II. Background
- Not affected by systemic Blood Pressure
- Sensitive to blood pCO2
- Hyperventilation lowers Intracranial Pressure
III. Technique
- Counsel patient to try to relax
- Avoid Hyperventilation (lowers pressure)
- Avoid straining (raises pressure)
- Patient lies in lateral decubitus position
- Legs and neck should be in neutral position
- Opening pressure not accurate in sitting position
IV. Interpretation
- Unit Conversions
- cmH2O = 1.3 x mmHg
- cmH2O = mmH2O / 10
- Normal
- Adults and older children: 10 to 15 mmHg (13 to 20 cm H2O)
- Younger children: 3 to 7 mmHg (4 to 9 cm H2O)
- Term Infants: 1 to 6 mmHg (2 to 8 cm H2O)
- Rangel-Castillo (2008) Neurol Clin 26(2): 521-41 [PubMed]
- Modifying Factors that increase Intracranial Pressure
- With pulse: 1 to 4 mmHg (2 to 5 cm H2O)
- With respirations: 3 to 8 mmHg (4 to 10 cm H2O)
- With sitting upright (compared with lateral decubitus): 11.4 mmHg (14.8 cm H2O)
- Decreased: Intracranial Hypotension (Opening Pressure <60 mmH2O or <6 cmH2O, uncommon)
- Trauma with secondary Cerebrospinal Fluid Leak
- Recent Lumbar Puncture (Spinal Headache)
- Spontaneous, Idiopathic Intracranial Hypotension (associated with positional Headache)
- Increased: Intracranial Hypertension (Opening Pressure >250 mmH2O, >25 cm H2O)
- Mild if 20 to 30 mmHg (26 to 39 cmH2O)
- See Increased Intracranial Pressure Causes
V. Calculation: Cerebral Perfusion Pressure (CPP)
- Cerebral Perfusion Pressure (CPP) = Mean Arterial Pressure (MAP) - Intracranial Pressure (ICP)
- Critical to maintain in Increased Intracranial Pressure in Trauma
- If continuous ICP monitoring, Arterial Line transducer should zeroed at the ear (kept at same height of head)
- Decreased Cerebral Perfusion Pressure risks brain ischemia
- Monroe-Kellie Hypothesis
- CSF volume (blood, brain, csf) remains constant
- When one volume increases (e.g. blood in Intracranial Hemorrhage), then another decreases (e.g. csf, brain)
- Typical volumes (total 1450 ml)
- Brain: 1300 ml
- CSF: 65 ml
- Blood: 110 ml
- CSF volume (blood, brain, csf) remains constant
VI. References
- Kooiker in Roberts (1998) Procedures in ER, p. 1067-75
- Ravel (1995) Lab Medicine, Mosby, p. 294-9
- Tunkel in Mandell (2000) Infectious Disease, p. 974-8
- Seehusen (2003) Am Fam Physician 68:1103-8 [PubMed]
Images: Related links to external sites (from Bing)
Related Studies
| Definition (CSP) | manometric pressure of the cerebrospinal fluid as measured by lumbar, cerebroventricular, or cisternal puncture. |
| Definition (MSH) | Manometric pressure of the CEREBROSPINAL FLUID as measured by lumbar, cerebroventricular, or cisternal puncture. Within the cranial cavity it is called INTRACRANIAL PRESSURE. |
| Concepts | Clinical Attribute (T201) |
| MSH | D015170 |
| SnomedCT | 167715003, 144942008, 144938005, 86189008, 281668000 |
| English | Cerebrospinal Fluid Pressure, Cerebrospinal Fluid Pressures, Fluid Pressure, Cerebrospinal, Fluid Pressures, Cerebrospinal, Pressure, Cerebrospinal Fluid, Pressures, Cerebrospinal Fluid, cerebrospinal fluid pressure, CSF - Cerebrospinal fluid pres, CSF pressure NOS, CSF pressure NOS (finding), CSF PRESSURE, PRESSURE CSF, CSF PRESSURES, PRESSURES CSF, Cerebrospinal fluid press obs, pressure csf, csf pressures, csf pressure, cerebrospinal fluid pressures, pressure cerebrospinal fluid, Cerebrospinal fluid pressure NOS, CSF pressure NOS (observable entity), Cerebrospinal fluid pressure NOS (finding), Cerebrospinal fluid pressure, CSF - Cerebrospinal fluid pressure, CSF pressure, Cerebrospinal fluid pressure observation, Cerebrospinal fluid pressure (observable entity), Cerebrospinal fluid pressure finding (finding), Cerebrospinal fluid pressure finding |
