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jtitle_s:("anesti Prog")
1.  Effect of nitrous oxide on the concentrations of opioid peptides, substance P, and LHRH in the brain and beta-endorphin in the pituitary. 
Anesthesia Progress  1991;38(6):206-211.
Many studies have indicated that nitrous oxide (N2O) exposure results in specific effects on the reproductive system, some of which are antigonadotropic. The neurochemical events regulating the pituitary-gonadal axis are probably influenced by N2O, but precise documentation is lacking. The effects of exposure to 30% N2O in air on the brain tissue concentrations of luteinizing hormone releasing hormone (LHRH), substance P (SP), met-enkephalin, and beta-endorphin and on beta-endorphin concentrations of the pituitary gland are described in this study. Female rats were exposed to either N2O or air for 8 hr a day over one estrous cycle, and the brain and pituitary tissues were collected and processed. Neuropeptide concentrations were measured by specific radioimmunoassays. Exposure to N2O resulted in significant elevation of LHRH in the preoptic area, with a concomitant decrease in SP. The SP concentration of the medial basal hypothalamus was significantly elevated in N2O-exposed animals. Exposure to N2O resulted in significant increases in met-enkephalin in the brainstem area and beta-endorphin in the pituitary. These results suggest that exposure to N2O alters the interactive neural system activity regulating gonadotropin secretion from the pituitary. The significance of increased met-enkephalin in the brainstem of N2O-exposed animals is not known.
PMCID: PMC2148704  PMID: 1726817
2.  Methohexital: a practical review for outpatient dental anesthesia. 
Anesthesia Progress  1991;38(6):195-199.
Methohexital is an ultrashort-acting barbiturate widely used in dentistry because of its rapid onset, predictable effects, and short duration of action. Like other barbiturates, methohexital exerts its effects through the gamma-aminobutyric acid (GABA) receptor complex. By binding to its own receptor on the complex, methohexital augments the inhibitory effect of GABA on neurons and additionally can exert a similar effect independent of GABA. After intravenous injection, maximal brain concentrations are achieved within 30 sec and then quickly fall as the drug is redistributed to other tissues, yielding a duration of action after a single dose of 4 to 7 min. Hepatic metabolism accounts for elimination of the drug. Methohexital at conventional doses in healthy individuals is a mild respiratory depressant with modest cardiovascular effects. Adverse effects, however, can include apnea, cardiovascular depression, laryngospasm, hiccough, and allergic-like reactions. Although more recently introduced drugs, such as midazolam, etomidate, and propofol, have specific advantages, methohexital remains a drug of choice for dental outpatient anesthesia because of its low cost, rapid onset, short duration, lack of secretory or emetic properties, and proven history.
PMCID: PMC2148703  PMID: 1842156
3.  An evaluation of lidocaine hydrocarbonate compared with lidocaine hydrochloride for inferior alveolar nerve block. 
Anesthesia Progress  1991;38(6):212-216.
The purpose of this study was to measure the degree of anesthesia obtained with 2.2% lidocaine hydrocarbonate, 2.2% lidocaine hydrocarbonate with 1:100,000 epinephrine, and 2% lidocaine hydrochloride with 1:100,000 epinephrine for inferior alveolar nerve block. Using a repeated-measures design, 30 subjects randomly received an inferior alveolar injection of each solution over the course of three successive appointments. The first molar, first premolar, lateral incisor, and contralateral canine (control) were blindly tested with an Analytic Technology pulp tester at 3-min cycles for 60 min. Anesthetic success was defined as no subject response to the maximum output (80 reading) of the pulp tester within 16 min and maintenance of this reading for the remainder of the testing period. Although subjects felt numb subjectively, anesthetic success as defined here ranged from 3% to 10% for the plain lidocaine hydrocarbonate; for the lidocaine hydrocarbonate and lidocaine hydrochloride solutions with epinephrine, success ranged from 37% to 63%. We conclude that 2.2% lidocaine hydrocarbonate without vasoconstrictor is not as effective as the other two preparations for inferior alveolar nerve block. The 2.2% lidocaine hydrocarbonate with epinephrine and 2%.
PMCID: PMC2148701  PMID: 1842158
4.  Transient suppression of involuntary movements in cerebral palsy patients during dental treatment. 
Anesthesia Progress  1991;38(6):200-205.
