Skip to main content

Raised ICP,the hyperosmolar therapy..Part1..Pathophysiology


Raised intracranial pressure (ICP) appears to be quite lethal: in traumatic brain injury patients, those with ICP > 40 mm Hg had a mortality of 56%, compared to 18% for those with ICP < 20 mm Hg. Most traumatic brain injuries causing long-term disability also initially presented with raised intracranial pressure.
As volume increases inside the skull, intracranial pressure exponentially rises after it passes an inflection point of ~20-25 mm Hg. As ICP passes 50-60 mm Hg and approaches arterial pressure, global brain ischemia and eventual brain death result. The brain is 80% water, so using hyperosmolar agents to create an osmolar gradient between the inside of the brain and the systemic circulation has strong theoretical appeal. Hypertonic saline and mannitol are effective because they do not cross the blood-brain barrier (much), and thereby draw cerebrospinal fluid out of the cranium and fluid out of the injured brain, reducing pressure and further injury.
In brain injuries that include disruption of the blood-brain barrier, hyperosmolar therapy may be less effective.
There is no definitive evidence from prospective randomized trials that reducing intracranial pressure with hyperosmolar therapy saves lives or prevents disability. The theoretical evidence for its benefit is so persuasive, though, that placebo-controlled trials will not be performed.Post hoc analyses of randomized trials of brain injured patients, along with observational trials, suggest that reducing intracranial pressure does improve outcome.
Labels:

Comments

Post a Comment

Popular posts from this blog

power injectable peripherally inserted central catheters

Clinical experience with power injectable peripherally inserted central catheters in intensive care patients     Introduction In intensive care units (ICU), peripherally inserted central catheters (PICC) may be an alternative option to standard central venous catheters, particularly in patients with coagulation disorders or at high risk for infection. Some limits of PICCs (such as low flow rates) may be overcome by the use of power-injectable catheters . Method We have retrospectively reviewed all the power injectable PICCs inserted in adult and pediatric patients in the ICU during a 12-month period, focusing on the rate of complications at insertion and during maintenance. Results We have collected 89 power injectable PICCs (in adults and in children), both multiple and single lumen. All insertions were successful. There were no major complications at insertion and no episodes of catheter-related blood stream infection. Non-infective complications ...
1 comment
Read more

The 12 decision making steps for post dural puncture headache treatment

Treatment decision-making algorithm for postdural puncture headache. 1. When diagnosis is made, all patients should receive supportive measures (reassurance, bed rest, analgesics, hydration, quiet environment). 2. Severity of symptoms should be classified using VAS scale (mild 1–3, moderate 4–6, severe 7–10). 3. Virtually all patients will improve in time even without additional therapy. (dashed lines) 4. Symptoms worsen or fail to resolve within 5 days. 5. Patient preference dictates the choice between pharmacologic (less effective) and epidural blood patch (EBP). 6. In patients with severe symptoms, EBP is strongly suggested. 7. The most common pharmacologic measure is  caffeine  prescription. 8. The failure, worsening, or recurrence of symptoms after pharmacologic measures favors the use of EBP. 9. In addition to EBP, other epidural treatment options can be considered in select patients (eg,  dextran , saline). 10. A period of 24 h should lapse before repeating EBP. 11...
1 comment
Read more

Things to Avoid in Anesthesia for Pregnant with Pulmonary hypertension

Anesthesia for Pregnant woman with Pulmonary Hypertension is a real challenge for anesthesiologist. It is very crucial to remember the pathophysiology of pulmonary hypertension in pregnant women and to avoid some practices that will worsen the cardiac status. 1-Avoid single shot spinal anesthesia. Some authorities consider pulmonary hypertension as absolute contraindication for single shot spinal anesthesia specially in patients with NYHA III ,IV. Spinal anesthesia causes major hemodynamic instability(decrease SVR, decrease VR, decrease in CO) The preferred neuroaxial techniques are (epidural anesthesia and CSE with minimal spinal dose) 2-Avoid PAC. Pulmonary Artery catheters insertion may lead to pulmonary artery rupture or thrombosis. TEE is better cardiac monitor/Arteial line is mandatory. 3-Avoid Nitrous oxide in gas mixture.N2O increase the PVR 4-If MV to be started, avoid High TV and PEEP 5-Avoid Oxytocin Boluses, or rapid administration of Pitocin. Oxytocin causes ...
Post a Comment
Read more