At a glance
ClinicalIndex Comparison RecordStandardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.
Upper Esophageal Sphincter Pressure Variation During Anesthesia Induction
In Brief
An observational study evaluating type of hypnotic used for induction of general anesthesia for Aspiration. Completed, enrolled 20 participants.
Detailed Summary
Upper esophageal sphincter is a high pressure zone of the pharynx and protects airway from aspiration of esophageal or gastric contents. Existing literature concludes that many of the drugs employed to induce general anesthesia descend that pressure. However, most participants of those studies were under 64 years old and were given sedatives or local anesthetics to ease the esophageal measurements which can interfere with the results obtained. The hypothesis was to confirm the hypnotics effects on upper esophageal sphincter with the aim to find out which of them could be a better choice in order to reduce airway aspiration risk during induction of anesthesia, specially during emergency surgery, when a empty stomach is not guaranteed. Twenty patients who were planned for general surgery were studied: 12 men and 8 women, aged 39 to 84 years old. The effect of three commonly used hypnotics was tested: propofol, etomidate, and thiopental. Written informed consent was explained to all participants who freely signed it after having understood and accepted it. After 6-8 hours fast, patients were monitored with entropy (which gives information about patients´ level of consciousness), electrocardiogram, pulse oximetry (measures blood oxygen), and sphingomanometry (measures blood pressure). Registry of upper esophageal sphincter pressure was obtained through solid state high resolution manometry. A lubricated manometric probe was introduced through the nostril to locate it from the pharynx to the stomach using no sedation. After 1 minute to make the patient feel more comfortable, the induction of anesthesia took place employing one of the three drugs for this purpose mentioned above. Comparison of upper esophageal sphincter pressures before and after the hypnotic administration, should give information about which of the three hypnotics, if any, would not led to an unprotected airway and so at increased risk of aspiration.