The Relationship Between BCM, Arterial Stiffness and Hemodynamic Instability During Induction of General Anesthesia

Summary

Arterial hypotension during induction of general anesthesia is a risk factor for developing postoperative cardiovascular complications. After induction of general anesthesia patients have a high risk of developing arterial hypotension due to anesthetic drugs who can depress cardiac contractility and determine vasodilatation. Previous studies have shown that even short periods of hypotension with a mean arterial pressure of less than 55 mmHg during surgery is associated with an increased incidence of cardiac injury and acute kidney injury in the postoperative period.

The volemic status of the patients in the preoperative period is very difficult to quantify and can vary due to comorbidities of the patient, chronic treatment, preoperative fasting. Bioimpedance is recognized by over 30 years as a simple and non invasive technique to determine the volemic status especially in the hemodialysed patients. A new device BCM- Body Composition Monitoring (Fresenius Medical Care) offers a simple method to determine extracellular water and total body water. These volumes are determined by measuring impedance at 50 different frequencies thru electrodes placed at the ankle and wrist. BCM can also determine lean tissue mass and adipose tissue mass.

Increasing arterial stiffness is the main characteristic of arterial aging; this increase determines the increase of the afterload, left ventricular hypertrophy, the decrease of coronary and tissue perfusion. Arterial applanation tonometry is a non-invasive technique that has been shown to reliably provide indices of arterial stiffness.

In this study investigators wish to determine if there is a correlation between the hidric status determined by BCM, carotid-femural pulse wave velocity determined with SphygmoCor system and the development of hypotension during induction of general anesthesia. The measurements will be obtained before induction of general anesthesia in the pre-surgical area. During induction of general anesthesia with standard induction agents and Bispectral index monitoring, brachial blood pressure will be measured by a cuff every minute after the loss of verbal contact with the patient up to ten minutes after tracheal intubation. A hypotensive response to anesthesia will be defined as a drop in mean arterial pressure below 55mmHg or a drop in mean arterial pressure with more than 40% than the base line value of the patient before the surgery.

Measurement of the hidric status and aortic stiffness may represent a valid indicator of the risk of hypotension during anesthesia induction.

Conditions

• Vascular Stiffness
• Hypotension on Induction
• Anesthesia; Reaction

Interventions

DIAGNOSTIC_TEST

bioimpedance spectroscopy

Bioimpedance spectroscopy-The technique involves attaching electrodes to the patient's forearm and ipsilateral ankle, with the patient in a supine position. The BCM measures the body resistance and reactance to electrical currents of 50 discrete frequencies, ranging between 5 and 1000 kHz. Based on a fluid model using these resistances, the extracellular water (ECW), the intracellular water (ICW) and the total body water (TBW) are calculated. These volumes are then used to determine the amount of fluid. Carotid-femoral pulse wave velocity-will be determined by arterial applanation tonometry using the Sphygmocor system by sequentially recording ECG-gated carotid and femoral artery waveforms.. Pulse wave signals will be recorded by tonometers positioned at the base of the right common carotid artery and over the right femoral artery.

Sponsors & Collaborators

• Grigore T. Popa University of Medicine and Pharmacy

  lead OTHER

Principal Investigators

• Dimitrie Siriopol, MD, PhD · GRT POPA

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2017-01-03

Primary Completion

2019-03-01

Completion

2019-07-01

Countries

• Romania

Study Locations