Nurse Hazel receives emergency laboratory results for a client with chest pain and immediately informs the physician. An increased myoglobin level suggests which of the following?
A. Liver disease
B. Myocardial damage
C. Hypertension
D. Cancer
Correct Answer: B. Myocardial damage
Detection of myoglobin is a diagnostic tool to determine whether myocardial damage has occurred. Myoglobin, an oxygen-carrying protein found in cardiac muscle and striated skeletal muscle, presents an attractive alternative to CPK and LDH in the emergency department setting for identification of acute myocardial infarction. Myoglobin levels may be elevated in the serum within one hour after myocardial cell death with peak levels reached within four to six hours.
Option A: Liver disease usually has elevated hepatic enzymes, elevated serum bilirubin, elevated serum ammonia, low levels of glucose, and elevated creatinine, among others. In chronic liver disease, there is inflammation and destruction of hepatocytes that leads to the release of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), hence the high levels of these markers in the blood. Other parameters (ALP and GGT) of LFTs also appear elevated in cholestatic conditions like PBC.
Option C: Initial laboratory tests for hypertension may include urinalysis; fasting blood glucose; hematocrit; serum sodium, potassium, creatinine, and calcium; and lipid profile. The evaluation consists of looking for signs of end-organ damage and consists of the following: blood workup including complete blood count, ESR, creatinine, eGFR, electrolytes, HbA1c, thyroid profile, blood cholesterol levels, and serum uric acid; 12 lead ECG (to document left ventricular hypertrophy, cardiac rate, and rhythm); and urine albumin to creatinine ratio.
Option D: Cancer is diagnosed based on a number of diagnostic tests and procedures and radiology. The 2015 NHIS findings show that the utilization of cancer screening tests for cervical, colorectal, and breast cancer was below Healthy People 2020 target. In 2015, rates for Pap tests, mammography, colorectal cancer screening were 80%, 70%, and just above 60 %, respectively, whereas the HP 2020 targets are 93% for Pap tests, 81% for mammography, and 70.5 % for colorectal cancer screening.