The efficacy of nitrous oxide (N2O) and oxygen (O2) inhalation in reducing involuntary movements in cerebral palsy (CP) dental patients was examined using electromyography (EMG) and H-reflex techniques. Quantification and analysis of the EMG data revealed a progressive elimination of these movements to a point resembling the state of a normal muscle at rest. There was a gradual decline in the number of bursts and an increase in the silent periods of the EMG while under N2O. The recovery period after cessation of N2O was characterized by a successive increase in the number of bursts and a simultaneous decrease in the silent periods of the EMG to a state similar to the baseline recorded prior to inhalation of N2O/O2. The H-reflex also was found to decrease gradually during inhalation of N2O/O2 to about one-half of the baseline. This parameter also returned to baseline after N2O wash-out. Our findings demonstrate quantitatively the effectiveness of N2O in reducing the central motor neuron pool excitability to an extent that suppresses involuntary movements and allows more controllable and comfortable dental management.
PMCID: PMC2148697  PMID: 1842157
5.  Monitoring sedation levels by EEG spectral analysis. 
Anesthesia Progress  1991;38(6):227-231.
Real-time electroencephalographic power spectra were obtained for a group of 37 volunteers undergoing sedation with enflurane at different concentrations in air. In part one, 17 subjects were given 0.5%, 0.75%, and 1.0% for 4 min at each level, and recovery after 5 min was assessed by the Trieger method. There was considerable variation in subject response to the different doses, but adequate sedation was indicated by the presence of a strong alpha rhythm (9-11 Hz) and suppression of frequencies below 5 Hz. Overdose was indicated by an initial shift in the alpha frequency to a lower value (6-7 Hz) followed by the appearance of delta waves (0.5-4 Hz) and loss of alpha waves. In part two, 20 volunteers inhaled enflurane at 0.5% for 10 min to allow adequate absorption, followed by a 10-min recovery period. Equal numbers showed sedation or a failure to respond to enflurane at this concentration. In the responders, sedation was accompanied by a marked shift in the ratio of the power in two frequency bands: 1-4 Hz and 8-12 Hz. Progress of the frequency band power ratio followed closely the state of the subject into sedation, overdose, and recovery. This measure was further improved by the use of multivariate analysis, which showed good discrimination of the alert, sedated, and overdosed states of the subject.
PMCID: PMC2148696  PMID: 1842161
6.  The effects of epinephrine and norepinephrine administered during local anesthesia on left ventricular diastolic function. 
Anesthesia Progress  1991;38(6):221-226.
To evaluate the effects of epinephrine (E) and norepinephrine (NE) administered during local anesthesia on left ventricular diastolic function, we examined transmitral inflow patterns with pulsed Doppler echocardiography. Arterial blood pressure, heart rate, and transmitral inflow patterns were measured in 10 healthy volunteers when 3.6 mL of 2% lidocaine containing 1:80,000 E or 1:25,000 NE was injected supraperiosteally in the maxilla. The dosage of drug administered was 45 micrograms for E and 144 micrograms for NE. After the administration of E, heart rate was increased, but blood pressure was unchanged. Peak early velocity (R), peak atrial velocity (A), the ratio of A to R (A/R), and the deceleration rate (Dc) were increased, whereas the isovolumic relaxation time (IVRT) was shortened. The increase of R and Dc and the shortening of IVRT indicated an activation of left ventricular relaxation. After the administration of NE, blood pressure was increased and heart rate was decreased. A decrease in Dc, shortening of the acceleration half-time (AcT), and prolongation of IVRT were observed. These changes reflect impeded myocardial relaxation. We conclude that E activates left ventricular diastolic function and that NE, in contrast, impairs it.
PMCID: PMC2148695  PMID: 1842160
7.  Laryngeal granuloma: a complication of prolonged endotracheal intubation. 
Anesthesia Progress  1991;38(6):232-234.
Laryngeal granuloma is an uncommon complication arising from irritation of the laryngeal structures. We present a case where bilateral laryngeal granulomas became clinically evident 3 mo after orthognathic surgery. The patient, a 19-yr-old female, developed acute dyspnea after experiencing gradual voice loss. Excision of the lesions under endotracheal general anesthesia led to an uneventful outcome. The causes, predisposing factors, diagnostic features, and treatment of laryngeal granuloma are reviewed.
PMCID: PMC2148694  PMID: 1842162
8.  The influence of propranolol on the cardiovascular effects and plasma clearance of epinephrine. 
Anesthesia Progress  1991;38(6):217-220.
The purpose of the present study was to determine how propranolol modifies the circulatory effects of epinephrine infused to produce plasma concentrations achieved during dental local anesthesia and to evaluate the effects of propranolol on the plasma clearance of epinephrine. The study was performed on six healthy male volunteers ranging in age from 25 to 34 yr. Five measurement series were performed on each of these subjects at the following times: pretreatment control, 15 min after the beginning of the first epinephrine infusion (10 ng/kg/min), 15 min after the cessation of the first epinephrine infusion, 3 min after the intravenous injection of propranolol 40 micrograms/kg, and 15 min after the beginning of the second epinephrine infusion. Plasma epinephrine clearance decreased to 54.7 +/- 9.3% of the control value after propranolol was given. Epinephrine showed initially a predominantly beta-adrenergic action, but this action was inhibited by propranolol. A relative alpha-dominant state may then occur, even when a routine volume of dental local anesthetic is administered to a chronic user of a nonselective beta blocker, and it is postulated that myocardial ischemia may develop in such patients.
