is effective in preventing PCA opioid-related side effects. Naloxone infusion at 0.25 microg x kg(-1) x h(-1) not only attenuates these side effects but appears to reduce postoperative (beyond 4-8 h) opioid requirements. This dosing regimen can be prepared with 400 microg naloxone in 1,000 ml crystalloid given in 24 h to a patient weighing 70 kg.

Adult↗
PubMed1997

How to manage drug interactions.

Multiple drugs are used to provide anaesthesia. On average, four to six drugs are used during anaesthesia and, therefore, drug interactions are common. These interactions are primarily either pharmacokinetic or pharmacodynamic. Due to the relatively short duration of drug administration for anaesthesia, pharmacokinetic drug interactions resulting from alterations in drug metabolism do not generally produce clinically significant effects. Pharmacodynamic-drug interactions between anaesthetic drugs, however, are potentially serious. This may reflect that anaesthesia is not a single entity, but a process provided by a combination of drugs; i.e. loss of consciousness, analgesia and neuromuscular blockade. An understanding of each drug's pharmacokinetics, pharmacodynamics and drug interactions will allow clinicians to administer drugs to provide a more optimal anaesthetic.

Anesthesia↗
PubMed1996

Patient-controlled analgesia for conscious sedation during endoscopic retrograde cholangiopancreatography: a randomized controlled trial.

BACKGROUND: Adequate comfort is essential to patients undergoing invasive procedures. This study was designed to evaluate whether patient-controlled analgesia could improve sedation for ERCP. METHODS: Patients were randomized to receive standard sedation (n = 31) or patient-controlled analgesia (n = 31). The patients were blinded to the randomization. After the procedure the patient, physician, and nurse each rated their satisfaction with sedation using a verbal rating scale. RESULTS: There was no significant difference between the patient's mean satisfaction score for the conventional and patient-controlled analgesia groups (9.3 and 9.6, respectively, p = 0.5). The physicians rated sedation higher in the conventional group compared with the patient-controlled analgesia group (8.6 and 8.2, respectively, p = 0.02). Physicians and nurses' scores correlated (r = 0.53, p = 0.0001), but there was no correlation between scores reported by either physicians or nurses and the patients' scores (r = 0.2 and r = 0.05, respectively). Oxygen saturation less than 90% occurred for more than 1 minute in three patients who received standard sedation but in none who used patient-controlled analgesia. CONCLUSION: This trial demonstrates that patient-controlled analgesia during ERCP is as effective as standard sedation with respect to patient satisfaction. Physicians and nurses, however, are not good proxies for assessing patient satisfaction.

Adolescent↗
PubMed1996

Intravenous ondansetron in established postoperative emesis in children. S3A-381 Study Group.

BACKGROUND: In pediatric postsurgical patients, postoperative vomiting is a common occurrence that can delay recovery and result in unplanned hospital admissions after outpatient surgery. This randomized, double-blind, placebo-controlled, multicenter study evaluated the efficacy and safety of ondansetron in the control of established postoperative emesis in outpatients aged 2-12 yr. METHODS: Screened for the study were 2,720 ASA physical status 1-3 children undergoing outpatient surgery during general anesthesia, which included nitrous oxide. Children experiencing two emetic episodes within 2 h of discontinuation of nitrous oxide were given intravenous ondansetron (n = 192; 0.1 mg/kg for children weighing < or = 40 kg; 4 mg for children weighing > 40 kg) or placebo (n = 183). RESULTS: The proportion of children with no emetic episodes and no use of rescue medication was significantly greater (P < 0.001) in the ondansetron group compared with placebo for both 2- and 24-h periods after study drug administration (78% of the ondansetron group and 34% of the placebo group for 2 h; 53% of the ondansetron group and 17% of the placebo group for 24 h). Among patients with at least one emetic episode or with rescue medication use, the median time to onset of emesis or rescue was 127 min in the ondansetron group compared with 58 min in the placebo group (P < 0.001). The median time from study drug administration until discharge was significantly shorter (P < 0.01) in the ondansetron group (153 min, range 44-593 min) compared with the placebo group (173 min, range 82-622 min). The incidence of potentially drug-related adverse events was similar in the ondansetron (3% of patients) and the placebo (4% of patients) groups. CONCLUSION: A single dose of ondansetron (0.1 mg/kg up to 4 mg) is effective and well tolerated in the prevention of further episodes of postoperative emesis in children after outpatient surgery. Administration of ondansetron also may result in a shorter time to discharge.

