Heparin-induced thrombocytopenia - Revision history

Danbot: Strip excess bold

2026-03-22T09:34:50Z

Strip excess bold

← Older revision		Revision as of 09:34, 22 March 2026
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	[[File:PMC3555208 hr-2012-4-e20-g002.png\|thumb\|Lower extremity gangrene secondary to both arterial and venous thrombosis.]]		[[File:PMC3555208 hr-2012-4-e20-g002.png\|thumb\|Lower extremity gangrene secondary to both arterial and venous thrombosis.]]
	*The 4 T's: (formal scoring system below)		*The 4 T's: (formal scoring system below)
	**[[Thrombocytopenia\|~~'''T'''hrombocytopenia~~]]		**[[Thrombocytopenia\|Thrombocytopenia]]
	**~~'''T'''iming~~ (5-14d)		**Timing (5-14d)
	**[[thromboembolism\|~~'''T'''hrombosis~~]]		**[[thromboembolism\|Thrombosis]]
	**No ~~o'''T'''her~~ cause		**No oTher cause

	===Immediate Symptoms===		===Immediate Symptoms===
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	==Management==		==Management==
	*Discontinue all [[heparin]] products <ref>Cuker A, Arepally GM, Chong BH, Cines DB, Greinacher A, Gruel Y, Linkins LA, Rodner SB, Selleng S, Warkentin TE, Wex A, Mustafa RA, Morgan RL, Santesso N. American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia. Blood Adv. 2018 Nov 27;2(22):3360-3392. doi: 10.1182/bloodadvances.2018024489. PMID: 30482768; PMCID: PMC6258919.</ref>		*Discontinue all [[heparin]] products <ref>Cuker A, Arepally GM, Chong BH, Cines DB, Greinacher A, Gruel Y, Linkins LA, Rodner SB, Selleng S, Warkentin TE, Wex A, Mustafa RA, Morgan RL, Santesso N. American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia. Blood Adv. 2018 Nov 27;2(22):3360-3392. doi: 10.1182/bloodadvances.2018024489. PMID: 30482768; PMCID: PMC6258919.</ref>
	*Do ~~'''~~not~~'''~~ give [[platelets]] (may precipitate thrombosis)		*Do not give [[platelets]] (may precipitate thrombosis)
	*Start anticoagulation with no heparin based compound such as a direct thrombin inhibitor: [lepirudin (unless renal failure), [[argatroban]] (unless hepatobiliary disease), [[bivalirudin]]] or direct Xa inhibitor ([[fondaparinux]], danaparoid)		*Start anticoagulation with no heparin based compound such as a direct thrombin inhibitor: [lepirudin (unless renal failure), [[argatroban]] (unless hepatobiliary disease), [[bivalirudin]]] or direct Xa inhibitor ([[fondaparinux]], danaparoid)
	**4T Score ≥4 with/without thrombosis and average bleeding risk should receive ~~'''~~therapeutic~~'''~~ dose		**4T Score ≥4 with/without thrombosis and average bleeding risk should receive therapeutic dose
	**4T Score ≥4 with/without thrombosis and high bleeding risk should receive ~~'''~~prophylactic~~'''~~ dose		**4T Score ≥4 with/without thrombosis and high bleeding risk should receive prophylactic dose
	*''Avoid [[warfarin]] until platelets >100K-150K''		*''Avoid [[warfarin]] until platelets >100K-150K''
	**Those already on warfarin should receive vitamin K to restore protein C & S levels		**Those already on warfarin should receive vitamin K to restore protein C & S levels

Danbot: Add HIT_4Ts_Calculator to page

2026-03-21T16:32:13Z

Add HIT_4Ts_Calculator to page

← Older revision		Revision as of 16:32, 21 March 2026
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	==Disposition==		==Disposition==
	*Admit (with hematology consult)		*Admit (with hematology consult)

			== Calculators ==
			{{HIT_4Ts_Calculator}}

	==See Also==		==See Also==

Rossdonaldson1: /* Clinical Features */

2023-06-07T21:34:22Z

Clinical Features

← Older revision		Revision as of 21:34, 7 June 2023
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	[[File:PMC1865550 1752-1947-1-13-1.png\|thumb\|Gangrenous right hand and left foot in a patient with antibody-confirmed HIT.]]		[[File:PMC1865550 1752-1947-1-13-1.png\|thumb\|Gangrenous right hand and left foot in a patient with antibody-confirmed HIT.]]
	[[File:PMC4763479 cvja-26-e13-g003.png\|thumb\|Ischaemic changes in the right hand (A), right foot (B), and left food (C) from HIT.]]		[[File:PMC4763479 cvja-26-e13-g003.png\|thumb\|Ischaemic changes in the right hand (A), right foot (B), and left food (C) from HIT.]]
			[[File:PMC3555208 hr-2012-4-e20-g002.png\|thumb\|Lower extremity gangrene secondary to both arterial and venous thrombosis.]]
	*The 4 T's: (formal scoring system below)		*The 4 T's: (formal scoring system below)
	**[[Thrombocytopenia\|'''T'''hrombocytopenia]]		**[[Thrombocytopenia\|'''T'''hrombocytopenia]]

