Blood coagulation failure Normal blood coagulation definition of
Blood coagulation failure
Normal blood coagulation -definition of Haemostasis the arrest of bleeding, preventing loss of blood from the blood vessels. - mechanism of coagulation. - ﬁbrinolysis: dissolving of fibrin clot formation to maintain the patency of the circulation. -Fibrinolysis is the breakdown of ﬁbrin and occurs as a response to the presence of clotted blood.
Stages of blood clotting When tissues are damaged and platelets break down, thromboplastin is released. Thromboplastin leads to the conversion of prothrombin into thrombin: a proteolytic (protein-splitting) enzyme. Thrombin converts fibrinogen into fibrin to form a network of long, sticky strands that entrap blood cells to establish a clot. The coagulated material contracts and exudes serum, which is plasma depleted of its clotting factors. This is the final part of a complex cascade of coagulation involving a large number of different clotting factors (simply named Factor I, Factor II etc. in order of their discovery). It is equally important for a healthy person to maintain the blood as a ﬂuid in order that it can circulate freely.
- The coagulation mechanism is normally held at bay by the presence of heparin, which is produced in the liver. -Unless ﬁbrinolysis takes place, coagulation will continue. - It is achieved by the activation of a series of enzymes culminating in the proteolytic enzyme plasmin. - This breaks down the fibrin in the clots and produces fibrin degradation products (FDPs).
Disseminated intravascular coagulation (DIC) definition of DIC : Inappropriate coagulation occurs within the blood vessels, which leads to the consumption of clotting factors , a result, clotting fails to occur at the bleeding site cause of (DIC) is not fully understood. - reaction to severe tissue trauma -rarely occurs when the fetus is alive -starts to resolve after birth. - DIC is never a primary disease - occurs as a response to another disease process.
Events that trigger DIC include: placental abruption intrauterine fetal death, including delayed miscarriage amniotic fluid embolism intrauterine infection, including septic miscarriage pre-eclampsia and eclampsia.
A im s o f t he m a na g e m e nt o f DI C ◦ manage the underlying cause and remove the stimulus provoking DIC ◦ maintenance of the circulating blood volume ◦ replace the used up clotting factors
-The midwife should be alert for conditions that affect DIC, as well as the signs that clotting is abnormal. - assessment of the clot should be part of the midwife's routine observation during the third stage of labour. - Oozing from a venepuncture site or bleeding from the mucous membrane of the woman's mouth and nose must be noted and reported.
* Blood tests include ; -CBC& blood group -clotting studies -levels of platelets - ﬁbrinogen and fibrin degradation products (FDPs).
-Treatment of DIC: 1 -replacement of blood cells and clotting factors. 2 - administration of fresh frozen plasma and platelet concentrates. 3 - packed red cells. - Management by a team of obstetricians, anaesthetists, haematologists, midwives and other healthcare professionals.
Care by the midwife -Frequent and accurate observations to monitor the woman's condition. - monitor VS -Fluid balance is monitored (I&O)for any sign of renal failure. - client & her partner share them in care with psychological support.
Hepatic disorders and jaundice - disorders are speciﬁc to pregnant women, and some pre-existing or co- existing disorders may complicate the pregnancy, .
He pa t ic diso r de r s o f pr e g na ncy Specific to pregnancy Intrahepatic cholestasis of pregnancy Acute fatty liver in pregnancy Pre-eclampsia and eclampsia Severe hyperemesis gravidarum. Pre- or co-existing in pregnancy Gall bladder disease Hepatitis
C a use s o f ja undice in pr e g na ncy Not specific to pregnancy Viral hepatitis – A, B, C Cytomegalovirus (CMV), Epstein–Barr virus, toxoplasmosis or herpes simplex Gall stones Drug reactions Alcohol/drug misuse Budd–Chiari syndrome
Pregnancy-specific causes Acute fatty liver (AFLP) HELLP (haemolysis, elevated liver enzymes, low platelets) syndrome Intrahepatic cholestasis of pregnancy Hyperemesis gravidarum Note: Jaundice is not an inevitable symptom of liver disease in pregnancy
Obstetric cholestasis (OC) idiopathic condition may be 1 -genetic 2 - geographical 3 -and environmental factors in the third trimester of pregnancy can occasionally present as early as the ﬁrst trimester. -resolves spontaneously following birth -recurrence rate in subsequent pregnancies It is not a life-threatening condition
increased risk of pre-term labor fetal compromise meconium staining stillbirth risk
Clinical presentation pruritus without a rash fatigue as a result of the pruritus insomnia fever abdominal discomfort nausea and vomiting urine may be darker and stools paler than usual a few women develop mild jaundice.
Investigations differential diagnoses such as other liver disease or pemphigoid gestations hepatic viral studies (HBCAg, HCV) -ultrasound of the hepatobiliary tract -an autoantibody screen. Blood tests for bile acids serum alkaline phosphatase bilirubin liver transaminases(ALT, AST)raised.
What is pemphigoid gestation : a rare autoimmune disease of late pregnancy that mimics OC)
Management of OC local antipruritic agents, such as antihistamines. Vitamin K supplements are administered to the woman, 10 mg orally daily, to avoid prothombinaemia which predisposes her to obstetric haemorrhage(APHge, IPHge, PPHge). Monitor fetal wellbeing by Doppler of the umbilical artery blood flow. elective birth when the fetus is mature, or fetal condition appears to be compromised, becausev bile acids are raised, this is associated with impending intrauterine death. psychological care to the woman. Advise the woman that her pruritus disappear within 3– 14 days of the birth. use of OCP, advised that her liver function should be monitored.