Effects of i.v. metoclopramide, atropine and their combination on gastric insufflation in children anaesthetized with sevoflurane and nitrous oxide.
METHODS
To determine effects of i.v. metoclopramide, atropine and their combination on the airway pressures at which gastric insufflation occurs in children, 45 healthy infants and children (ASA I) received an inhalational induction of anaesthesia with sevoflurane, N2O and O2. A blinded observer used a stethoscope to auscultate over the upper abdomen for any air entry. First, proximal airway pressure was slowly increased by closing the pop-off valve of the anaesthesia machine until gas was heard entering the stomach (pop-off point, control measurement). If the peak inspiratory pressure reached 40 cm H2O, the patient was to be excluded from the study. Then, all subjects randomly received i.v. atropine 0.01 mg.kg-1, metoclopramide 0.2 mg.kg-1, or atropine 0.01 mg.kg-1 plus metoclopramide 0.2 mg.kg-1 (n=15 each), and determination of the pop-off point was repeated 5 min later. The stomach was evacuated before each measurement.


RESULTS
Atropine significantly decreased the pop-off point [from 21 +/- 3 to 19 +/- 2 cm H2O (mean +/- SD), P < 0.05], while metoclopramide significantly increased the pop-off point (from 20 +/- 3 to 26 +/- 6 cm H2O, P < 0.05). The combination of metoclopramide and atropine did not alter the pop-off point (from 20 +/- 2 to 19 +/- 5 cm H2O).


CONCLUSIONS
Since metoclopramide exerts only mild effect on the pop-off point, cricoid pressure still remains the standard anaesthetic practice to prevent gastric insufflation in children. Prophylactic i.v. metoclopramide may be restricted to, and its clinical usefulness should be determined in, symptomatic patients with gastro-oesophageal reflux.
Department of Anaesthesia, Institute of Clinical Medicine, Tsukuba University School of Medicine, Ibaraki, Japan.
A
A
Suga
M
M
Tanaka
H
H
Toyooka
D000768:Anesthesia, General / Q000009:adverse effects*; D018685:Anesthetics, Inhalation; D000932:Antiemetics / Q000008:administration & dosage*; D001285:Atropine / Q000008:administration & dosage*; D002648:Child; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004943:Esophagogastric Junction / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007223:Infant; D007262:Infusions, Intravenous; D007327:Insufflation; D008738:Methyl Ethers; D008787:Metoclopramide / Q000008:administration & dosage*; D009609:Nitrous Oxide; D011312:Pressure; D012137:Respiratory System / Q000503:physiopathology; D000077149:Sevoflurane; D013270:Stomach / Q000503:physiopathology; D014839:Vomiting / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control
D018685:Anesthetics, Inhalation; D000932:Antiemetics; D008738:Methyl Ethers; D000077149:Sevoflurane; D001285:Atropine; D009609:Nitrous Oxide; D008787:Metoclopramide