PMCID: PMC2148693  PMID: 1842159
10.  Local anesthetics. 
Anesthesia Progress  1991;38(4-5):128-141.
PMCID: PMC2190304  PMID: 1819966
11.  Adult sedation: oral, rectal, IM, IV. 
Anesthesia Progress  1991;38(4-5):154-171.
PMCID: PMC2190303  PMID: 1819968
12.  Nitrous oxide. 
Anesthesia Progress  1991;38(4-5):142-153.
PMCID: PMC2190300  PMID: 1819967
13.  General anesthesia. 
Anesthesia Progress  1991;38(4-5):172-186.
PMCID: PMC2190299  PMID: 1819969
14.  Introduction: Evolution in Pain and Anxiety Control 
Anesthesia Progress  1991;38(4-5):119.
PMCID: PMC2190308  PMID: 19598705
15.  Peripheral beta-endorphin and pain modulation. 
Anesthesia Progress  1991;38(3):75-78.
Beta-endorphin is a peptide with morphine-like effects produced primarily in the anterior lobe of the pituitary gland. After its cleavage from the parent molecule, proopiomelanocortin, beta-endorphin is circulated via the blood stream to interact with specific opioid receptors located throughout the body. The peptide produces analgesia by inhibiting the firing of peripheral somatosensory fibers. It also affects other senses, such as vision, hearing, and smell. Whereas the ability to increase beta-endorphin secretion during times of surgical stress is positively correlated with amelioration of pain, the administration of exogenous opioids, such as fentanyl, reduces plasma beta-endorphin. Decreased beta-endorphin concentrations may play a role in trigeminal neuralgia, migraine headache, and rheumatoid arthritis.
PMCID: PMC2161980  PMID: 1814247
16.  Propofol for anesthesia in a patient susceptible to malignant hyperthermia. 
Anesthesia Progress  1991;38(3):96-98.
Propofol may be a useful anesthetic in the management of malignant hyperthermia patients. It appears not to trigger malignant hyperthermia while providing stress-free conditions. This case report, along with a small number of others, documents the safe use of propofol for this patient population.
PMCID: PMC2161979  PMID: 1839946
17.  Conscious sedation and desensitization. 
Anesthesia Progress  1991;38(3):113.
PMCID: PMC2161977  PMID: 1814246
18.  An Evaluation of 4% Prilocaine with 1:200,000 Epinephrine and 2% Mepivacaine with 1:20,000 Levonordefrin Compared with 2% Lidocaine with 1:100,000 Epinephrine for Inferior Alveolar Nerve Block 
Anesthesia Progress  1991;38(3):84-89.
The purpose of this study was to measure the degree of anesthesia obtained with 4% prilocaine with 1:200,000 epinephrine and 2% mepivacaine with 1:20,000 levonordefrin compared with 2% lidocaine with 1:100,000 epinephrine for inferior alveolar nerve block. Using a repeated measures design, 30 subjects randomly received an inferior alveolar injection using masked cartridges of each solution at three successive appointments. The first molar, first premolar, lateral incisor, and contralateral canine (control) were blindly tested with an Analytic Technology pulp tester at 3-min cycles for 50 min. Anesthetic success was defined as no subject response to the maximum output of the pulp tester (80 reading) within 16 min and maintenance of this reading for the remainder of the testing period.
Although subjects felt numb subjectively, anesthetic success as defined here occurred in 46% to 57% of the molars, in 50% to 57% of the premolars, and in 21% to 36% of the lateral incisors. No statistically significant differences in onset, success, failure, or incidence were found among the solutions. We conclude that the three preparations are equivalent for inferior alveolar nerve block of 50-min duration.
PMCID: PMC2161976  PMID: 1814249
19.  An anaphylactic reaction to protamine sulfate. 
Anesthesia Progress  1991;38(3):99-100.
Presented is a case in which protamine sulfate administration caused an immediate allergic-like reaction. The patient, a 50-year-old woman, had received protamine previously to reverse the anticoagulant effect of heparin after open heart surgery. In a similar operation 7 years later, protamine was used again for the same reason. Immediately following intravenous infusion of 3 mg/kg protamine sulfate, a sudden drop of the mean arterial blood pressure to 40 mm Hg occurred, and the heart rate increased from 100 to 130 beats/min. Severe angioneurotic edema of the face and trunk also developed. The reaction was successfully treated with vasopressors, steroids, and volume expansion. Subsequent skin testing revealed a positive reaction to protamine sulfate.
