Upper Esophageal Sphincter Pressure Variation During Anesthesia Induction
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 20
- 主要终点
- Change from baseline upper esophageal sphincter pressure at loss of conciousness.
研究概览
简要总结
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.
详细描述
BACKGROUND
Upper esophageal sphincter is a high pressure zone, behind the cricoid cartilage, which protects airway from aspiration. It consists on striated muscle fibers distributed in two zones: rapid twich oblique fibers correspondent to tyropharyngeal muscle and rapid but mostly slow twich horizontal fibers belonging to cricopharyngeal muscle. This permits sphincter maintain a constant basal tone but, at the same time, respond quickly to reflexes (1).
Upper esophageal sphincter pressure is distributed asymmetrically being greater anteroposteriorly than laterally. Peak anterior pressure is located more cranially than peak posterior pressure (2).
This makes manometric measurements difficult and some unreliable, unless high resolution manometry is used. Upper esophageal sphincter pressure is labile: it decreases with age and deterioration of the level of consciousness; while increases with stress, anxiety, inspiration and phonation. Patients referring dysphagia or gastroesophageal reflux may present altered manometric measurements (3).
Upper esophageal sphincter has a dynamic function, taking part during burps, in deglutition, and airway reflexes such as: esophagus-sphincter reflex, glottic- pharynx reflex and coughing ( 3).
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 35 Years 至 85 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Candidates ought to comply with all these conditions:
- •Had been classified by an anesthesiologist (not participating in the study) , at the preanesthetic consult as I, II or III class from the ASA (American Society of Anesthesiologists) classification in reference to his/her anesthetic risk.
- •Patients of any gender.
- •Patients aged 35 to 85 years old.
- •Candidates to planned general surgery to be given general anesthesia.
- •Be correctly informed through orally and in writing about the study.
- •Voluntary acceptance to participate in the study, voluntary signing the informed consent , which could be revoked at any time through the study.
- •Not presenting any of the exclusion criteria.
排除标准
- •Presenting known allergy or hypersensitivity to any of the drugs to be potentially administered.
- •Pregnancy.
- •Psychiatric history or being on treatment with psychotropic drugs.
- •Being on treatment with any of these drugs (which can cause alterations in esophageal motility): prokinetics, sedatives, calcium channel antagonists, nitrates, anticholinergics, tricyclic antidepressants, teophyline.
- •Having had esophageal surgery.
- •Those who, from an anesthetic or medical point of view could present complications during the process. For example: difficult airway or problems with ventilation.
- •Renal or hepatic alteration which may interfere with hypnotics pharmacokinetics.
- •Renounce to sign informed consent, therefore not authorizing to participate in the study.
- •Not presenting any of the inclusion criteria.
- •Esophageal pathology, including gastroesophageal reflux or dysphagia. Given the high frequency of presenting any of these two lasts, tests were given to the candidates to discard their presence. Two questionnaires were employed: "GERD-Q" (GastroEsophageal Disease- Questionnaire) and "EAT-10" (Eating Assesment Tool) for dysphagia.
研究组 & 干预措施
propofol
Those patients planned for general surgery, who received propofol as an induction agent for general anesthesia.
干预措施: type of hypnotic used for induction of general anesthesia (Drug)
etomidate
Those patients planned for general surgery, who received etomidate as an induction agent for general anesthesia.
干预措施: type of hypnotic used for induction of general anesthesia (Drug)
thiopental
Those patients planned for general surgery, who received thiopental as an induction agent for general anesthesia.
干预措施: type of hypnotic used for induction of general anesthesia (Drug)
结局指标
主要结局
Change from baseline upper esophageal sphincter pressure at loss of conciousness.
时间窗: Time frame: 1 minute after inserting the manometric probe, a basal measure was noted. An average of 1 minute after the hypnotic was given, once entropy had fallen below 60 or otherwise clinical signs showed unconsciousness, another measure was noted.
Solid state high resolution manometry (Sierra Scientific Instruments, Given Imaging, Los Angeles, California Medtronic, Ireland) was used. High resolution manometry module Manoscan™ permits adquisition and recording of manometry studies. Manometric probe has a diameter of 4.2 mm and consists of 36 circunferential sensors at 1 cm intervals (Medtronic, Irlanda). Each sensor consists of 12 segments distributed radially, detecting pressures in 2.5 mm length. A pressure image is created using 432 measurement points. Sectorial pressures are averaged inside of each sensor through pressure transduction technology "Tact Array". Data adquired using manometry are represented in real time as "topographic" plots. Contour plots show different colours, each of them correspondent to a concrete pressure. Location is represented in the vertical axis and time in the horizontal axis. Data obtained using Manoscan are recorded and posteriorly analized through Manoview Software V. 3.01 (Medtronic Irlanda).
次要结局
- Spectral Entropy(Although entropy, as all the variables, was measured through all the study, two time points were relevant: Basal and an average of 1 minuteafter the hypnotic was given. Especially important if the second measurement reached a value of 60 or less.)
研究者
Elena Sanz Sanjosé
Principal Investigator
Hospital San Carlos, Madrid