Psychosomatische, sedative und hämodynamische Reaktionen nach präoperativer oraler Gabe von Midazolam bei Kindern

Abstract

Since childrens' intellectual perception is limited, the preoperative visit by an anesthesiologist alone can rarely help to free the small patients from fear and restlessness prior to elective surgery. In order to relieve anxiety which should be the primary goal of premedication in any patient - children need anxiolytic premedicant agents. Drugs for premedication administered by intramuscular or rectal route in children often cause pain, fear and discomfort. The present study was performed in order to investigate oral given midazolam in the premedication of children with special regard to the practical suitability of this method. 100 children, 0.5 to 10 years of age (group A: 0.5-4 years, group B: 5-10 years) undergoing elective urological surgery received 0.4 mg/kg midazolam orally about 20 minutes prior to the arrival in the operation unit. After insertion of a venous cannula into a forearm vein anesthesia was induced with thiopental and maintained by inhalation with Isoflurane, nitrous oxide and oxygen (fi O₂:0.3). Degree of sedation, state of mind and behaviour (for 100 children) as well as blood pressure and heart rate (seperately for group A and B) were registered preoperatively at defined, comparable and representative circumstances. Side effects prior and during induction phase of anesthesia were documented. The personal data (Tab. 1) are representative for a normal population of children with typical urological diseases. Oral administered midazolam had only a mild or non sedative effect in 76-84% of the children (Fig. 1). 70-84% of the small patients showed an indifferent or euphoric state of mind (Fig. 2) and 67-88% behaved cooperatively or passively (Fig. 3). The circulatory parameters were altered only moderately. Systolic blood pressure (SBP) and heart rate (HR) showed slight but significant changes compared to the values obtained during the preoperative visit with a maximum immediately after the insertion of the venous cannula (group A: SBP 15%, HR 20%; group B: SBP 7%, HR 16%) (Figs. 4, 5). Diastolic blood pressure remained nearly constant in both groups. As side effects hiccough (5%) and vomitus (2%) could be observed. Anxiolysis is the predominant effect of oral given midazolam (0.4 mg/kg in the premedication of children. Mild sedation, indifferent or euphoric state of mind and passive or cooperative behaviour make the children well tolerate the insertion of a venous cannula prior to the induction of anesthesia. Side effects during the induction period were rare. In order to avoid traumatic or discomfortable alterations in the premedication of children resulting from intramuscular injections or rectal applications, the oral administration of midazolam can be recommended.

Zusammenfassung

100 Kinder im Alter von 0,5-10 Jahren (Gruppe A: 0,5-4 Jahre, Gruppe B: 5-10 Jahre), die sich elektiven urologischen Eingriffen unterziehen mußten, wurden ca. 20 Minuten vor Ankunft im OP-Trakt mit Midazolam oral (0,4 mg/kg Körpergewicht) prämediziert. Die Beurteilung der psychosomatischen und sedativen Reaktionen erfolgte mittels eigener Fremdbeurteilungsschemata zu bestimmten vorgegebenen klinisch relevanten Meßzeitpunkten. Die Kinder zeigten in der Mehrzahl der Fälle eine fehlende bis geringgradige Sedierung (76-84%), eine indifferente bis euphorische Stimmung (70-84%) und ein passives bis kooperatives Verhalten (67-88%). Hämodynamisch ergaben sich mäßige aber dennoch signifikante Veränderungen mit Maximalwerten nach Anlegen der intravenösen Infusion. Die Nebenwirkungen (Singultus 5%, Erbrechen 2%) waren gering ausgeprägt. Die Möglichkeit der Vermeidung traumatischer oder unangenehmer Erlebnisse durch Spritze oder Rektiole hat, zusammen mit den zufriedenstellenden Ergebnissen dieser Studie, dazu geführt, daß die Prämedikation mit Midazolam oral in der Kinderanaesthesie im Bereich der Urologischen Klinik Homburg/Saar zur Methode der Wahl geworden ist.