| Japanese | ＣＳＦ圧, CSFｱﾂ, 脊髄液圧, 髄液圧, 脳脊髄液圧 |
| Swedish | Likvortryck |
| Czech | mozkomíšní mok - tlak, Tlak mozkomíšním moku |
| Finnish | Likvoripaine |
| French | Pression du LCS, Pression du liquide céphalo-rachidien, Pression du liquide céphalorachidien, Pression du LCR, Pression du liquide cérébrospinal |
| Russian | SPINNOMOZGOVOI ZHIDKOSTI DAVLENIE, SPINAL'NOI ZHIDKOSTI DAVLENIE, СПИНАЛЬНОЙ ЖИДКОСТИ ДАВЛЕНИЕ, СПИННОМОЗГОВОЙ ЖИДКОСТИ ДАВЛЕНИЕ |
| Croatian | Not Translated[Cerebrospinal Fluid Pressure] |
| Spanish | hallazgo relacionado con la presión del líquido cefalorraquídeo, hallazgo relacionado con la presión del líquido cefalorraquídeo (hallazgo), hallazgo en la presión del líquido cefalorraquídeo (hallazgo), hallazgo en la presión del líquido cefalorraquídeo, presión del líquido cefalorraquídeo, SAI (entidad observable), CSF pressure NOS, presión del líquido cefalorraquídeo, SAI, presión del LCR, SAI, presión del líquido cefalorraquídeo, SAI (hallazgo), Presión del Líquido Cerebroespinal, presión de LCR, presión del líquido cefalorraquídeo (entidad observable), presión del líquido cefalorraquídeo, Presión del LCR, Presión del Líquido Cefalorraquídeo |
| Polish | Ciśnienie płynu mózgowo-rdzeniowego |
| Hungarian | Liquor nyomás |
| Italian | Pressione del liquido cerebrospinale, Pressione del fluido cerebro-spinale, Pressione del fluido cerebrospinale |
| Norwegian | Cerebrospinalvæsketrykk, Trykk i cerebrospinalvæske |
| Portuguese | Pressão do Líquido Espinhal, Pressão do Líquido Cefalorraquiano, Pressão do LCR, Pressão do Líquido Cefalorraquidiano |
| Dutch | CSV druk, Druk, liquor-, Liquordruk |
| German | Liquordruck |
Ontology: Intracranial Pressure (C0021880)
| Definition (MSH) | Pressure within the cranial cavity. It is influenced by brain mass, the circulatory system, CSF dynamics, and skull rigidity. |
| Definition (CSP) | pressure within the cranial cavity, influenced by brain mass, the circulatory system, cerebrospinal fluid dynamics, and skull rigidity. |
| Concepts | Organ or Tissue Function (T042) |
| MSH | D007427 |
| SnomedCT | 250844005 |
| English | Intracranial Pressure, Intracranial Pressures, Pressure, Intracranial, Pressure, Subarachnoid, Pressures, Intracranial, Pressures, Subarachnoid, Subarachnoid Pressure, Subarachnoid Pressures, intracranial pressure, intracranial pressures, pressure intracranial, Intracranial pressure, ICP - Intracranial pressure, Intracranial pressure (observable entity) |
| Swedish | Intrakraniellt tryck |
| Czech | intrakraniální tlak, nitrolební tlak, subarachnoidální tlak |
| Finnish | Aivopaine |
| French | Pression subarachnoïdienne, Pression sous-arachnoïdienne, Pression intracrânienne |
| Italian | Pressione subaracnoidea, Pressione endocranica |
| Russian | VNUTRIMOZGOVOE DAVLENIE, VNUTRICHEREPNOE DAVLENIE, SUBARAKHNOIDAL'NOE DAVLENIE, ВНУТРИМОЗГОВОЕ ДАВЛЕНИЕ, ВНУТРИЧЕРЕПНОЕ ДАВЛЕНИЕ, СУБАРАХНОИДАЛЬНОЕ ДАВЛЕНИЕ |
| Japanese | 脳内圧, 脳圧, クモ膜下圧, くも膜下圧, 頭蓋内圧 |
| Portuguese | Pressão Subaracnóidea, Pressão Intracraniana |
| Croatian | INTRAKRANIJSKI TLAK |
| Polish | Ciśnienie wewnątrzczaszkowe, Ciśnienie śródczaszkowe |
| Norwegian | Intrakranielt trykk |
| Spanish | presión intracraneal (entidad observable), presión intracraneal, Presión Subaracnoidea, Presión Intracraneal |
| German | Intrakranieller Druck, Subarachnoidaler Druck |
| Dutch | Druk, intracraniale, Intracraniale druk |
