Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_208_библиотеки_им_акад_М_И_Перельмана
.pdf
82 Laboratory Medicine in Psychiatry and Behavioral Science
Complete blood count (CBC) (continued)
Interfering factors See entries for test components.
Cross-references See entries for CBC components.
American Association for Clinical Chemistry: Testing.com. Available at: https://www.testing.com. Ac-
cessed November 2021.
Chernecky CC, Berger BJ: Laboratory Tests and Diagnostic Procedures, 5th Edition. St. Louis, MO, WB
Saunders, 2008
Fauci AS, Braunwald E, Kasper DL, et al (eds): Harrison’s Principles of Internal Medicine, 17th Edition.
New York, McGraw-Hill, 2008
Fischbach FT, Fischbach MA: A Manual of Laboratory and Diagnostic Tests, 10th Edition. Philadelphia,
PA, Wolters Kluwer Health/Lippincott Williams and Wilkins, 2018
https://t.me/med1917
83 Laboratory Tests
Comprehensive metabolic panel (CMP)
Type of test Blood
Background and explanation
of test
The CMP includes 14 tests:
• Glucose
• Calcium
• Albumin
• Protein (total protein)
• Sodium
• Potassium
• Carbon dioxide
• Chloride
• BUN
• Creatinine
• ALT
• AST
• Bilirubin
• ALP
Relevance to psychiatry and In patients presenting with psychiatric signs/symptoms,
behavioral science the CMP may be useful for rapid assessment of metabolic
status. In psychiatry and behavioral medicine, this panel is
used in preference to the BMP because it includes LFTs. The
CMP is a high-yield, low-cost test.
Preparation of patient Usually none, although overnight fasting yields a more
meaningful glucose measurement in many cases. For opti
-
mal testing, see preparations recommended for individual
tests.
Indications • Metabolic screen for patients presenting with psychiat-
ric signs/symptoms
• Routine health screen
• Monitoring specific lab values in a hospitalized patient
Reference range See entries for individual tests.
Critical value(s) See entries for individual tests.
Increased levels See entries for individual tests.
Decreased levels See entries for individual tests.
Interfering factors See entries for individual tests.
Cross-references Basic Metabolic Panel
See entries for individual tests.
https://t.me/med1917
84 Laboratory Medicine in Psychiatry and Behavioral Science
Computed tomography scan, head
Type of test Imaging
Background and explanation
of test
In a head CT scan, the attenuation of X-ray beams by tissues
of differing density distinguishes gray and white matter,
bone, CSF, and blood. Different “windows” can be requested
in addition to the standard brain window (e.g., bone win
-
dow, or subdural window to improve detection of a sus-
pected subdural hematoma). A CT study can be performed
nonenhanced (“without” contrast), or it can be enhanced
with iodinated dye administered intravenously (“with” con
-
trast). Contrast improves visualization of lesions such as
stroke, tumor, and abscess.
CT is preferred to MRI in the detection of calcified lesions,
meningeal tumors, and acute blood. CT is less degraded by
motion artifact than is MRI. It is inferior to MRI in the detec
-
tion of ischemia or demyelination and is not as well able to
visualize the brainstem, cerebellum, or temporal lobes due
to artifact created at the bone-tissue interface.
CT slice thickness ranges from 1 mm to 10 mm. Thicker cuts
reduce the time of the study but also reduce sensitivity be
-
cause smaller lesions may be missed. Even with thin slices,
CT is a shorter study than MRI, and the cost is about half that
of MRI. Spatial resolution of structures in CT is inferior to
that of MRI.
The axial CT scan image is presented as if one were viewing
the brain from the foot of the bed while the patient lies su
-
pine, so the right side of the brain appears on the viewer’s
left. Brightness on the CT scan is proportional to the density
of the tissue, so bone and calcium are very bright (white),
CSF and fat are black, and gray matter is lighter gray than
white matter. Appendix B contains further information.
Relevance to psychiatry and
behavioral science
CT is a relatively low-cost, high-yield testing modality in
certain patient populations, including those with new-onset
headaches or new neurological deficits. In addition, CT (or
MRI) is indicated for patients with a first episode of psycho
-
sis, prolonged catatonia, or first onset of psychosis, mood
disorder, or personality changes after age 50 years.
Preparation of patient The scan takes about 10 minutes. Radiation exposure is little
more than that of plain films of the skull, but cumulative
effects can be significant. CT contrast agent more likely than
MRI gadolinium to cause an allergic reaction, which can be
serious; anaphylaxis can occur. Allergic reactions are more
common in patients with asthma or seafood allergies.
