ICU MANAGEMENT OF LIVER CIRRHOSIS

Abstract

The liver is the largest organ in the body. Anatomically, it has two lobes; the right andthe left lobes. They are separated by the falciform ligament, the fissure for the ligamentum venosum and the fissure for the ligamentum teres. It has double blood supply. The portal vein; brings venous blood and the hepatic artery;supplies the liver with arterial blood.Venous drainage from the liver is into the right and left hepatic veins which enter the inferior vena cava. A functional liver anatomy is now recognized based upon vascular and biliary anatomy.The Bismuth classification divides the liver into four sectors, while the Couinaud classificationdefines eight segments (segments I-IV in the left lobe, V-VIII in the right lobe). These can be correlated with results seen with imaging techniques.Scanning by electron microscopy has shown the human liver as cords of liver cells radiating from a central vein, and interlaced by sinusoids. The liver is the central organ for metabolic homeostasis. It regulates uptake and processing of nutrients from the intestinal tract. The liver helps in the synthesis and biotransformation of proteins, carbohydrates, and lipids. It excretes the bile and eliminates hydrophobic compounds. It also contributes to regulation of energy metabolism. Liver also has Endocrine functions and mediates normal growth and development. Liver also has as immunological functions and contributes to drug metabolism and regulation of fluid balance. Liver cirrhosis is defined as an advanced stage of fibrosis, characterized by the formation of regenerative nodules of liver parenchyma that are separated by and encapsulated in fibrotic septa. It develops due to many causes, which may beinfective, toxic/drug-induced, metabolicorautoimmune causes. Fibrogenesis is characterized by the continuous accumulation of fibrillar ECM associated with continuous degradation and remodeling in a context of chronic tissue damage. The most common and relevant mechanism leading to liver fibrosis is the chronic activation of the wound-healing reaction. This processleads to progressive scarring when tissue damage is chronic. Hepatic stellate cells (HSCs) are considered the key profibrogenic cells. The process of HSC activation and transformation into myofibroblasts and their profibrogenic role represents an important basis for the hepatic fibrogenic process.It isevident that distinct ECM-producing cellscontribute to liver fibrosis, such as fibroblasts, myofibroblastsand smooth muscle cells. In the first steps of the wound repair reaction, fibroblasts and myofibroblasts are recruited to the site of injury in order to synthesize and secrete ECM components under the control of soluble factors secreted by the cell of the inflammatory infiltrate. The steps involved in the organization and functions of the inflammatory infiltrate are regulated by chemokines. A profibrogenic role of a tissue-specific renin-angiotensin-aldosterone system was elucidated. The involvement of oxidative stress has also been documented in all fibrogenic disorders characterized by chronic tissue damage and the over-expression of critical genes related to ECM remodeling and inflammation. The innate immune mechanisms of the liver represent an important first line of defence against bacterial products, toxins and food antigens. However, natural killer (NK) and NKT cells have been reported to participate in the inflammatory processes during hepatic diseases. HCV and HIV proteinswere proved to have a profibrogenic effect on the liver cells. Also Adipokines, particularly leptin, adiponectin and resistin, released by adipocytes, were proved to contribute the progression of NASH. Cannabinoids are a group of neuromodulatory lipids acting primarily via CB1 and CB2 receptors, forming the endocannabinoid system.It’s proved that