Lance Lichtor - Academia.edu (original) (raw)

Papers by Lance Lichtor

Journal of Substance Abuse, 1992

The effects of food deprivation on the subjective, psychomotor, and physiological responses to in... more The effects of food deprivation on the subjective, psychomotor, and physiological responses to intravenous fentanyl (50 micrograms/70 kg) were studied in 6 healthy male volunteers. A randomized, placebo-controlled, crossover design was used in which subjects were injected with fentanyl or saline after either 2, 12, or 24 hours of fasting. Subjects completed several subjective effects questionnaires as well as psychomotor tasks prior to, and at regular intervals, following the intravenous injection for a 3-hour period. An observer-rated behavioral checklist was completed at regular intervals during the session and several physiological measures (including measurement of pupil size) were recorded. Fentanyl induced opiate-like mood changes, miosis (pupil constriction), and impairment of extraocular muscle control, and 4 of the 6 subjects reported liking the effects; however, fasting had no impact on any of fentanyl's effects. We conclude that food deprivation up to 24 hours does not alter the subjective, psychomotor, or physiological response to the opiate, fentanyl.

Pharmacology Biochemistry and Behavior, 1995

Two double-blind, randomized, crossover trials were conducted to study whether the benzodiazepine... more Two double-blind, randomized, crossover trials were conducted to study whether the benzodiazepine antagonist, flumazenil, would interact with the subjective and psychomotor effects of nitrous oxide in healthy volunteers. In both experiments, eight subjects inhaled 30% nitrous oxide in oxygen for 35 min and were challenged, 10 min into the inhalation, with flumazenil. Experiment 1 tested a range of flumazenil doses used clinically (0, 0.25, 0.5, and 1 .O mg/70 kg) whereas Experiment 2 tested a supraclinical flumazenil dose (0 and 5.0 mg/70 kg). Nitrous oxide increased mood ratings of "high, " "drunk," and "tingling," and decreased psychomotor performance as assessed by the Digit Symbol Substitution Test. Flumazenil, at the supraclinical dose, significantly lowered the mood rating of "high." Decreases, though not significant (p < O.lO), were also obtained on the ratings "drunk," "elated," and "drug liking". Fhrmazenil, in both experiments, did not interact with the psychomotor effects of nitrous oxide. It appears that flumazenil, at a dose higher than that used clinically, may antagonize some of the subjective effects produced by nitrous oxide in humans.

Journal of Cardiothoracic Anesthesia, 1988

During one-lung ventilation, levels of oxygen and carbon dioxide in the blood are commonly assess... more During one-lung ventilation, levels of oxygen and carbon dioxide in the blood are commonly assessed by intermittent blood gas sampling. Transcutaneous PO2 (tcPO2) and transcutaneous PCO2 (tcPCO2) have been reported to accurately reflect arterial PO2 (PaO2) and arterial PCO2 (PaCO2) in hemodynamically stable patients. Transcutaneous monitors appear to be ideal for detecting trends toward hypoxia and hypercarbia, conditions that may not be evident when using intermittent blood gas sampling, while pulse oximetry, since it reflects saturation, may not detect hypoxia until it has already occurred. Thirty: one patients undergoing one-lung ventilation were monitored using both transcutaneous electrodes applied to the upper arm (group 1) or chest (group 2) and arterial blood gas sampling. Arterial blood gases were sampled while tcPO2 and tcPCO2 values were being recorded. Regression, correlation, and covariance analyses were performed. Correlation coefficients of PaO2 to tcPO2 varied from .05 to .99 for each patient. The slopes of individual regression lines varied from 0.03 to 1.16. Correlation coefficients of PaCO2 to tcPCO2 varied from .01 to .99, while the slopes of individual regression lines ranged from 0.02 to 5.89. Covariance analyses revealed considerable variation in PaO2 to tcPO2 and PaCO2 to tcPCO2 in individual patients even under stable hemodynamic conditions. Analysis of covariance also demonstrated that in group 2 the slopes comparing arterial and transcutaneous values were significantly different for PaO2 &amp;lt;100 mmHg and PaO2 &amp;gt;200 mmHg. In group 1, for PaO2 &amp;lt;100 mmHg, there was no difference in slopes but y-intercepts were significantly different (P &amp;lt; .05). However, transcutaneous indices were significantly different in both groups for PaO2 &amp;lt;100 mmHg and PaO2 &amp;gt;200 mmHg. It is concluded that transcutaneous monitoring is useful to indicate trends in arterial values in some patients, but blood gas analysis is still necessary to verify the reliability of such monitoring.