Indications •
Headache (sudden-onset severe or unilateral headache,
new headache in a pregnant patient [without contrast]),
new headache in suspected meningitis or encephalitis
[without contrast, to evaluate intracranial pressure])
• Ipsilateral Horner syndrome
• New focal neurological deficit
• Ataxia of acute onset
https://t.me/med1917
85 Laboratory Tests
Computed tomography scan, head (continued)
Indications (continued) • TIA (combined with CT angiography)
• Suspected subarachnoid hemorrhage, brain parenchy-
mal hemorrhage
• Suspected carotid or vertebral dissection
• First episode of psychosis with atypical presentation
• First onset of psychosis, mood disorder, or personality
changes after age 50 years
• Prolonged catatonia
Normal test • Normal anatomical landmarks identified
• No midline shift
• No extracerebral fluid accumulation (subdural or epi-
dural)
• No abnormal hypodense or hyperdense areas
• If atrophy is present, it is generalized and mild, or mod-
erate in a patient of advanced age
Abnormal test The following appear dark (less dense) on CT due to accu-
mulation of extravascular fluid:
• Infarction
• Demyelination
• Inflammation
• Gliosis
• Most cancers
• Cysts
The following appear light (more dense) on CT:
• Acute blood
• Meningiomas
• Thrombosis
• Calcified masses
• Calcified tubers
• Colloid cysts
• Certain primary lymphomas
Interfering factors Motion artifact interferes with image acquisition.
Cross-references Additional Information on Neuroimaging (Appendix B)
Angiography, Computed Tomography (Cerebrovascular)
Magnetic Resonance Imaging
Stroke
https://t.me/med1917
86 Laboratory Medicine in Psychiatry and Behavioral Science
Computed tomography scan, head (continued)
American College of Radiology: Appropriateness Criteria: Acute Mental Status Change, Delirium, and
New Onset Psychosis. Reston, VA, American College of Radiology, 2018.
Available at: https://
acsearch.acr.org/docs/3102409/Narrative. Accessed June 2021.
Holt RE: The role of computed tomography of the brain in psychiatry. Psychiatr Med 1:275–285, 1983
Pearlson GD, Veroff AE, McHugh PR: The use of computed tomography in psychiatry: recent applica-
tions to schizophrenia, manic-depressive illness and dementia syndromes. Johns Hopkins Med J
149:194–202, 1981
https://t.me/med1917
87 Laboratory Tests
Cortisol
Type of test Blood, saliva, urine
Background and explanation
of test
Cortisol is a steroid hormone released by the adrenal glands
in response to stimulation by ACTH from the anterior pitu
-
itary gland. Cortisol has significant physiological effects, par-
ticularly on carbohydrate metabolism. Its level in the
circulation normally peaks in the morning hours, drops in the
evening, and reaches a nadir around midnight.
In conditions involving excessive release of cortisol, the peak
serum level may be normal, but the diurnal drop may not be
seen. In testing for these conditions, levels might be drawn at
8:00
A.M. and 4:00 P.M., and sometimes also at 8:00 P.M.
In testing for c
onditions involving decreased cortisol release,
a single morning sample is used.
In distinguishing Cushing’s syndrome from simple obesity, a
24-hour urine free cortisol level might be used. Urine free cor
-
tisol is proportional to serum free cortisol and is the most sen-
sitive and
specific test
for initial
screening for Cushing’s
syndrome.
Salivary cortisol reflects unbound cortisol and its diurnal
variation in serum. Morning salivary cortisol levels are de
-
creased in adrenal insufficiency, and evening salivary cortisol
levels—drawn between 11:00
P.M. and midnight—are in-
creased in Cushing’s syndrome.
Relevance to psychiatry and
behavioral science
HPA axis abnormalities are associated with a range of psychi-
atric disorders, including mood disorders, PTSD, schizophre-
nia, substance use disorders, and dementia. Glucocorticoids
such as cortisol have regulatory effects on serotonergic func-
tion and stimulant-like effects on dopamine neurotransmis-
sion. Excessive glucocorticoid activity likely contributes to
symptoms of psychotic mood disorders.
In general, cortisol levels are elevated along with corticotro-
pin-releasing factor (CRF) from the hypothalamus in major
depression and stress, whether short-lived or sustained. In
contrast, in PTSD, studies have found that cortisol levels are
low, although CRF levels in CSF are increased. This pattern is
consistent with increased sensitivity of the negative feedback
loop of the HPA axis. Further supporting this idea is the ex-
aggerated suppression of cortisol in response to dexametha-
sone in PTSD.
