Preanesthetic Sedation Research Articles

Comparison of Rectal to Intranasal Administration of Midazolam for Premedication of Children

Sixty children aged 3 to 9, undergoing minor surgical procedures, were studied to compare 0.5 mg/kg intranasal with 0.5 mg/kg rectal midazolam as a premedication. The children were evaluated for their ability to tolerate the medication, preanesthetic sedation, and alertness after anesthesia. Both premedication routes were equally effective in sedating the children. In both groups, a significant loss of effectiveness was noted if induction of the anesthesia began more than 30 minutes after administration of the medication (p < 0.0003). Rectal midazolam was much better tolerated by the children than the intranasal route (30 versus 3, p < 0.0001). We advocate the rectal over the intranasal route for premedication with midazolam in children, and anesthetic induction should occur no more than 30 minutes after administration of premedication.

Reply

Peter J. Davis, M.D., Associate Professor of Anesthesiology, Critical Care Medicine, and Pediatrics.Julie A. Tome, M.D., Assistant Professor of Anesthesiology, University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh, 3705 Fifth Avenue at DeSoto Street, Pittsburgh, Pennsylvania 15213-2583.Francis X. McGowan, Jr., M.D., Assistant Professor of Anesthesiology and Pediatrics, Department of Anesthesiology, Children's Hospital, 300 Longwood Avenue, Boston, Massachusetts 02115-5747.Ira Todd Cohen, M.D., Assistant Professor of Anesthesiology, Department of Anesthesiology, Children's Hospital National Medical Center, 111 Michigan Avenue, NW, Washington, D.C. 20010-2970.In Reply:--Orman raises two important issues. The ideal route of preanesthetic drug administration in children has yet to be defined. Acceptability, effectiveness, and recovery profile are all factors in assessing a drug's utility as a preanesthetic medication. Nasal midazolam can be irritating and cause crying during the first minute after administration. Although we do not have formal statistics on parent/child acceptance, at our institution many parents ask to take nasal midazolam (the nose drops) home for use after surgery.The second issue raised by Orman--drug use for unapproved indications in pediatric patients--is a serious and ethically disturbing matter. Pediatric anesthesiologists frequently administer medications for indications that are not included in the labeling approved by the Food and Drug Administration (the package insert). As Orman suggests, this practice places the physician at risk both legally and financially. In addition, the lack of approved drug labeling has made children

Adverse effects of administration of propofol with various preanesthetic regimens in dogs

Summary: The effects of propofol on anesthetic induction were evaluated in 40 dogs anesthetized with isoflurane. Propofol is a rapidly acting, nonbarbiturate drug that induces anesthesia of ultrashort duration with iv administration. Four preanesthetic regimens were used: anesthesia without preanesthetic drugs; or with preanesthetic administration of acepromazine (0.1 mg/kg of body weight, im), diazepam (0.2 mg/kg, iv), or acepromazine (0.02 mg/kg) and butorphanol (0.4 mg/kg) im. Heart rate, systolic arterial blood pressure (sap), respiration, quality of induction and recovery, and adverse effects were recorded. Intravenous propofol administration induced a variable period of apnea in 34 of 40 dogs. Cyanosis (in 2 dogs) and signs of pain on injection (in 3 dogs) were infrequently observed during induction. One dog developed ventricular premature depolarizations after propofol administration. Venous CO2 tension increased and pH decreased immediately after propofol administration, regardless of preanesthetic regimen. The sap significantly (P &lt; 0.05) decreased after propofol administration in dogs treated with acepromazine (sap, 178 mm of Hg before vs 128 mm of Hg after propofol) and with acepromazine/butorphanol (sap, 184 mm of Hg before vs 98 mm of Hg after propofol). When used for induction, propofol induces anesthetic-related adverse effects, some of which can be minimized by preanesthetic medication. Recovery characteristics varied with preanesthetic medication, independent of propofol administration.

Preanesthetic sedation of preschool children using intranasal midazolam.

Preanesthetic sedation of preschool children using intranasal midazolam.

The effect of ketamine on the functional residual capacity in young children.

The effect of ketamine on the functional residual capacity (FRC) was measured in nine ASA class I children prior to elective surgery. FRC was determined by the closed-circuit helium dilution method on the day prior to surgery in the awake state and also following induction of anesthesia on the day of the operation. Anesthesia consisted of ketamine by continuous intravenous infusion following preanesthetic sedation with atropine and triclofos or flunitrazepam. There were no significant differences in FRC between the measurements in the awake state and anesthetized (392 +/- 43 SEM ml, and 411 +/- 53 SEM ml, respectively), and the authors conclude that ketamine does not affect resting lung volume in young children.