Behavioural Pharmacology, 1992

Anesthesia & Analgesia, 1998

Anesthesia & Analgesia, 1996

Transnasal butorphanol is effective in relieving migraine and postoperative pain. The extent to w... more Transnasal butorphanol is effective in relieving migraine and postoperative pain. The extent to which this drug preparation impacts on cognitive and psychomotor performance, as well as mood, has not been examined. Accordingly, the cognitive and psychomotor, subjective, and physiological effects of two clinically relevant doses of transnasal butorphanol (1 and 2 mg) were compared to that of placebo, and a common analgesic drug combination given for pain relief in ambulatory settings, 600 mg of acetaminophen and 60 mg of codeine, in healthy volunteers (n = 10). The larger transnasal butorphanol dose impaired psychomotor performance for up to 2 h, and produced subjective effects for up to 3 h. The smaller dose had no psychomotor-impairing effects, but had subjective effects (including increased ratings of "sleepy"). All three active drug conditions including miosis. These laboratory results suggest that patients should use caution when using the 1-mg dose of transnasal butorphanol, and should curtail certain activities if they administer the 2-mg dose of transnasal butorphanol for analgesia.

Anesthesia & Analgesia, 1993

presented determining that such a drug combination improves postoperative analgesia. Indeed, Tabl... more presented determining that such a drug combination improves postoperative analgesia. Indeed, Table 4 confirms that in the postoperative period there was no statistically significant difference between the group that received morphine plus epinephrine and the group that received just morphine in the subarachnoid space along with local anesthetic. The only conclusion that could possibly be made is that intraoperative analgesia but not postoperative analgesia was improved with the drug combination.

Baillière's Clinical Anaesthesiology, 1992

ABSTRACT

Transplantation proceedings, 1991

Ventricular dysfunction, then, does indeed occur during liver transplantation, particularly at th... more Ventricular dysfunction, then, does indeed occur during liver transplantation, particularly at the time of reperfusion. Pulmonary embolism contributes to right ventricular and right atrial encroachment on left-heart filling, and paradoxical embolism may occur. Pericardial effusions, tricuspid regurgitation, hypothermia, and the release of substances, particularly potassium from the donor liver, may further contribute to compromises in ventricular function. Proper monitoring and appropriate treatment, however, lead to successful operative outcomes in most cases.

Pain Medicine, 2008

Objectives. To compare within the same individuals two typically prescribed doses of hydrocodone/... more Objectives. To compare within the same individuals two typically prescribed doses of hydrocodone/ acetaminophen and oxycodone/acetaminophen products for their subjective, psychomotor, and physiological effects in healthy volunteers. Design. A randomized, placebo-controlled, double-blind, crossover, six-session clinical laboratory study, enrolling 16 healthy participants (27.2 ± 4.4 years of age). Participants received 5 mg hydrocodone/325 mg acetaminophen, 10 mg hydrocodone/650 mg acetaminophen, 5 mg oxycodone/ 325 mg acetaminophen, 10 mg oxycodone/650 mg acetaminophen, 650 mg acetaminophen, and placebo in different sessions. Results. Oxycodone/acetaminophen and hydrocodone/acetaminophen at the 5-mg opioid dose produced few subjective effects and no significant psychomotor impairment. Relative to placebo, the 10-mg oxycodone combination produced a wider spectrum of subjective effects that were statistically significant than did the 10-mg hydrocodone combination. The 10-mg oxycodone combination also produced a greater degree of miosis than the 10-mg hydrocodone combination. Both drug combinations impaired psychomotor performance at the 10-mg opioid dose. Conclusions. The results of this study, albeit in pain-free individuals, may inform physicians who prescribe, and pharmacists who dispense, two widely prescribed opioid/acetaminophen combination products on how patients might be feeling from the drugs. Patients prescribed either of the two opioid/acetaminophen combination products may experience a number of subjective effects, including effects that would contraindicate certain activities, and they should be cautioned accordingly. However, this study documented rather large differences in magnitude of subjective effects between 10 mg oxycodone/650 mg acetaminophen and placebo, and physicians and pharmacists, and ultimately patients, should be aware of these differences.

Journal of Clinical Anesthesia, 1998

Study Objective: To increase the contact rate with eligible patients for quality assurance/ im~ro... more Study Objective: To increase the contact rate with eligible patients for quality assurance/ im~rouement surveys by modafiing survey rounds to accommodate the schedules of individual nursing units. Design: Twophase, interventional time sem'es study. Setting: Postoperative inpatients at a university hospital. Patients: 498 aduLt@ostoperative inpatients who remeined hospitalized du,ring the second postoperative day. Interventions:-Between the first and second measurement @Cods, efforts were made to learn the schedule of each nursing unit and to improve the efficiency of survey rounds so that a larger proportion of patients could be contacted. Measurements and Main Results: The contact rate for eligible patients was improved from 66% to 80% (p < 0.01). I m movement during the second period was attributed to pfewer patients being away from the nursing unit (20 % vs. 12 %, p < 0.05) or otherwise occupied by attending physicians on rounds (9% vs. 4 %, p < 0.05). Conclusion: Strategies individualized to patient care units can improve the ejiciency and credibility of inpatient survey research. We descm'be the strategies most helpful in improving the efficiency of survey rounds at one medical center. 0 I998 by Elsevier Science Inc.

BJA: British Journal of Anaesthesia, 1991

Patients who arrive home several hours after outpatient surgery may drink alcohol. The extent to ... more Patients who arrive home several hours after outpatient surgery may drink alcohol. The extent to which residual drugs used in outpatient surgery interact with alcohol is not known. The purpose of this study was to determine if two i.v. drugs commonly used together in outpatient surgery, midazolam and fentanyl, have residual effects which would interact with alcohol drunk 4 h after injection. Twelve healthy male volunteers participated in a double-blind, randomized, placebo-controlled and cross-over study. Subjects were studied four times successively with a period of 1 week between trials. On each day of testing, the subjects received randomly, by slow i.v. injection (30 s), either saline followed immediately by saline, or midazolam 0.1 mg kg-1 followed immediately by fentanyl 2 micrograms kg-1. Four hours after the injection, the subjects consumed a beverage which either did or did not contain alcohol 0.7 g kg-1. Before and 1, 3, 5 and 7 h after injection (and before and 1 and 3 h after consumption of beverage), psychomotor performance and mood were assessed. While both the combination midazolam-fentanyl and alcohol had independent effects on the dependent measures in this study, there was no interaction between midazolam-fentanyl and alcohol (no potentiating of effects of alcohol by i.v. sedation). We conclude that the effects of benzodiazepines and opioids that are short-acting and used in outpatient surgery have probably dissipated by the time a patient arrives home, and that effects from alcohol ingested at home will probably not be affected by recent administration of these drugs.

Behavioural Pharmacology, 1996

The present study examined the subjective, psychomotor and reinforcing effects of 10%, 20%, 30% a... more The present study examined the subjective, psychomotor and reinforcing effects of 10%, 20%, 30% and 40% nitrous oxide in oxygen in 16 healthy volunteers using a choice procedure in which sampling (e.g. 20% nitrous oxide and oxygen-placebo) and choice trials (e.g. 20% nitrous oxide vs. oxygen placebo) were within the same session. Across the four-session study, nitrous oxide dose was varied. Nitrous oxide in a dose-related manner altered subjective effects (e.g. increased visual analog scale ratings of &amp;quot;high&amp;quot;, &amp;quot;stimulated&amp;quot; and &amp;quot;tingling&amp;quot;) and decreased performance on the Digit Symbol Substitution Test. 10%, 20%, 30% and 40% nitrous oxide were chosen over oxygen by 6, 7, 7 and 8 subjects, respectively. We conclude that nitrous oxide across a range of subanesthetic doses did not function as reinforcer in the majority of subjects tested.