Clinician’s Corner: 9-month old with a coagulopathy

CASE PRESENTATION

Nine-month-old female presented with 5-day history of fever, cough, loose stools and vomiting. Over this period, she had decreased breastfeeding and oral intake. Her 3-year-old brother and parents at home had similar symptoms. She was an otherwise healthy child born via a planned C-section. Her immunizations were all up-to-date. On examination at presentation, she was irritable, crying with minimal tears and had dry mucosal membranes. Her vitals on presentation were: temp 39.7, 167 bpm, Respiration Rate (RR) 24 and 94% on room air (RA). The remainder of the physical examination was unremarkable. She was admitted for intravenous (IV) hydration and urinalysis; urine and blood cultures were sent. Her nasopharyngeal swab was eventually positive for Influenza A. On day 3 of her admission, her urine was positive for Escherichia coli and due to her clinical symptoms persisting, she was treated with a single dose of ceftriaxone 640 mg IV followed by Amoxicillin 80 mg/Clavulanate for 10 days. On day 3 after a routine heel-prick for blood work, it was noticed that she was continuing to ooze from the site 12 hours later and had an episode of epistaxis with no other signs of bruising or bleeding elsewhere. Coagulation studies were ordered. The results came back with her prothrombin time (PT) >120.0, activated partial thromboplastin time (APTT) 127.8 and INR not calculable (Table 1). Further evaluation established the diagnosis.

Table 1.

CBC and coagulation studies trend from admission to discharge

Lab test	Day 1	Day 4	Day 4.5	Day 5	Day 5.5	Day 8	Day 9
LKC (5.0–15.0 × 10*9/L)	6.4	6.9	5.7	7.1			6.9
HgB (90–160 g/L)	84	76	67	98			96
HCT (0.270–0.450)	0.264	0.243	0.207	0.299			0.299
MCV (70.0–96.0 fL)	65.2	67	65.9	70.1			70.3
PLT (150–450 × 10*9/L)	284	466	497	569			765
APTT (25.1–37.6 s)		127.8		50.5	41.9		25.8
PT (10.6–13.2 s)		>120.0		18.5	13.7	13.2	11.8
PT/INR (0.8–1.2 s)		Can’t be calculated		1.6	1.2	1.1	1.0
APTT 50/50 mix (25.1–37.6 s)		38.9
PT 50/50 mix (10.6–13.2 s)		15.3
Fibrinogen (1.90–4.60 g/L)		3.08
Factor IX (0.40–1.50 U/ml)		0.02					0.87
Factor X (0.50–1.50 U/ml)		0.05					1.12
Factor VII (0.50–1.50 U/ml)		<0.02					1.66
Factor V (0.50–1.50 U/ml)		1.22					1.11
Factor II (0.40–1.50 U/ml)		0.08					1.06

APTT Activated partial thromboplastin time; CBC Complete Blood Count; HgB Hemoglobin; INR International Normalized Ratio; LKC Leukocytes; MCV Mean corpuscular volume; PLT Platelet; PT Prothrombin time.

CASE DISCUSSION

Repeat studies remained unchanged ruling out lab error. The differential for a prolonged PT and aPTT includes congenital causes such as deficiencies in certain clotting factors or acquired pathology like Disseminated Intravascular Coagulation (DIC), sepsis, liver dysfunction, Vitamin K deficiency or anticoagulants (1) (Table 2). Her clinical condition made sepsis and DIC less likely. A 50:50 mixing study was ordered along with fibrinogen levels, quantitative measures of clotting factors II, V, VII, IX and X and repeat Complete Blood Count (CBC). Her fibrinogen level was found to be normal at 3.08 along with normal factor V level; however, factors II, VII, IX and X were decreased (Table 1). The 50:50 mixing study almost corrected the PT and aPTT values to 15.3 and 38.9 seconds, respectively. Although the time for PT and aPTT had not completely returned to normal range but remained slightly higher (Table 1) the deficiency in factors II, VII, IX and X prompted us in the direction of Vitamin K deficiency causing the prolonged PT and aPTT. Thus, after consultation with hematology, 5 mg of oral Phytonadione was prescribed for 5 days instead of the IM route to prevent a hematoma formation. Normal liver enzymes and function tests ruled out liver dysfunction. A Coombs test was ordered to rule out hemolysis, and was negative. The patient’s low admission Hgb of 84, given her age, was thought to be secondary to her depleted iron stores. She was given Fresh Frozen Plasma (FFP) and a unit of pRBC under the advisement of Hematology for a drop in HgB to 67 which was felt to be partly dilutional given her declining hematocrit.

