Equipment Application and Cleanliness Perform Quality Control Procedures

The quality of care you provide depends in part on the proper performance of the equipment you use to diagnose or treat your patients Quality control (QC) is a process designed to ensure that the devices you use on patients regularly perform as expected Ensures consistently accurate measurements with diagnostic equipment Ensures proper device function and patient safety with therapeutic equipment

NBRC Expectations You are familiar with the basics of QC, as applied to common medical devices used in respiratory care

Laboratory Blood Gas and Hemoximery Analyzers Quality control processes focus on eliminating errors in: Sample collection (pre-analytical phase) Sample measurement (post-analytical phase) Reporting (post analytical phase)

Pre-Analytical Phase Blood collection and handling procedures prior to sample analysis Most common pre-analytical errors that affect measurements are: Air contamination Venous admixture Excess anticoagulant Continued blood metabolism Need to Be proficient in sampling techniques/equipment used to draw from various sites Strictly comply with applicable infection control procedures Avoid interpretation errors by documenting FiO2 Oxygen delivery device Mode of ventilation Results of related assessments made at time of sampling Always ensure that the blood sample is free of these common errors.

Analytical Phase Involves four key elements Analyzer calibration and calibration verification Calibration is the process whereby the response of an instrument is compared and adjusted to a known standard Standards used to calibrate ABG machines include precision gases and buffer solutions with know values for pH, PCO2, and PO2 Standards used to calibrate hemoximeters are solutions with known values for total Hb, HbO2, carboxyhemoglobin (COHb), and methemoglobin (MetHb) Calibration involves adjusting the analyzer to ensure that its response is accurate and linear Two-point calibration adjusts both the offset (zero point) and gain (slope) of the instrument. Devices with automated calibration require calibration verification by analyzing a pre-prepared control media with known measurement values.

Analytical Phase (cont.) Actual sample testing Always performed by individuals who meet specific competency requirements for the procedures Sample testing must follow protocol aligned with manufacturer operation specifications When performing the analysis you must Confirm that the specimen was properly labeled and stored prior to analysis Assess the sample for any obvious pre-analytical errors (air bubbles or clots Confirm that the applicable analyzer calibration procedures were completed prior to analysis Analyze the sample within an acceptable period of time Ensure that the sample is properly aspirated / injected into analyzer

Analytical Phase (cont.) Interpretation of the results Test should always be interpreted by the ordering physician and must consider rationale for the measurement and the related patient information / situation Alert or panic values should be pre-established for notification and follow-up Ongoing review of quality control and proficiency testing results Must record and continuously monitor data using accepted statistical methods Commonly plotted on a Levy-Jennings chart where control media analyses over multiple measurements are compared to the mean and standard deviation for the control media Frequent measurements (errors) outside the standard deviation indicate an instrument that is “out of control” Problem identification, appropriate corrective action, and confirmation of analyzer accuracy is required.

Point of Care Analyzers All POCT must be auditable (traceable to patient tested, instrument operator, date and time of test, and instrument and process used) Most POCT analyzers use self-contained cartridges for calibration. Failure to calibrate stops machine from functioning First, rerun with new cartridge Second, remove from service if still unable to calibrate Most facilities require POCT results to be compared to results from a calibrated bench-top analyzer as part of QC program

Pulmonary Function Equipment Quality assurance program makes certain PFT data is accurate and reproducible Must include: Proper technician training and review Accurate spirometry equipment Confirm absolute volume and flow values Check volume and flow linearity Assess system leakage Validate time measurements Daily spirometer checks

Pulmonary Function Equipment, cont. Individual maneuver validity checks Accurate data depends on Proper instruction and coaching of the patient Recognition and correction of errors due to poor or incorrect patient performance Obtain at least 3 error–free maneuvers that meet basic acceptability standards, free of: A slow or false start to the maneuver Coughing during the maneuver Breathing during the maneuver Variable effort Exhalation time less than 6 seconds Ensure reproducibility of results by confirming that the two largest values for both the FVC and FEV1 are within 0.150L of each other Monthly spirometer quality reports Documentation of equipment maintenance

Mechanical Ventilators Operation verification via power-on self test (POST) and extended self-test (EST) POST Tests microprocessor function Zeros the sensors Performs some basic checks related to patient functions, such as leak tests. Always confirm successful POST before applying ventilator to patient and whenever circuit is changed EST POST + series of more comprehensive function checks Perform between each application of a ventilator on different patients Should be fully documented in writing A fail in any portion of a self-test requires removal from service for repair

Oxygen Analyzers Four steps for calibration Expose the sensor to a contained source of 100% O2 (in a plastic bag or glove) After the reading stabilizes, adjust the analyzer to 100% Remove the sensor from the 100% O2 source After restabilization confirm a reading of 21% Calibration should occur under same conditions under which measurement will occur (temperature, atmospheric pressure, humidity)

Pulse Oximeters Operational verification procedure Connect the device to a normal person Compare the pulse reading with the actual pulse measured manually Check and confirm an SpO2 reading of 97-100% Confirm loss of signal detection by removing the device

Common Errors to Avoid on the Exam Never aspirate an arterial blood gas sample or mix it if it contains air bubbles Do not use any gas analyzer that is not or cannot be calibrated at two points in the range of expected results Do not use any pH / blood gas analyzer for reporting results if the most recent quality control results violate any of the rules for acceptable performance Never proceed with pulmonary function testing if the spirometer has an uncorrected leak Never apply a ventilator to a patient if it has failed its operational verification testing Never circumvent medical gas connection safety systems (PISS, DISS)

Exam Sure Bets Always perform a two-point calibration prior to using a gas analyzer or monitor Always use tonometry whenever the accuracy of a blood gas analyzer’s PO2 and PCO2 measurements is in doubt Always document the patient’s FiO2, oxygen delivery device, mode of ventilation, and the results of any related assessments made when obtaining a blood sample for analysis Always perform leak testing on spirometers before volume calibration

More Exam Sure Bets Always perform an operational verification test prior to using a mechanical ventilator on any patient Always include a statement about test quality in the final report of every pulmonary function test When establishing quality assurance programs, an assessment of the competency of the technician(s) must be performed initially and periodically thereafter.

Jones and Bartlett Publishers Reference: Certified Respiratory Therapist Exam Review Guide, Craig Scanlon, Albert Heuer, and Louis Sinopoli Jones and Bartlett Publishers