Dr. Frank Rasulo U.O. Neurorianimazione Università di Brescia pertensione Intracranica: alutazione con TCD LA NEUROSONOLOGIA NELLAMBITO DELLE NEUROSCIENZE:

Dr. Frank RasuloU.O. Neurorianimazione

Università di Brescia

pertensione Intracranica: pertensione Intracranica:

alutazione con TCD alutazione con TCD

LA NEUROSONOLOGIA NELL’AMBITO DELLE

NEUROSCIENZE:

Primo Corso teorico praticoBRESCIA

12-13 NOVEMBRE 2010U.O. NeurorianimazioneSpedali Civili di Brescia

VASOSPASM VASOSPASM

INTRACRANIAL INTRACRANIAL HYPERTENSIONHYPERTENSION

CEREBRAL CEREBRAL CIRCULATORY ARRESTCIRCULATORY ARREST

AUTOREGULATION AUTOREGULATION

STENOSISSTENOSIS

SUBARACHNOID HEMORRHAGE HEAD TRAUMA

STROKE

BRAIN DEATH

TCD in the ICU TCD in the ICU

SSVD Neurorianimazione ,Spedali Civili, Brescia,Dr. FRANK RASULOTCD PER LA DIAGNOSI DI IPERTENSIONE INTRACRANICATCD PER LA DIAGNOSI DI IPERTENSIONE INTRACRANICA

http://www.spedalicivili.brescia.it/

iagnosing high ICP

The gold standard forthe measurement ofICP is its invasive measurement.



ypes of Devices



However there are various situations where a non invasive measurement may be useful…

-mild and moderate head injury

-Ischemic & hemorrhagic stroke, vasospasm

-meningo-encephalytis

-faulty ICP cathters

-outside the ICU (ER, OR, etc.)

on invasive evaluation of high ICP



CD waveform analysis for the evaluation of intracranial pressure



Mean flow velocity

partial information regarding cerebral hemodynamics, not optimal to assess biophysical properties of the brain.

Systolic flow velocity

FV systolic is predominantly dependant on the cardiac output systemic hemodynamics, rather than depicting cerebral hemodynamics.

Diastolic flow velocity

Pulsatility index

-derived parameters



Mean flow velocity





Pulsatility index

-derived parameters



Mean flow velocity





Pulsatility index

-derived parameters



Mean flow velocity





Pulsatility index

-derived parameters



CD for non invasive ICP EVALUATION


http://stroke.ahajournals.org/content/vol28/issue3/images/large/hs0370195002.jpeg






Chan KH. The effect of changes in cerebral perfusion pressure upon middle cerebral artery blood flow velocity and jugular bulb venous

oxygen saturation after severe brain injury. J Neurosurg. 1992 Jul;77(1):55-61.

“a reduction of CPP by rising ICP or by falling BP in head injured patients, resulted in a greater fall in diastolic flow velocity than other flow parameters”

Pediatric head trauma study, an end-diastolic velocity less than 25 cm/s was associated with a poor prognosis

Trabold F. The prognostic value of transcranial Doppler studies in

children with moderate and severe head injury. Intensive Care Med. 2004;30(1):108-12

-derived parameters



Il flusso diastolico normale in un feto

Il flusso diastolico assente richiede invece la valutazione di altri distretti fetali quali l'arteria cerebrale media ed il dotto venoso, due vasi che danno informazioni sul benessere fetale,

Il flusso diastolico invertito rappresenta una condizione particolarmente a rischio e come tale deve essere gestita.

Monitorare il ritardo di crescita: la flussimetria dell'arteria ombelicale




Mean flow velocity





Pulsatility indexFVm

FVdFVsPI

-derived parameters



CD waveform analysis for the evaluation of intracranial pressure

PULSATILITY INDEX



CD for ICP EVALUATION

The pulsatility of blood flow through conductance vessels reflects distal vascular resistance.

Gosling et al. 1969

ΣN

A2n1A2

n=1

PI =



Gosling RG, King DH. Arterial assessment by Doppler Shift ultrasound. ProcRsoc Med 1974;67:447–9.