Rossdonaldson1: /* Clinical Features */

2023-06-07T21:31:07Z

Clinical Features

← Older revision		Revision as of 21:31, 7 June 2023
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	==Clinical Features==		==Clinical Features==
	[[File:PMC1865550 1752-1947-1-13-1.png\|thumb\|Gangrenous right hand and left foot in a patient with antibody-confirmed HIT.]]		[[File:PMC1865550 1752-1947-1-13-1.png\|thumb\|Gangrenous right hand and left foot in a patient with antibody-confirmed HIT.]]
			[[File:PMC4763479 cvja-26-e13-g003.png\|thumb\|Ischaemic changes in the right hand (A), right foot (B), and left food (C) from HIT.]]
	*The 4 T's: (formal scoring system below)		*The 4 T's: (formal scoring system below)
	**[[Thrombocytopenia\|'''T'''hrombocytopenia]]		**[[Thrombocytopenia\|'''T'''hrombocytopenia]]

Rossdonaldson1: /* Clinical Features */

2023-06-07T21:26:39Z

Clinical Features

← Older revision		Revision as of 21:26, 7 June 2023
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	==Clinical Features==		==Clinical Features==
			[[File:PMC1865550 1752-1947-1-13-1.png\|thumb\|Gangrenous right hand and left foot in a patient with antibody-confirmed HIT.]]
	*The 4 T's: (formal scoring system below)		*The 4 T's: (formal scoring system below)
	**[[Thrombocytopenia\|'''T'''hrombocytopenia]]		**[[Thrombocytopenia\|'''T'''hrombocytopenia]]

Rossdonaldson1 at 18:11, 31 May 2023

2023-05-31T18:11:21Z

← Older revision		Revision as of 18:11, 31 May 2023
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	==Differential Diagnosis==		==Differential Diagnosis==
	{{Thrombocytopenia}}		{{Thrombocytopenia}}
			{{Hemolytic anemia DDX}}

	~~{{Hemolytic anemia DDX}}~~		==Evaluation==
			*Serotonin release assay (SRA) = gold standard
			*Anti-PF4 plus SRA has combined sensitivity of 99% <ref>Warkentin TE, et al. Chest. 2008;133(6 Suppl):340S-380S.</ref>
			*Positivity determined by optical density (OD) reported with assay (same concept as a titer)
			**OD <1 = <5% chance of HIT
			**OD 1.4 = 50% chance of HIT
			**OD >2 = 90% chance of HIT

	==Pre-test Probability Scoring (The 4 T Score)<ref>Janz TG, Hamilton GC: Disorders of Hemostasis, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 7. St. Louis, Mosby, Inc., 2010, (Ch) 120: p 1578-1589.</ref>==		===Pre-test Probability Scoring (The 4 T Score)<ref>Janz TG, Hamilton GC: Disorders of Hemostasis, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 7. St. Louis, Mosby, Inc., 2010, (Ch) 120: p 1578-1589.</ref>===
	*Thrombocytopenia		*Thrombocytopenia
	**2 points: platelets > 50% fall AND nadir > 20k		**2 points: platelets > 50% fall AND nadir > 20k
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	**≤3 is low risk and do not require further testing or heparin discontinuation		**≤3 is low risk and do not require further testing or heparin discontinuation
	**≥4 should have serologic testing performed, heparin discontinued, and alternative anticoagulation started		**≥4 should have serologic testing performed, heparin discontinued, and alternative anticoagulation started

	~~==Evaluation==~~
	*Serotonin release assay (SRA) = gold standard
	*Anti-PF4 plus SRA has combined sensitivity of 99% <ref>
	~~Warkentin TE, et al. Chest. 2008;133(6 Suppl):340S-380S.</ref>~~
	*Positivity determined by optical density (OD) reported with assay (same concept as a titer)
	**OD <1 = <5% chance of HIT
	**OD 1.4 = 50% chance of HIT
	**OD >2 = 90% chance of HIT

	==Management==		==Management==

Rossdonaldson1: Rossdonaldson1 moved page Heparin-Induced Thrombocytopenia (HIT) to Heparin-induced thrombocytopenia over redirect

2023-05-31T18:09:01Z

Rossdonaldson1 moved page Heparin-Induced Thrombocytopenia (HIT) to Heparin-induced thrombocytopenia over redirect

← Older revision	Revision as of 18:09, 31 May 2023
(No difference)

