Haemodynamic Stability and Instability

Flashcards reviewing key concepts related to hemodynamic stability and instability, including definitions, parameters to monitor, underlying pathophysiology, pharmacological interventions, and management approaches.

Haemodynamics

The study of blood flow and pressures within the cardiovascular system.

Stable patient indicators

Normal heart rate (HR), blood pressure (BP), cardiac output (CO), and adequate tissue perfusion and oxygenation.

Key Parameters to Monitor for Haemodynamic Stability

Heart Rate, Blood Pressure (Systolic/Diastolic/Mean Arterial Pressure), Central Venous Pressure (if central line present), Oxygen Saturation, Capillary refill time, urine output

Preload

Volume of blood returning to the heart

Afterload

Resistance the heart must pump against

Contractility

Strength of heart muscle contraction

Fluids (Crystalloids, colloids)

Restore circulating volume (↑ preload)

Vasopressors (Noradrenaline, phenylephrine)

↑ SVR and BP (vasoconstriction)

Inotropes (Dobutamine, adrenaline)

↑ myocardial contractility

Chronotropes (Atropine, adrenaline)

↑ heart rate

Antiarrhythmics (Amiodarone, lignocaine)

Correct dysrhythmias

Anaesthetic agents (Propofol, volatile agents)

May ↓ BP (monitor carefully)

Signs & Symptoms of Haemodynamic Instability

Hypotension (MAP < 65 mmHg), Tachycardia or bradycardia, Poor perfusion: cold, clammy skin, ↓ urine output, ↓ LOC, ECG changes, Low SpO₂ despite oxygen therapy

Hypovolaemia Examples

Bleeding, dehydration

Cardiogenic Examples

MI, arrhythmias, heart failure

Distributive Examples

Sepsis, anaphylaxis

Obstructive Examples

Pulmonary embolism, cardiac tamponade

Airway & Breathing Management for Haemodynamic Instability

Oxygen therapy, secure airway if needed

Circulation Management for Haemodynamic Instability

Rapid IV fluids for hypovolaemia, Vasopressors/inotropes for shock, Control bleeding if present, Cardiac monitoring and rhythm management, Blood products if haemorrhaging

Pharmacology for Hypovolaemia

IV fluids → blood products → vasopressors if needed

Pharmacology for Cardiogenic Shock

Inotropes (dobutamine), antiarrhythmics, vasodilators (with caution)

Pharmacology for Septic Shock

Fluids + vasopressors (noradrenaline), antibiotics

Pharmacology for Anaphylaxis

Adrenaline, antihistamines, corticosteroids