Preparing for the CRT (Certified Respiratory Therapist) exam? Blood Gas Qc is one of the areas our deck drills hardest: 10 of its 1040 flashcards focus on blood gas qc, covering topics like QC, SD, External Quality Control, Proficiency Testing. Try the sample questions below — every card is a real question-and-answer pair from the full deck.
10
Cards on this topic
1040
Total CRT cards
$7
Full access
A blood gas analyzer's pH quality control (QC) results show six consecutive points gradually increasing toward the +2 standard deviation (SD) limit, though still within range. What is this pattern called and what are the most likely causes?
Show answer →This is a TREND. Trends indicate a gradual loss of reliability in the sensing system. Common causes: 1. Deteriorating reagent/buffer solution. 2. Electrode aging or protein buildup on the membrane. 3. Gradual failure of electronic components. NBRC Tip: Distinguish this from a SHIFT (sudden jump). Trends require proactive maintenance before the analyzer goes out of control.
Name the three primary electrodes in a standard blood gas analyzer and identify which specific electrochemical principle each utilizes to measure its respective parameter.
Show answer →1. Sanz Electrode (pH): Uses two half-cells (measuring and reference) to determine hydrogen ion activity via voltage difference. 2. Severinghaus Electrode (PCO2): A modified pH electrode measuring CO2 via a bicarbonate buffer and permeable membrane. 3. Clark Electrode (PO2): Uses polarography (amperometry) where oxygen is reduced at the cathode, generating a measurable current.
According to NBRC standards, what is the required frequency for performing a 1-point and 2-point calibration on a benchtop blood gas analyzer?
Show answer →1-Point Calibration: Must be performed before every patient sample or at least every 30 minutes to adjust for electronic drift (intercept). 2-Point Calibration: Must be performed every 8 hours or after every 50 samples to adjust for the slope (sensitivity). Note: Modern analyzers often perform auto-cal at these intervals. Always ensure the analyzer is in control before reporting patient results.
What is the purpose of External Quality Control (Proficiency Testing), and how does it differ from Internal Quality Control?
Show answer →Internal QC (Levey-Jennings) ensures the machine is consistent with itself over time (precision). External QC (Proficiency Testing) involves an outside agency (e.g., CAP) sending blind samples to the lab. The lab's results are compared to other labs using the same equipment. This ensures ACCURACY (validity) and is required by CLIA '88 regulations for lab certification.
A patient's ABG results are: pH 7.42, PaCO2 38, PaPO2 152. The patient is on room air. Why should the therapist question the validity of these results?
Show answer →The PaPO2 is physiologically impossible on room air ($FiO_2$ 0.21). Using the Alveolar Air Equation, the maximum $PAO_2$ on room air at sea level is ~100 mmHg. A $PaPO_2$ of 152 suggests: 1. Analyzer calibration error. 2. Pre-analytical error (massive air bubble in sample). 3. Error in recorded $FiO_2$ (patient was actually on oxygen). Strategy: Always cross-check $PaPO_2$ against $FiO_2$ to ensure clinical consistency.
Keep going
You just saw a few. The full deck covers every CRT topic.
One-time payment · less than 1¢ per card · 30-day money-back guarantee
Try 30 free CRT cards firstThe full CRT deck contains 1040 flashcards, and 10 of them focus on blood gas qc. This page shows 5 free samples.
Our CRT deck dedicates 10 of 1040 cards (1%) to blood gas qc — always cross-check the official NBRC exam outline for the current blueprint weighting.
Yes — the samples on this page are free, and the CRT preview page has 30 more free cards. Full access to all 1040 cards is a one-time $7.
Assessment
110 cards
Basics
70 cards
Diagnostics
210 cards
Emergency
20 cards
Management
140 cards
Monitoring
90 cards
Pathology
80 cards
Pharmacology
90 cards
Procedures
220 cards
CRT practice test
20 mixed questions across every topic, with answers — see where you stand →
CRT study guide
Topic weights, difficulty breakdown and a 5-step study plan →
Eligibility rules, fees, question counts and passing standards are set by the certifying body and change over time. Always confirm them at the source before you apply or schedule your exam — our flashcards are practice material, not the official handbook.