Which of the following ECG rhythm interval measures is considered abnormal?
QTc interval 0.33 to 0.47 seconds
QT interval that varies with HR
QRS interval <0.12 seconds
PR interval 0.12 to 0.24 seconds
The Correct Answer is A
The QTc (corrected QT) interval is a measure of the time it takes for the ventricles to depolarize and repolarize during a cardiac cycle. It is corrected for heart rate (HR) to account for variations in the cardiac cycle length.
The normal range for the QTc interval varies depending on the calculation method used but generally falls within 0.36 to 0.44 seconds. In the given options, the range of 0.33 to 0.47 seconds for the QTc interval is wider than the normal range, suggesting a prolonged QTc interval, which can be indicative of a potential risk for arrhythmias, including ventricular tachycardia and torsades de pointes.
B. QT interval that varies with HR in (option B) is normal because The QT interval alone can vary with heart rate, and this is considered a normal physiological adaptation.
C. QRS interval <0.12 seconds in (option C) is normal because The QRS interval represents the time it takes for ventricular depolarization and is normally less than 0.12 seconds.
D. PR interval 0.12 to 0.24 seconds in (option D) is normal because The PR interval represents the time it takes for atrial depolarization and conduction through the AV node. The normal range is typically 0.12 to 0.20 seconds.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
Hemorrhagic shock is characterized by severe blood loss, leading to inadequate tissue perfusion and hypovolemia. The primary goal in the initial management of hemorrhagic shock is to restore intravascular volume and improve tissue perfusion. Administering intravenous fluids, such as normal saline solution, is a critical intervention to address hypovolemia and improve blood pressure.
A. Give Plasmanate 1 unit now in (option A) is incorrect because: Plasmanate is a plasma-derived product used to replace coagulation factors. While it may be necessary to address coagulation abnormalities, administering intravenous fluids to restore volume takes priority over specific blood products.
B. Prepare for endotracheal intubation in (option B) is incorrect because Endotracheal intubation may be required in cases of impending respiratory failure or compromised airway, but it should not be the first action in addressing hypovolemic shock.
D. Type and crossmatch for 4 units of packed red blood cells (PRBCs) in (option D) is incorrect because transferring packed red blood cells is an important intervention to address blood loss and improve oxygen-carrying capacity. However, before administering blood products, it is crucial to stabilize the patient's hemodynamics through fluid resuscitation.
Therefore, in a patient with hemorrhagic shock, the nurse's first priority among the given options is to give normal saline solution of 250 mL/hr to restore intravascular volume and improve tissue perfusion.
Correct Answer is B
Explanation
Fresh frozen plasma (FFP) is a blood product that contains various clotting factors, including factors II, V, VII, VIII, IX, X, XI, and XIII. These clotting factors are essential for the normal coagulation process. In patients with shock, coagulation abnormalities can occur, and administration of FFP can help replenish the deficient clotting factors and restore proper coagulation function.
The other options mentioned are not the primary components replaced by fresh frozen plasma:
A. Red blood cells are in (option A) is incorrect because Red blood cells carry oxygen and are typically replaced by packed red blood cell transfusions in cases of significant blood loss or anemia. Fresh frozen plasma does not contain a significant amount of red blood cells.
C. Platelets in (option C) is incorrect because: Platelets play a role in blood clotting and are typically replaced by platelet transfusions in cases of thrombocytopenia or platelet dysfunction. Fresh frozen plasma may contain a small number of platelets but is not the primary source for platelet replacement.
D. White blood cells in (option D) is incorrect because White blood cells are part of the immune system and are not typically replaced using fresh frozen plasma. Fresh frozen plasma does not contain a significant amount of white blood cells.
Therefore, fresh frozen plasma is primarily administered to patients in shock to replace clotting factors and help restore proper coagulation function.
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