Morning Announcements - Frank W. Cox High School

JOURNAL OF INSURANCE MEDICINE
Copyright 䊚 2001 Journal of Insurance Medicine
J Insur Med 2001;33:257–259
GRAPHICS SECTION
The Pregnant Applicant: Normal Alterations in
Physiologic Parameters and Testing
David S. Williams, MD
Pregnancy affects virtually every organ system, and ‘‘baseline’’ normal laboratory test levels change throughout gestation.
Address: Ohio National Financial
Services, One Financial Way, Cincinnati, OH 45242.
Correspondent: David S. Williams,
MD, FACP.
Key words: Pregnancy, organ systems, laboratory tests.
Received: April 10, 2001.
Accepted: May 1, 2001.
P
regnancy affects virtually every organ
system, and ‘‘baseline’’ normal laboratory
test levels change throughout gestation. According to US Census data (1994), about 8%
of women from ages 14 to 44 years will be
pregnant in any given year. Thus, an awareness of normal changes in the profile of a
pregnant insurance applicant may be useful
in better assessing risk in this not uncommon
condition. The following are instances of such
normal changes.
many therapeutic drugs (which may necessitate dosing changes). The white blood count
typically ranges from 5000 to 12,000, often
with a small left shift. Although clotting time
remains unchanged, certain coagulation factors are increased, thereby shortening the PT
and PTT. As a result, thromboembolism risk
is 1.8 times greater in pregnancy, rising to 5.5
times immediately postpartum. The platelet
count decreases marginally during pregnancy. Because fibrinogen levels are increased,
the blood sedimentation rate is increased,
rendering it useless as a screening test (Table
1).
BLOOD
Plasma volume increases by approximately
33% during pregnancy and total blood volume by about 45% at term. Because red cell
mass expands at a slightly slower rate, a dilutional anemia early in pregnancy might be
mistaken for a pathologic process. Mean hemoglobin level in pregnancy is between 10.2
and 11.6 gm/dL. Similarly, serum proteins
are diluted, as well as the concentration of
HEART
Heart rate, size, and stroke volume increase
during pregnancy. Cardiac output increases
by 30–50%, often producing a benign systolic
flow murmur. The systolic blood pressure decreases 5–10 mm Hg, while the diastolic
blood pressure decreases 10–15 mm Hg.
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JOURNAL OF INSURANCE MEDICINE
Table 1.
Summary of Laboratory Changes in Pregnancy
Lab Test
Normal Range
Pregnancy Effect
Sodium
Potassium
Creatinine
Creatinine phosphokinase
Glucose (fasting)
Fibrinogen
Urea nitrogen
Hematocrit
Hemoglobin
Leukocyte count
135–145 mEq/L
3.5–4.5 mEq/L
0.6–1.1 mg/dL
26–140 U/L
65–105 mg/dL
200–400 mg/dL
12–30 mg/dL
36–46%
12–16 g/dL
4000–10,000/cumm
Lower 2–4 mEq/L
Lower 0.2–0.3 mEq/L
Lower 0.3 mg/dL
Raise 2–4 fold
Lower 10%
Raise 600 mg/dL
Lower 50%
Lower 4–7%
Lower 1.4–2.0 g/dL
Raise 3500/cumm
Platelets
150,000/cumm
400,000/cumm
Gestational Timing
By midpregnancy
By midpregnancy
By midpregnancy
After labor (mg bands present also)
Gradual reduction
By term
First trimester
Nadir at 30–34 weeks
Nadir at 30–34 weeks
Gradual increase to term (up to
25,000/cumm in labor)
Slight decrease
Adapted from: Barclay ML. Critical physiologic alterations in pregnancy. In: Pearlman MD, Tintinalli JE, eds. Emergency Care of the Woman. New York: McGraw Hill; 1998:303–312.
Table 2.
