Für den Inhalt dieser Seite ist eine neuere Version von Adobe Flash Player erforderlich.

Adobe Flash Player herunterladen

Für den Inhalt dieser Seite ist eine neuere Version von Adobe Flash Player erforderlich.

Adobe Flash Player herunterladen

Transkaranielle Messung Intraoperativ Extrakranielle Messung Monitoring Funktionstest Dopplersonographie HAL Image Map Transcranial Operativ Excranial Monitoring Function Test Doppler Sonography HAL Image Map

Sickle Cell Anemia

Sickle cell disease belongs to the subgroup of haemolytic anaemia (see below) and is the most common haemoglobinopathy: About 20-40% of population in tropic Africa and about 5-10% of the black population in America are heterozygote carriers of mutant chromosome 11 (only one of both chromosomes carries the mutation, which causes an abnormal ß-chain of haemoglobin). Mutation, which, as previously mentioned, is located on chromosome 11, causes production of HbS. “S” stands for “sickle”.The deoxygenated HbS (e.g. physical stress, sport, low air pressure in high altitudes) precipitates, which causes deformation of the erythrocytes. They assume a sickle-like shape (see figure above), lose their deformability and occlude smallest arteries, which can result in organ infarction: e.g. renal, splenic, mesenterial and cerebral infarction. From those, especially cerebral infarction (=stroke) is a feared complication. Most common are splenic infarctions, which influence its function negatively (functional asplenia) and cause frequent infections.



Definition „Anaemia“
The term of “anaemia” means a reduction to less than normal range of the haemoglobin concentration, haematocrit (solid blood particles) or erythrocyte count. This reduction can be caused e.g. by haemolysis (damage of blood cells).

Aetiology, incidence und clinical relevance

Sickle cell disease belongs to the subgroup of haemolytic anaemia (see below) and is the most common haemoglobinopathy: About 20-40% of population in tropic Africa and about 5-10% of the black population in America are heterozygote carriers of mutant chromosome 11 (only one of both chromosomes carries the mutation, which causes an abnormal ß-chain of haemoglobin). Incidence is about 400/100,000 people in Central-Africa. Presumably, this mutation could have been established evolutionary because of its increased resistance against Malaria. In Western Europe this disease is primarily important among immigrants. Mutation, which, as previously mentioned, is located on chromosome 11, causes production of HbS. “S” stands for “sickle”.






The deoxygenated HbS (e.g. physical stress, sport, low air pressure in high altitudes) precipitates, which causes deformation of the erythrocytes. They assume a sickle-like shape (see figure above), lose their deformability and occlude smallest arteries, which can result in organ infarction: e.g. renal, splenic, mesenterial and cerebral infarction. From those, especially cerebral infarction (=stroke) is a feared complication. Most common are splenic infarctions, which influence its function negatively (functional asplenia) and cause frequent infections.

Heterozygote carriers are often asymptomatic. However, homozygotes develop haemolytic episodes even in the early infant age, which requires early treatment.

Transplantation is the only available causal therapy. Symptomatic therapy includes avoidance of oxygen deficiency. Transfusion of blood products (erythrocyte concentrates) is made only after strict diagnostic evaluation but can influence patient´s outcome significantly. Today, in the US and Western Europe about 85-90% of suffering children achieve the age of an adult.

Diagnostics


Diagnosis of sickle cell disease is made microscopically using blood smear, molecular-genetically and/or using haemoglobin electrophoresis.

Transcranial Doppler ultrasound does not have its importance in diagnosis but in treatment decisionmaking and prognosis.

TCD examinations
Available studies (especially STOP I + II trials, Adams et al.) suggest that using TCD measurements children, who may benefit from blood transfusions, can be identified even months before stroke. This relies on the fact that agglomerations of polymerized HbS cause intracerebral arterial stenosis, which can be detected by measurement of elevated blood flow velocities (BFV).

STOP I + II showed that increased risk of stroke was significantly associated with increased BFV >200 cm/s.



