Patient Groups
This cross-sectional study included patients to be applied with the TEE procedure who were screened with a full perioperative anaesthesia evaluation before TEE in the Cardiology Clinic of Adana Training and Research Hospital between 1 January 2019 and 1 January 2021.
Patients were not included in the study if they had acute or end-stage liver or kidney disease, acute coronary syndrome, end-stage chronic obstructive pulmonary disease, malignancy, active infection within the last 2 weeks, bleeding time disorder, grade III or IV heart disease, pulmonary failure, left ventricle systolic function disorder, known pathology in the oropharynx, oesophagus, or gastric region, body mass index (BMI) > 30, or if they survived for less than 1 year, or did not wish to participate in the study.
From a total of 652 patients screened, 401 were found to be suitable for inclusion, comprising 198 males and 203 females with a mean age of 52.9 ± 14.8 years. In accordance with the Helsinki Declaration on Human Biomedical Research, the protocol was approved by the Institutional Ethics Committee. Signed informed consent was obtained from all the patients.
A detailed history was taken from each patient and detailed physical examinations were made. Before the procedure, pulse in normal sinus rhythm was recorded. Accompanying cardiac and non-cardiac systemic diseases were noted. The blood biochemistry of all the patients was evaluated with hemograms. The biochemical tests were performed before the TEE procedure after a period of 12-hour fasting. Measurements were taken of urea, creatinine, uric acid, alanine aminotransferase, aspartate aminotransferase, and C-reactive protein. Full blood count and white cell count were also obtained. The height and weight measurements of each patient were taken and BMI was calculated as weight (kg)/height (m2).
Anaesthesia Evaluation, Grouping According To The Drug Administered For Sedoanalgesia, And Perioperative Hemodynamic Evaluation
Before the procedure, all the patients underwent preoperative anaesthesia evaluation, during which first the American Society of Anaesthesiologists (ASA) score of all the cases was evaluated. Patients who were confirmed as suitable for anaesthesia for TEE were instructed to fast for at least 12 hours before admission for the TEE procedure the following morning. On the morning of the procedure, the patients were rested for at least 10 mins on a bed, during which measurements were taken of basal systolic blood pressure (SBP), diastolic blood pressure (DBP), heartrate, and basal SaO2 without oxygen.
The decision for TEE with sedation was taken jointly by the Anaesthesia and Cardiology Clinics. The selection of the sedo-analgesia was completely based on the experience of the anaesthesia physician, and was administered by the anaesthesia team. The patients included in the study were separated into 2 groups as those administered midazolam or propofol.
The propofol used for sedation (PROPOFOL-PF 1%, Polifarma, Turkey) was started at a dose of 1mg/kg at a slow intravenous (IV) rate, and the maintenance dose was defined as 4mg/kg/hr.
Midazolam (Zolamid, Vem İlaç, Turkey) was administered over a long period at a slow IV rate to be 0.003 mg/kg for 1 min.
Throughout the procedure, nasal O2 was administered to be 2–8 L/min and SaO2 > 95%. Monitorisation of SaO2, electrocardiography, and blood pressure was continued throughout the procedure. A full hemodynamic evaluation was made every 3–5 mins. SBP and DBP monitorisation was performed non-invasively from the left brachial artery using a sphingomanometer (Philips Healthcare M4555B Non-Invasive Blood Pressure Easy Care Cuff ve IntelliVue MMS X2 Measurement module and patient monitor). O2 saturation measurements were taken with a pulse oxymeter on an Avance CS2 Pro anaesthesia device (GE Healthcare, Madison, WI, USA).
Any sudden increase or decrease in pulse, SBP, and DBP was noted. Changes in pulse, SBP, and DBP were calculated as the difference between the minimum and maximum values. When the TEE procedure was finished, the probe was removed and the IV infusion was terminated. The patients were transferred to the recovery area after the procedure and follow up of vital signs was continued. The residual sedation status was defined with the Ramsey sedation score (RSS). If the patient was not fully awake 4 hours after the procedure, was unreactive or disorientated, this was defined as prolonged recovery. All the patients were discharged from the hospital by the evening of the same day.
The time of onset of the anaesthesia effect was defined as the time from obtaining sufficient anaesthesia with the initiation of IV midazolam or propofol to entry of the TEE probe to the oropharynx. The duration of the procedure was defined as the time from entry of the TEE probe to removal of the probe. The time to recovery was recorded as the time from cessation of the IV infusion to elimination of the anaesthetic effect (RSS ≤ 2). The absolute changes in SaO2, pulse, SBP and DBP were recorded as the difference between the minimum and maximum of these values monitored throughout the procedure.
Transesophageal Echocardiography Method
The TEE procedure was performed using an ACUSON SC2000 PRIME echocardiography device (Siemens Medical Solutions USA, Inc., 2018) with a Z6Ms transducer (frequency range: 3.0–6.3 MHz, Siemens Medical Solutions USA, Inc., 2018). Local anaesthesia of 1% lidocaine was applied to the oropharyngeal region immediately before starting IV anaesthesia. The IV sedation to be applied was determined before the procedure.
All the patients were monitored with non-invasive arterial blood pressure measurements, electrocardiogram, and pulse oxymetry. When sufficient target sedation was obtained, the TEE probe was advanced slowly to the orpharyngeal region. The decision for administration of additional sedative agent was made by the anaesthesiologist when necessary during the procedure. TEE images were acquired in accordance with the recommendations of the TEE guidelines of the American Echocardiography Association (7). All the TEE proceedures in this study were performed by a cardiology specialist with at least 10 years of experience of the TEE procedure who performed more than 100 TEE procedures per year.
Statistical analysis
Data obtained in the study were analysed statistically using SPSS 22.0 software (Chicago, IL, USA). The conformity of continuous variables to normal distribution was evaluated using the Kolmogorov-Smirnov test. Continuous variables were stated as mean ± standard deviation (SD) values and categorical variables as number (n) and percentage (%). The Student’s t-test was applied in the comparisons of continuous data with normal distribution. Categorical variables were compared using the Ch-square test. A value of p < 0.05 was accepted as statistically significant.