System
Cardiovascular
ECG
Pulmonary
Hematologic
Gastrointestinal
Genitourinary
Central Nervous
Critical Physiologic Changes that Occur During Pregnancy
Physiologic Change
Consequences
Cardiac output is increased by 40%; pulse increased by 20–30% to 85–90 beats/min;
mild decrease in BP seen in second trimester; blood volume is increased by 40% at
term; CVP declines during gestation from 9
mmHg to 4–5 mmHg in third trimester.
A left axis shift occurs from elevation of the
diaphragm
Tidal volume and respiratory rate increase;
minute ventillation increased by 40–50%;
reduced functional residual capacity; increased sensitivity to CO2 with resulting
partially compensated respiratory alkalosis.
Oxygen consumption increased 10–20% by
term. Diaphragm is elevated by 4 cm at
term.
Blood volume is increased, more than RBC
mass, resulting in dilutional ‘‘anemia’’;
WBC increased (to 18,000); sedimentary
rate increased, but CRP remains normal. Fibrinogen and factors 7, 8, 9 and 10 increased
Hypomotility present; gastric emptying delayed; esophageal reflux more frequeny; increased acid production.
Hypomotility of collecting systems; increased
GFR. Anterior and superior displacement of
bladder with progressing gestation.
Some decreased coordination in later gestation
Supine position reduces venous return (treat
with left lateral displacement of the uterus);
relative tachycardia is normal; blood loss
will exceed 30% of total blood volume before hypotension is manifest. Retroperitoneal
bleeds may not by readily manifest
Flattened T waves, possible inversion in lead
3, possible Q waves in leads 3 and F.
Persistent respiratory alkalosis; mild tachypnea; shorter anesthesia induction time.
False dilution anemia may be diagnosed; potentially false diagnosis of infection based
on WBC; change in coagulation factors increases risk for thromboembolic problems,
especially with immobilization.
Risk of aspiration increased with anesthesia induction or unconsiousness.
Ureteral dilatation on radiographic studies
(right ⬎ left) as early as 10th week; risk of
infection increased with stasis and catheterization; BUN and creatinine normally decrease.
Increased emotional lability.
Source: Lavery JP, Staten-McCormick M. Management of moderate to severe trauma in pregnancy. Obstet Gynecol
Clin North Am 1995;22:69–90
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WILLIAMS—THE PREGNANT APPLICANT
Heart size increases by 12%, which, combined with upward displacement by the diaphragm, produces a larger cardiac silhouette on chest X-ray. Shifting cardiac position
often results in LAD on the EKG. ST and T
changes on EKG have been reported in up to
14% of normal pregnant women (Table 2).
creatinine level to 0.5–0.75 mg/dL; thus, a serum creatinine over 1.0 mg/dL is considered
abnormal in pregnancy. Impaired tubular
reabsorption of glucose and increased GFR
may produce glycosuria (Table 2).
LUNGS
In general, pregnancy produces a state of
partially compensated respiratory alkalosis.
The PCO2 decreases by 10 mm Hg to a normal
pregnant range of about 30 mm Hg, pH increases to 7.40–7.45, and serum bicarbonate
decreases to a range of 18–22 meq/L. Tidal
volume, alveolar, and minute ventilation all
increase, while respiratory rate, peak flow
rates, and vital capacity remain unchanged.
These changes are all perceived, and 70% of
normal healthy woman may report dyspnea
during pregnancy (Table 2).
Organ displacement and hormonal
changes make heartburn, constipation, and
cholelithiasis more common. Serum alkaline
phosphatase may increase 400% compared
with nonpregnant levels. In combination with
normal dilutional decreases in serum albumin to 3.0 g/dL and the clinical findings of
spider angiomata and palmar erythema
caused by increased estrogen, these normal
findings may falsely suggest liver disease (Table 2).
KIDNEYS
The GFR increases about 50% by the second trimester, reducing the normal serum
1. Halls G, Crump T. The pregnant patient. Emerg Med
Rep. 2000;21(6):53–74.
2. Haughey M, Calderon Y. Trauma in pregnancy.
Emerg Med Rep. 2000;21(16):177–186.
GASTROINTESTINAL
REFERENCES
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