Hipertensão Intracraniana Usp

6.8. Solução Salina Hipertônica O efeito da solução salina hipertônica (SSH) na redução do volume cerebral, é conhecido, há vários anos, mas a avaliação na redução da PIC passou a ser estudada a partir dos anos oitenta (80). A SSH é um efetivo agente osmótico, que cria uma força para atrair a água do interstício e espaço intracelular do cérebro para o compartimento intravascular. A redução do volume de água cerebral causa diminuição da pressão intracraniana. O cloreto de sódio tem um maior coeficiente de reflexão que o manitol. O coeficiente de reflexão é definido como a habilidade da barreira hematoencefálica para excluir uma substância. A osmolaridade da solução salina 23,4% (8008 mOsm/L) é seis vezes maior que a do manitol (1372 mOsm/L). Esses dados podem explicar que a SSH é melhor que o manitol(37). A SSH pode ser usada em “bolus” de 30 ml, durante quinze (15) a vinte (20) minutos, por um cateter venoso central, quando a HIC é detectada. Essa dose é equimolecular, a 0,5 a 1,0 g/Kg. 6.9. Hipotermia A hipotermia tem o efeito de diminuir a pressão intracraniana, do fluxo sanguíneo cerebral e do consumo de O2 pelo cérebro. A aplicação dessa metodologia foi abandonada devido às complicações clínicas, principalmente infecciosas, oriundas baixa temperatura. No início dos anos noventa (90), surgiram trabalhos, mostrando que a hipotermia moderada (34°C) leva à benefícios importantes na redução ao tratamento da HIC, sem aumentar significantemente as complicações clínicas. A hipotermia é efetiva na prevenção do aumento da PIC, no intervalo de 20 a 40 mmHg, quando as medidas convencionais já foram tomadas. Pacientes com ingrutitamento difuso não respondem à hipotermia moderada, sendo que pacientes com lesões focais evolvem bem(38). CARLOTTI JR CG; COLLI BO & DIAS LA. Intracranial hypertension. Medicina, Ribeirão Preto, 31: 552-562, out./dez. 1998. ABSTRACT: The relation between the volume of the brain and the skull determines the intracranial pressure (ICP). The increase of the intracranial content promoted by expansive processes results in the increase of the intracranial pressure. The cranial expansive process can be ruptured abscesses, brain tumors, or traumatic injury, among others. The pressure in the brain results in headache, vomiting and papilledema. The most important subsidiary exams are the image methods mainly the Computed Tomography (CT) and the Magnetic Resonance Imaging (MRI). Monitorization of the intracranial pressure is important for severe cases of ICH. Several therapeutic modalities can be used, as hypocapnia induced by hyperventilation, osmotic diuretics, barbiturates, hypothermia and special general measures with the patient. UNITERM: Intracranial Pressure. Diagnosis. REFERÊNCIAS BIBLIOGRÁFICAS 1 - MARIAROU A & TABADDOR K. Intracranial pressure: physiology and pathophysiology. In: COOPER PR, ed. 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Recebido para publicação em 04/03/98 Aprovado para publicação em 07/10/98