The biochemistry telephone limits for Berkshire are listed below.
Results outside of these limits will be notified by telephone to the requesting location or to the out of hours GP service, as appropriate. These limits are based where possible on the Royal College of Pathologists document: ‘The Communication of Critical and Unexpected Pathology Results, 2017’.
Results falling outside the RED limits indicate significantly abnormal results and will be phoned on a 24/7 basis with an indicative timescale of 2 hours.
Results falling outside the amber limits but NOT the RED limits will be telephoned at the next opportunity, including the next working day if out of hours.
Analyte | Age | Amber Telephone Limit | Red Telephone Limit | ||
Low | High | Low | High | ||
Sodium | 0-15 y | 130 | 150 | ||
≥16 y | 125 | 120 | 150 | ||
Potassium | 2.8 | 2.5 | 6.5 | ||
Urea | 0-15 y | 10 | |||
≥16 y | 30 | ||||
CKD | 50 | ||||
Creatinine | 0-15 y | 200 | |||
≥16 y | 354 | ||||
CKD | 800 | ||||
AKI | 1 (if K > 6.0) | 2 & 3 | |||
Glucose | 0-15 y | 2.5 | 15 | ||
≥16 y | 20 | 2.5 | 25 | ||
Diabetic | 25 | 2.5 | 30 | ||
Ad Calcium | 3.0 | 1.8 | 3.5 | ||
Magnesium | 0.4 | ||||
Phosphate | 0.4 | 0.3 | |||
ALT | 510 | ||||
Amylase | 350 | 500 | |||
AST | 480 | ||||
CK | 1500 | 5000 | |||
Bicarbonate | 10 | 40 | |||
Bile Acids | >15 IF pregnant | ||||
Bilirubin | 1d | 100 | |||
2-5d | 200 | ||||
6-24d | 500 | ||||
25d-1y | 21 | ||||
Bilirubin (Conj) | <1m | 25 | |||
CRP | GP/Outpatient | 200 | |||
Inpatient | 300 | ||||
Iron | <10y | 40 | |||
Triglyceride | 20 | ||||
Urate | 340 IF pregnant | ||||
Paracetamol | All detectable (>1.2) | ||||
Salicylate | 300 | ||||
Digoxin | 2.5 | ||||
Lithium | 1.0 | 1.5 | |||
Phenytoin | 25 | ||||
Theophylline | 25 | ||||
Cortisol | 100 | ≤50 | |||
Short Synacthen Test | 30 min <100 | ||||
TSH | 30 | 100 | |||
FT4 | 35 | ||||
FT3 | 10 | ||||
Troponin T | GP | >14 | |||
Xanthochromia | All Positive | ||||
Ammonia | <4w | 100 | |||
1m-15y | 50 | ||||
≥ 16y Male | >55 | ||||
≥ 16y Female | >48 | ||||
Ethanol | 1-15y | All Detectable | |||
≥ 16y | 4000 | ||||
Urine PCR | 30 IF Pregnant | ||||
PLGF | <100 | ||||
External Laboratory Results | Any abnormal results phoned from an external laboratory must by urgently phoned |