Subgaleal hemorrhage, also known as subgaleal hematoma, is

bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethr ...

in the

potential space In anatomy, a potential space is a space between two adjacent structures that are normally pressed together (directly apposed). Many anatomic spaces are potential spaces, which means that they are potential rather than realized (with their realiz ...

between the skull

periosteum The periosteum is a membrane that covers the outer surface of all bones, except at the articular surfaces (i.e. the parts within a joint space) of long bones. (At the joints of long bones the bone's outer surface is lined with "articular cartila ...

and the scalp galea aponeurosis (dense

fibrous tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesode ...

surrounding the skull).

Symptoms

The diagnosis is generally clinical, with a fluctuant boggy mass developing over the

scalp The scalp is the area of the head where head hair grows. It is made up of skin, layers of connective and fibrous tissues, and the membrane of the skull. Anatomically, the scalp is part of the epicranium, a collection of structures covering th ...

(especially over the occiput) with superficial skin

bruising A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises occur clo ...

. The swelling develops gradually 12–72 hours after delivery, although it may be noted immediately after delivery in severe cases. Subgaleal hematoma growth is insidious, as it spreads across the whole calvaria and may not be recognized for hours to days. If enough blood accumulates, a visible fluid wave may be seen. Patients may develop periorbital ecchymosis (" raccoon eyes"). Patients with subgaleal hematoma may present with hemorrhagic shock given the volume of blood that can be lost into the potential space between the skull periosteum and the scalp galea aponeurosis, which has been found to be as high as 20-40% of the neonatal blood volume in some studies. The swelling may obscure the

fontanel A fontanelle (or fontanel) (colloquially, soft spot) is an human body, anatomical feature of the infant human skull comprising soft Membrane, membranous gaps (suture (joint), sutures) between the cranial bones that make up the calvaria (skull), ...

and cross cranial suture lines, distinguishing it from

cephalohematoma A cephalohematoma (American English), also spelled cephalohaematoma (British English), is a hemorrhage of blood between the skull and the periosteum at any age, including a newborn baby secondary to rupture of blood vessels crossing the periosteu ...

, in which the bleed is confined by its subperiosteal location. Patients with subgaleal hemorrhage may also have significant hyperbilirubinemia due to resorption of hemolyzed blood. Laboratory studies may demonstrate reduced hemoglobin and hematocrit due to blood loss into the subgaleal space, and coagulation studies may reflect an underlying coagulopathy. Mortality has been reported to occur in 12-14% of cases, generally as a consequence of massive blood loss presenting with shock, often in the setting of uncorrected coagulopathy. However, with early identification and prompt treatment, the prognosis is good, and there are usually no long-term consequences.

Causes

The majority of neonatal cases (90%) result from applying a vacuum to the head at delivery ( ventouse-assisted delivery). The vacuum assist ruptures the

emissary vein The emissary veins connect the extracranial venous system with the intracranial venous sinuses. They connect the veins outside the cranium to the venous sinuses inside the cranium. They drain from the scalp, through the skull, into the larger men ...

s (i.e., connections between dural sinus and scalp veins) leading to accumulation of blood under the aponeurosis of the scalp muscle and superficial to the periosteum.AAP Textbook of Pediatrics Additionally, subgaleal hematoma has a high frequency of occurrence of associated head trauma (40%), such as intracranial hemorrhage or skull fracture. The occurrence of these features does not correlate significantly with the severity of subgaleal hemorrhage.

Diagnosis

Early recognition of this injury is crucial for survival. Infants who have experienced a difficult operative delivery or are suspected to have a SGH require ongoing monitoring including frequent vital signs (minimally every hour), and serial measurements of hematocrits and their occipital frontal circumference, which increases 1 cm with each 40 mL of blood deposited into the subgaleal space. Head imaging, using either CT or MRI, can be useful for differentiating subgaleal hemorrhage from other sources of cranial bleeding. Head ultrasound is useful for the diagnosis of SGH in the hands of an operator experienced in imaging the neonatal head and scalp, and is preferable to CT due to lack of ionizing radiation. Coagulation studies are required to detect coagulopathy that may be associated with the bleeding.

Management

Management consists of vigilant observation over days to detect progression and, if required, manage complications (e.g. hemorrhagic shock, unconjugated hyperbilirubinemia and

jaundice Jaundice, also known as icterus, is a yellowish or, less frequently, greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving ...

from hemolyzed red blood cells). The subgaleal space is capable of holding up to 40% of a newborn baby's blood and can therefore result in acute shock and death. Fluid bolus may be required if blood loss is significant and the patient becomes tachycardic. Transfusion and phototherapy may be necessary. Investigation for

coagulopathy Coagulopathy (also called a bleeding disorder) is a condition in which the blood's ability to coagulate (form clots) is impaired. This condition can cause a tendency toward prolonged or excessive bleeding ( bleeding diathesis), which may occur s ...

may be indicated.

References

External links