Midazolam Malate as an Intravenous Induction Agent for Open Heart Surgery

Midazolm, a water-soluble benzodiazpine that is shorter-acting, more potent, and less irri-tating toveins than diazepam, has been suggested for use for inducation of anesthesia. The cardiovascular effect of an induction dose(0.2~03mg/kg) of midazolam in ASA class 111cardiac surgical patients(N=15) were compared in a double-blind fashion with a similar group og patients(N=15) receiving thiopental(5.0mg/kg). The patients were premedicated by triflupromazine, pethidine, hydroxyzine, atropine and diazepam. The results were summarized as follows. 1) The thiopental group were more decreased in blood pressure and increase in heart rates than midazolam group. 2) Spontaneous eye closing time and loss of eyelash reflexe were observed. But those were a poor sign of adequate inducation because of heavy preanesthetic sedation. 3) The changes of blood pressure and puls rate after induction and intubation were almost, depends on preload state before inducation. From the above results, midazolam was sufficient as an induction agent for open heart cases. But a hypovolemic patients and completely beta blocked patiens should be used cautiously because they may be developed severe hypotention and tachycardia

Changes of pulmonary function following transfusion of stored blood.

Ventilatory volumes, blood gases and other aspects of pulmonary function were measured before and after intra‐operative transfusion in 16 patients who had undergone operation under general anesthesia. One group consisted of eight patients transfused with 1275 ml of stored blood passed through a standard nylon mesh filter (SF group) and the other consisted of eight patients transfused with stored blood passed through a dacron wool filter (DWF group).Since respiration of the patients was depressed slightly due to preanesthetic sedation, lowered Ve, Vt, and elevated Paco2, respiratory dead space ratio Vd/Vt were observed either in the SF or DWF group before anesthesia and transfusion. Even after the recovery of patients from anesthesia Vd/Vt remained high and Feco2 decreased in the SF group. In contrast, Vd/Vt decreased almost to normal and Feco2 remained normal in the DWF group. Fraction of physiological shunt Qs/Qt tended to decrease after anesthesia and transfusion either in the SF or DWF group. The ventilation‐perfusion ratio increased relatively more markedly and pHa elevated definitely in the SF group after transfusion.The above data indicate that microembolism occurs after transfusion of stored blood, even in an amount of 1,000 ml, with a standard nylon mesh filter and concealed pulmonary dysfunction is observable. Therefore, a fine filter, such as a dacron wool filter or a polyester mesh filter, is recommended to avoid the pulmonary microembolism and the consequent respiratory distress following the transfusion of stored blood.

Efficacy of Oral Psychosedative Drugs for Preanesthetic Medication

The effectiveness of five oral preanesthetic medications has been evaluated in a blind, randomized study of 712 elective surgical patients predicted to become apprehensive preoperatively. A barbiturate (pentobarbital sodium, 200 mg), a nonbarbiturate hypnotic sedative (ethchlorvynol, 1,000 mg and 400 mg), and three minor tranquilizers (diazepam, 20 mg and 10 mg; hydroxyzine hydrochloride, 200 mg; and oxazepam, 60 mg) were the pharmacological classes investigated. Pentobarbital, ethchlorvynol, and diazepam were statistically differentiated from hydroxyzine, oxazepam, and a placebo. Antiapprehensive activity could only be demonstrated in patients who also became drowsy. Three methods of evaluation (nurse observerinterviewer, patient self-assessment, anesthetist's impression) were employed. It is proposed that when preanesthetic sedation is required, the use of oral drug forms can provide a safer route of administration and eliminate the risks of injection.

Preanesthetic sedation of children with intramuscular methohexitol sodium : D. S. Elman and J. S. Denson. Anesth. Analg. 44:494-8, 1965

Preanesthetic sedation of children with intramuscular methohexitol sodium : D. S. Elman and J. S. Denson. Anesth. Analg. 44:494-8, 1965

Preanesthetic Drug Evaluation with the Galvanic Skin Response

Preanesthetic Drug Evaluation with the Galvanic Skin Response

Anesthesia for cardiac surgery: The immediate postoperative period ∗

The problems that arise in the immediate postoperative period following cardiac surgery are primarily related to events in the preoperative preparation and the anesthetic and surgical manipulation in the operating room. The difficulty may be increased by failure to provide adequate support for an inefficient respiratory mechanism and a precariously balanced circulation with little reserve. Emphasis should be placed on complete preoperative preparation including adequate digitalization and a baseline neurologic examination. The use of minimal doses of preanesthetic drugs, anesthetic agents and muscle relaxants is essential. The sternal-splitting incision and minimal handling of heart and lungs is recommended. Early use of a mechanical respiratory assistor through a cuffed tracheostomy tube should be considered the conservative approach when indicated. The need for sufficient replacement of blood to provide an effective circulating volume and the judicious use of sympathomimetic amines are outlined.

Study of narcotics and sedatives for use in preanesthetic medication.

The use of preanesthetic medication is primarily to produce sedation, but the degree of sedation desirable prior to anesthesia and operation is debatable. Narcotics, while unequaled as analgesics, have many undesirable side-effects. The routine use of narcotics for preoperative medication, therefore, exposes all patients to the hazards of these drugs. There was little difference in the influence of the various preanesthetic drugs on satisfactory induction of anesthesia with any given anesthetic agent, but the complications of the induction period varied according to the preanesthetic drug and the anesthetic agent. The continued routine use of narcotics for preanesthetic medication is unwise and unwarranted. Preoperative medication should be tailored to meet the needs of the patient and his operation.