PMCID: PMC2161974  PMID: 1814251
21.  Variability of argon laser-induced sensory and pain thresholds on human oral mucosa and skin. 
Anesthesia Progress  1991;38(3):79-83.
The variability of laser-induced pain perception on human oral mucosa and hairy skin was investigated in order to establish a new method for evaluation of pain in the orofacial region. A high-energy argon laser was used for experimental pain stimulation, and sensory and pain thresholds were determined. The intra-individual coefficients of variation for oral thresholds were comparable to cutaneous thresholds. However, inter-individual variation was smaller for oral thresholds, which could be due to larger variation in cutaneous optical properties. The short-term and 24-hr changes in thresholds on both surfaces were less than 9%. The results indicate that habituation to laser thresholds may account for part of the intra-individual variation observed. However, the subjective ratings of the intensity of the laser stimuli were constant. Thus, oral thresholds may, like cutaneous thresholds, be used for assessment and quantification of analgesic efficacies and to investigate various pain conditions.
PMCID: PMC2161972  PMID: 1814248
22.  Dental fear of Japanese residents in the United States. 
Anesthesia Progress  1991;38(3):90-95.
The purpose of this study was to investigate dental fear in a sample of Japanese adults and to make preliminary comparisons with a previously described US sample. The survey instrument was translated into Japanese and then translated back into English and was sent to 839 Japanese residing in the Seattle area. A total of 419 (49.9%) usable questionnaires were returned. Results indicate a level of fear higher than the US population (only 17.9% were not at all afraid). Fear level did not vary by age; most respondents (73.3%) acquired their fear in early childhood. While reported utilization was lower than the American sample, the percentage of Japanese respondents who reported being hurt at the last appointment was high (68.0%). Japanese respondents indicated that 35% of dentists appeared to be in a hurry, hurry being associated with being hurt. Japanese coping practices appeared to differ from the American sample. For example, 14.7% of the Japanese whereas 28.2% of the US sample requested the dentist to stop treatment.
PMCID: PMC2161975  PMID: 1814250
23.  Pharmacological considerations for conscious sedation: clinical applications of receptor function. 
Anesthesia Progress  1991;38(2):33-38.
Most drugs used in conscious sedation regimens act by reasonably well-defined receptor mechanisms. The variety of clinical effects produced by these agents is generally extensive, and often can be explained by their activity at more than one receptor type. Rote memorization of drug effects is a futile exercise, especially when one considers the number of new agents introduced each year. An appreciation of receptors and their effects is a more logical approach. This article reviews fundamental concepts of receptor dynamics that are applicable to agents used for conscious sedation. Using this approach, the effects and indications for various agents can be predicted based on their activity at specific receptor sites.
PMCID: PMC2148692  PMID: 1667349
24.  Macro- and microvascular effects of nitrous oxide in the rat. 
Anesthesia Progress  1991;38(2):57-64.
The aims of this study were: (1) to determine the macro- and microvascular actions of nitrous oxide (N2O) in the rat, and (2) to determine whether the vascular actions of N2O involved specific interaction with alpha-adrenergic receptors or opioid receptors. Systolic blood pressure, heart rat, total tail blood flow, blood cell velocity in subepidermal capillaries of the tail, and percentage of capillaries exhibiting flow were monitored in conscious rats during the administration of N2O before and after administration of clonidine (an alpha 2-adrenergic agonist), prazosin (an alpha 1-adrenergic antagonist) or naloxone (an opioid antagonist). Total tail blood flow increased significantly in a dose-dependent manner with N2O at 20% and 40% with oxygen. This action of N2O was not blocked by clonidine, prazosin, or naloxone. Capillary flow velocity increased during 20% and 40% N2O compared to 100% O2, but the changes were not statistically significant nor did they correlate with the changes in tail blood flow. These data suggest that the peripheral vascular action of N2O does not involve specific actions at alpha-adrenergic receptors or opioid receptors and may be the result of direct actions on the peripheral vasculature.
PMCID: PMC2148690  PMID: 1667350
25.  Epidural buprenorphine or morphine for the relief of head and neck cancer pain. 
Anesthesia Progress  1991;38(2):69-71.
We present three cases in which epidural buprenorphine or morphine was used for intractable cancer pain of the head and neck. Excellent pain relief and minimal side effects offered by epidural opioids were of significant benefit. The use of epidural opioids prior to the administration of high doses of oral morphine may be the treatment of choice for pain from malignancy of the head and neck, especially when there is tumor extension or distant metastasis.
PMCID: PMC2148689  PMID: 1811431

Results 1-25 (38)