Should You Continue Normal Saline in This Patient?
No—you should immediately discontinue normal saline and switch to a balanced crystalloid solution (Lactated Ringer's or Plasma-Lyte) to prevent further worsening of renal function and avoid exacerbating hyperchloremic metabolic alkalosis. 1, 2
Why Normal Saline Is Harmful in This Clinical Context
Your patient has three critical features that make continued normal saline administration dangerous:
- Worsening acute kidney injury on chronic kidney disease (creatinine rising from 1.34 to 1.46, BUN from 29 to 32) despite initial fluid resuscitation 2
- Low chloride (96 mEq/L) with metabolic alkalosis (bicarbonate 27, normal anion gap), which paradoxically indicates prior volume contraction and chloride depletion from prolonged immobilization 1, 2
- Stage 3 CKD baseline (prior eGFR 50-55), making the kidneys particularly vulnerable to further injury from high-chloride fluids 2, 3
Normal saline contains 154 mEq/L of chloride—far above physiologic levels—and causes renal vasoconstriction, worsening kidney perfusion and increasing the risk of progressive AKI and need for dialysis. 2, 4, 3
The Correct Fluid Choice: Balanced Crystalloids
Switch immediately to Lactated Ringer's or Plasma-Lyte as your primary resuscitation fluid. 1, 2
These balanced solutions offer critical advantages:
- Physiologic chloride content (98-109 mEq/L vs. 154 mEq/L in normal saline) prevents hyperchloremic acidosis 2, 4
- Lactate or acetate buffers that metabolize to bicarbonate, helping correct metabolic derangements 2
- Reduced major adverse kidney events compared to normal saline, demonstrated in the SMART trial (15,802 critically ill patients) 2
- Lower 30-day mortality in patients with baseline renal impairment 2
If normal saline must be used for any reason, limit the total volume to a maximum of 1-1.5 liters. 1, 2 You have already given 2 liters—exceeding this threshold.
Addressing the Rising Creatinine
The creatinine trend (1.34 → 1.46 over 3 days without IV fluids) suggests ongoing volume depletion despite oral intake, likely from:
- Post-immobilization diuresis after prolonged ground-lying (3 days) with muscle breakdown and fluid shifts 5
- Inadequate oral replacement in an elderly SNF patient who may have impaired thirst mechanism
- Possible rhabdomyolysis (not mentioned but should be evaluated with CK, myoglobin given the fall and prolonged immobilization)
Resume IV fluid replacement with balanced crystalloids at 75-100 mL/hour, monitoring for clinical euvolemia. 1
Clinical Indicators to Guide Fluid Management
Monitor these parameters every 6-12 hours to determine when to discontinue IV fluids: 1
- Stable blood pressure without tachycardia indicates euvolemia 1
- Wet mucous membranes, capillary refill <2 seconds, normal JVP confirm adequate volume status 1
- Stabilization or improvement in creatinine and BUN (recheck BMP in 12-24 hours) 1
- Serum electrolytes (sodium, potassium, chloride) every 6-12 hours 1
- Urine output should be adequate (≥0.5 mL/kg/hour) without being polyuric
Managing the New Hyperglycemia
The glucose elevation (89 → 128 mg/dL) is modest but requires attention:
- Review medications for steroids or other diabetogenic agents
- Assess dietary intake in the SNF setting
- Consider stress hyperglycemia from acute illness and AKI
- Avoid dextrose-containing fluids unless hypoglycemia develops 6
This level does not require insulin therapy but warrants monitoring with each BMP.
Critical Pitfalls to Avoid
Do not use hypotonic solutions (0.45% saline or D5W) in this patient—they are contraindicated in elderly patients at risk for cerebral edema and provide inadequate sodium replacement. 7
Do not assume the low chloride (96) means you should give more normal saline—this is a common error. The low chloride reflects prior volume contraction and will correct with balanced crystalloids. 1, 2
Do not wait for further creatinine elevation before acting—the trend is already concerning, and balanced crystalloids reduce the risk of progression to dialysis-requiring AKI. 2, 3
Monitoring Plan Going Forward
Recheck BMP in 12-24 hours after switching to balanced crystalloids to assess: 1
- Creatinine and BUN trend (should stabilize or improve)
- Chloride normalization (target 98-106 mEq/L)
- Sodium stability (currently 136, acceptable)
- Potassium (currently 4.1, monitor as balanced solutions contain 4-5 mEq/L) 2
Discontinue IV fluids when: 1
- Creatinine stabilizes or begins to decline
- Patient achieves clinical euvolemia (stable BP, good skin turgor, adequate oral intake)
- No signs of ongoing volume depletion
The potassium content (4-5 mEq/L) in balanced crystalloids is not contraindicated unless severe hyperkalemia (>6.0 mEq/L) exists, which is not the case here. 2