A 76-year-old female nursing home resident was admitted to the hospital for complicated urinary tract infection and hypernatremia. The patient is confused and has a blood pressure of 80/40, heart rate of 110 bpm, temperature of 38.5°C, respiratory rate of 16/min, and saturation of 95% on room air. Her initial labs are significant for white blood cell count of 15,000 with 10% bands, sodium of 169, bicarbonate of 18, blood urea nitrogen of 32, and creatinine of 2.0 (baseline creatinine is normal).
1. What is the best intravenous fluid solution to administer and at what rate in this case?
This patient is hypotensive secondary to severe sepsis or possible septic shock. She also has hypernatremia most likely related to dehydration. Half-normal saline and dextrose 5% are the best fluids for patients with hypernatremia. However, this patient is in shock and she needs aggressive volume resuscitation. Half-normal saline or 5% dextrose does not support the blood pressure as isotonic fluids do. The best fluid in this case is normal saline. The initial rate should be given as boluses until the central venous pressure is >8 and the mean arterial blood pressure is >65. Of note, the sodium concentration in NS is 154 mEq/L, which is lower than this patient's serum sodium concentration, so NS will not worsen her hypernatremia. Once the patient is stable, fluids can be changed to 1/2 NS or D5W to correct the hypernatremia.
Intravenous fluids are “medications” that have side effects. Using them in inappropriate settings can cause serious complications and prolong hospitalization stays. For example, patients with acute respiratory distress syndrome (ARDS) do better when they are on conservative fluid management. Loading patients with a high volume of fluids can cause pulmonary edema even in patients with no history of heart failure.
The most important indications for intravenous fluids will be summarized (Table 27-1) and the suggested type of fluids to use for each of them will be suggested. Table 27-2 summarizes the compositions of different intravenous fluids.
Table 27-1. Indications for Intravenous Fluids |Favorite Table|Download (.pdf)
Table 27-1. Indications for Intravenous Fluids
Hypercalcemia/tumor lysis syndrome/rhabdomyolysis
Contrast-induced nephropathy prophylaxis
Spontaneous bacterial peritonitis management
After large-volume paracentesis in cirrhosis patients
Table 27-2. Intravenous Fluids Composition |Favorite Table|Download (.pdf)
Table 27-2. Intravenous Fluids Composition
|Parameter||Human Serum||D5W||0.45 NS||0.9 NS||Lactated Ringers||Albumin||Hypertonic Saline|