In major depression, cortisol suppression is reduced in re-
sponse to dexamethasone. In schizophrenia, cortisol levels
are elevated, and nonsuppression of cortisol in response to
dexamethasone is associated with negative symptoms and
cognitive impairment. Stress and cortisol elevation have been
implicated in numerous studies of relapse in substance-
dependent patients. Drugs such as cocaine, amphetamines,
alcohol, nicotine, and naloxone are associated with increased
cortisol levels.
https://t.me/med1917
88 Laboratory Medicine in Psychiatry and Behavioral Science
Cortisol (continued)
Preparation of patient Patients should fast from food and fluids for 4–8 hours before
testing and should refrain from physical activity for 10–
12 hours before testing. They should relax in the recumbent
position for 30 minutes before blood is drawn.
Indications • Diagnosing Cushing’s syndrome (hypercortisolism)
• Diagnosing Addison’s disease (hypocortisolism)
• Monitoring treatment for hypercortisolism or hypocor-
tisolism
• Evaluating stress-related conditions
Reference range Total cortisol
•8:00
A.M. 5–23 μg/dL
•4:00 P.M. 3–16 μg/dL
•8:00 P.M. <50% of 8:00 A.M. values
Free cortisol
•8:00
A.M. 0.6–1.6 μg/dL
•4:00 P.M. 0.2–0.9 μg/dL
Saliva free cortisol
•7:00
A.M. 1.4–10.1 ng/mL
• 10:00 P.M. 0.7–2.2 ng/mL
Urine free cortisol, 24-hour
• By radioimmunoassay: ≥21 years: 20–90 μg/day
• By high-performance liquid chromatography: ≤50 μg/day
Critical value(s) Extreme cortisol elevation in the morning coupled with lack
of diurnal variation suggests presence of carcinoma.
Increased levels •
Cushing’s syndrome/disease
• Ectopic ACTH production
• High stress (thermal, traumatic, or psychological)
• Metabolic syndrome (with hypertension, obesity)
• Burns, trauma, shock
• Postoperative state (e.g., post–coronary artery bypass
grafting)
• Severe disease (liver or kidney)
• Acute infectious or inflammatory disease
• Hyperpituitarism
• Hyperthyroidism
• Pregnancy
• Strenuous exercise
• Hypoglycemia
https://t.me/med1917
89 Laboratory Tests
Cortisol (continued)
Increased levels (continued) • Depression
• Drugs: corticotropin, estrogens, oral contraceptives, yo-
himbine, and vasopressin
Decreased levels • Adrenal insufficiency (Addison’s disease)
• Chromophobe adenoma
• Craniopharyngioma
• Hypophysectomy/Hypopituitarism
• Hypothyroidism
• Liver disease
• Postpartum pituitary necrosis (Sheehan’s syndrome)
• PTSD
• Rheumatoid arthritis
• Drugs: dexamethasone
Interfering factors Cortisol level increases with bright light exposure.
Delay in spinning sample may give spuriously decreased re-
sult.
Certain drugs can cause false elevations: interferon-γ, meto-
clopramide, quinacrine, and spironolactone.
Other drugs can cause decreased cortisol levels: lithium,
levodopa, phenytoin (in females), morphine, etomidate, and
ketoconazole.
Cross-references Adrenal Insufficiency
Cushing’s Syndrome
American Association for Clinical Chemistry: Testing.com. Available at: https://www.testing.com. Ac-
cessed May 2010.
Fauci AS, Braunwald E, Kasper DL, et al (eds): Harrison’s Principles of Internal Medicine, 17th Edition.
New York, McGraw-Hill, 2008
Fischbach F, Dunning MB: A Manual of Laboratory and Diagnostic Tests, 8th Edition. Philadelphia, PA,
Wolters Kluwer Health/Lippincott Williams and Wilkins, 2009
Sadock BJ, Sadock VA, Ruiz P (eds): Kaplan and Sadock’s Comprehensive Textbook of Psychiatry. Phila-
delphia, PA, Lippincott Williams and Wilkins, 2009
Wu AHB: Tietz Clinical Guide to Laboratory Tests, 4th Edition. St. Louis, MO, WB Saunders, 2006
https://t.me/med1917
90 Laboratory Medicine in Psychiatry and Behavioral Science
C-reactive protein (CRP)
Type of test Blood
Background and explanation
of test
CRP is an acute-phase reactant secreted by the liver in re-
sponse to inflammation or tissue injury when cytokines such
as interleukin-6 are present in the circulation. CRP levels are
very low or undetectable in the serum of healthy individu
-
als. CRP levels rise within hours when the inflammatory re-
sponse is stimulated and fall rapidly when inflammation
subsides.
