CHAPTER 33 • HEMATOLOGY IN THE ATHLETE 195
2.Source of this bleeding is seldom detectable; it is the-
orized to arise form acute transient ischemia or
mechanical contusion (e.g., cecal slap syndrome)
(Selby and Eichner, 1994; Harris, 1995; Cook, 1994;
Selby, 1991).
- In the absence of this or other pathology, bleeding
is seldom significant enough to cause anemia
(Fields, 1997).
- Note use of nonsteroidal anti-inflammatory drugs
(NSAID) is common among athletes and may cause
enough cumulative blood loss to impact RBC mass
(Selby and Eichner, 1994; Eichner, 1997; Selby,
1991). All GI bleeding warrants thorough investiga-
tion to rule out serious conditions.
- Menstrual blood loss: Menstrual blood and iron
losses often coupled with inadequate iron replacement
are common causes of anemia in women. Menstrual
flow and adequacy of iron replacement for chronic
menstrual losses should be considered when evaluat-
ing all women athletes with anemia. Treatment is
focused on reduction of menstrual flow if excessive
and iron replacement. Indications of significant men-
strual losses:
- Heavy and/or frequent menses
- Twelve or more soaked pads throughout menses
(Lee, 1999c)
- Passage of clots beyond the first day (Lee, 1999c)
- Flow greater than seven days (Lee, 1999c)
5.More than one episode of menstrual flow per month
- Diet is inadequate to compensate for cumulative
menstrual losses (e.g., low intake of dietary iron
sources) (Harris, 1995).
- Exertional hemolysis (e.g., Footstrike hemolysis):
Intravascular destruction of RBCs may occur in asso-
ciation with various exertional activities. Originally
described as “march hemoglobinuria” in foot soldiers
in the late 1800s, it was thought arise from the foot-
strike causing compression of capillaries and ruptur-
ing RBCs; however, it is also seen in swimmers,
rowers, and weight lifters, though usually to a much
lesser degree (Selby and Eichner, 1994; Eichner, 1992;
Selby, 1991). It is now hypothesized that intravascular
turbulence, acidosis, and elevated temperature in
muscle tissues may be causative factors as well
(Eichner, 1997).
- Typically hemolysis is not significant enough to
affect CBC parameters (Selby and Eichner, 1994;
Eichner, 1992; 1997).
- Reticulocyte count, RDW, and MCV may be ele-
vated (Selby and Eichner, 1994; Eichner, 1992;
1997).
- Haptoglobin levels may be reduced if there is
enough cumulative hemolysis (Selby and Eichner,
1994; Eichner, 1992; 1997).
- Transient hemoglobinuria may occur if hemolysis
exceeds binding capacity of serum haptoglobin
(approximately 20 cc of blood) (Selby and Eichner,
1994; Eichner, 1992; 1997).
- Generally no treatment is necessary; reducing impact
forces to the feet (e.g., improved shoe cushioning,
softer running terrain) may benefit some, particularly
elite level runners (Eichner, 1997).
SICKLE CELL TRAIT
- Sickle cell trait(SCT), the heterozygous state where
Hgb S is present with Hgb A in RBCs is a common
condition. It typically does not cause anemia and has
little impairment of athletic performance (Fields,
1997; Eichner, 1993).
- Present in 8% of Blacks in the United States
(Eichner, 1993; Kark and Ward, 1994).
- May confer heightened risk of complications with
exercise at altitude: sickling may be provoked in
hypoxic environments, particularly altitudes above
10,000 ft and cause a clinical picture similar to
sickle cell anemia. Vigorous exertion at altitudes of
5000 ft or more may produce enough hypoxic and
metabolic stress to induce sickling and its sequelae
(Eichner, 1993; Kark and Ward, 1994).
3.Epidemiologically associated with increased risk of
sudden death in heat stress environments and settings
of rapid accelerated conditioning and sustained max-
imal exertion efforts (Kark and Ward, 1994).
- May manifest mild microscopic hematuria inde-
pendent of physical exertion which is rarely signif-
icant (Eichner, 1993).
- May confer higher risk of exertion related rhab-
domyolysis particularly in heat stress conditions
(Eichner, 1993).
ERYTHROCYTHEMIA (POLYCYTHEMIA)
- Red blood cell mass may be increased as a physio-
logic response to hypoxic stress, disease processes or
induced by drug use. Smoking, carbon monoxide
exposure (e.g., ice rinks), and training at altitude may
also increase RBC mass in athletes. A spurious ery-
throcytosis may also arise from transient plasma
volume contraction (e.g., exercise, dehydrated status)
(Means, 1999). True polycythemia arises from condi-
tions of excess RBC production, either as part of a
hyperplastic marrow response (polycythemia vera) or
secondary response to excess erythropoietin produc-
tion (secondary polycythemia).
