An 82-year-old man presented to the emergency department complaining of dyspnea, increased sputum and somnolence.
Relevant personal history included: hypertension, diabetes mellitus, paroxysmal atrial fibrillation, associated oropharyngeal radical syndrome and squamous cell carcinoma T3N0M0 with inappropriate Secretion Syndrome.
Its usual treatment consists of 100 mg acetylsalicylic acid, 1 mg lorazepam, 8 mg silidosin and 20 mg acetylsalicylic acid, all in a single daily dose (tolvaptan suspended after last admission).
The patient was admitted with a diagnosis of bilobar pneumonia due to bronchoaspiration associated with hypoosmolar hyponatremia (sodium 101 meq/L (normal range (N.R.) 135-145 meq/L), 280 mmol/L).
He has severe dysphagia and bleeding associated with pharyngeal tumor planning gastrostomy and starting parenteral nutrition through peripheral route, empirical antibiotic treatment with meropenem 1000 mg/8h and normal saline replacement with normal saline (IDMD 500-4 mL 0.9%).
Upon admission to Internal Medicine, clinical and analytical improvement was observed (sodium 130 meq/L), and the Nephrology Department assessed paraneoplastic SIADH with good response to therapy that suspended serum.
Low-dose tolvaptan treatment was restarted to avoid excessive correction (7.5 mg/24 h) and then increased at the usual dose of 15 mg/24 h.
The patient had a febrile syndrome with no clear focus. Empirical treatment was started with cefepime 2000 mg/12 h, vancomycin 1000 mg/12 h and oseltamivir 75 mg/12 h.
Haemocultives were requested and tested positive for Streptococcus epidermis methicillin-resistant, sensitive to vancomycin (MIC = 2 mg/L), so antibiotic treatment was maintained considering catheter bacteremia.
Transthoracic echocardiography was performed ruling out endocarditis.
Blood cultures were negative.
Three days after starting treatment, vancomycin was increased to 1250 mg/12 h due to persistent fever peaks, CRP 9.6 mg/dL (R.N: 0.0-0.5 mg/dL) and procalcitonin (0.01 mcg/dL).
After two days, new plasma concentrations were extracted, being even lower (8.4 Pharmacokinetic μg/mL) (the possibility of error in sample extraction or in the accuracy and precision of the diagnostic test was assessed by performing a 1000-mg
Oral metronidazole 500 mg/8 h was added to treatment due to persistent Clostridium difficile diarrhea. Two days later, worsening of renal function was observed due to digestive losses, causing pre-renal failure with pre-renal hyponatremia serum levels of vancomycin (sodium:
Acute renal failure developed and creatinine values of 5.07 mg/dL were reached in the days after discontinuation of intravenous vancomycin.
Nine days after suspension, elimination remains very slow, with a t1/2 of 132 h and plasma concentration of 25.5 μg/mL is reached.
Concentrations below the therapeutic range are not reached within 15 days after discontinuation of antibiotic therapy.
The Nephrology Department administers enteral nutrition to prevent diarrhea, and performs natremic correction by suspending treatment with enteral nutrition, increasing the volume of mL of vancomycin and forced voiding therapy (saquinavir therapy).
Vancomycin is administered by gastrostomy due to persistent Clostridium difficile diarrhea despite treatment with oral metronidazole.
Subsequently, the patient presents hypertension, with abundant diuresis and very positive free water, resulting in hypernatremia (sodium 157 meq/L) despite the suspension of tolvaptan, which is why salty sera are reduced.
She also had metabolic acidosis that was corrected with bicarbonate, and respiratory alkalosis. A chest X-ray was performed for suspected left pleural effusion.
Due to persistent high plasma concentrations of vancomycin and hypernatremia, serum therapy is readjusted and desmopressin is added.
Finally, resolution of bacteremia associated with Streptococcus epidermc methicillin-resistant vancomycin managed conservatively and enteral nutrition was suspended after renal therapy with vancomycin intoxication, paulatin resolution of the diarrhea episode, recovery of metronidazole
