Comparison Of Ultrasound-Based Measures Of Inferior Vena Cava And Internal Jugular Vein For Prediction Of Hypotension During Induction Of General Anesthesia
Condition: Ultrasound Based IVC IJV
MeSH terms: Hypotension
Study type: Observational

Summary: 
      Hypotension after induction of general anesthesia is a frequent event in routine practice.
      Even a short period of hypotension may lead to tissue hypoperfusion and predispose to
      postoperative complications. Intra-operative hypotension is associated with renal injury,
      ischemic stroke, myocardial injury and postoperative mortality in patients having non-cardiac
      surgery under general anesthesia. Underlying hypovolemia is an important and modifiable risk
      factor for hypotension after anesthetics administration. Ultrasonographic studies of the
      inferior vena cava (IVC) and the internal jugular vein (IJV) for evaluation of intravascular
      volume status and prediction of hypotension during induction of general anesthesia have been
      established.

      The present study was designed to compare, on ultrasound-based measures, between inferior
      vena cava and internal jugular vein for prediction of prolonged hypotension during induction
      of general anesthesia. The study was conducted at Kasr Al-Ainy hospital, Cairo University in
      Patients undergoing elective non-cardiac surgery under general anesthesia.
    

Detailed description: 
      Upon arrival to the operating room, routine monitors in the form of pulse oximetry,
      electrocardiogarm and non-invasive blood pressure monitors were applied. Intravenous line was
      secured and routine premedications (ranitidine 50 mg and ondansetron 4 mg) were administered.

      IVC evaluation was done for the patients in the supine position. The examination was
      performed after 5 minutes rest. A curved ultrasound transducer set to abdominal mode (1-5
      MHz; Acuson x300; Siemens Healthcare, Seoul, Korea) was placed in the subcostal area to
      visualize the IVC in the paramedian long-axis view. The IVC was visualized using
      two-dimensional mode as it enters the right atrium; then, pulse wave doppler was used to
      differentiate the IVC from the aorta. Respiratory variations of the IVC diameter were
      evaluated using M-mode imaging at medium sweep speed 2 to 3 cm distal to the right atrium.
      The measures were obtained 3 times and their average was calculated. Maximum and minimum IVC
      diameters over a single respiratory cycle were used to calculate the collapsibility index as
      follows:

      (dIVCmax- dIVCmin)/dIVCmax Collapsibility index was expressed as a percentage.

      IJV measurements were obtained in the supine position using a linear ultrasound transducer (5
      - 13 MHz; Acuson x300; Siemens Healthcare, Seoul, Korea). The probe was placed horizontally
      at the middle level of the thyroid cartilage. After obtaining a clear transverse view of the
      right IJV, the IJV area was measured. The measures were repeated after changing the patient's
      position to the 10° Trendelenburg position. The maximum area of the IJV in the supine and
      Trendelenburg positions was recorded and the rate of change in IJV area was calculated as
      follows:

      IJV change rate with posture = (IJV area in Trendelenburg position - IJV area in supine
      position)/(IJV area in Trendelenburg position) All ultrasonographic measurements were
      performed by a single trained anesthesiologist.

      IJV measurements were obtained in the supine position using a linear ultrasound transducer (5
      - 13 MHz; Acuson x300; Siemens Healthcare, Seoul, Korea). The probe was placed horizontally
      at the middle level of the thyroid cartilage. After obtaining a clear transverse view of the
      right IJV, the IJV area was measured. The measures were repeated after changing the patient's
      position to the 10° Trendelenburg position. The maximum area of the IJV in the supine and
      Trendelenburg positions was recorded and the rate of change in IJV area was calculated as
      follows:

      IJV change rate with posture = (IJV area in Trendelenburg position - IJV area in supine
      position)/(IJV area in Trendelenburg position) All ultrasonographic measurements were
      performed by a single trained anesthesiologist.
    

Intervention name(s): Ultrasound-based measurements of IVC & IJV.
Intervention type(s): Other
Intervention description(s): Ultrasound-based measurements of IVC & IJV.
Observational model: Case-Only
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Patients undergoing elective non-cardiac surgery under general anesthesia in Kasr Al-Ainy
        hospital.