Table 1.
Technologies Available for Hemodynamic Monitoring in COVID-19 Patients
| Monitoring Device | Measurement Method | Parameters | Major Advantages | Major Disadvantages |
|---|---|---|---|---|
| PAC | Thermodilution | Measurements: right atrial and ventricular pressures, PAP, PCWP, SvO2 (continuously with specialized PACs) Calculations: CO, SVR, PVR, RVEF |
Provides numerous variables to gauge volume status and cardiac function; minimizes expenditure of hospital resources; reliable in ARDS management | High PEEP could lead to overestimation of LV volume by increasing PADP; invasive monitor with risk of PA perforation; equivocal effectiveness in altering clinical outcomes |
| PiCCO | TPTD, pulse wave analysis | CO, SV, SVV, PPV Volumetric assessments: GEDV, EVLW, PVPI |
Continuous, accurate CO relative to PAC; provides volumetric measures of preload (GEDV) and pulmonary edema (EVLW, PVPI); associated with favorable ARDS outcomes | Invasive monitor that requires CVC and arterial catheter* |
| LiDCO | Transpulmonary lithium dye dilution, pulse wave analysis | CO, SV, SVV, PPV | Continuous, accurate CO relative to PAC; requires arterial catheter without the need for CVC | Unreliable with use of muscle relaxants; not yet examined in ARDS management* |
| FloTrac | Pulse wave analysis | CO, SV, SVV, PPV | Easy-to-use, operator-independent system | Accuracy of CO remains equivocal, especially in the setting of low SVR; SVV is poorly predictive of volume responsiveness* |
| NICOM | Thoracic bioreactance | CO, SV, SVV | Continuous, accurate CO that correlates with fluid responsiveness, irrespective of hemodynamic instability or arrhythmias; noninvasive device that uses electrodes | Not yet examined in ARDS management |
| Esophageal Doppler | Doppler ultrasound in the esophagus at 45° relative to the descending aorta | CO, SV | Accurate assessment of CO and fluid responsiveness; provides invaluable information about preload, afterload, and contractility | Expertise required because improper positioning of the esophageal probe can underestimate CO |
| Echocardiography (transthoracic, transesophageal) | 2D and 3D imaging; pulsed wave Doppler | CO; dynamic parameters of volume responsiveness, ie, respiratory variations in venocaval size, as well as changes in ventricular size, LVOT, VTI, and LV filling pressure | Detects numerous pathophysiological states, such as wall motion abnormalities, LV diastolic dysfunction, and pericardial effusions | No continuous monitoring; expertise required |
Abbreviations: CO, cardiac output; CVC, central venous catheter; EVLW, extravascular lung water; GEDV, global end-diastolic volume; LiDCO, lithium dilution cardiac output; LV, left ventricle; LVOT, left ventricular outflow tract; NICOM, noninvasive cardiac output monitoring; PAC, pulmonary artery catheter; PADP, pulmonary artery diastolic pressure; PAP, pulmonary arterial pressure; PCWP, pulmonary capillary wedge pressure; PEEP, positive end-expiratory pressure; PiCCO, pulse index contour cardiac output; PPV, pulse pressure variation; PVPI, pulmonary vascular permeability index; PVR, pulmonary vascular resistance; RVEF, right ventricular ejection fraction; SvO2, mixed venous oxygen saturation; SV, stroke volume; SVV, stroke volume variation; SVR, systemic vascular resistance; TPTD, transpulmonary thermodilution; VTI, velocity-time integral.
Pulse contour analysis may be less accurate in the setting of arrhythmias, valve pathology, intracardiac shunts, and extracorporeal circulation.