Once the abdominal wall can no longer expand, any further fluid leaking into the tissue results in fairly rapid rises in the pressure within the closed space. Initially this increase in pressure does not cause organ failure but does prevent organs from working properly – this is called intra-abdominal hypertension and is defined as a pressure over 12 mmHg in adults. ACS is defined by a sustained IAP(intra-abdominal pressure) above 20 mmHg with new-onset or progressive organ failure. Severe organ dysfunctionent syndrome. These pressure measurements are relative. Small children get into trouble and develop compartment syndromes at much lower pressures while young previously healthy athletic individuals may tolerate an abdominal pressure of 20 mmHg very well. The underlying cause of the disease process is capillary permeability caused by the systemic inflammatory response syndrome (SIRS) that occurs in every critically ill patient. SIRS leads to leakage of fluid out of the capillary beds into the interstitial space in the entire body with a profound amount of this fluid leaking into the gut wall, mesentery and retroperitoneal tissue. Abdominal compartment syndrome follows a destructive pathway similar to compartment syndrome of the extremities. When increased compression occurs in such a hollow space, organs will begin to collapse under the pressure. As the pressure increases and reaches a point where the abdomen can no longer be distended it starts to affect the cardiovascular and pulmonary systems. When abdominal compartment syndrome reaches this point without surgery and help of a silo the patient will most likely die.
CNS stimulants tend to be less effective for IH than they are for narcolepsy and may be less well tolerated. Stimulants
The main treatment of excessive daytime sleepiness is done through central nervous system stimulants. Methylphenidate and Dextroamphetamine are most used stimulants to controlled EDS. Increased dopamine release is felt to be the main property explaining wake-promotion from these medications. Insomnia is another common side effect and may require additional treatment. Non-stimulant wake-promoting medications
Solriamfetol is the first and only dual-acting dopamine and norepinephrine reuptake inhibitor approved by the FDA to improve wakefulness in adults living with excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea.Pitolisant, a selective histamine 3 (H3) receptor antagonist/inverse agonist, was approved by FDA during August 2019. It works by increasing the synthesis and release of histamine, a wake-promoting neurotransmitter in the brain. Modafinil and Armodafinil elevate hypothalamic histamine levels, and they are known to bind to the dopamine transporter, thereby inhibiting dopamine reuptake. Modafinil can cause uncomfortable side effects, including nausea, headache, and a dry mouth for some patients, while other patients report no noticeable improvement even on relatively high dosages. They may also "interact with low-dose contraceptives, potentially reducing efficacy, although the scientific data supporting this claim is weak and rests on poorly documented anecdotes." Sleep promoting medications
Sodium oxybate is an orphan drug which was designed specifically for the treatment of narcolepsy. Common side effects include nausea, dizziness, and hallucinations. A 2016 study by Leu-Semenescu et al.