NUR 254 Shock 2
- Shock Definition
Answer A SYNDROME resulting from
- a decrease in blood flow ’ inadequate oxygenation ’ ischemic organs/tissues ’
life-threatening cellular dysfunction
**Manifestations of shock result from the body's attempts to maintain vital organs (heart and brain)**
- Shock Overview
Answer *Cellular metabolism requires O2 in and waste to be removed out.
*Key concepts when evaluating shock (think plumbing)
- Cardiac Output (heart pump)
- O2 Delivery is maintained by blood vessels and their diameter/tone & blood volume
- Tissues need to be able to extract & use O2
*If anyone of these are disrupted ---- > SHOCK*
*Sufficient Cardiac Output is Required*
- Overview of Hemodynamic Monitoring
Answer Stroke Volume (SV) 1 / 4
Cardiac Output (CO)
- (CO = SV X HR)
Mean Arterial Pressure (MAP)
- (2 x DBP + SBP divided by 3)
Systemic Vascular Resistance (SVR) Central Venous Pressure (CVP)
- Cardiac Output Overview
Answer *What are determinants of Stroke Volume? (Preload, Afterload, Contractility)
- Oxygen Delivery (DO2)
Answer Amount of O2 delivered to tissues.
Assessed by evaluating cardiac output and arterial O2 content.
- Oxygen Consumption (VO2)
Answer Reflects the amount of O2 extracted from blood at the tissue level.
- MixedVenous O2 Saturation (SVO2)
Answer The amount of oxygenated blood returned to the right side of the heart.
Normal SVO2 levels are 60-80%, measured via a pulmonary artery catheter (Swan-Ganz).When this level falls below normal, tissues are extracting more oxygen than normal.
Falls when supply is less than the demand or use, resulting from decreased oxygen delivery (DO2) and is an indicator of how much oxygen debt is present.
**The longer there is an imbalance between oxygen supply and demand, the larger the oxygen debt becomes.** 2 / 4
- The nurse understands that which of the following increases as the delivery of oxygen (DO2)
to the tissues falls below the tissue's requirements (select all that apply)
- VO2 (oxygen consumption)
- Oxygen Debt
- SVO2 (mixed venous O2 sat)
- PaO2
- Preload
Answer A & B
Shock = O2 demand (VO2) > supply (DO2)
SVO2 (how much oxygenated blood returns to heart would decrease as would PaO2).Decreased preload is a cause of decreased DO2.Oxygen consumption (VO2 would increase to meet the needs because oxygen delivery is less).Result is increased oxygen debt.
- Mike Adams is admitted to ED c/o SOB. Hx
Answer HTN & well-controlledType 2 DM. VS
T-101.9°F (38.8°C), P-120 bpm, 90% RA, RR- 20, BP- 90/54 mm Hg. CXR=
Pneumonia. A&OX4.dizziness w/ changing positions. Orders are
- IV 0.9% normal saline @125 mL/hr. 3 / 4
- Labs
CBC, BMP, blood cultures
- O2 @ 2 L/min via nasal cannula
- cefotaxime 2 g IV q8h
In what order would you perform these interventions? How are blood cultures drawn?
Is the oxygen order typical of what you have seen in clinical?In what order would you perform the interventions?
- Apply oxygen
- IV start with labs drawn
- then Normal saline and Cefotaxime
How are blood cultures drawn?
- Two different sites
- chlorhexidine wiped on vials and site
- timed drying
- anaerobic and aerobic culture bottles.
- Facility dependent.
Is the oxygen order typical of what you have seen in clinical?
- Yes and No, parameters are needed, and we need an order for continuous SPO2 monitoring,
most likely would need more than 2 liters
- Stages of Shock
Four (4) Stages
Answer
- Initial
- Compensatory
- Progressive
- Refractory
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