Sweat Chloride
(SCT)

Sample type

Sweat

Uses

A sweat test is used to diagnose cystic fibrosis.

Precautions

Patient Preparation:

-Each patient being considered for sweat collection should be: >48 hours old, well-hydrated, clinically stable, free of acute illness, not receiving mineralocorticoids, not on oxygen by open delivery, and should not be receiving bromide or iodide (as this interferes with chloride).

-should avoid applying any creams or lotions to the skin for 24 hours before the procedure.

Interfering factors

Improper testing technique

Atopic dermatitis

Untreated adrenal insufficiency

Glycogen storage disease

Panhypopituitarism

Hereditary nephrogenic diabetes insipidus

Hypothyroidism

Pancreatitis

Malnutrition

Mucopolysaccharidosis

Ectodermal dysplasia

Prostaglandin E1 infusion

Bromide or Iodide

Pre-analytical errors

Sweat collection yielding <15 uL of specimen within the 30 minute, patient receiving bromide or iodide,unlabeled sample.

The corrective actions

The sample should be rejected and another sample requested.

Post-analytical errors

1-Writing a wrong result or wrong name in the report

2-report were sent to incorrect patient

The corrective actions

1- If the report is not delivered to the patient and this error is discovered, the correct result or the correct name must be written, but if the report is delivered to the patient, you must communicate with the patient, apologise to him, and tell him that an error has occurred and replace it with the correct report.

2-Communicate with patient ,apologizing for the error, and providing him with the correct report.

Reference range

Newborns <6 months-

Negative: 0-29 mEq/L

Borderline: 30-59 mEq/L

Positive: >OR = 60mEq/L

-Children > 6 months

Negative: 0-39 mEq/L

Borderline: 40-59 mEq/L

Positive: >OR= 60 mEq/L