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PubMed2004

Antagonism of cisatracurium and rocuronium block at a tactile train-of-four count of 2: should quantitative assessment of neuromuscular function be mandatory?

UNLABELLED: With a train-of-four (TOF) ratio >0.70 as the standard of acceptable recovery, postoperative residual paralysis is a frequent occurrence in postanesthesia care units (PACUs). However, detailed information regarding prior anesthetic management is rarely provided. We examined the incidence of postoperative weakness after the administration of cisatracurium and rocuronium when using a rigid protocol for muscle relaxant and subsequent neostigmine administration. Under desflurane, N(2)O, and opioid anesthesia, tracheal intubation was accomplished after either cisatracurium 0.15 mg/kg or rocuronium 0.60 mg/kg. The response of the thumb to ulnar nerve stimulation was estimated by palpation. Additional increments of muscle relaxant were given as needed to maintain the TOF count at 1 or 2. At the conclusion of surgery, at a TOF count of 2, neostigmine 0.05 mg/kg plus glycopyrrolate 10 micro g/kg was administered. The mechanical TOF response was then measured with a force transducer starting 5 min postreversal. Patients were observed until a TOF ratio of 0.90 was achieved. There were no significant differences in the recovery profiles of cisatracurium versus rocuronium. TOF ratios at 10 min postreversal were 0.72 +/- 0.10 and 0.76 +/- 0.11, respectively. At 15 min postreversal, only one subject in each group had a TOF ratio of <0.70. No patient in either group arrived in the PACU with a TOF ratio <0.70. Our results suggest that if cisatracurium or rocuronium is administered by using the TOF count as a guide, critical episodes of postoperative weakness in the PACU should be an infrequent occurrence. IMPLICATIONS: After the administration of cisatracurium or rocuronium, train-of-four (TOF) ratios <0.70 should rarely be observed in the postanesthesia care unit if neostigmine-assisted antagonism of residual block is delayed until the tactile TOF count at the thumb is 2 or more.

Adolescent↗

PubMed2000

Sedative and cardiorespiratory effects of medetomidine, medetomidine-butorphanol, and medetomidine-ketamine in dogs.

OBJECTIVE: To determine sedative and cardiorespiratory effects of i.m. administration of medetomidine alone and in combination with butorphanol or ketamine in dogs. DESIGN: Randomized, crossover study. ANIMALS: 6 healthy adult dogs. PROCEDURES: Dogs were given medetomidine alone (30 micrograms/kg [13.6 micrograms/lb] of body weight, i.m.), a combination of medetomidine (30 micrograms/kg, i.m.) and butorphanol (0.2 mg/kg [0.09 mg/lb], i.m.), or a combination of medetomidine (30 micrograms/kg, i.m.) and ketamine (3 mg/kg [1.36 mg/lb], i.m.). Treatments were administered in random order with a minimum of 1 week between treatments. Glycopyrrolate was given at the same time. Atipamezole (150 micrograms/kg [68 micrograms/lb], i.m.) was given 40 minutes after administration of medetomidine. RESULTS: All but 1 dog (given medetomidine alone) assumed lateral recumbency within 6 minutes after drug administration. Endotracheal intubation was significantly more difficult when dogs were given medetomidine alone than when given medetomidine and butorphanol. At all evaluation times, percentages of dogs with positive responses to tail clamping or to needle pricks in the cervical region, shoulder region, abdominal region, or hindquarters were not significantly different among drug treatments. The Paco2 was significantly higher and the arterial pH and Pao2 were significantly lower when dogs were given medetomidine and butorphanol or medetomidine and ketamine than when they were given medetomidine alone. Recovery quality following atipamezole administration was unsatisfactory in 1 dog when given medetomidine and ketamine. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that a combination of medetomidine with butorphanol or ketamine resulted in more reliable and uniform sedation in dogs than did medetomidine alone.

Adjuvants, Anesthesia↗

PubMed1998

Hemolink-induced effects on intestinal motor function and attenuation of these effects by selected agents.

