thiopental and Muscle-Rigidity

Topics: Anesthesia, Intravenous; Anesthetics, Intravenous; Female; Humans; Middle Aged; Muscle Rigidity; Muscle Tonus; Reflex, Stretch; Spasm; Succinylcholine; Thiopental; Time Factors

To determine whether the incidence of masseter muscle rigidity is affected by the anaesthetic induction sequence, we prospectively studied for ten months the anaesthetic course in 5,641 infants and children who received muscle relaxation to facilitate tracheal intubation. The anaesthetic induction sequence consisted of intravenous sodium thiopentone (STP) 5 mg.kg-1 alone, halothane induction alone 1-4%, or halothane followed by STP. Inhalational inductions with halothane included nitrous oxide and oxygen. Tracheal intubation was facilitated by either intravenous succinylcholine (Sch) at least 1.5 mg.kg-1 or by a non-depolarizing muscle relaxant. The induction sequence and all episodes of MMR were recorded. Ninety percent of the patients received Sch and 10% received a non-depolarising agent. Of those who received Sch, 88% (5,064 patients) were anaesthetised with STP and 12% (607 patients) were anaesthetised with halothane alone or halothane followed by STP. Masseter muscle rigidity was defined clinically by the transient inability to distract the mandible from the maxilla such that the mouth could not be opened or could only be opened with force. No children anaesthetised with STP followed by Sch developed MMR. One child (0.9%) developed MMR after halothane and Sch and two developed MMR after halothane, STP and Sch (0.4%). The incidence of MMR after Sch was less with STP than with halothane alone or with halothane and STP (P < 0.025). The peak CPK values in the three children who developed MMR were 17,580 IU.L-1 after halothane and Sch, and 7,280 IU.-1 and 3,273 IU.-1 after halothane, STP and Sch. There was no evidence of MH reactions in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Anesthesia, Inhalation; Anesthesia, Intravenous; Child; Child, Preschool; Drug Interactions; Halothane; Humans; Incidence; Infant; Intubation, Intratracheal; Malignant Hyperthermia; Masseter Muscle; Muscle Rigidity; Neuromuscular Nondepolarizing Agents; Nitrous Oxide; Prospective Studies; Succinylcholine; Thiopental

The pharmacological properties of (R)-4-chloro-2-(2-hydroxy-3-morpholinopropyl)-5-phenyl-4-isoxaz olin-3-one hydrochloride (CS-722), a newly synthesized, centrally acting muscle relaxant, were studied in rats. The drug CS-722 reduced the radio frequency decerebrate rigidity in a dose-dependent manner (25-100 mg/kg, p.o.); it inhibited the increase in discharges from Ia afferent fibers, gamma-motor activity, which was induced by stimulation of the reticular formation. The compound, however, showed no effect on the basal discharge of Ia afferent fibers. The polysynaptic reflex was depressed by CS-722, with less influence on the monosynaptic reflex in intact and spinal preparations and CS-722 did not prolong thiopental-induced sleeping time. In rats anesthetized with halothane, CS-722 did not affect the electroencephalogram (EEG) arousal response, which was elicited by stimulation of the reticular formation. The results of this study suggest that CS-722 can exert a muscle relaxant action, at a dose range at which depression of the ascending reticular activating system was negligible. The results also suggest that depressions of the gamma-motor system and the polysynaptic reflex may contribute to the muscle relaxant action of CS-722.

Topics: Animals; Clonidine; Decerebrate State; Dose-Response Relationship, Drug; Electroencephalography; Evoked Potentials; Isoxazoles; Male; Morpholines; Motor Neurons, Gamma; Muscle Relaxants, Central; Muscle Rigidity; Parasympatholytics; Rats; Rats, Wistar; Sleep; Spinal Cord; Thiopental

Topics: Anesthesia, Intravenous; Child; Humans; Male; Masseter Muscle; Muscle Rigidity; Succinylcholine; Thiopental; Time Factors

This study was undertaken to search for an alternative experimental model in the evaluation of fentanyl-induced muscle rigidity. Unanesthetized, spontaneously ventilating Sprague-Dawley rats, and rats anesthetized with either ketamine or thiopental whose ventilation was mechanically controlled, were studied. Intravenous administration of fentanyl (25, 50, or 100 micrograms/kg) caused an increase in electromyographic (EMG) activity in both unanesthetized and ketamine-anesthetized, but not in thiopental-anesthetized, animals. Muscle rigidity was more prominently manifested in the gastrocnemius muscle, when compared with the rectus abdominis muscle. Hypoxemia was exhibited during the course of rigidity by both spontaneously ventilating and ketamine-anesthetized rats, but not by thiopental-anesthetized animals. In addition, unanesthetized, spontaneously ventilating rats developed hypercarbia and respiratory acidosis. The authors suggest that, in addition to using unanesthetized animals, EMG activity in the gastrocnemius muscle of rats anesthetized with ketamine in whom ventilation is controlled may provide an alternative approach in the evaluation of fentanyl-induced muscle rigidity.

Topics: Anesthesia; Animals; Blood Pressure; Carbon Dioxide; Fentanyl; Heart Rate; Injections, Intravenous; Ketamine; Male; Muscle Rigidity; Oxygen; Rats; Rats, Inbred Strains; Thiopental

The use of dantrolene to reverse severe unexplained postanaesthetic muscle rigidity in a previously "healthy" 13-year-old male is described. Anaesthesia was induced with thiopentone. After intubation with pancuronium, the patient had an entirely uneventful nitrous oxide, oxygen and halothane anaesthetic. Immediately following reversal of the relaxant, the patient developed generalized muscle tightness and rigidity involving the trunk and extremities. This was prolonged and severe enough to interfere with adequate ventilation. The patient also had a prolonged recovery from the anaesthetic. After ruling out malignant hyperthermia and some other causes of rigidity, a tentative diagnosis of myotonia was made. The symptoms responded to IV dantrolene in a total dose of 2.0 mg.kg-1. Further testing failed to establish a definite diagnosis. Dantrolene could be a useful drug in treating such unexplained muscle rigidity.

Topics: Adolescent; Anesthesia, General; Anesthesia, Inhalation; Dantrolene; Halothane; Humans; Male; Muscle Rigidity; Nitrous Oxide; Pancuronium; Postoperative Complications; Thiopental

The authors investigated the hemodynamic, metabolic, electroencephalographic (EEG), and electromyographic (EMG) characteristics of narcotic-induced rigidity during induction of anesthesia with alfentanil (175 micrograms/kg) in 10 patients. Thiopental (4 mg/kg) was administered to a ten-patient control group. Rigidity was quantified in eight muscle groups (sternocleidomastoid, deltoid, biceps, forearm flexors, intercostal, rectus abdominus, vastus medialis/lateralis, and gastrocnemius). Marked rigidity was observed in all muscle groups in all patients receiving alfentanil and in none receiving thiopental. Central venous pressure increased with onset of rigidity, while mean arterial pressure and cardiac index remained unchanged. Manual ventilation was extremely difficult during alfentanil-induced rigidity. Arterial oxygen tension decreased more rapidly during rigidity than during the same time interval in the control group, while patients experiencing rigidity were more acidotic, as reflected by greater increases in base deficit. The EEG demonstrated an anesthetic state without seizure activity. The immediate increase in central venous pressure with the onset of rigidity, along with occasional simultaneous parallel variations in central venous pressure and the EMG, strongly suggest a mechanical mechanism for the change in central venous pressure. The metabolic changes during rigidity may be partly related to the absence of the normal cardiovascular reflexes that are reported to occur during voluntary isometric muscle contractions. A neurochemical mechanism of narcotic-induced rigidity is briefly reviewed.

Topics: Alfentanil; Electroencephalography; Electromyography; Fentanyl; Hemodynamics; Humans; Muscle Rigidity; Oxygen; Receptors, GABA-A; Thiopental; Venous Pressure

Alfentanil in combination with etomidate and N2O/O2 was given to 50 patients as single dosage (0.024 mg/kg b.w.) or with repeated injections for surgical interventions up to 90 minutes duration. In 68% of these cases sufficient analgesia was obtained. The most frequent side-effects were rigidity of the thorax (54%), quick, extensive changes in blood pressure (32%) and bradycardia (28%). The recovery phase was very short, postoperative sickness and vomiting were seen in 6% of all cases. Still, after repeated injections phases with prolonged sleep can appear. While using Alfentanil, exact monitoring is necessary, as quick and unexpected changes of blood pressure and pulse can appear.

Topics: Adolescent; Adult; Aged; Alfentanil; Anesthesia, General; Atropine; Blood Pressure; Child; Etomidate; Female; Fentanyl; Hemodynamics; Humans; Male; Methohexital; Middle Aged; Muscle Rigidity; Nitrous Oxide; Preanesthetic Medication; Thiopental

Topics: Diazepam; Electromyography; Humans; Male; Middle Aged; Muscle Rigidity; Tetanus; Thiopental

Topics: Anesthesia, General; Appendectomy; Child; Halothane; Heart Arrest; Humans; Male; Malignant Hyperthermia; Muscle Rigidity; Nitrous Oxide; Succinylcholine; Thiopental

Topics: Adult; Anesthesia, General; Appendectomy; Creatine Kinase; Female; Humans; Isoenzymes; L-Lactate Dehydrogenase; Male; Malignant Hyperthermia; Muscle Rigidity; Muscles; Pedigree; Succinylcholine; Thiopental

Topics: Chills; Humans; Muscle Rigidity; Nervous System Physiological Phenomena; Parkinson Disease; Reflex; Thiobarbiturates; Thiopental