Antiemetics↗
PubMed1996

Double-blind, randomized comparison of ondansetron and intraoperative propofol to prevent postoperative nausea and vomiting.

BACKGROUND: Breast surgery is associated with a high incidence of postoperative nausea and vomiting. Propofol and prophylactic administration of ondansetron are associated with a lower incidence of postoperative nausea and vomiting. To date no comparison of these two drugs has been reported. A randomized study was done to compare the efficacy of ondansetron and intraoperative propofol given in various regimens. METHODS: Study participants included 89 women classified as American Society of Anesthesiologists physical status 1 or 2 who were scheduled for major breast surgery. Patients were randomly assigned to one of four groups. Group O received 4 mg ondansetron in 10 ml 0.9% saline and groups PI, PIP, and PP received 10 ml 0.9% saline before anesthesia induction. Group O received thiopental, isoflurane, nitrous oxide-oxygen, and fentanyl for anesthesia. Group PI received propofol, isoflurane, nitrous oxide-oxygen, and fentanyl. Group PIP received propofol, isoflurane, nitrous oxide-oxygen, and fentanyl. Thirty minutes before expected skin closure, isoflurane was discontinued and 50 to 150 micrograms.kg-1.min-1 propofol was given intravenously to maintain anesthesia. Group PP received propofol for induction and maintenance of anesthesia, nitrous oxide-oxygen, and fentanyl. Postoperative pain relief was provided with morphine administered by a patient-controlled analgesia pump. The incidence of nausea and vomiting, requests for rescue antiemetic and sedation, pain scores, and hemodynamic data were recorded for 24 h. RESULTS: Within 6 h of surgery, groups O and PP had a lower incidence of nausea compared with groups PI and PIP (P < 0.05). Fewer patients in group PP (19%) vomited during the 24-h period compared with groups O (48%), PI (64%), and PIP (52%) (P < 0.05). The incidence of antiemetic use was also less in group PP (P < 0.05). Patients in group PP had lower sedation scores at 30 min and at 1 h (P < 0.05). There were no differences among the groups in pain scores, blood pressure, heart rate, respiratory rate, and incidence of pruritus. CONCLUSIONS: Propofol administered to induce and maintain anesthesia is more effective than ondansetron (with thiopental-isoflurane anesthesia) in preventing postoperative vomiting and is associated with fewer requests for rescue antiemetic and sedation in the early phase of recovery. It is equally effective in preventing postoperative nausea as ondansetron in the first 6 h after operation. Propofol used only as an induction agent or for induction and at the end of surgery were not as protective against postoperative nausea and vomiting.

Adult↗
PubMed1996

Pharmacokinetic model-driven infusion of fentanyl in children.

