hemodynamic monitoring

continuous monitoring of the movement of blood and the pressures being exerted in the veins, arteries, and chambers of the heart. Current invasive techniques permit the monitoring of intra-arterial blood pressure, pulmonary artery pressure, left atrial pressure, and central venous pressure. Invasive pressure monitoring requires the insertion of a catheter into an artery (usually the radial, brachial, or femoral artery), vein (the antecubital, jugular, or subclavian vein), or a heart chamber. The swan-ganz catheter is a pulmonary catheter that can permit measurement of pulmonary artery diastolic and systolic pressure, pulmonary-capillary wedge pressure (PCWP), left atrial filling pressure, central venous pressure, and cardiac output.
In all physiologic monitoring systems the catheter is connected to a pressure extension line attached to a transducer in an airtight, solution-filled system. The transducer converts pressure into an electrical signal that is displayed on an oscilloscope or recorder. The amplifier enlarges the signal being produced by the transducer; it contains a digital or analogue meter to indicate pressure, controls for setting alarms, audible and visual alarm systems, and a selector switch for systolic, diastolic, and mean pressures.
Invasive hemodynamic pressure monitoring permits continuous assessment of the status of critically ill patients and their response to ongoing therapy, thus providing information essential for more precise diagnosis and prompt correction of a problem. Measurement of intra-arterial blood pressure is especially helpful in the care of hemodynamically unstable patients, including those receiving potent drugs that affect the vascular system. Pulmonary artery pressure readings are indicated for patients in cardiogenic shock secondary to myocardial infarction, and for monitoring pulmonary congestion due to elevated pulmonary wedge pressure. Central venous pressure measures right-sided heart pressures (in the vena cava and right atrium) to determine the adequacy of central venous return.
The major risks of invasive hemodynamic pressure monitoring are sepsis, bleeding, cardiac arrhythmias, and the formation of thrombi and emboli.

Cardiac pressure waveforms can be visualized on the oscilloscope in hemodynamic monitoring. A, Typical pulmonary artery pressure tracing. B, Typical pulmonary artery wedge pressure tracing. From Ignatavicius and Workman, 2002.

hemodynamic monitoring

Clinical medicine A general term for the ongoing evaluation of hemodynamics

hemodynamic monitoring

(hē″mō-dī-năm′ĭk) A general term for determining the functional status of the cardiovascular system as it responds to acute stress such as myocardial infarction and cardiogenic or septic shock. This may include frequent assessments of blood pressure, pulse, mental status, urinary output, intracardiac pressure changes, and cardiac output. The data obtained permit the critical care team to follow the patient's course closely. See: table

Parameter	Formula	Normal Values
cardiac index (CI)	cardiac output/body surface area	2.5-4 L/min
cardiac output (CO)	heart rate x stroke volume	4-8 L/min
central venous pressure (CVP)		2-8 mm Hg
cerebral perfusion pressure (CPP)	mean arterial pressure − intracranial pressure	80-100 mm Hg
ejection fraction (EF)	(ventricular end systolic volume/end diastolic volume) x 100	55-70%
heart rate (HR)		60-100 beats/min
left atrial pressure		8-12 mm Hg
mean arterial pressure (MAP)	systolic blood pressure + (diastolic blood pressure x 2)/3	70-110 mm Hg
pulmonary artery pressure (PAP)		systolic: 15-30 mm Hg; diastolic: 5-12 mm Hg
pulmonary artery wedge pressure (PAWP)		8-12 mm Hg
right atrial pressure		2-8 mm Hg
stroke volume (SV)	(cardiac output/heart rate) x 1000	60-120 ml/beat
systemic vascular resistance (SVR)	[(mean arterial pressure − right atrial pressure)/cardiac output] x 100	800-1200 dynes/sec/cm²
urinary output (UO)		> 0.5 ml/hr/kg