Monthly Archives: May 2015
What is a “spot sign”?
- presence of contrast extravasation into an intracerebral hematoma at the time of CTA
- SIGNIFICANCE: indicates active hemorrhage
- IMPLICATION: associated with increased risk of hematoma expansion and mortality
Note: increase of hematoma volume >33% or >12.5 mL is considered a hematoma expansion [but varies among studies].
Early vs Delayed Spot Sign:
- Early spot sign
- detected by first-pass CTA
- acquired within 30 seconds after contrast injection [arterial phase]
- Delayed spot sign
- detected by second-pass CTA or post-contrast CT or CTP
- performed between 40 seconds to 3 minutes after contrast injection and assess spot sign during venous phase
- may help detect spot sign with increased time interval during which contrast is circulating and permating into the hematoma
CRITERIA FOR SPOT SIGN
Spot sign can be defined according to this criteria:
- serpiginous or spot-like appearance within the margin of a parenchymal hematoma without connection to an outside vessel
- contrast density >1.5 mm in diameter
- contrast density (Hounsfield units, HU) >2x background hematoma
- no hyperdensity at the corresponding location on non-contrast CT
Another criteria is listed in the Table below:
The Spot Sign Score can be calculated as follows:
A. mRS by 3-month follow up by spot sign score:
B. In-hospital mortality and overall outcome by spot sign score
PREDICT STUDY [Predicting Hematoma Growth and Outcome in ICH Using Contrast Bolus CT] for spot-positive patients, sensitivity for expansion was only 51%. Are there other radiologic clues to risk of hematoma expansion in ICH? (1) margin irregularity, (2) density heterogeneity, (3) fluid levels
- Fluid-blood levels (or blood sedimentation level) observed in anticoagulant-associated ICH
- shape and density variation of the hematoma [irregular margins / heterogeneous density associated with expansion]
LIMITING HEMATOMA EXPANSION:
- Mechanism of hematoma expansion is unclear:
- dysregulation of hemostasis via inflammatory cascade activation and matrix metalloproteinase overexpreesion
- breakdown of BBB
- sudden increase in ICP leading to local tissue distortion and disruption
- vasculr engorgement due to reduced venous outflow
Can hematoma expansion be restricted?
- few clinical trials on restricting hematoma expansion
- hemostatic therapy
- cautious lowering of high BP
- INTERACT [Intensive BP Reduction in Acute ICH Trial] and ATACH [Antihypertensive Treatment of Acute ICH] trials: SBP reduction might restrict hematoma expansion in hyperactue phase
- quick reversal of prior anticoagulation
- use of rFVIIa limits hematoma expansion in non-coagulopathic ICH but there was an increase in thromboembolic risk with no clear clinical benefit in unselected patients
- surgical evacuation
- many clinical trials have failed to show an outcome benefit of surgery over conservative treatment
- STICH: no overall benefit of early surgical clot evacuation, although subgroup analysis show potential benefit in lobar ICH within 1 cm of cortical surface
- AHA/ASA indications for surgical intervention:
- for most patients with ICH, the usefulness of surgery is uncertain
- cerebellar hemorrhage who are deteriorating neurologically or who have brainstem compression and/ or hydrocephalus from ventricular obstruction should undergo surgical removal of the hemorrhage as soon as possible
- lobar clots >30 mL and within 1 cm of the surface, evacuation of supratentorial ICH by standard craniotomy might be considered
- effectiveness of minimally invasive clot evacuation utilizing either stereotactic or endoscopic aspiration with or without thrombolytic usage is uncertain and is considered investigational
Blacquiere, Dylan et al. “Intracerebral Hematoma Morphologic Appearance On Noncontrast Computed Tomography Predicts Significant Hematoma Expansion”. Stroke 46.11 (2015): 3111-3116. Web.
Delgado Almandoz, J. E. et al. “The Spot Sign Score In Primary Intracerebral Hemorrhage Identifies Patients At Highest Risk Of In-Hospital Mortality And Poor Outcome Among Survivors”. Stroke41.1 (2009): 54-60. Web.
Du, Fei-Zhou et al. “The Accuracy Of Spot Sign In Predicting Hematoma Expansion After Intracerebral Hemorrhage: A Systematic Review And Meta-Analysis”. PLoS ONE 9.12 (2014): e115777. Web.
Han, Ju-Hee et al. “The Spot Sign Predicts Hematoma Expansion, Outcome, And Mortality In Patients With Primary Intracerebral Hemorrhage”. J Korean Neurosurg Soc 56.4 (2014): 303. Web.
- Type 1 is due to plaque rupture with thrombosis
- Type 2 is secondary to an imbalance between myocardial oxygen demand and supply with fixed atherosclerotic obstruction, vasospasm, or endothelial dysfunction playing a permissive role
- Type 3 includes patients with sudden death having fatal MI even though cardiac biomarker evidence is lacking.
- Types 4 and 5 include patients with MI associated with PCI and
REFERENCE: J Intensive Care Med May 2015 vol. 30 no. 4 186-200
differential diagnosis for sinus tachycardia
4 major differentials in ICU
- Malignant hyperthermia