neonatal hemorrhage
Introduction
Introduction to neonatal hemorrhagic disease Neonatal hemorrhagic disease (hemorrhagicdisease of newborn, HDN) is caused by a decrease in vitamin K-dependent coagulation factors II, VII, IX, and X. Neonates born within 1 week are called neonatal hemorrhagic disease. basic knowledge The proportion of illness: 0.003% Susceptible people: children Mode of infection: non-infectious Complications: intracranial hemorrhage
Cause
Causes of neonatal hemorrhagic disease
(1) Causes of the disease
The cause of vitamin K deficiency due to vitamin K deficiency is:
1. Low vitamin K storage: Due to the poor permeability of vitamin K through the placenta, the pregnant mother vitamin K rarely enters the fetus. Only 10% of the pregnant mother's vitamin K can reach the fetus through the placenta, and the fetal vitamin K storage is small. Therefore, the blood vitamin K level is generally low at birth, and the vitamin K storage in the liver is also low. In premature infants, low birth weight infants such as small gestational age have lower vitamin K levels.
2. Insufficient intake: The content of vitamin K in breast milk (15g/L) is only 1/4 of milk (60g/L), while the intestinal flora of breast-fed infants produces less vitamin K, and the amount of newborn breast milk is insufficient. Etc. Therefore, the incidence of breastfeeding is 15 to 20 times higher than that of milk-fed, and the mother's diet lacks vitamin K, such as green vegetables, beans, liver and eggs, and vitamin K deficiency.
3. Insufficient synthesis: Vitamin K is mainly synthesized by normal intestinal flora. The intestinal flora of newborn newborns has not been established, affecting the synthesis of vitamin K. Intestinal inflammation or oral antibiotics can inhibit the normal intestinal flora, resulting in vitamin K. Not enough synthesis.
4. Others: Children with hepatobiliary disorders, congenital biliary atresia, etc., due to reduced bile secretion, can affect the absorption of vitamin K, increase vitamin K deficiency, some factors can cause bleeding in neonates with vitamin K deficiency, such as maternal production Pre-application of certain drugs, such as anti-shock drugs, anticoagulants (dual coumarin), rifampicin, isoniazid, etc., complications such as pregnancy or childbirth, can increase vitamin K deficiency.
(two) pathogenesis
Vitamin K deficiency causes bleeding because the coagulation biological activity of some coagulation factors is directly dependent on the presence of vitamin K. The glutamic acid residues of coagulation factors II, XII, IX, and X need to undergo carboxylation, and their valleys The amino acid residue needs to be carboxylated to -carboxyglutamic acid, has more Ca2 binding sites, and increases the calcium binding site to have the biological activity of blood coagulation. This carboxylation process requires a vitamin K-dependent Carboxylase is involved, so these four coagulation factors are also known as vitamin K-dependent factors. If vitamin K deficiency occurs, these four coagulation factors have no activity. The above four coagulation factors are only non-functional proteins and cannot participate in the coagulation process. Coagulation dysfunction, leading to bleeding.
Prevention
Neonatal hemorrhagic disease prevention
After intramuscular injection of vitamin K1 1mg intramuscularly once, can effectively prevent the occurrence of this disease, breastfeeding, breastfeeding mothers should eat more foods rich in vitamin K, 2 to 3 weeks after birth, give newborns vitamin K1 5mg, in order to prevent late bleeding, pregnant mothers receiving anticonvulsant medication, should be oral vitamin K1 5mg every day for 3 months at the end of pregnancy, can prevent the baby from developing this disease, in previous years, thought that the injection of vitamin K will increase Carcinogenicity, but this view has been denied after a clinically controlled study.
Complication
Neonatal hemorrhagic complications Complications intracranial hemorrhage
Intracranial hemorrhage, pulmonary hemorrhage, hemorrhagic anemia or hydrocephalus, severe intracranial hemorrhage often left behind various sequelae.
Symptom
Neonatal hemorrhagic symptoms Common symptoms Nasal bleeding Frequent neonates hematemesis and blood in the stool Bloody stools Intracranial hemorrhage Hematemesis hemorrhage Bleeding gastrointestinal bleeding Neonatal umbilical hemorrhage
The main feature is that the child suddenly has bleeding, and other conditions are normal, there is no serious underlying disease, platelet count and fibrinogen are normal, there is no fibrin degradation product in the blood, after injection of vitamin K1, it can bleed within a few hours. Can be stopped quickly, according to the age of onset and comorbidities, can be divided into three types.