Table 2.

An approach to differential diagnosis for prolonged PT, aPTT or both

	Inherited	Acquired
Prolonged PT	Factor VII deficiency	Liver disease
		Warfarin
		Acquired inhibitor of Factor VII
Prolonged aPTT	Factor VIII, IX or XI deficiency	Heparin
	von Willebrand disease	Inhibitors of Factors VIII, IX, XI or XII
		Acquired von Willebrand disease
Prolonged PT and aPTT	Fibrinogen or Factor, II V or X deficiency	Liver disease
	Combined factor deficiencies	Disseminated intravascular coagulation
		Sepsis
		Anticoagulants
		Vitamin K deficiency
		Inhibitors of factor II, V, X or fibrinogen

aPTT Activated partial thromboplastin time; PT Prothrombin time.

Repeat coagulation studies showed a decrease in PT to 13.7 with INR 1.2 and aPTT 41.9 after 1 day of Vitamin K and normalization occurred 3 days later.

Further history was taken in order to determine the potential cause of the Vitamin K deficiency. The patient had received her prophylactic 1 mg IM Vitamin K dose at birth and had not been on antibiotics in the past. She was being breastfed with limited supplemental food. A previous study has shown that despite adequate prophylaxis at birth, on average exclusively breastfed infants at 26 weeks have serum Vitamin K concentration of only 0.24 ± 0.23 ng/mL with the lower limit of adult normal in plasma being 0.5 ng/mL and breastmilk concentration of only 0.87 ± 0.50 mg/mL. Thus, this study has shown that in order to avoid Vitamin K deficiency in infants due to possible low maternal intake or decreased ability of penetration into human milk, supplementing lactating mother with 5 mg of Vitamin K will significantly increase the concentration in the breastmilk and the infant (2). It was revealed that although the mother did not have diarrhea, she had significantly decreased her intake of fats due to her recent history of biliary colic. Since Vitamin K is a fat soluble vitamin along with Vitamin A, D and E, it was speculated that the mother’s limited diet and restricted intake of greens, a predominant source of Vitamin K, made the breastmilk even lower in Vitamin K levels than it usually would contain and potentially caused clotting abnormalities seen in the patient. The patient’s Vitamin D levels were found to be mild to moderately deficient at 47 nmol/L (ideal 76 to 200 nmol/L). In addition, our patient received Ceftriaxone and Amoxicillin which potentially could have affected her gut flora, since exposure to antibiotics can affect the intestinal flora that are responsible for the synthesis of Vitamin K₂, which could have contributed to her coagulopathy.

CLINICAL PEARLS

1. While Vitamin K Deficiency Bleeding is classically divided into the following three types: early (within 24 hours), classical (within 1 to 7 days) and late (within 2 to 12 weeks), this case study shows that despite receiving adequate prophylaxis at birth, infants can develop a coagulopathy secondary to Vitamin K deficiency outside the above time frame.

2. Prolonged exclusive breastfeeding without consumption of vitamin K rich foods may be a risk factor for vitamin k deficiency in infancy.

3. It is possible that in times of illness, being treated with antibiotics along with an already deficient state can lead to a vitamin K deficient coagulopathy.