Hemolink, an oxidized, ring-opened raffinose-crosslinked hemoglobin-based oxygen carrier produced by Hemosol Inc., stimulates esophageal peristalsis, possibly by interference with neural NO-mediated effects. The effects of Hemolink on jejunal tone and contractions, arterial pressure and heart rate were measured in anesthetized rats, and the effect of selected agents in attenuating or reversing these effects was studied. Infusion of L-NAME was used to validate the study model; it caused an immediate increase in tone and initiated phasic contractions indicating that the model was responsive to NO-mediated effects. Hemolink administration caused effects on intestinal motor function similar to those caused by L-NAME, including increases in basal tone and contraction amplitude. Rat whole blood caused none of these changes. The Hemolink-induced effects were less immediate in some animals compared to those observed after L-NAME. As well there was greater inter-animal variability on the effects. Hemolink administration also caused a mild increase in arterial blood pressure and a reciprocal decrease in heart rate in some animals. Co-administration of morphine, a common analgesic that has been reported to influence the motility of the GI tract; L-arginine, a substrate for NO synthesis; and glycopyrrolate, an anti-cholinergic agent, did not significantly modulate the Hemolink effects, whereas nitroglycerin, an NO donor; and nifedipine, a slow calcium-channel blocker, attenuated or reversed these effects.

Analgesics, Opioid↗

PubMed2001

Origins of heart rate variability: autonomic blockade of large magnitude, transient bradycardia in conscious rabbits.

BACKGROUND: Heart period sequences are composed of recurrent, similarly shaped, physiologically meaningful, transient heart period structures. One such structure is a large magnitude transient bradycardia (LMTB), which resembles published reports of responses to alerting stimuli. Alerting responses are sensitive to alpha1-adrenoceptor and cholinergic receptor blockade. OBJECTIVES: To determine whether LMTBs are related to alerting responses by assessing the response of rabbit LMTBs to autonomic inhibitors. ANIMALS AND METHODS: Using a Latin square, crossover design, six conscious, unsedated rabbits received placebo, intramuscular glycopyrrolate 0.05 mg/kg and intravenous prazosin 0.15 mg/kg, and six rabbits received placebo, intravenous metoprolol 0.15 mg/kg and intravenous ICI-118,551 0.1 mg/kg. Heart period and blood pressure were continuously recorded, digitized and analyzed off-line. RESULTS: LMTBs were suppressed by 93% and 95% by alpha1-adrenergic and muscarinic blockade, respectively, but not by beta1-adrenergic or beta2-adrenergic blockade. The drugs altered none of the morphological parameters of shape, magnitude or duration, or any of the hypotensive features. CONCLUSIONS: LMTBs are similar to alerting responses; they are both expressed as transient hypotensive and bradycardic events that are markedly reduced by muscarinic and alpha1-adrenoceptor blockade but not by beta-adrenoceptor blockade. The presence of LMTBs may indicate ongoing, subtle changes in the laboratory environment.

Adrenergic alpha-1 Receptor Antagonists↗

PubMed2003

The sedative and behavioral effects of nalbuphine in dogs.

We compared the degree of sedation and frequency and intensity of adverse behaviors in dogs associated with nalbuphine when combined with acepromazine or xylazine compared with those of acepromazine or xylazine alone. Twenty-four dogs (13 female, 11 male) undergoing routine ovariohysterectomy or castration were randomly assigned to one of four groups. Group NX received 0.5 mg/kg nalbuphine and 0.5 mg/kg xylazine subcutaneously (s.c.). Group X received 0.5 mg/kg xylazine s.c. Group NA received 0.5 mg/kg nalbuphine and 0.05 mg/kg acepromazine s.c. Group A received 0.05 mg/kg acepromazine s.c. All dogs received 0.01 mg/kg glycopyrrolate s.c. All doses were administered preoperatively. Preoperative resting measurements of heart rate, respiratory rate, rectal temperature, and body weight were obtained. Sedation was scored both inside and outside a kennel prior to drug administration and at 10, 20, and 30 min after drug administration. Dogs were assessed for behavioral responses (leg withdrawal, shivering, rigidity, orienting, panting, struggling, vocalization, wide-eyed facial expression, breath holding, salivating, hiding, biting, or requiring a muzzle) during three time periods: placing the dog on the table, clipping and prepping of forelimb, and intravenous catheterization. Postoperative recovery behaviors were scored. Expired halothane concentrations were recorded at 15, 30, and 45 min postinduction. Significant differences occurred in the level of sedation at 30 min between dogs receiving nalbuphine and xylazine or xylazine only compared with dogs receiving acepromazine. There was a significant difference in behavioral scores with respect to leg withdrawal and orienting during clipping/prepping between dogs receiving nalbuphine and xylazine compared with dogs receiving xylazine. The combination of nalbuphine and xylazine is a useful premedicant which provided greater sedation than acepromazine and reduced some anxiety behaviors more than did xylazine alone. Nalbuphine is an inexpensive opioid and currently is not a controlled substance in the U.S.

Acepromazine↗

PubMed1992

Hemodynamic and sedative effects of dexmedetomidine in dog.

This study investigated hemodynamic and sedative effects of a single dose of the selective alpha-2 adrenoceptor agonist dexmedetoimidine (DMED) in isoflurane-anesthetized dogs. DMED (20 micrograms/kg i.v. 2-min infusion) was given to all dogs. In Group 1 the effects of DMED (time control; N = 10) were studied over 4 hr. In Group 2 (N = 11) glycopyrrolate (40 micrograms/kg initial dose followed by 20 micrograms/kg repeated every 30 min) was used to modulate the DMED-induced vagally mediated changes in heart rate. In Group 3 (N = 8), two doses of nifedipine were used to offset the DMED-induced increase in arterial blood pressure, low dose nifedipine = 10 micrograms/kg bolus followed by 2.5 micrograms/kg/min infusion for 20 min, high dose nifedipine = 20 micrograms/kg bolus followed by 5 micrograms/kg/min infusion for 20 min. DMED administration reduced isoflurane anesthetic requirements by 89% at 30 min and by 50% at 4 hr. Maximum increase in mean arterial blood pressure (MABP) +67 mm Hg occurred 1 min after DMED. MABP remained significantly elevated throughout the 4 hr studied (about +20%). Concomitant with the transient peak in MABP, heart rate (129 +/- 6 to 60 +/- 8 bpm) and cardiac output (3.5 +/- 0.3 to 0.9 +/- 0.1 l/min) decreased, whereas systemic vascular resistance (2460 +/- 210 to 14,700 +/- 1330 dynes.sec.cm-5) and left ventricular end diastolic pressure (4 +/- 1 to 27 +/- 4 mm Hg) increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Agonists↗

PubMed1990

Anticholinergic pre-treatment in rigid bronchoscopy. Effect on heart rate, arterial blood pressure and cardiac arrhythmias.

The effect of anticholinergic pre-treatment on the hemodynamic changes during rigid bronchoscopy was studied. Eighty four adult patients in three groups received intravenous saline (control), atropine or glycopyrrolate several minutes before anesthesia and venturi ventilation with intermittent thiopentone and suxamethonium. The rises in heart rate and blood pressure and the incidence of cardiac dysrhythmias were least in the control group. Transient bradycardia rarely occurred, even in the control group, despite repeat doses of suxamethonium. Although most of the results were not statistically significant, they suggest that preoperative anticholinergic administration may aggravate some of the cardiovascular effects of bronchoscopy resulting from sympathoadrenal stimulation.

Aged↗

PubMedDate not supplied

Four-arm radial open maze (FAROM) as a tool for assessing the effect of atropine in spatial memory of the rats.

Place learning behaviour for working (short term) memory and reference (long term) memory is studied with the Four-arm radial open maze (FAROM) in 18 rats divided equally in three groups. In group I, 0.5 mg of atropine was injected intra-peritoneally 30 minutes before the trial. In group II, saline and in group III Glycopyrrolate were injected instead. Twenty three hours hungry animals were tested on each day in the maze to search for food kept in one of the eight cul-de-sacs of maze. The latency i.e. the time to reach the goal cul-de-sacs, as well as the error score i.e. the number of entries in the non-goal cul-de-sacs were counted during six consecutive trials, per day. Each trial duration was 5 minutes or the time taken by the animal to search the goal compartment whichever was less. The inter-trials period was 10 min and the work was carried out for a period of 3 weeks. The results show that atropine does block effectively both the memory faculties i.e. working and reference memory and that level of memory deficit induced by atropine is related to the rate of drug uptake by the central cholinergic receptors.

Animals↗

PubMed1988

Sedative doses of midazolam depress hypoxic ventilatory responses in humans.