1. Early onset bleeding : a small number of infants have bleeding during the delivery process or within 24 hours after birth, and are more related to the use of pregnant mothers, such as anticoagulants (dual coumarin), antiepileptic drugs (phenytoin, phenobarbital) And anti-tuberculosis drugs (rifampicin, isoniazid), etc., these drugs can interfere with the function of fetal vitamin K, the degree of bleeding is different, the bleeding site is different, from mild skin bleeding, umbilical stump bleeding to a large number of stomach Intestinal hemorrhage and fatal intracranial, thoracic or abdominal bleeding.
2. Typical neonatal hemorrhagic disease : 2 to 7 days after birth, most of the disease occurs on the second or third day, premature infants can be as late as 2 weeks, more common in breast-fed infants, the degree of bleeding varies, For small or medium amount of bleeding, but some mild bleeding can be a prodromal symptom of severe fatal bleeding (such as intracranial hemorrhage), in a few cases can occur in the digestive tract or umbilical hemorrhage leading to shock, bleeding site to the gastrointestinal tract (stool blood and hematemesis) The most common, other umbilical cord stump, skin bleeding is most common in the pressure, large areas of ecchymosis at the pressure, and even develop into a hematoma, puncture site for a long time bleeding, nose bleeding, pulmonary hemorrhage, aponeurosis, Intracranial hemorrhage, oozing from the injection site or surgical wound, urine blood, vaginal bleeding, etc. can be seen.
Examine
Examination of neonatal hemorrhagic disease
Prothrombin time and partial thromboplastin time in children with neonatal hemorrhagic disease (prothrombin time is more than 2 times the control is diagnostic), but bleeding time, platelet count is normal, conditional units can directly measure blood Vitamin K levels.
In order to identify the blood in the vomit is swallowed into the mother blood or gastrointestinal bleeding, can be used for the Apt test: take 1 part of the spit and add 5 parts of water, stir well, then stand or centrifuge (2000 rev / min) for 10 min, take the supernatant 5 parts of liquid and 1% sodium hydroxide (0.25N) 1 part, mix and let stand for 2min, the supernatant is still pink, indicating that the blood contains more fetal hemoglobin (HbF), bleeding from newborns; The liquid is converted to brownish yellow, which is the maternal blood, because 80% to 90% of Hb in newborns is HbF, and Hb97% in adults is adult hemoglobin (HbA). HbF has an anti-alkaline effect.
If necessary, B-ultrasound, CT and MRI examinations, such as suspected intracranial hemorrhage, B-ultrasound, CT or MRI examination is helpful for diagnosis, not only can understand the bleeding, determine the location of bleeding, range, but also follow-up efficacy, Prognosis judgment.
Diagnosis
Diagnosis and diagnosis of neonatal hemorrhagic disease
diagnosis
Healthy newborns develop natural bleeding 2 to 5 days after birth, platelets and bleeding time are normal, may consider this disease, if prothrombin time and partial thromboplastin time prolonged, clotting time is normal or slightly prolonged, but bleeding time is normal , can be diagnosed, injection of vitamin K1 or fresh plasma and other effective treatment, can be used for diagnosis.
Differential diagnosis
1. Gastrointestinal bleeding: It should be differentiated from gastrointestinal bleeding caused by swallowing syndrome, stress ulcer, gastrointestinal malformation and infection. These children have no coagulopathy. The swallowing syndrome is the mother who swallows when the newborn is born. The blood of the birth canal or the amniotic fluid with blood, vomiting occurs shortly after birth, the vomit is brown, and there may be bloody stools, but the blood volume is small, and the vomiting can be stopped after gastric lavage. In addition, the alkali denaturing test (Apt test) Helps identify maternal blood and blood.
2. Injury hemorrhage: occurs mostly in the exposed part of childbirth, appears after birth, but it should be noted that the birth injury can coexist with the disease at the same time, making the bleeding worse.
3. Others: If the umbilical bleeding should be connected with the umbilical cord, umbilical infection or granuloma, etc., vaginal bleeding should be differentiated from "false menstruation", hereditary telangiectasia can occur early in the newborn Gastrointestinal bleeding.
