THROMBOLYTIC THERAPY IN CRITICAL CARE NURSING

OVERVIEW

Thrombolytic therapy, also known as fibrinolytic therapy, is a cornerstone intervention in critical care for the rapid dissolution of intravascular thrombi. These agents restore perfusion to ischemic tissues and organs in time-sensitive, life-threatening conditions such as acute myocardial infarction (STEMI), ischemic stroke, and massive pulmonary embolism.

            In critical care nursing, thrombolytic therapy demands precise assessment, vigilant monitoring, and rapid recognition of complications, especially hemorrhage.

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 DEFINITION      Thrombolytic therapy refers to the administration of pharmacological agents that activate the fibrinolytic system, leading to the breakdown of fibrin clots and restoration of blood flow.

 PHYSIOLOGY OF COAGULATION AND FIBRINOLYSIS

Coagulation	Fibrinolysis
Formation of a fibrin clot to stop bleeding	Breakdown of fibrin clot after healing
Involves thrombin and fibrin	Involves plasmin
Protective mechanism	Regulatory mechanism

§  MECHANISM OF ACTION

Normal Fibrinolytic Pathway

1. Plasminogen, an inactive plasma protein, is incorporated into the fibrin clot
2. Endogenous tissue plasminogen activator (tPA) converts plasminogen → plasmin
3. Plasmin degrades fibrin into fibrin degradation products (FDPs)

Thrombolytic agents enhance or mimic endogenous tPA, leading to accelerated clot dissolution.

Step-by-Step Action:

1. Drug binds to fibrin or circulating plasminogen
2. Conversion of plasminogen to plasmin
3. Plasmin breaks fibrin meshwork
4. Thrombus dissolves
5. Blood flow is restored

⚠ Because plasmin also degrades fibrinogen and clotting factors, systemic bleeding risk increases.

CLASSIFICATION OF THROMBOLYTICS:

Table : Classification of Thrombolytic Drugs

Class	Drugs	Characteristics
1st Generation	Streptokinase, Urokinase	Non-fibrin specific, higher bleeding risk
2nd Generation	Alteplase (tPA)	Fibrin-specific, shorter half-life
3rd Generation	Reteplase, Tenecteplase	Longer half-life, greater fibrin specificity

 

Table : Comparison of Common Agents

Drug	Source	Fibrin Specificity	Half-life
Streptokinase	Bacterial protein	No	30–80 min
Alteplase	Recombinant tPA	Yes	4–6 min
Tenecteplase	Modified tPA	High	20–24 min

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§  INDICATION

ü  Acute ST-elevation myocardial infarction (STEMI)

ü  Acute ischemic stroke (within therapeutic window)

ü  Massive pulmonary embolism with hemodynamic instability

ü  Selected cases of:

v  Extensive DVT

v  Thrombosed vascular access device

§  CONTRAINDICATION

Absolute:

ü  Active internal bleeding

ü  History of intracranial haemorrhage

ü  Recent major surgery or head trauma

ü  Known bleeding disorders

ü  Uncontrolled severe hypertension

Relative: Pregnancy, Peptic ulcer disease, Recent invasive procedures

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§  NURSING MANAGEMENT

Pre-Therapy

ü  Confirm time of symptom onset

ü  Baseline neurological and cardiovascular assessment

ü  Obtain coagulation profile

(PT, aPTT, INR)

ü  Establish IV access (minimum punctures) & explain procedure and obtain consent

Intra-Therapy

ü  Continuous ECG monitoring

ü  Vital signs every 15 minutes initially & Maintain bed rest.

ü  Strict bleeding surveillance (gums, urine, stool, IV sites)

ü  (NCLEX TIP) Must Avoid:

1.      IM injections

            2. Unnecessary catheterisation

Post-Therapy

ü  Frequent neurological assessment (stroke patients)

ü  Monitor laboratory values

ü  Maintain hemodynamic stability

ü  Prepare for adjunct therapy (antiplatelets, anticoagulants)

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§  MANAGEMENT OF BLEEDING

EMERGENCY CARE FOCUSED

• Stop thrombolytic infusion immediately
• Inform the physician and ICU team
• Maintain airway and oxygenation
• Monitor hemo-dynamics
• Prepare for blood products or reversal agents

 

§  ROLE OF CRITICAL CARE NURSE

• Early recognition of complications
• Accurate documentation
• Patient and family education
• Coordination of multidisciplinary care

§  COMPLICATIONS

Complication	Nursing Significance
Hemorrhage	Most common and life-threatening
Intracranial bleeding	Sudden neurological deterioration
Hypotension	Especially with streptokinase
Reperfusion arrhythmias	Seen after MI
Allergic reactions	Common with streptokinase

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§  CONCLUSION

Thrombolytic therapy is a time-dependent, high-risk, high-benefit intervention. Advanced nursing knowledge and vigilance are essential to maximise therapeutic outcomes while minimising complications in critically ill patients.

§  BIBLIOGRAPHY

1. Hinkle JL, Cheever KH. Brunner & Suddarth’s Textbook of Medical-Surgical Nursing. 14th ed. Philadelphia: Wolters Kluwer; 2018.
• Volume 1, Chapter: Cardiovascular Disorders, pp. 760–772
2. Lewis SL, Bucher L, Heitkemper MM, Harding M. Medical-Surgical Nursing: Assessment and Management of Clinical Problems. 11th ed. Elsevier; 2020.
• Chapter 35: Acute Coronary Syndromes, pp. 748–756

§  JOURNAL REFERENCE

3. Ibanez B, et al. 2017 ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation. European Heart Journal. 2018;39(2):119–177.