The effect of midazolam on the hypoxic ventilatory response of eight healthy volunteers was examined during isocapnic rebreathing. The magnitude of the slope of the ventilatory response to hypoxia (VE vs SaO2) decreased from 1.48 +/- 0.24 to 0.70 +/- 0.13 L.min-1.%SaO2(-1) (means +/- SE, P less than 0.005) after midazolam 0.1 mg/kg IV. The calculated ventilation at an arterial saturation of 90% also decreased from 28.6 +/- 4.4 to 19.9 +/- 2.7 L/min (P less than 0.05). Before midazolam, hypoxia to an SaO2 of 75 +/- 2% was associated with a 23 +/- 3 beats/min increase in heart rate; after midazolam, the increase in heart rate with hypoxia was only 4 +/- 2 beats/min (P less than 0.001). Additionally, a double-blind crossover study evaluated the effect of physostigmine on awareness and hypoxic ventilatory response after midazolam. The change in hypoxic response slope after physostigmine 2.0 mg IV (an increase of 0.28 +/- 0.34 L.min-1.%SaO2(-1] did not differ significantly from that after placebo (an increase of 0.03 +/- 0.22 L.min-1.%SaO2(-1], although physostigmine significantly increased awareness. It is concluded that a sedative dose of midazolam depresses hypoxic ventilatory response and attenuates the hyperpnea and tachycardia associated with hypoxemia. Furthermore, physostigmine-glycopyrrolate reversal of midazolam-induced sedation was associated with nausea (five subjects), vomiting (three subjects), and tachycardia without reversal of the depressed hypoxic ventilatory response.

Adult↗

PubMed1987

Effect of anticholinergic preanesthetic medicaments on the requirements of halothane for anesthesia in the cat.

To study the effects of anticholinergics on anesthetic requirements, minimal alveolar concentrations (MAC) for halothane in the cat were measured before and after IM administration of an anticholinergic (atropine sulfate [0.045 mg/kg], glycopyrrolate [0.011 mg/kg], or scopolamine hydrobromide [0.02 mg/kg]) or a physiologic saline control. The study was performed in 8 adult cats, using a randomized-block experimental design. There was no significant difference between the mean MAC obtained before and after administration of any of the test drugs or vs the control values. The mean MAC of halothane in cats was 0.985% atmosphere.

Anesthesia, Inhalation↗

PubMed1987

Priming with atracurium.

Priming with atracurium was evaluated by dividing 39 patients into 2 groups. All received 0.2 mg IV glycopyrrolate and fentanyl, 50 micrograms IV. Group 1 received saline, group 2 received 0.06 mg/kg atracurium and a stop watch was started. After 3.5 min the patients were asked to lift their heads and maximum negative inspiratory pressure (MIP) was measured. Anesthesia then commenced with thiopental and a twitch monitor was applied to the ulnar nerve. At 5 min group 1 received 0.36 mg/kg atracurium and group 2 was given 0.30 mg/kg atracurium. At 6.5 min intubation was accomplished in all but one patient in group 1 and all but one in group 2. Mean T4/T1 ratios at 90 sec were 0.73 in group 1 and 0.51 in group 2. This difference was statistically significant (P less than 0.001). Bucking on the endotracheal tube occurred in 72% of patients in group 1 and 62% of those in group 2 (not significant). Intubating conditions were "excellent" in 56% of those in group 1 and 75% in group 2 (not significant). "Good" conditions were seen in 33% of group 1 and 15% of group 2 patients (not significant). "Fair" conditions were noted in 6% of patients in group 1 and 5% of group 2 patients (not significant). The time to maximum twitch depression was 11.3 min and 11.5 min in groups 1 and 2 respectively (not significant). All patients in group 1 could sustain head lift whereas four patients in group 2 could not (not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1986

Effects of oral potassium supplements on upper gastrointestinal mucosa: multicenter clinical comparison of three formulations and placebo.

In a carefully controlled multicenter investigation of the effects of oral potassium chloride (KCl) supplements on the gastrointestinal mucosa, 120 healthy men with no endoscopically apparent gastrointestinal lesions were confined to a research ward for 18 days. By random assignment, they were given 60 mEq/day (20 mEq TID) of KCl as either a microencapsulated gelatin capsule, a wax/polymer matrix tablet, or a powder-in-liquid formulation or a placebo capsule for two weeks. All subjects were given glycopyrrolate concomitantly to delay gastric emptying. After treatment was completed, endoscopic examinations of the esophagus, stomach, and duodenum were performed and evaluated by specialists blinded to the particular treatment given. Mild to moderate gastrointestinal irritation, characterized by erythema and edema, was found with similar frequency in all four treatment groups. Two of 30 subjects given the microencapsulated KCl had a single erosion each. Single or multiple erosions were also observed in 14/30 men given the wax/polymer matrix tablet, in 7/30 given the powder, and in 1/30 given placebo. One subject given the wax/polymer matrix tablet had a gastric ulcer. The incidence of gastrointestinal injury with the microencapsulated form was significantly less (P less than 0.01) than that with the wax/polymer matrix tablet and was not significantly different from that seen with either the powder or placebo.