Athorne: /* Management */

2023-05-20T14:11:06Z

Management

← Older revision		Revision as of 14:11, 20 May 2023
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	==Management==		==Management==
	*Discontinue all [[heparin]] products		*Discontinue all [[heparin]] products <ref>Cuker A, Arepally GM, Chong BH, Cines DB, Greinacher A, Gruel Y, Linkins LA, Rodner SB, Selleng S, Warkentin TE, Wex A, Mustafa RA, Morgan RL, Santesso N. American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia. Blood Adv. 2018 Nov 27;2(22):3360-3392. doi: 10.1182/bloodadvances.2018024489. PMID: 30482768; PMCID: PMC6258919.</ref>
	*Do '''not''' give [[platelets]] (may precipitate thrombosis)		*Do '''not''' give [[platelets]] (may precipitate thrombosis)
	*Start anticoagulation with no heparin based compound such as a direct thrombin inhibitor: [lepirudin (unless renal failure), [[argatroban]] (unless hepatobiliary disease), [[bivalirudin]]] or direct Xa inhibitor ([[fondaparinux]], danaparoid)		*Start anticoagulation with no heparin based compound such as a direct thrombin inhibitor: [lepirudin (unless renal failure), [[argatroban]] (unless hepatobiliary disease), [[bivalirudin]]] or direct Xa inhibitor ([[fondaparinux]], danaparoid)
			**4T Score ≥4 with/without thrombosis and average bleeding risk should receive '''therapeutic''' dose
			**4T Score ≥4 with/without thrombosis and high bleeding risk should receive '''prophylactic''' dose
	*''Avoid [[warfarin]] until platelets >100K-150K''		*''Avoid [[warfarin]] until platelets >100K-150K''
			**Those already on warfarin should receive vitamin K to restore protein C & S levels

	==Disposition==		==Disposition==

Athorne: /* Pre-test Probability Scoring (The 4 T Score)Janz TG, Hamilton GC: Disorders of Hemostasis, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 7. St. Louis, Mosby, Inc., 2010, (Ch) 120: p 1578-1589. */

2023-05-20T14:07:14Z

Pre-test Probability Scoring (The 4 T Score)Janz TG, Hamilton GC: Disorders of Hemostasis, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 7. St. Louis, Mosby, Inc., 2010, (Ch) 120: p 1578-1589.

← Older revision		Revision as of 14:07, 20 May 2023
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	**1 point: possible		**1 point: possible
	*Scoring		*Scoring
	**~~≤ 3,~~ low ~~probability (≤5%)~~		**≤3 is low risk and do not require further testing or heparin discontinuation
	**~~4-5~~, ~~intermediate prob (~15%)~~		**≥4 should have serologic testing performed, heparin discontinued, and alternative anticoagulation started
	**≥ 6, ~~high prob (~65%)~~

	==Evaluation==		==Evaluation==

Athorne: /* Clinical Features */

2023-05-20T14:05:25Z

Clinical Features

← Older revision		Revision as of 14:05, 20 May 2023
Line 18:		Line 18:

	==Clinical Features==		==Clinical Features==
	*The 4 T ~~Score~~: ~~0-2 points assigned to each~~		*The 4 T's: (formal scoring system below)
	**[[Thrombocytopenia\|'''T'''hrombocytopenia]]		**[[Thrombocytopenia\|'''T'''hrombocytopenia]]
	**'''T'''iming (5-14d)		**'''T'''iming (5-14d)
	**[[thromboembolism\|'''T'''hrombosis]]		**[[thromboembolism\|'''T'''hrombosis]]
	**No o'''T'''her cause		**No o'''T'''her cause
	*≤3 is low risk and do not require further testing or heparin discontinuation
	*≥4 should have serologic testing performed, heparin discontinued, and alternative anticoagulation started

	===Immediate Symptoms===		===Immediate Symptoms===

← Older revision		Revision as of 21:34, 7 June 2023
Line 20:		Line 20:
	[[File:PMC1865550 1752-1947-1-13-1.png\|thumb\|Gangrenous right hand and left foot in a patient with antibody-confirmed HIT.]]		[[File:PMC1865550 1752-1947-1-13-1.png\|thumb\|Gangrenous right hand and left foot in a patient with antibody-confirmed HIT.]]
	[[File:PMC4763479 cvja-26-e13-g003.png\|thumb\|Ischaemic changes in the right hand (A), right foot (B), and left food (C) from HIT.]]		[[File:PMC4763479 cvja-26-e13-g003.png\|thumb\|Ischaemic changes in the right hand (A), right foot (B), and left food (C) from HIT.]]
			[[File:PMC3555208 hr-2012-4-e20-g002.png\|thumb\|Lower extremity gangrene secondary to both arterial and venous thrombosis.]]
	*The 4 T's: (formal scoring system below)		*The 4 T's: (formal scoring system below)
	**[[Thrombocytopenia\|'''T'''hrombocytopenia]]		**[[Thrombocytopenia\|'''T'''hrombocytopenia]]