BACKGROUND: This study determined the accuracy of previously defined adult fentanyl pharmacokinetics in children having surgery; from this population, the pharmacokinetics of fentanyl were characterized in children when administered via a computerized assisted continuous-infusion device. METHODS: Twenty children between the ages of 2.7 and 11 y scheduled to undergo elective noncardiac surgery were studied. After induction, anesthesia was maintained with 60% nitrous oxide in oxygen supplemented with fentanyl (n = 10) or fentanyl plus isoflurane (n = 10). Fentanyl was administered via computerized assisted continuous-infusion to target concentrations determined by clinical requirements. Plasma fentanyl concentrations were measured and used to evaluate the performance of the fentanyl pharmacokinetics and then to determine a new set of pharmacokinetic parameters and the variance in the context-sensitive half-times simulated for these patients. RESULTS: The original adult fentanyl pharmacokinetics resulted in a positive bias (10.4%), indicating that measured concentrations were mostly greater than predicted. A two-compartment model with age and weight as covariates provided the optimal pharmacokinetic parameters. These resulted in a residual performance error of -1.1% and a median absolute performance error of 17.4%. The context-sensitive times determined from this pediatric population were considerably shorter than the context-sensitive times previously published for adults. CONCLUSIONS: The pharmacokinetics of fentanyl administered by computerized assisted continuous-infusion differ between adults and children. The newly derived parameters are probably more suitable to determine infusion schemes of up to 4 h in children between the ages of 2 and 11 y.

Anesthetics, Intravenous↗
PubMed1995

Intensified diabetes management: lessons from the diabetes control and complications trial.

The results of the multicenter diabetes control and complications trial are examined and methods for the implementation of the findings for individuals with type I and type II diabetes are discussed. More than a decade ago the question was raised of whether tight glycemic control would prevent or slow the progression of microvascular complications. In 1993, having studied 1441 individuals with type I diabetes randomized to either intensive glycemic control (HbA1c < 7%) or conventional glycemic control (HbA1c > 9%), it was concluded that a reduction in risk of retinopathy, neuropathy and nephropathy could be realized if near normal glycemic control were achieved. Some questions remained, however. For example, could intensive treatment be achieved in routine practice under the auspices of primary care physicians? Are the findings in this study applicable to individuals with type II diabetes? These questions are addressed through the introduction of staged diabetes management (SDM), an innovative approach to the treatment of diabetes and the prevention of its complications. SDM is designed as a data-based systematic approach to diabetes treatment that targets blood glucose control. Studied in 40 clinical sites throughout the United States and evaluated in 30 sites worldwide, SDM promises to provide appropriate clinical guidance to both primary care and specialist physicians seeking to alter current practice patterns by adopting a systematic approach to diabetes management.

Chromatography, High Pressure Liquid↗
PubMed1994

A survey on the clinical use of epidural catheters for acute pain management.

Indwelling epidural catheters are commonly used to provide analgesia in the postoperative setting. In an attempt to determine how epidurals are used in clinical practice, a survey was conducted at the 1992 annual meeting of the American Society of Pain Management Nurses (ASPMN). A total of 42 institutions were surveyed regarding epidural management practices and procedures. Although there were numerous variations in practice, certain similarities and themes regarding drug choice, patient monitoring, and levels of activity are evident. Technology has made possible continuous infusions of drugs on intermediate care floors, with most institutions relying upon nursing personnel for monitoring.

Acute Disease↗
PubMed1994

Cockayne syndrome: a case report.

A 4-year-old female with Cockayne syndrome presented for cataract extraction under general anesthesia. She was thin and frail; her neck, epiglottis and larynx were stiff; she was deaf and blind; and she could not speak, sit unaided, or perspire. At the time of her admission, she weighed 5.5 kg. Cockayne syndrome is a disease of childhood characterized by mental retardation and premature aging. Although the underlying abnormality appears to be autosomal recessive inheritance or metabolic (possibly thymic) dysfunction, there is no consensus on etiology. The multiple organ involvement carries significant implications for the anesthetist. Intubation can be technically difficult, and care of the skin can be problematic. Essential hypertension, hepatic deficiencies, osteoporosis, deafness, blindness, and other effects of premature aging may be encountered making perioperative management a challenge.

Anesthesia, General↗
PubMed1993

The esophageal temperature gradient in anesthetized children.