Preanesthetic management of the dental patient

George Bernard Shaw’s statement that anesthesia spares us nothing but the knife,1 while not as true today as when it was written in 1906, nevertheless, still has an element o f truth in it. Since the ideal preanesthetic sedative is yet to be discovered, it is necessary to make the best use of what is available. In the past 20 years much has been learned about the psychodynamics of anxiety and ap­ prehension and their treatment with psy­ chotherapy. The interest of the dental profession is evidenced by the creation during the past decade o f numerous academies, institutes and societies de­ voted to “ dental psychosomatics” 2 and “ hypnodontia.” As is customary whenever a sudden interest in a particular scientific subject is manifested, many untried theories are proposed, and there is a great deal o f misinformation and wishful thinking. The dental literature has been filled with enthusiastic reports and, almost in equal volume, criticisms o f sedation. Fewer practitioners are trained in this difficult psychiatric field than would appear from the number of authors who have ven­ tured into the vast field o f theory and therapy o f anxiety and apprehension.3 It is not at all surprising therefore that the psychosomatic approach to this sub­ ject has met with considerable resistance from many members in the profession who base their judgments on more solid ground than much o f the current theoriz­ ing. The terms “ tender-minded” and “ tough-minded,” originally proposed by the psychologist William James, may be applied to scientists. T he “ tenderminded” scientist in interpreting facts might base his judgment roughly 60 per cent on reason and 40 per cent on such commendable but emotion-fraught at­ tributes as faith, hope and charity. In contrast, the “ tough-minded” scientist might make use o f as much as 80 or 90 per cent o f the “ rationalization poten­ tial.” 4 In the matter o f “ dental psychoso­ matics” and “ hypnodontia,” it would ap­ pear that the “ tender-minded scientists” are in the ascendancy, in view o f the pre­ ponderance of hopeful predictions in re­ gard to simple and easy methods for allaying anxiety and apprehension as well as for elevating the threshold o f pain. The

Preanesthetic sedation of children; analysis of the effects for tonsillectomy and adenoidectomy.

THE NECESSITY for preanesthetic sedation before tonsillectomy and adenoidectomy in children is a much debated question. Many otolaryngologists avoid giving sedation because of the danger of depression of the cough reflex and the attendant hazard of aspiration of blood and debris into the lungs. On the other hand, pediatricians and psychiatrists believe that undesirable personality changes may be related to inadequate preoperative preparation and sedation. The anesthesiologist finds himself in a dilemma; he does not wish to add to the risks of operation and anesthesia, yet wants to avoid the unpleasant task of anesthetizing apprehensive, struggling, or crying children. The investigation reported herein was begun in order to obtain answers to such problems. Is the incidence of crying (and presumably the danger of psychic trauma) higher in children given only a belladonna drug before anesthesia? Does the employment of sedatives increase the hazards of anesthesia and operation? METHOD OF STUDY

Pain relief for children

The rationale has been stated of basing depressant drug dosage in children upon the supposed parallel curves for cell irritability and metabolic activity rather than solely upon age and weight. Satisfactory accomplishment of pain relief and of pre-anesthetic sedation with morphine and scopolamine has been described. Attention has been directed to the desirability of combining these two drugs in the proportion of twenty-five to one unless physical signs indicate a variation from this combination. Complete familiarity with a given combination of depressant drugs, and individualization of their dosage has afforded more satisfactory pain relief and pre-anesthetic sedation than attempts to change from one combination of drugs to another. It is our belief that ninety minutes is the optimum interval between a pre-anesthetic hypodermic of morphine and scopolamine and the induction of inhalation anesthesia. The time interval between administration of premedication and induction of inhalation is as important as the dose of agent. Disturbance of oxygen ingress to, and carbon dioxide egress from, the tissues of the body is a more likely fault of anesthesia than is an ill-advised choice of agent. Careful supervision of respiration throughout the period of anesthetic drug action is essential.

Preanesthetic medication

The use of non-volatile sedative and other drugs before operation to prepare the patient for anesthesia and surgical manipulation is common practice. Preanesthetic sedation is a rational procedure based upon well established principles; these principles have been discussed. The pharmacologic actions of the drugs commonly employed have been described briefly. Factors which may modify the choice of drug, in individual cases, are also presented. No single drug or combination of drugs can be suited to all cases. Satisfactory results are obtained clinically by various individuals using different drugs, with the same general actions. Experience in the use of any of these drugs, particularly with regard to the adjustment of dose and time factor will result in increasing success. Routine prescription without individualization cannot be satisfactory. The most consistently good results are obtained when the various influencing factors are carefully weighed, the available drugs considered and following the choice and administration, the effects both advantageous and otherwise accurately observed and recorded. The anesthetist, who is thoroughly grounded in the physiologic and pharmacologic principles of sedative drug prescription, experienced in assessment of the varying factors in individual cases, and familiar with the conditions under which the anesthesia and operation are to be performed is best fitted to prescribe sedation for any patient. Training and experience are more often reflected in the success or failure of preanesthetic medication than in any other phase of the anesthetic procedure.

Preanesthetic Drugs

Preanesthetic Drugs