Session 10: hemodynamic monitoring in shock
MAP: mean arterial pressure (average of systolic and diastolic BP)
- We want it above 65 mmHg
Systolic BP: want this to be above 90 mmHg in most cases for adequate perfusion
- SBP -DBP: greater than 40 is vasodilation. Less than 40 is vasoconstriction.
- In septic shock there is vasodilation
- In cardiogenic shock there will be vasoconstriction.
CVP – central venous pressure. Venous central line that measures end vena cava pressure.
ABP – Arterial blood pressure. Catheter inserted into the radial or femoral arteries usually. The tubing is pressurized to overcome the arterial blood pressure. To get an accurate reading the fixture that measures the pressure must be level with the patient.
Changes in venous O2 or Arterial O2 (SvO2 vs ScvO2)
- Increased O2 delivery from: increased SaO2, Increased HGB, Increased cardiac output
- Decreased O2 consumption: decreased need(hypothermia), access(vasoconstriction), and capability(tissue death)
- Decreased O2 delivery: decreased O2 sat, decreased HGB, decreased CO
|Cardiogenic||up||down (Low PP)||Up w/ crackles||down||down|
|Hypovolemic||up||down (Low PP)||Up then D||down||down|
|Neurogenic||down||down (high PP)||dysfunction||dysfunction||Normal to high|
|Anaphylactic||up||down (high PP)||up||incontinence||Normal to high|
|Septic||up||down (high PP)||up||Down (none)||Down, increased late|
|obstructive||up||down (Low PP)||up||down||Normal to down|
Cardiogenic shock: pump issue
- Decreased stroke volume, decreased stroke volume
- Causes MI, arrhythmias,
- s/s: tachypnea, crackles, anxiety,
Hypovolemia: decreased fluid volume
- absolute hypovolemia: hemorrhage, DI, Diuretics
- Relative hypovolemia: fluid moving out of the vasculature into extra vasculature. Burns and liver failure.
- Increased HR, CO, RR
- Decreased: SV, CVP, PAP (pulmonary arterial pressure)
- The body can compensate for about a 15% volume deficit
Distributive: poor distribution of circulating blood.
- Neurogenic shock:
- T6 or above trauma
- Hypotension, bradycardia, vasodilation relative hypovolemia,
- Anaphylactic reaction
- Profound vasodilation, capillary permeability, edema, leading to bronchospasm
- Angioedema(facial swelling), hives
obstructive: physical blockage to flow.
- Cardiac tamponade
- Pulmonary embolism