OBJECTIVE: Our objective was to study the effect of the temperature of the anesthetic gas mixture (AGM) on esophageal temperature measurements made in children whose tracheas had been intubated for anesthesia. We also sought to establish the optimal site for the temperature sensor in the esophagus and to find a way to accurately place the sensor. METHODS: Special esophageal temperature probes with thermistors located at 1-cm intervals were used for data collection on a multiplex system. Esophageal temperature measurements were made every 15 minutes for a period of 120 minutes in anesthetized children receiving heated (n = 30) and unheated (n = 30) anesthetic gases. RESULTS: The temperature of the AGM (p < 0.001), the site of measurement (p < 0.001), and the interaction between AGM temperature and site of measurement (p < 0.007) all had a significant effect on esophageal temperature measurements. This effect was greatest at a point 3 cm distal to the level of the tip of the endotracheal tube when AGMs were not heated. CONCLUSION: We conclude that best results are obtained when care is taken to place the thermistor in the lower quarter of the esophagus. (We provide a simple formula for calculating this placement in pediatric patients of varying ages.) Placing the probe by acoustic criteria cannot consistently be relied on to provide good thermometry.

Analysis of Variance↗
PubMed1993

Evaluation of flumazenil for reversing the effects of midazolam-induced conscious sedation or general anesthesia.

To evaluate the effectiveness of flumazenil in reversing midazolam-induced conscious sedation and general anesthesia, we gave either flumazenil or placebo to 55 patients in a double-blind manner after surgery. Whether surgery was done under conscious sedation (CS group) or general anesthesia (GA group) depended on the procedure. Recovery was assessed by an Observer Assessment of Alertness and Sedation (OAAS) Scale, Finger-Nose (F-N) test, and picture recall and recognition. OAAS and F-N tests were done at baseline, 0 minutes (before the test drug administration), and at 5, 15, 30, 60, 120, and 180 minutes. Picture recall and recognition were tested at 180 minutes and 24 hours, respectively, after test drug administration. Patients who were sedated during surgery (CS group) received a mean of 10.3 +/- 5.3 mg midazolam. The patients receiving general anesthesia (GA group) were given 21.0 +/- 8.2 mg midazolam. In the CS group, improvement in scores on the OAAS scale and F-N test was similar after administration of both flumazenil and placebo. In the GA group, flumazenil produced significantly greater improvement in the OAAS scores at 5 and 15 minutes, and in the F-N test scores at 15 minutes. In both groups, picture recall and recognition improved significantly immediately after flumazenil administration, but this improvement was generally not sustained for pictures shown at later times. These results imply that flumazenil is beneficial for reversing amnesia briefly after midazolam-induced sedation. However, flumazenil hastens recovery only when larger doses of midazolam are used for general anesthesia.

Adult↗
PubMed1992

Use of patient-controlled analgesia to compare the efficacy of epidural to intravenous fentanyl administration.

Fentanyl, unlike morphine, is highly lipophilic and rapidly diffuses out of the epidural space. Respiratory depression is, therefore, unlikely when fentanyl is given epidurally. However, much of fentanyl's analgesic effect is mediated by systemic rather than spinal receptor binding. To test this hypothesis, we performed a prospective, double-blind, cross-over study comparing epidural and intravenous (IV) administration of fentanyl in 16 patients for the first 12 h after lower abdominal or lower extremity surgery. To allow direct comparison of these two routes of administration, patient-controlled analgesia was used so patients could self-titrate their analgesia. Patients were randomized to receive fentanyl initially by an epidural (group A, n = 8) or IV (group B, n = 8) catheter for 6 h, after which they were crossed-over to the alternate route by means of a hidden three-way stopcock. The degree of analgesia was subjectively evaluated by a visual analogue scale, and by an observer rating patient's comfort and sedation. Cumulative dosage of fentanyl was recorded, and plasma fentanyl concentrations were measured. The onset of analgesia and increase in plasma fentanyl concentrations were more rapid with intravenous fentanyl. However, after 60 min, analgesia (visual analogue scale 2-4 cm) or plasma fentanyl concentrations (0.3-0.7 ng/mL) did not differ between the two routes of administration. There were also no significant differences in the cumulative dosage of fentanyl within each group (epidural vs IV) or between the groups. Thus, the analgesic effects of epidural fentanyl appear largely mediated by systemic absorption. Intravenous fentanyl achieves a similar degree of analgesia and a more rapid onset of effect without the need for epidural catheterization.