Two separate CRP assays are available, both measuring the
same molecule in blood, although using different assays:
• CRP measures the molecule in the range 10–1,000 mg/L.
• High-sensitivity C-reactive protein (hsCRP) measures
the molecule in the range 0.5–10 mg/L.
The hsCRP test is used in the assessment of risk for vascular
events (e.g., heart attack, stroke), whereas CRP is used in the
evaluation of patients at risk of bacterial infections or major
inflammatory processes. CRP is analogous to the ESR, with
the latter reflecting conditions involving increased plasma
protein/fibrinogen levels such as autoimmune disease, and
CRP reflecting inflammation from infection or trauma. High
CRP levels have been identified in severe COVID-19 infec
-
tion, even though CRP elevation is not usually found with
viral infections. CRP is strongly associated with the severity
and prognosis of COVID-19 infection.
Relevance to psychiatry and
behavioral science
CRP can be helpful in the evaluation of conditions such as
bacterial meningitis, SLE, or pancreatitis. Elevation of CRP
is associated with delirium and the metabolic syndrome.
There is some evidence that CRP might be useful as a marker
of the phases of illness in schizophrenia.
Preparation of patient None
Indications CRP
• Assessing activity of autoimmune disease
• Assessing activity of inflammatory disease
• Assessing severity and monitoring treatment of bacte-
rial infection
• Evaluating pancreatitis
• Detecting infection after surgery
• Detecting transplant rejection
hsCRP
• Stratification of risk for cardiovascular disease
Reference range CRP <10 mg/L generally accepted as normal
In most healthy adults, CRP <3 mg/L
https://t.me/med1917
91 Laboratory Tests
C-reactive protein (CRP) (continued)
Reference range (continued) hsCRP cardiovascular risk stratification:
• Low risk: < 1.0 mg/L
• Average risk: 1.0–3.0 mg/L
• High risk: 3.1–9.9 mg/L
• Very high risk: >9.9 mg/L
Critical value(s) CRP >50 mg/L is strongly associated with bacterial infection
See risk stratification above for hsCRP.
Increased levels Large increase: active inflammation, cancer, serious bacterial
infection, burns
Minor increase: mucosal infection (e.g., sinusitis, periodonti-
tis), obesity, insulin resistance, pancreatitis, smoking, ure-
mia, cardiac ischemia, oral hormone replacement therapy,
sleep disturbance, chronic fatigue, alcohol use, depression,
aging
Decreased levels Not applicable
Interfering factors Obesity and late-stage pregnancy affect results.
Chronic inflammatory conditions such as arthritis may in-
terfere with the evaluation of new inflammatory process.
Recent illness may invalidate hsCRP risk stratification.
Cross-references Delirium
Erythrocyte Sedimentation Rate
High-Sensitivity C-Reactive Protein
Meningitis
Metabolic Syndrome
Systemic Lupus Erythematosus
Cardiovascular Risk Assessment (Appendix C)
Abi-Saleh B, Iskandar SB, Elgharib N, et al: C-reactive protein: the harbinger of cardiovascular diseases.
South Med J 101:525–533, 2008
American Association for Clinical Chemistry: Testing.com. Available at: https://www.testing.com
. Ac-
cessed November 2021.
ARUP Laboratories: C-reactive protein, in Lab Test Directory. Salt Lake City, UT, ARUP Laboratories,
2021. Available at:
https://ltd.aruplab.com/Tests/Pub/0050180. Accessed November 2021.
Ben-Yehuda O: High-sensitivity C-reactive protein in every chart? The use of biomarkers in individual pa-
tients. J Am Coll Cardiol 49:2139–2141, 2007
Bray C, Bell LN, Liang H, et al: Erythrocyte sedimentation rate and C-reactive protein measurements and
their relevance in clinical medicine. WMJ 115(6):317–321, 2016
NACB LMPG Committee Members, Myers GL, Christenson RH, et al: National Academy of Clinical Bio-
chemistry Laboratory Medicine Practice Guidelines: emerging biomarkers for primary prevention of
cardiovascular disease. Clin Chem 55(2):378–384, 2009
https://t.me/med1917
Соседние файлы в папке Библиотека им академика М.И. Перельмана