BACKGROUND: Delayed vitamin K deficiency is characterized by acute onset, severe illness and high fatality rate. 33%-50% survivors accompany with other various nervous system sequelas. Therefore, diagnosis and treatment of intracranial hemorrhage in time become a key factor for improving healing rate and reducing fatality rate and incidence of sequela.OBJECTTVE: To investigate the clinical situation, experimental characteristics, CT examination and terminative characteristics of infants with intracranial hemorrhage induced by delayed vitamin K deficiency.DESIGN: Case analysis.SETTING: Department of Pediatrics, Zhongshan Hospital Affiliated to Xiamen University.PARTICIPANTS: A total of 17 infants with intracranial hemorrhage induced by delayed vitamin K deficiency aged 1-3 months including 11 boys and 6 girls were selected from Department of Pediatrics, Zhongshan Hospital Affiliated to Xiamen University from January 1994 to December 2005. All infants had drowsiness,rejective milk, spiting milk, gaze of both eyes, tic, coma, full anterior fontanelle, high muscular tension and cerebral hia, etc. Experimental examination demonstrated that infants had anemia at various degrees;prothrombin time and partial thromboplastin time were prolonged; platelet count was normal. CT examination indicated that screenages of subarachnoid hemorrhage, subdural hematoma, cerebral parenchyma hemorrhage and intraventricular hemorrage were changed. Hemorrhage was stopped by the application of vitamin K. All patients provided informed consent.METHODS: ① Clinical situation and physical sign of infants were observed after hospitalization and scanned with rapid spiral CT scanning system. The thickness and average space of layers were 8-10 mm and the scanning time was 5 s with window width of 30-80 Hu and window position of 28-35 Hu. ② After hospitalization, four items of blood coagulation was measured with Futura meter and biochemical indexes of blood, such as serum calcium, serum alkaline phosphatase, total bilirubin, direct bilirubin and indirect bilirubin,were detected with Roche Modular PPI automatic biochemistry analyzer. ③ After hospitalization, infants were given 5-10 mg vitamin K1 for 3-5 days, and then, they were transfused with 10-15 mL/kg fresh plasma or whole blood for 1-3 times and received other relative therapies. Therapeutic effects were evaluated based on clinical diagnosis and criteria.MAIN OUTCOME MEASURES: ① Clinical situation, physical sign and CT examination; ② results of experimental examination; ③ treatment and termination.RESULTS: A total of 17 infants with intracranial hemorrhage were involved in the final analysis. ① Clinical situation, physical sign and CT examination: All infants had pale facial expression and full or bossing anterior fontanelle. Among them, 13 infants had drowsiness or dysphoria, 12 rejective milk or emesis, 11 tic, 13 injection site hemorrhage, 2 gastrointestinal hemorrhage, 3 cerebral hia, 11 high muscular tension and 6 cervical rigidity. CT examination demonstrated that most infants (88%, 15/17) had subarachnoid hemorrhage;10 (59%, 10/17) had subdural hematoma; 8 (47%, 8/17) had cerebral parenchyma hemorrhage; few had intraventricular hemorrhage. In addition, results of CT examination also indicated that 17 infants had intracranial hemorrhage. Hemorrhage sites of 12 infants were equal to or more than 2, which was accounted for 70%(12/17); meanwhile, partial cases accompanied with a large area of focus of cerebral infarction or cerebral hypoxia-ischemia lesion. ② Results of experimental examination: There were 6 infants with elongation of prothrombin time, 5 with partial elongation of prothrombin time, 4 with decrease of serum calcium (1.69-2.25 mmol/L), 3 with increase of serum alkaline phosphatase, 3 with increase of total bilirubin, 3 with increase of direct bilirubin, and 3 with increase of indirect bilirubin. ③ Treatment and termination: After treatment, 12 infants were cured well, 3 improved, 1 given up and 1 died. Later, ten infants received CT re-examination at 3 months after treatment. The results indicated that 3 infants had simple subarachnoid hemorrhage and 4 had subarachnoid hemorrhage accompanying with subdural hematoma. Their focuses were absorbed well and not show as obvious sequela. One infant had subdural hematoma accompanying with subarachnoid hemorrhage,cerebral parenchyma hemorrhage, intraventricular hemorrage and cerebral hypoxia ischemia, and then, after hematom absorption, obvious cerebral malacia focus, hydrocephalus, brain atrophy and inferior accumulating fluid of dura mater were observed; 2 had subdural hematoma accompanying with subarachnoid hemorrhage and cerebral hypoxia ischemia, and then, after bleeding absorption, brain atrophy was changed remarkably;changes of hydrocephalus were observed in one infant.CONCLUSION: ① Symptoms of pale facial expression, full or bossing anterior fontanelle, drowsiness and dysphoria are observed in infants with delayed vitamin K deficiency. ② Experimental indexes demonstrate that prothrombin time and partial prothrombin time are prolonged, and numbers of infants having decrease of serum calcium are in the third place. ③ Poly-intracranial hemorrhage is a notable characteristic of CT examination.Partial infants who have poly-intracranial hemorrhage always accompany with cerebral hypoxia-ischemia lesion or cerebral infarction. Clinical situation and prognosis of infants a large area of intracranial hemorrhage and cerebral hypoxia-ischemia changes are poor; however, those　of infants who have simple subarachnoid hemorrhage or combination of subarachnoid hemorrhage with subdural hematoma are well. ④ Effect of vitamin K on this kind of disease is well.