Peak to peak amplitude of the Doppler shift recordingMean valuePI =

INDICA L’ANDAMENTO DELLA CURVA DI VELOCITA’ DURANTE UN CICLO CARDIACO



The earliest sign of increased ICP is increased pulsatility.

ICP


PI Normal value < 1 SSVD Neurorianimazione ,Spedali Civili, Brescia,Dr. FRANK RASULOTCD PER LA DIAGNOSI DI IPERTENSIONE INTRACRANICATCD PER LA DIAGNOSI DI IPERTENSIONE INTRACRANICA


influenced by certain factors that influences flow velocity

HemodynamicRespiratoryHematologic

Tissue compliance

Parameters

Ratio – therefore not infuenced by the angle of insonation

The arterioles are greater influenced than in the larger vessels

Increased with the increaseof downstream resistance(vasocostriction, ICP)

Reduced with the reduction of upstream blood supply (stenosis, CO, hypotension)

Upstream - Downstream




ICP- 20 ICP- 60

aveform analysis of high ICP



Can we be satisfiedwith a qualitative measurment ?

s a waveform enough?



FVm

RIPAMPIC

Houmburg AM. et al. Transcranial Doppler recording in raised intracranial pressure Acta Neurol Scand 1993:87:488-493

Chan KM et all. Transcranial Doppler waveform differences in hyperemic and non hyperemics patients after severe injury- Sur Neurol 1992;87:488-93

Klingelhofer J. et all Evaluation of intracranial pressure from transcranial Doppler studies in cerebral desease. J Neurosonol 1988;235:159-62

FVm

FVdFVsPI

FVm

FVdFVsPI

FVs

FVdFVsRI

FVs

FVdFVsRI

rigins of non invasive assessment

slid and the Fourier analysis

PA1= ampiezza della prima armonica dell’onda che descrive la

pressione arteriosa

FV1 = ampiezza della prima armonica dell’onda che descrive la

velocità di flusso

151

1 FV

FVmPAePPC

Aaslid R. et all Estimation of cerebral perfusion pressure from arterial blood pressure and transcranial Doppler recordings in Intracranial pressur IV Berlin Spnger-Verlag 1986 pp226-29

10 pazienti

< 27 mmHg 95% delle stime

< 10 mmHg 52% delle stime

PAM = pressione arteriosa media

FVd = Velocità di flusso diastolica

FVm = Velocità di flusso media

14FVm

FVdPAMnPPC

ambridge proposal



25 pazienti

≤ 5 mmHg 49%

≤ 10 mmHg 81%

≤ 15 mm Hg 94%

Schmidt EA et all. Preliminary experience of the estimation of cerebral perfusion pressure using transcranial Doppler ultrasonography J Neurol Neurosurg and Psycjiatry 2001;170:198204

ambridge proposal

Czosnyka M, et al. Cerebral perfusion pressure in head injured patients: a non invasive assessment using transcranial doppler ultrasonography. J Neurosurg 1998; 88:802-8



Aaslid et al

151

1 FV

FVmAPeCPP

< 27 mmHg 95%

< 10 mmHg 52%

14FVm

FVdMAPnCPP

< 21 mmHg 95% dellestime

< 10 mmHg 81% dellestime

Czosnykaet al.

CD for CPPCPP EVALUATION



OUR RESULTS OUR RESULTS

21 pazienti21 pazienti

530 stime530 stime

21 pazienti21 pazienti

530 stime530 stime

0% 20% 40% 60% 80% 100%

<20 (96,79%)

<15 (89,81%)

<10 (81,51%)

<5 (56,04)

Err

ore

ass

olu

to

(mm

Hg

)

<5 mmHg 5-10 mmHg 5-15 mmHg 15-20 mmHg

33%

33%

24%

5% 5% ESA

EIP

TC

MENINGITE

ISCHEMIA




Head Trauma

Brain Infarct

Menengtis /Encephalytis

Decompressive Craniectomy



Bellner J et al. Transcranial Doppler sonography pulsatility index (PI) reflects intracranial pressure (ICP). Surg Neurol 2004;62:45,51.

