Class A fires involve wood, paper clothing or other combustibles. This is the only class of fire that can be put out with water, other fires may become more dangerous if water is added. Class D fires involve combustible or reactive metals such as sodium, potassium, magnesium, or lithium. Class C fires involve electrical equipment. Class B fires involve flammable liquids or gases such as paint or propane. Fire extinguishers are available for all classes of fires, but should only be used by trained individuals who are sure that the extinguisher type is correct for the type of fire. Large fires and fires involving multiple classes of fire must be handled by trained firefighting personnel.

Specimens for cholesterol testing require centrifugation. Tests that are carried out on whole blood, such as CBC, hemoglobin A1c, whole blood lead analysis, and cyclosporine do not require centrifugation; however, if they are accidentally centrifuged, it may be possible to carry out testing on some specimens after the specimens are examined by a technician. Collection tubes with whole blood specimens are usually placed in a device that gently rocks the tubes while awaiting examination.

If petechiae are noted on the patient's skin distal to the tourniquet, this suggests that the patient may have a coagulation defect, such as thrombocytopenia, and may have excessive bleeding after venipuncture. Other causes of petechiae can include medications (e.g„ aspirin, anticoagulants) and some types of infectious/inflammatory disorders. Petechiae are nonraised lesions that are small (<3 mm) in diameter.

Newborn screening should be carried out after the first 24 hours of life. If a neonate is discharged from the hospital prior to 24 hours and tested before discharge, the parent(s) should be advised to have the child retested because some tests are not accurate prior to the first 24 hours. The test is usually carried out with a capillary specimen from a heelstick. Tests included in newborn screening may vary somewhat from one state to another, but typically include tests for metabolic disorders, hormone disorders, hemoglobin disorders, and other rare conditions.

After collecting a blood sample, a tube containing sodium citrate as an additive should be inverted 3-4 times rather than the 5-10 times required of other additives. Sodium citrate is an anticoagulant that binds to calcium, preventing blood clotting. Sodium citrate is preferred for coagulation tests (partial thromboplastin time [PTT] and activated partial thromboplastin time [aPTT]) because it best preserves coagulation factors. Tubes that contain sodium citrate have light- blue colored stoppers or black stoppers in special tubes used for the erythrocyte sedimentation rate. Shaking or inverting too much may activate the platelets, resulting in a shortened coagulation time.