Hemodynamic monitoring

BEDSIDE HEMODYNAMIC MONITORING

• Indications and evidence for effectiveness– Sepsis – CHF– Peri-op

• Insertion• Complications• Measurement

Bedside Hemodynamic MonitoringOutline

Bedside Hemodynamic MonitoringDefinition

• The use of an indwelling catheter to measure– pulmonary artery pressure– pulmonary capillary wedge pressure– right atrial pressure– pulmonary artery oxygen saturation– thermodilution cardiac output

in the intensive care unit.

• “To help direct management in medical patients in whom hemodynamics will alter treatment and clinical estimates are unreliable”

• “To assist management of surgical patients”• “To establish or assist in establishing specific diagnoses”

– Cardiac vs. non-cardiac pulmonary edema– VSD vs. MR in acute MI– Pericardial tamponade– RV MI

IndicationsSummary of ACP/AHA/ACC Expert Panel

Friesinger et al. JAMA 1990; 15: 1460

• Randomized trial of PAC vs. no PAC– 433 pts hospitalized with CHF and volume overload– In PAC group: goal PCW 15 and RA 8– PAC group had greater wt loss (4.0 vs 3.2 kg) but

similar final BUN/creat– 9 serious adverse events in PAC group (infection,

bleed, catheter knot, VT, pulmonary infarction)

Evidence for EffectivenessDecompensated Heart Failure: ESCAPE trial

ESCAPE Investigators. JAMA 2005; 294: 1625


• For the primary endpoint, there was no difference between intervention and control groups:




• For the secondary endpoints:– No change in exercise

capacity– Change in QoL at 1

month only– Improved patient

assessment of health state (TTO) at 1 & 6 months


Evidence for EffectivenessMedical ICU: PAC-Man trial

• Randomized trial of PAC vs. no PAC– 1041 pts admitted to ICU who attending thought

needed a PAC. 66% medical. 65% multi-organ dysfunction.

– Therapy at the discretion of the clinician– Serious complications occurred in 10% of pts in the

PAC group

Harvey et al. Lancet 2005; 366: 472

• For the primary endpoint, there was no difference between intervention and control groups:

Evidence for EffectivenessMedical ICU: PAC-Man trial

Harvey et al. Lancet 2005; 366: 472

P = 0.381

Evidence for EffectivenessPeri-operative management

ResultNStudy

No differences1994Sandham. 2003

No differences100Bonazzi. 1992

Borderline ↓ mort in PAC group120Valentine. 1998

No differences104Bender. 1997

No differences89Berlauk. 1991

No differences102Isaacson. 1990

↓ mortality in PAC group88Shoemaker. 1988

↓ mortality in PAC group70Schultz. 1985

Evidence for EffectivenessMeta-analysis

Shah et al. JAMA 2005; 294: 1664

Combined OR 1.04 (0.90 – 1.20)

• Quantitative review of 13 RCTs of PAC vs. no PAC in – medical– surgical– cardiac patients

demonstrated nomortality benefit:

PAC better No PAC better

Bedside Hemodynamic MonitoringIndications and Evidence for Effectiveness

• Despite assertions by experts, there is no demonstrated benefit on mortality or length of stay associated with bedside hemodynamicmonitoring

• Its use should be limited to “rescue” situations where all other options have failed, and diagnostic situations where non-invasive options have been inconclusive

… So if you really feel like you absolutely have to use it …

• Choose insertion site to minimize complications– Subclavian vs femoral:

subclavian preferred– Subclavian vs IJ:

not tested; likely IJ has > infection rate and < severe mechanical complications (except arterial puncture)

– Consider brachial in patients with coagulopathy

Bedside Hemodynamic MonitoringInsertion

Complication rates

19.8%17.3%

4.5%

18.8%

Infectious Mechanical

Femoral Subclavian

Taupenot et al. NEJM 2002; 348: 12.Merrer et al. JAMA 2001; 286: 700.

• Other potential complications:– Infection– Thrombosis and thromboembolism– Hemorrhage– Pneumothorax and hemothorax– Nerve injury– Pneumomediastinum– Air embolus– Foreign body embolus– RBBB– Ventricular arrhythmias– Pulmonary infarction– Pulmonary artery rupture– Heparin-induced thrombocytopenia (heparin-bonded catheter)

Bedside Hemodynamic MonitoringInsertion- complications

• Risk factors for complications:– Insertion site– Time taken for insertion– Duration of insertion– Operator experience (>50 vs <50)– Site preparation

• Scheduled insertion changes don’t decrease rates of complications

Bedside Hemodynamic MonitoringInsertion- complications

Bedside Hemodynamic MonitoringWaveform analysis- normal values

68 – 76%Mixed venous O2 saturation

2.2 – 3.6Cardiac index

2-14Pulmonary wedge

25-40 / 10-20Pulmonary artery

40 (sys) / 9 (end diastolic)Right ventricle

0-7 mmHgRight atrium

Bedside Hemodynamic MonitoringWaveform analysis

Right Atrium Pulmonary Artery

Right Ventricle Wedge

Bedside Hemodynamic MonitoringWaveform analysis: Respiratory variation

End-expiratory

Bedside Hemodynamic MonitoringWaveform analysis- diagnosing pathology

“dip & plateau”

Bedside Hemodynamic MonitoringCardiac Output

• Measured by thermodilution:– Inject cool saline or warm the blood in the RA– Measure change in temperature with time in the PA– Integral of T vs. t curve is used to compute CO

• There are many pitfalls in bedside CO measurement; be skeptical when the “number”doesn’t match the clinical data

• Cardiac output is an imperfect indicator of circulatory function

• Useful check on accuracy of cardiac output• Can be used to confirm “wedged” position• Can be used to diagnose (relatively large)

intracardiac shunts

Bedside Hemodynamic MonitoringOxygen saturation

Hemodynamic monitoring

Health & Medicine

Transcript of Hemodynamic monitoring