11 - Quality Assurance and Infection Control

quality control (QC)

(set of) procedure(s) intended to ensure product/service adheres to defined set of criteria or meets requirements of client/customer

quality assurance (QA)

program for systematic monitoring and evaluation of aspects of project/service/facility to ensure standards are met

quality improvement (QI)

systematic and continuous actions that lead to measurable improvement in health services and health of patients

elements of quality assurance

• methodology

type of equipment, manufacturer’s recommendations

elements of quality assurance

• equipment maintenance

• type and complexity of tests (short-/long-term)

• daily maintenance (replace disposable items)

• preventative maintenance (scheduled)

• corrective maintenance (unscheduled)

elements of quality assurance

• control methods

• known test sample used to determine accuracy and precision

• needed software and hardware

• biologic controls (healthy people)

elements of quality assurance

• testing techniques

methods, guidelines, schedules, and protocols

accuracy

how true something is

precision

reproducibility

bias

systematic inaccuracy

linearity

resemblance to a straight line

QA for spirometers

• equipment calibration

• can measure ≥ 8 L

• exhalation maneuvers for ≥ 15 seconds

• volume accuracy: ±2.5% or ±0.05 L, whichever is greater

  • flow range: 0-14 L/sec

  • 3-L syringe accuracy: ±0.5%

• flow accuracy: ±5% (-14 to +14 L/sec)

  • sensitivity: 0.25 L/sec

• flow and volume linearity: syringe used 3 times for each

QA for spirometers

• calibration schedule

TEST	MINIMUM INTERVAL	ACTION
volume	daily	calibration check with 3-L syringe
leak	daily	3 cmH2O constant pressure for 1 minute
volume linearity	quarterly	1-L increments with calibrating syringe
flow linearity	weekly	test ≥ 3 different flow ranges
time	quarterly	mechanical recorder check with stopwatch

QA for spirometers

• technique validation (FVC and FEV₁)

• ATS criteria

• repeatability criteria

• convert values to BTPS

QA for body plethysmograph

• equipment calibration (TLC)

• performed daily

  • mouth pressure via manometer

    • > ±50 cmH2O at ≥ 8 Hz

  • mouth flow and volume via 3-L syringe

  • change in box pressure via small pump

    • ±0.2 cmH2O

• biological controls tested regularly (bimonthly)

• Levey-Jennings plot

QA for body plethysmograph

• technique validation (TLC)

• allow sufficient time for temperature stabilization

• patient wears nose clips and holds cheeks while panting

• repeat panting until ≥ 3 FRCs within ±5%

• inspiratory VC after panting

QA for D_LCO

• equipment calibration

• volume measurements (daily)

  • volume ±2% over 8-L range

• He and CO analyzer linearity

  • max error ≤ ±0.5%

• computer timing

  • ±1% in 10 seconds

• dead space of circuit <200 mL

• QC done weekly using calibrated syringe

QA for D_LCO

• technique validation

• inhaled volume ≥ 90% of best VC

• inhale test gas within 4 seconds

• alveolar gas sample within 4 seconds of exhalation

• minimum of 2 tests (4 seconds between)

• tests within 2 mL/min/mmHg of each other

QA for gas analyzers

• calibrated to match physiologic range of measurements

• 2-point calibration

  • O₂, He, CO, NO

• calibrated before each patient

ABGs

• CLIA

Clinical Laboratory Improvement Amendment

ABGs

• pre-analytical

• air bubbles

• venous admixture

• continued metabolism (ice if >15 minutes)

• infection control

ABGs

• analytical (including hemoximeters)

• analyzer calibration/verification

• values

  • pH: 6.840 + 7.384

  • PO₂: 80 + 150

  • PCO₂: 40 + 80

• sample testing

• review QC and proficiency testing

infection control

• closed-circuit with volumetric spirometer

• bellows flushed with room-air 5 times between tests

• change non-disposable circuits after each patient

infection control

• open-circuit

follow department’s guidelines on how to clean/dispose equipment