Administration, Oral↗

PubMed1985

Cardiopulmonary effects of an intravenous infusion of guaifenesin, ketamine, and xylazine in dogs.

A 5% solution of dextrose in water containing 50 mg of guaifenesin, 0.25 mg of xylazine, and 1 mg of ketamine/ml was infused IV at the rate of 2.2 ml X kg-1 X hour-1 in dogs. Heart rate, systemic vascular resistance, mean arterial blood pressure, rate-pressure product, and arterial oxygen tension were not altered significantly from baseline values during 2 hours of anesthesia. Cardiac index was significantly (P less than 0.05) decreased from base-line values. Hypoventilation resulted in increased arterial carbon dioxide tension and decreased arterial pH. After the dogs were given glycopyrrolate, cardiac index returned to base line, and heart rate, mean arterial pressure, and rate-pressure product were significantly greater (P less than 0.05) than base-line values.

Anesthesia, General↗

PubMed1984

Esophageal spasm associated with apnea and bradycardia in an infant.

A newborn infant was found to have diffuse esophageal spasm in association with apnea and bradycardia. This association has not been physiologically documented before. The infant's condition improved after the administration of glycopyrrolate, an anticholinergic agent. It is speculated that the association of esophageal spasm and bradycardia may be mediated by the vagus.

Apnea↗

PubMed1994

Edrophonium is better than neostigmine to antagonize residual vecuronium induced neuromuscular block.

Edrophonium (EDR) has the advantages of a quick onset of action and reduced cholinergic effects compared to neostigmine (NST) when they are used to antagonize neuromuscular block (NMB). There are few studies about antagonism of very weak residual NMB. Therefore we compared hemodynamic stability, train-of-four (TOF) characteristics and reversal time (time from administration of antagonists to train-of-four-ratio (TR) at least 0.70) of EDR 0.5 mg kg-1 + atropine (ATR) 0.007 mg kg-1 to NST 0.04 mg kg-1 + glycopyrrolate (GLY) 0.008 mg kg-1 when they were used to antagonize a residual vecuronium (VEC)-induced NMB (T1 25-75%). The NMB was monitored in 64 patients using the evoked electromyogram of the hypothenar muscle of the hand. An adequate antagonism was defined as a TR of 0.70 or higher. Heart rate was significantly higher in NST+GLY group 2 min after administration of the antagonists in comparison with the EDR+ATR group. The advantages of EDR (higher T1, TR and percentage of patients with an adequate recovery) were obvious during the first 5 min of reversal time. Therefore we conclude, that under the conditions described in the present study, EDR antagonizes residual VEC induced NMB faster than NST.

Adult↗

PubMed1999

Total intravenous anesthesia for office-based laser facial resurfacing.

BACKGROUND AND OBJECTIVE: Providing general anesthesia in an office-based setting can be time consuming, risky, and expensive. The purpose of this study was to describe a technique for total intravenous anesthesia (TIVA) technique that can be easily utilized by anesthesiologists in an office-based setting for laser facial resurfacing. STUDY DESIGN/MATERIALS AND METHODS: Twenty-five American Society of Anesthesiologists (ASA) status classification I-II patients (22 females and three males) elected general anesthesia for laser facial resurfacing. All patients were premedicated with glycopyrrolate (0.2 mg IV). All anesthetics were administered by board-certified anesthesiologists, and ASA Standards for Anesthesia Monitoring were strictly followed. An induction dose of propofol (2. 0-2.5 mg/kg IV) was followed by laryngeal mask airway insertion (size 3 or 4). TIVA was maintained with a propofol infusion (50-250 mcg/kg/minute IV). Supplemental midazolam (2-4 mg IV), fentanyl (0. 05-0.20 mg IV), and oxygen (2-4 l/minute) were administered as needed. After completion of the laser procedure, TIVA was discontinued and the patients were allowed to awaken. Patients were discharged after achieving a Modified Post-Anesthetic Discharge Score of >/= 9. RESULTS: Mean procedure duration was 48 +/- 21 minutes, and time to discharge after the procedure was 16 +/-6 minutes. All procedures and anesthetics were well tolerated and without complications. The only post-procedure complaint was an isolated, minor, and temporary sore throat. CONCLUSIONS: TIVA is an excellent method for providing anesthesia for laser facial resurfacing in an office-based setting.