Ract C et al. Transcranial Doppler ultrasound goal-directed therapy for the early management of severe traumatic brain injury. Inten Care Med 2007;33:645-51.

Splavski B et al. Transcranial Doppler ultrasonography as an early outcome forecaster following severe brain injury. Br J Neurosurg 2006; 20:386-90.

Literature suggests that the PI is useful as a non invasive estimate of ICP and CPP in adult TBI and SAH




et al.

First prospective prospective study to investigate the relationship between ICP and TCD derived PI.

ICP higher than 20 mm Hg could be detected with a sensitivitysensitivity of 0.89 and specificityspecificity of 0.92.




There is a strong correlation between PI and ICP ( ICP values > 20 mmHg ), and between PI and CPP ( CPP values < 70 mmHg). Voulgaris et al.




TALIP ASIL et al.

- Increased PI correlated with midline shifts on CT scans.

- Early outcomes of pts who had increased PI were poorer.




Cerebral hemodynamic changes gauged by transcranial Doppler ultrasonographyin patients with post-traumatic brain swelling treated by surgical decompression

EdsonBor-Seng-Shuet al. J Neurosurg 104:93-100, 2006

CVR = FV + PI




INTERHEMISPHERIC PRESSURE GRADIENTS TRANSMANTLE PRESSURE GRADIENTS

PRESSURE GRADIENTS BETWEEN THE SUPRA AND INFRATENTORIAL SPACES

PRESSURE GRADIENTS WITHIN THE CEREBROSPINAL AXIS




Cardoso ER, Kupchak JA. Evaluation of intracranial pressure gradients by means of transcranial Doppler sonography. Acta Neurochir 1992; 55 (Suppl): 1-5.

Intracranial pressure gradients generated by mass lesions are responsible for the asymmetry of TCD readings.










CBF

ABP160mmHg

50mmHg

CBF = CPP/R

PIMaximumVasodilationR = Rmin

MaximumVasoconstrictionR = Rmax

CriticalClosing Pressure

5

TCD identification of changing autoregulatory thresholdsafter autoregulatory impairment.

Lewis SB et al. Neurosurgery 2001:49(6);1484-85



CD for Emergency ICP EVALUATION



AdmissionAdmission velocities, FVm< 30 cm/s, were related to GCS, and correctly predicted early outcome.

Chan KH et al.

Admission Admission FVd< 25 cm/s and PI > 1.3 is associated with a poor outcome

Trabold et al.







24 TBI pts. Anormal TCD values (group 1) Normal TCD values (group 2)

3-month GOS was significantly poorer in group 1 than in group 2.




Comparison of TCD and Ultrasound for non-invasive estimation of intracranial hypertension and its prediction during the early phase

following severe head trauma.


??

TCDTCD ECOECO


2° STARLING RESISTOR2° STARLING RESISTORbridging Veinsbridging Veins

1° STARLING RESISTORArteriolar resistance vessels

= MAP - CCPCPP

TCD & Critical Closing Pressure TCD & Critical Closing Pressure

= MAP - ICPCPP

P = T/rP = T/rP = T/rP = T/rP = pressione transmuraleP = pressione transmuraleT = tensione di pareteT = tensione di pareter = raggio del vasor = raggio del vaso

P < T/rP < T/rP < T/rP < T/r

MAP ICP

Tono vasomostore

MABPMABP

CVPCVP



y = 2,189x - 78,71R² = 0,996

0

20

40

60

80

100

120

140

160

180

200

0 20 40 60 80 100 120 140

MC

A

PRESS

CCP DX

CCP DX

Lineare (CCP DX)

CCP = 35,96

Weyland A. et all

Cerebrovascular tone rather than intracranialpressure

determinesthe effective downstreampressure of the

cerebralcirculation in the absence of intracranial hypertension

J Neurosurg Anesth 2000;12:210-16

TCD and CCP TCD and CCP



flusso



TCD

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Dr. Frank Rasulo U.O. Neurorianimazione Università di Brescia pertensione Intracranica: alutazione con TCD LA NEUROSONOLOGIA NELLAMBITO DELLE NEUROSCIENZE: