10 June 2023
: Case report 
Diagnostic Dilemma in a Case of Lyme Borreliosis Presenting as Severe Anion Gap Metabolic Acidosis: A Case Report
Unusual clinical course, Challenging differential diagnosis, Rare coexistence of disease or pathology
Lindsey A. Wallace1ABDEF*, Sarah Cullison1AE, Jacob Bowdon1BCDEF, Aditya Shah2DE, Sumera Ahmad3ADEFDOI: 10.12659/AJCR.939196
Am J Case Rep 2023; 24:e939196
Table 1. Pertinent abnormal laboratory values on day of admission.
| Patient’s result | Reference range | |
|---|---|---|
| Venous pH | 6.94 | 7.32–7.43 |
| Venous carbon dioxide | 33 mmHg | 41–51 mmHg |
| Venous bicarbonate | 7 mmol/L | |
| Lactate | 10.8 mmol/L | 0.5–2.2 mmol/L |
| White blood cell count | 15.4×10/L | 3.4–9.6×10/L |
| Potassium | 5.9 mmol/L | 3.6–5.3 mmol/L |
| Anion gap | 27 | 7–15 |
| Bicarbonate (from basic metabolic panel) | 6 mmol/L | 22–29 mmol/L |
| Phosphorus | 5.4 mg/dL | 2.5–4.5 mg/dL |
| eGFR by Cystatin C | 46 mL/min/BSA | >60 mL/min/BSA |
| Osmolality (serum) | 322 mOsm/kg | 275–295 mOsm/kg |
| Osmolar gap | 20 mOsm/kg | <10 mOsm/kg |
| Acetaminophen | <10 mcg/mL | Therapeutic range 10–30 mcg/mL |
| Salicylate | <0.3 mcg/dL | <30 mcg/dL |
| Blood drug screen | Not detected | Not detected |
| Heavy metal screen | Not detected | Not detected |
| Urine drug screen | Negative | Negative |
| * Calculated, see bicarbonate from basic metabolic panel for normal ranges. ** Normal range for osmolar gap []. *** Blood drug screen tested the following: acetone, methanol, isopropanol, methanol, and ethylene glycol. # Heavy metal screen tested the following: arsenic, cadmium, lead, and mercury. ## Urine drug screen tested the following: Tetrahydrocannabinol, barbiturates, benzodiazepines, phencyclidine, amphetamines, opioids, cocaine, ethanol, and tricyclic antidepressants. eGFR – estimated glomerular filtration rate. | ||