Adult↗

PubMed1996

Continuous infusion of ketamine in mechanically ventilated children with refractory bronchospasm.

OBJECTIVE: To determine whether ketamine infusion to mechanically ventilated children with refractory bronchospasm is beneficial. DESIGN: Retrospective chart review. SETTING: Pediatric intensive care unit (PICU) of a children's hospital. PATIENTS: Seventeen patients, ages ranging from 5 months to 17 years (mean 6 +/- 5.7 years), were admitted to our PICU over a 3-year period and received ketamine infusion during a course of mechanical ventilation. The patients had acute respiratory failure associated with severe bronchospasm due to status asthmaticus (n = 11), bronchiolitis caused by respiratory syncytial virus (n = 4), and bacterial pneumonia (n = 2). INTERVENTIONS: All patients had been mechanically ventilated for 1-5 days (2.2 +/- 1.5 days) and received conventional treatment to relieve bronchospasm for more than 24 h prior to the initiation of ketamine treatment. An intravenous bolus of ketamine of 2 mg/kg, followed by continuous infusions of 20-60 micrograms/kg per minute (32 +/- 10 micrograms/kg per minute) was administered to all patients without changing their preexisting bronchodilatory regimen. Benzodiazepines were also given intravenously to all patients during the ketamine treatment. MEASUREMENTS AND MAIN RESULTS: The PaO2/FIO2 ratio in all patients (n = 17) and the dynamic compliance in the volume-preset mechanically ventilated patients (n = 12) were calculated. The PaO2/FIO2 ratio increased significantly from 116 +/- 55 before ketamine, to 174 +/- 82, 269 +/- 151, and 248 +/- 124 at 1, 8, and 24 h respectively, after the initiation of the ketamine infusion (p < 0.0001). Dynamic compliance increased from 5.78 +/- 2.8 cm3/cmH2O to 7.05 +/- 3.39, 7.29 +/- 3.37, and 8.58 +/- 3.69, respectively (p < 0.0001). PaCO2 and peak inspiratory pressure followed a similar trend of improvement with ketamine administration. The mean duration of the ketamine infusion was 40 +/- 31 h. One patient required glycopyrrolate 0.4 mg/day to control excessive airway secretions and one patient required an additional dose of diazepam to control hallucinations while emerging from ketamine. All patients were successfully weaned from mechanical ventilation and discharged from the PICU. CONCLUSION: Continuous infusion of ketamine to mechanically ventilated patients with refractory bronchospasm significantly improves gas exchange and dynamic compliance of the chest.

Adolescent↗

PubMed1990

A simulation of neuromuscular function and heart rate during induction, maintenance, and reversal of neuromuscular blockade.

We developed a two-compartment model to simulate neuromuscular function and heart rate following the administration of four nondepolarizing neuromuscular blocking agents (atracurium, vecuronium, pancuronium, and d-tubocurarine), three neuromuscular block reversal agents (edrophonium, neostigmine, and pyridostigmine), and two anticholinergic agents (atropine and glycopyrrolate). Twitch depression, train-of-four ratio, and heart rate were modeled during fentanyl, halothane, enflurane, or isoflurane anesthesia, optionally supplemented with nitrous oxide. Simulation results, compared with published values for each drug, fell within the clinical accuracy range (onset time 6.1 +/- 3.9% [mean +/- SEM]; duration, 1.7 +/- 3.5%, 50% effective dose, 0.5 +/- 5.7%; and 95% effective dose, 2.1 +/- 1.1%). The simulation graphically demonstrates the pharmacokinetics, pharmacodynamics, and interactions between neuromuscular blocking agents, reversal agents, and anticholinergic agents. During a simulation, the need for frequent monitoring and repeated delivery of a neuromuscular blocking agent to keep neuromuscular blockade stable becomes apparent, especially with the intermediate-acting neuromuscular blocking agents. When inhalational agents are given concomitantly, the task becomes even more difficult, since potentiation changes with anesthetic uptake. Recurarization, tachycardia, or bradycardia may be seen with the simulation if an improper drug regimen is followed. Concurrent simulation of two identical patients allows comparison of different modes of administration, choice of anesthetic agents, and drug doses.

Administration, Inhalation↗