Screening of the young patients should be started at age of 24 months (Adams et al. 2005) and should be repeated at least once or twice a year up to the age of 10 years (low risk patients) or 18 years (high risk patients) (Mazumdar et al., 2007)

The study of Bernaudin et al. (2011) showed that a TCD guided, intensified therapy reduced stroke risk from 11% to 1.9% per anno.

Comparison with other methods
Results from TCCD (transcranial color-coded Doppler) measurements are comparable to TCD results (Krejza et al. 2007). Additionally, echocardiography provides prognostic value to evaluate possible pulmonary hypertension, which can also result from sickle cell disease.

Use of TCD in Germany
Although some studies imply that TCD allows optimized and timed guidance of blood transfusion treatment, it seems to play a minor role in treatment decision of sickle cell anaemia patients in German.

Other literature:
Herold Innere Medizin, 2011.
Downloads

Literature: Sickle Cell Anemia (SCA)
Open PDF (119 KB)

Pictures

Sickel Cell Anemia

Atlas of Doppler Sonography

Literaturresearch

download pdfAnästhesie (EN) PDF | 144 KB
download pdfAutoregulation (EN) PDF | 163 KB
download pdfDemenz (EN) PDF | 178 KB
download pdfEmbolie Differenzierung (EN) PDF | 113 KB
download pdfEmbolie Gefäßchirurgie (EN) PDF | 232 KB
download pdfEmbolie Schlaganfallrisiko (EN) PDF | 182 KB
download pdfFunktionelle TCD (EN) PDF | 198 KB
download pdfHirndruck (EN) PDF | 141 KB
download pdfHirntod (EN) PDF | 233 KB
download pdfICU (EN) PDF | 162 KB
download pdfMikrodoppler (EN) PDF | 124 KB
download pdfParkinson (EN) PDF | 85 KB
download pdfReanimation (EN) PDF | 94 KB
download pdfRechts-Links Shunt (EN) PDF | 201 KB
download pdfSichelzellenanämie (EN) PDF | 152 KB
download pdfSonothrombolyse (EN) PDF | 175 KB
download pdfSchlaganfall (EN) PDF | 192 KB
download pdfVasospasmus (EN) PDF | 140 KB
download pdfAnaesthesiology (PDF | 144 KB)
download pdfAutoregulation (PDF | 163 KB)
download pdfDementia (PDF | 178 KB)
download pdfEmboli differentiation (PDF | 113 KB)
download pdfEmboli vascular surgery (PDF | 232 KB)
download pdfEmboli stroke risk (PDF | 182 KB)
download pdfFunctional TCD (PDF | 198 KB)
download pdfBrain pressure (PDF | 141 KB)
download pdfBrain death (PDF | 233 KB)
download pdfICU (PDF | 162 KB)
download pdfMicrodoppler (PDF | 124 KB)
download pdfParkinson (PDF | 85 KB)
download pdfReanimation (PDF | 94 KB)
download pdfRight-Left-Shunt Detection (PDF | 201 KB)
download pdfSickle cell anemia (PDF | 152 KB)
download pdfSonothrombolysis (PDF | 175 KB)
download pdfStroke (PDF | 192 KB)
download pdfVasospasm (PDF | 140 KB)

Products

 
• Reasonably priced entry-level model
• Compact design
• Integrated keyboard
• Optimised audio output
• Integrated DVD drive
• For use in the consulting room
 
• Can be connected to any PC
• Brilliant signal quality
• High-resolution image quality
• Measurement range to 1200 cm/s
• Doppler-M-Mode for 16 MHz
• Flexible and modular
 
• Ergonomic design
• Portable
• Integrated monitor
• Doppler M-Mode
• Upgradable software options
• Wide-ranging applications
 
• A state-of-the-art complete solution
• Best signal and image quality
• Ergonomic system cart
• Extendable operation cockpit
• Touchscreen remote control – programmable
• Fully adjustable monitor
• Integrated CO2 module - optional
 
 
• DWL-Doppler and Duplex in one
• Best signal and image quality
• Unique control concept
• Ergonomic system cart
• Extendable operation cockpit
• Touchscreen control unit and trackball
• Fully adjustable monitor