Search PubMed⌕ Search

Biomedical subjects

T H Stanley

Publications and source records attributed to T H Stanley.

At least 91 records · Page 5Linked to original sources
PubMed1985

Etomidate versus thiopental for induction of anesthesia.

Hemodynamic changes and side effects of anesthesia induction with etomidate or thiopental were evaluated in 83 ASA class I or II patients. Patients were randomly assigned to one of 12 groups according to pretreatment drug (fentanyl, 100 micrograms, or normal saline intravenously), induction agent (etomidate, 0.4 mg/kg, or thiopental, 4 mg/kg), and maintenance anesthetic technique (isoflurane-oxygen, isoflurane-nitrous oxide-oxygen, or fentanyl-nitrous oxide-oxygen). The purpose of this experiment, of factorial design, was to evaluate the combined effects of two or more experimental variables used simultaneously and to observe interaction effects. There were significant increases in heart rate in all groups, especially after tracheal intubation. These increases were attenuated but not eliminated by fentanyl pretreatment. Systolic arterial blood pressure increased significantly after intubation and was not affected either by fentanyl pretreatment or by the induction agent. Patients in whom anesthesia was induced with etomidate had a greater incidence of pain on injection and myoclonus and a lesser incidence of apnea than patients in whom anesthesia was induced with thiopental. Fentanyl pretreatment significantly decreased the incidence of pain on injection and myoclonus, but it increased the incidence of apnea when anesthesia was induced with etomidate. The incidence of postoperative nausea and vomiting was similar after thiopental and etomidate and was unaffected by fentanyl pretreatment. (ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Computer analysis of intraoperative cardiac rhythms using esophageal and surface leads.

Esophageal ECG lead and computer as arrhythmia monitor were elevated in 6 dogs and 23 patients. In dogs arrhythmias were induced by an epinephrine infusion during halothane anesthesia. The computer identified 1858 irregular beats, a cardiologist 2130. Bigeminy was correctly identified 82% of the time, trigeminy 72%, couplets 29%, and ventricular tachycardia 45%. The false positive rate was .03%. In the operating room the monitor identified an average of 44 abnormal beats per patient. In 5 patients junctional rhythm was correctly identified. This study shows the feasibility of using an esophageal ECG lead for computerized ventricular and supraventricular arrhythmia monitoring in the operating room.

Adult↗
PubMed1984

The effect of population habits on side effects and narcotic requirements during high-dose fentanyl anaesthesia.

We measured and compared the anaesthetic requirements, incidences of chest wall rigidity and intraoperative hypertension, and time for recovery from anaesthesia after high dose fentanyl-oxygen anaesthesia in patients with and without histories of smoking, alcoholic intake and caffeine consumption who were undergoing coronary artery bypass grafting operations. Patients without a history of smoking and alcohol or caffeine intake required less fentanyl for induction and maintenance of anaesthesia and experienced less chest wall rigidity and hypertension than similar patients who had been chronically exposed to and/or consumed these agents. Pretreatment with more pancuronium (1.5 vs 1.0 mg/70 kg) prior to anaesthetic induction and increased fentanyl (3 X vs 1 X the "sleep" dose) administered after anaesthetic induction but before incision reduced the incidences of chest wall rigidity and intraoperative hypertension in patients with positive histories of exposure to the agents to values similar to patients without histories of exposure. Our findings suggest that population habits may affect the incidence of undesirable side effects during high dose fentanyl anaesthesia but that modifications in anaesthetic technique can minimize or eliminate these problems.

Adult↗
PubMed1984

Opioid analgesics in anesthesia: with special reference to their use in cardiovascular anesthesia.

In this article, an attempt has been made to review the use of receptor stimulating pure agonist opioids in anesthesia, especially in patients with cardiovascular disease. Particular emphasis has been placed on the use of opioids in high doses to produce anesthesia, techniques that recently have become popular in cardiovascular anesthesia. A major benefit of opioid anesthesia is the cardiovascular stability obtained during induction and throughout operation, even in patients with severely impaired cardiac function. There is a considerable body of evidence to support this claim when fentanyl is used. Anesthetic doses of morphine are associated with a higher incidence of cardiovascular disturbances and other problems, and, therefore, more attention to detail is required in order to achieve adequate anesthesia and hemodynamic stability. Although other opioids have been used as sole or principal agents in anesthesia for cardiovascular surgery, none have gained widespread acceptance. Meperidine, for example, which is widely used in lower (nonanesthetic) doses as a supplement to nitrous oxide in cardiac and noncardiac surgery, has proved unsuitable because of severe hemodynamic disturbances when high doses are given. However, initial reports concerning two of the newer agonist opioids, sufentanil and alfentanil, suggest that they may prove to be suitable alternatives and perhaps provide advantages over morphine and fentanyl in patients with or without cardiovascular disease. Although cardiovascular stability usually can be assured in the chronically sick cardiac patient with opioid anesthesia, this is not always so with the healthier patient, particularly those presenting for coronary artery surgery. A frequently occurring problem in these patients is hypertension during or after sternotomy, which can result in myocardial ischemia and infarction. The incidence of severe hypertension (increases in systolic blood pressure greater than 20% of control values) can be reduced drastically by increasing the dose of opioid, e.g., up to 140 micrograms/kg of fentanyl. However, despite such large doses, some patients will continue to need treatment with vasodilators, inhalation anesthetics, or other supplements at certain periods during cardiovascular operations. The use of very large doses of opioids also will prolong postoperative respiratory depression. High doses of opioids can reduce or prevent the hormonal and metabolic responses to the stress of surgery. However, even very large doses of fentanyl or its newer analogues do not prevent marked increases in plasma catecholamine concentrations in response to cardiopulmonary bypass.(ABSTRACT TRUNCATED AT 400 WORDS)

Alfentanil↗
PubMed1983

Anaesthetic induction with alfentanil: comparison with thiopental, midazolam, and etomidate.

The speed, side effects and cardiovascular changes associated with anaesthetic induction and endotracheal intubation following alfentanil (20 micrograms/kg/min, IV), thiopental (84 micrograms/kg/min, IV), etomidate (5 micrograms/kg/min, IV) and midazolam (20 micrograms/kg/min, IV) prior to halothane-nitrous oxide general anaesthesia were evaluated and compared in 80 patients undergoing elective general surgical operations. Anaesthetic induction was fastest with etomidate and thiopental (approximately one minute) and slowest with midazolam (about two minutes). Systolic arterial blood pressure (SBP) was decreased at the moment of unconsciousness with thiopental but unchanged with the other compounds. Heart rate (HR) was increased at unconsciousness with midazolam and thiopental but unchanged with etomidate and alfentanil. After intubation HR was increased in all groups except those induced with alfentanil. Arrhythmias were infrequent (5 per cent or less in all groups). Rigidity during induction only occurred with alfentanil (55 per cent) and pain on injection only with etomidate (35 per cent) and alfentanil (5 per cent). Postoperative vomiting was infrequent in all groups (15 per cent) except etomidate (55 per cent). No patient remembered any aspect of laryngoscopy or the operation and all rapidly regained consciousness at the end of operation. The results of this study demonstrate that with the exception of rigidity (which is easily overcome with succinylcholine) and a slightly slower onset of action, alfentanil compares favourably as an induction agent with thiopental and is better than midazolam and etomidate. Alfentanil is superior to all three other induction agents with respect to cardiovascular stability during induction and intubation.

Adjuvants, Anesthesia↗
PubMed1983

The cardiovascular effects of high-dose butorphanol-nitrous oxide anaesthesia before and during operation.

The cardiovascular effects of high doses of butorphanol (0.3-0.45 mg . kg-1) plus 60 per cent N2O anaesthesia were measured at unconsciousness, following tracheal intubation, and immediately before and at one and ten minutes after surgical stimulation in 17 A.S.A. class I and II patients undergoing elective gastric or gall bladder surgery. Butorphanol and N2O produced unconsciousness with only small decreases in heart rate and cardiac output but did not result in sufficient analgesia to block or treat stimulation of the cardiovascular system secondary to tracheal intubation or surgical incision, even when supplemented with additional butorphanol to high cumulative dose levels (1.0 mg . kg-1). The data suggest that even high dose butorphanol - N2O anaesthesia requires supplementation with other anaesthetics or anaesthetic adjuvants to prevent cardiovascular stimulation during general abdominal surgery.

Adjuvants, Anesthesia↗
PubMed1983

Catecholamine and cortisol responses to sufentanil-O2 and alfentanil-O2 anaesthesia during coronary artery surgery.

The effects of alfentanil-O2 and sufentanil-O2 anaesthesia on plasma catecholamines and cortisol were investigated in 32 patients undergoing coronary artery bypass grafting operations. After lorazepam-atropine premedication and pancuronium pretreatment, alfentanil was given to 16 patients at a rate of 3 mg.min-1 and sufentanil was given to 16 patients at 300 micrograms.min-1 until the patients were unconscious; at this time they were given succinylcholine and were intubated. After intubation an amount of alfentanil or sufentanil equal to the dose producing unconsciousness was infused over the next 30 min, at which time the operation began. Additional alfentanil or sufentanil were given whenever systolic arterial blood pressure increased more than 15 per cent of preanaesthetic values. Arterial blood samples were obtained for epinephrine, norepinephrine and cortisol assay and cardiovascular dynamics were recorded prior to anaesthetic induction, 5 min after tracheal intubation, immediately prior to and five min after incision, ten min after maximal sternal spread, just prior to beginning and after 30 and 60 min of bypass and at the end of operation. Cardiovascular dynamics were little changed throughout anaesthesia and operation. Plasma epinephrine and norepinephrine were not significantly changed until bypass. During bypass both hormones became increased and remained increased at the end of operation. Plasma cortisol decreased after incision and remained decreased until the end of operation. These data indicate that alfentanil-O2 and sufentanil-O2 anaesthesia produce similar changes in plasma catecholamines and cortisol as does fentanyl-O2 anaesthesia and hormonal effects are, therefore, not an explanation for any advantages the newer narcotics may have over fentanyl.

Adult↗
PubMed1983

Narcotics for acute postoperative pain. Is intramuscular administration passé?

Intramuscular (IM) injection of narcotic has been the mainstay of postoperative analgesia. However, problems inherent in IM administration--pulmonary dysfunction and inadequate pain control due to variable peak levels of drug concentration and variable absorption rate--have resulted in continuing efforts to find a more desirable method of administration. Intravenous (IV) infusion on a continuous or self-administered intermittent basis controls pain more effectively than IM injection. The total amount of drug required is significantly less and pulmonary dysfunction seems to occur less frequently. Some investigators are studying injection of narcotic into the epidural or subarachnoid space of the spine as a means of providing postoperative analgesia. This method provides an unusually intense, prolonged, and segmental analgesic action, as well as greater improvement in respiratory dynamics than with IV infusion. Although the advantages of the IV and spinal methods seem to outweigh the disadvantages, further research is needed before they can be recommended as alternatives to the standard IM method used to control postoperative pain.

Humans↗
PubMed1983

Ketanserin prevents platelet aggregation and endotoxin-induced pulmonary vasoconstriction.

Pulmonary hypertension secondary to sepsis is due, in part, to release of serotonin from platelets. This study examines the effects of ketanserin, a new, highly specific serotonin antagonist, on platelet aggregation and the cardiovascular changes associated with bacterial endotoxemia in dogs. Ketanserin markedly inhibits in vitro platelet aggregation induced by mixing serotonin and epinephrine. When ketanserin is administered to animals before endotoxin infusion, cardiac output is greater and mean pulmonary artery pressure (MPAP), pulmonary and systemic vascular resistance (PVR and SVR) and arteriovenous oxygen content difference [C(a-v)O2] are less than in animals not receiving ketanserin. Similar results for PVR, SVR, and C(a-v)O2 are obtained when ketanserin is administered after endotoxin infusion. The data indicate that ketanserin inhibits serotonin-induced platelet aggregation and modifies many cardiovascular changes associated with bacterial endotoxemia.

Animals↗
PubMed1983

The effect of ketanserin, a specific serotonin antagonist, on burn shock hemodynamic parameters in a porcine burn model.

A number of vasoactive substances, including serotonin, have been implicated in the pathophysiology of burn shock. Ketanserin, a specific serotonin antagonist, was investigated in a porcine burn shock model. Fifteen swine were given a mean 44% total body surface area full-thickness scald burn and received fluid resuscitation with Ringer's lactate for 24 hours postburn. The swine were divided into three groups: Group I (control group) received no ketanserin; Group II received ketanserin as a single intramuscular dose preburn and continuously via intravenous drip postburn; and Group III received ketanserin continuously via intravenous drip postburn only. The ketanserin-treated groups demonstrated improved cardiac index, decreased pulmonary artery pressures, and smaller arteriovenous oxygen content differences compared to the control group in the early postburn period. Ketanserin should be investigated further as a possible adjunctive therapeutic agent during burn shock resuscitation.

Animals↗
PubMed1983

Narcotic dosage and central nervous system opiate receptor binding.

Increasing doses of lofentanil (0, 0.08, 0.16, 0.31, 0.63, 1.25, 2.50, 5.00, and 10.0 micrograms/kg), a potent long-acting narcotic, were administered intravenously to rats to examine the relationship among narcotic dosage, degree of analgesia (inhibition of tail withdrawal reflex), anesthesia (no response to bone-crush injury), and central nervous system (CNS) opiate-receptor occupancy (inhibition of [3H] sufentanil binding). Our results demonstrate that increasing doses of lofentanil produce increasing analgesia and anesthesia and eventually complete opiate receptor occupancy. Analgesia occurs with doses of lofentanil (0.31 micrograms/kg) that result in levels of CNS opiate-receptor binding too low to be measured and anesthesia occurs with doses of lofentanil (1.25 micrograms/kg) that produce occupancy of about 25% of the available opiate receptors in subcortical areas and cortex. These findings in rats cannot be applied to narcotic usage in humans, but the data do indicate that in rats a dose eight times the anesthetic dose of lofentanil is needed to saturate virtually all available CNS opiate receptors (10.0 micrograms/kg). Whether saturation of most or all available CNS opiate receptors during narcotic anesthesia is of clinical importance remains to be determined.

Analgesia↗
PubMed1982

The influence of chronic preoperative propranolol therapy on cardiovascular dynamics and narcotic requirements during operation in patients with coronary artery disease.

We measured the dose of sufentanil required for unconsciousness as well as the entire operation in 44 patients (22 taking propranolol and 22 not taking propranolol) undergoing coronary artery bypass grafting (CABG) operations. The incidence of hypertension during operation, requirements for supplements to treat hypertension and recovery times were also determined. The data indicate that patients undergoing CABG operations taking propranolol require significantly less sufentanil for unconsciousness and the entire operation than patients not taking this drug. In spite of requiring less sufentanil, patients taking propranolol had less hypertension during operation and thus required less supplements. However recovery times in both groups were the same. The results of this study may partially explain the varying incidence of hypertension reported during high dose fentanyl and other narcotic-oxygen anaesthetic techniques.

Anesthesia, General↗