2026Shock States and Hemodynamics

Dr. Jennifer Coates, Spring 2026
With thanks to Dr. Beth Tomaszewski
DREXEL UNIVERSITY
College of Nursing and Health Professions

Perioperative: Monitoring is essential during surgical procedures to assess hemodynamic stability.
Instability: Patients demonstrating unstable vital signs may require closer monitoring.
Shock: Patients in shock need immediate and continuous assessment of hemodynamics for proper management.

Usage: Arterial lines are crucial in continuous blood pressure monitoring and can utilize angiocaths in emergency situations.
Overwire Kits: Preferred to minimize the chance of vascular injury during insertion.
CVC Kit: A single-lumen Central Venous Catheter (CVC) can be used for femoral arterial access; smaller gauge sizes are recommended.
Suturing: Once placed, arterial lines must be sutured into position to secure them.

Anacrotic Limb: Initial rise in the waveform corresponding to ventricular contraction.
Peak Systolic Pressure: The highest pressure during heart contraction.
Systolic Decline: The gradual decrease in pressure following the systolic peak.
Dicrotic Notch: Indicative of aortic valve closure.
Systolic Uptake: Reflects the intravascular pressure dynamics during the cardiac cycle.

120 mmHg: Systolic pressure
80 mmHg: Diastolic pressure
MAP (Mean Arterial Pressure): Derived from the area under the curve reflecting overall perfusion pressure; calculated as:
$ext{MAP} ext{(mean arterial pressure)} <br /> ightarrow ext{Area under the curve}$

There is a delay of 180 msec between the R wave on an ECG and the upstroke of the arterial waveform, representing the delay between ventricular depolarization and the signal at the pressure transducer.

The further an arterial line is placed from the aorta, the impact on recorded pressures is evident:
  - Taller Systolic Peaks: Corresponding to higher systolic pressures.
  - Dicrotic Notch Position: Distant placements see the dicrotic notch move further down.
  - End-Diastolic Pressure Decrease: As you move away from the aorta, end-diastolic pressures tend to drop.
  - Delayed Pulse Arrival: For instance, about 60 msec delay may be observed in the radial artery readings.

Dampened Waveform: Underestimates Systolic Blood Pressure (SBP).
Whipped Waveform: May indicate an SBP increase of 15-30 mmHg due to artifact.

Components include:
  - Pressure Bag: Maintains consistent pressure in the system.
  - Pressure Transducer with Automatic Flushing System: Ensures continuous flow of saline to prevent clotting in the line.
  - Arterial Line: Must consist of non-compressible saline-filled tubing.

Bleeding: Risk exists during line insertion and maintenance.
Infection: Sterile technique is crucial to avoid line-associated infections.
Arterial Laceration: Care must be taken, particularly when changing the direction of the introducer.
Venous Thromboembolism (VTE): Can arise from injury or immobility.
Brachial Artery Note: It is important to remember that the brachial artery has no collateral circulation.

Types: CVCs can have single, double, triple, or quadruple lumens and may include power ports.
Placement: Preferred placement sites include
  - Internal Jugular (IJ): Under ultrasound guidance; left over right for renal patients.
  - Subclavian (SC): Preferred unless coagulopathic or with pulmonary pathology.
  - Femoral (Right over Left): Used when necessary.

Atrial Fibrillation: May present with no a wave.
Tricuspid Stenosis: Will show a larger a wave.
Tricuspid Regurgitation: Characterized by Cannon v waves.
Impaired Ventricular Compliance/Pulmonary Hypertension/Pulmonary Embolism: Also may show Cannon v waves.
Mitral Regurgitation: Leads to larger v waves.
m or w Formation: Indicates decreased right ventricular compliance, with residual fluid left behind impacting fluid dynamics.

Components:
- Balloon Port : Used during placement and to monitor wedge pressures.
- Thermistor Port : Tracks changes in blood temperature, useful in metric calculations.

Requires insertion of the introducer (Cordis), testing the balloon, threading the Swan Ganz catheter, and inflating the balloon to achieve the wedge position in the pulmonary artery.
Observing changes in waveforms throughout insertion is critical.

Right Atrial Pressure (RAP): Normal range typically observed at about 0-5 mm Hg.
Right Ventricular Pressure (RVP): Normal values are 20-30 mm Hg for systolic and rise upwards to 5 mm Hg for diastolic measurements.
Pulmonary Artery Pressure: Systolic pressures normal at 20-30 mm Hg and diastolic measures at 10-20 mm Hg.
Pulmonary Capillary Wedge Pressure (PCWP): Normal averages are between 4-12 mm Hg.

Arrhythmias, poor flow, balloon rupture, pulmonary artery rupture, knots, thrombus formation, and risks of pulmonary infarct.

Aortic Stenosis: Often results in large a waves due to elevated pressures.
Aortic Regurgitation: May present with no dicrotic notch and increased RAP and PAP in addition to PCWP.
Mitral Valve Stenosis: Characterized by larger v waves.
Mechanical Ventilation: PCWP measures should be taken at end expiration during ventilatory cycles (vent measures occur at the valley of the waveform).

Definition: Shock refers to a state of ineffective tissue perfusion characterized by an absolute or relative decrease in systemic oxygen delivery due to either low cardiac output (CO) or low blood oxygen content, coupled with impaired utilization of the delivered oxygen.

Effective management focuses on restoring adequate tissue perfusion to prevent end-organ damage due to hypoxia and subsequent anaerobic metabolism.

Heart Rate (HR): 60-80 bpm
Central Venous Pressure (CVP): 2-6 mm Hg
Systemic Vascular Resistance (SVR): 800-1600 dyn sec
Pulmonary Vascular Resistance (PVR): 60-100 dyn sec
Pulmonary Artery Systolic (PAS): 20-30 mm Hg
Pulmonary Artery Diastolic (PAD): 8-15 mm Hg
Pulmonary Capillary Wedge Pressure (PCWP): 6-12 mm Hg
Stroke Volume (SV): 55-100 ml
Cardiac Output (CO): 4-7 L/min
Cardiac Index (CI): 2.5-4 L/min/m2
Mixed Venous Oxygenation (SVO2): 70-75%

Source: Manual of CCN, Swearingen & Keen