Aged↗
PubMed1992

Limb tourniquets and central temperature in anesthetized children.

We have observed an association between the use of tourniquets for limb surgery and a progressive increase in body temperature in pediatric patients. Consequently, we evaluated the effect of leg tourniquet(s) on intraoperative nasopharyngeal temperature in pediatric patients. We measured central temperature in three groups of children anesthetized with halothane and nitrous oxide: those with unilateral tourniquets (n = 15), those with bilateral tourniquets (n = 8), and a control group not requiring tourniquets (n = 24). Intraoperative ambient temperatures were maintained near 23 degrees C, respiratory gases were actively heated and humidified, and skin was warmed using a circulating water blanket set at 38 degrees C. The control patients remained normothermic during anesthesia and surgery. In contrast, central temperature increased 1.0 +/- 0.6 degrees C in 90 min in those with one tourniquet and 1.7 +/- 0.6 degrees C in those with bilateral tourniquets. The tourniquet-induced hyperthermia appeared to result from decreased effective heat loss from distal skin and from constraint of metabolic heat to the central thermal compartment. These data suggest that pediatric patients requiring intraoperative tourniquets should not be aggressively warmed during surgery.

Anesthesia↗
PubMed1992

Patient controlled analgesia: the relation of psychological factors to pain and analgesic use in adolescents with postoperative pain.

OBJECTIVE: To examine the relationship of psychological variables to pain and patient-controlled analgesia (PCA) use in adolescents undergoing orthopedic surgeries. DESIGN: Cohort. PATIENTS: Fifty adolescents and their parents. MAIN OUTCOME MEASURES: Visual analogue scales of pain, the McGill Pain Questionnaire, and questionnaires that assessed overall psychological distress, anxiety, and family environment. RESULTS: Correlations of the psychological variables with measures of pain and PCA use showed that high levels of anxiety and distress in adolescents were related to higher postoperative pain. Adolescents from controlling and conflicted families also had higher pain ratings and made more frequent PCA demands during the lockout interval when drug was unavailable. Parent anxiety and distress were also related to adolescent pain and PCA use. CONCLUSIONS: The psychological status of adolescents and their parents can significantly influence postoperative pain and PCA use.

Adolescent↗
PubMed1991

Clinical responses to ORG 9426 during isoflurane anesthesia.

To determine average dose requirements and pharmacodynamic characteristics before general clinical use, the dose-response curve, onset time, and recovery time for the neuromuscular relaxant ORG 9426 were determined in 72 adult patients given doses of 120, 160, 200, or 240 micrograms/kg after establishment of a steady-state expired isoflurane concentration of approximately 1%. Neuromuscular blockade was continuously recorded using the ulnar evoked electromyogram. Using the log probit method, ED95 was 268 micrograms/kg, ED90 was 251 micrograms/kg, and ED50 was 144 micrograms/kg. The time until 80% blockade was 1.9 min at 240 micrograms/kg, and the average time to peak effect was 4.6 min, which did not vary with dose. The clinical duration (injection until T1 returned to 25%) was 20.5 min, and the recovery index (T1 increased from 25% to 75% of control) was 15.4 min, after a total dose of 300 micrograms/kg. The duration of 75-micrograms/kg and 100-micrograms/kg repeat (maintenance) dose was 14.6 and 17.8 min, respectively, and no cumulative effect was apparent after as many as five maintenance doses. No cardiovascular side effects were seen at doses used in the study. We conclude that ORG 9426 is a nondepolarizing muscle relaxant with a rapid onset and short duration of action that deserves further clinical evaluation.

Adult↗