An 83-year-old woman with chronic stage 4 renal disease and a single functional kidney presents with severe metabolic acidosis (serum bicarbonate 7 mEq/L) and a one‑week history of dyspnea; which hospital floor should she be admitted to?

ICU Admission Required

This patient must be admitted to the intensive care unit (ICU) immediately. She meets multiple absolute criteria for ICU-level care based on severe metabolic acidosis (bicarbonate 7 mEq/L), respiratory distress, and high-risk comorbidities in the setting of advanced chronic kidney disease 1.

Critical Indicators for ICU Admission

Severe Metabolic Acidosis

• A serum bicarbonate of 7 mEq/L represents life-threatening metabolic acidosis requiring immediate intensive monitoring and potential ventilatory support 1.
• The European Society of Cardiology explicitly states that arterial pH <7.35 is an indication for intubation if respiratory failure cannot be managed non-invasively 1.
• With a bicarbonate this low, the patient's pH is almost certainly <7.20, which places her in the category requiring consideration for mechanical ventilation 1.

Respiratory Distress

• One week of progressive dyspnea in the context of severe acidosis indicates respiratory compensation failure 1.
• The European Society of Cardiology recommends ICU admission for patients with "persistent, significant dyspnea" and states this should be triaged to a location where immediate resuscitative support can be provided 1.
• Respiratory rate is likely >25 breaths/min given the degree of acidosis and dyspnea duration, which is a specific ICU criterion 1.

High-Risk Patient Profile

• Age 83 with stage 4 CKD and single functioning kidney represents extreme vulnerability to acute decompensation 1, 2.
• The combination of advanced age, chronic renal failure, and severe acidosis predicts high mortality risk requiring intensive monitoring 1, 2.

Immediate ICU Management Priorities

Ventilatory Support Readiness

• Non-invasive positive pressure ventilation (BiPAP/CPAP) should be immediately available and considered if respiratory rate >25/min or SpO2 <90% 1.
• The patient may require intubation if pH <7.35 with hypercapnia (PaCO2 >50 mmHg) or hypoxemia (PaO2 <60 mmHg) that cannot be managed non-invasively 1.
• Continuous pulse oximetry and arterial blood gas monitoring are essential 1, 2.

Hemodynamic Monitoring

• Continuous blood pressure monitoring is mandatory as severe acidosis can cause hemodynamic instability 1, 2.
• The European Society of Cardiology specifies that hemodynamic instability is an absolute ICU criterion 1.
• Cardiac monitoring for arrhythmias secondary to severe acidosis and potential electrolyte disturbances (hyperkalemia) is required 1.

Metabolic Correction Strategy

• Urgent arterial blood gas measurement is the first priority to determine actual pH and guide therapy 1.
• In critically ill patients with shock or severe acidosis, arterial sampling (not venous) is required for accurate assessment 1.
• Bicarbonate therapy may be considered, though guidelines note uncertainty about its effectiveness in tissue hypoperfusion states 1.
• The severe acidosis (bicarbonate 7 mEq/L) in stage 4 CKD represents both chronic metabolic acidosis and likely acute-on-chronic decompensation requiring intensive management 3, 4, 5.

Why Not a Regular Medical Floor

Inadequate Monitoring Capability

• Regular floors cannot provide the continuous cardiorespiratory monitoring this patient requires 1, 2.
• The risk of sudden respiratory failure requiring emergent intubation is too high for ward-level care 1.

Need for Immediate Intervention Capability

• The patient may deteriorate rapidly and require immediate ventilatory support that is not available on regular floors 1.
• Severe acidosis can cause cardiac arrhythmias requiring immediate cardioversion 1.

Renal Replacement Therapy Consideration

• With stage 4 CKD, single kidney, and severe metabolic acidosis, urgent dialysis may be needed 1, 4.
• ICU settings provide immediate access to continuous renal replacement therapy if indicated 1.

Common Pitfalls to Avoid

• Do not delay ICU admission to "try" medical management on a regular floor first – the severity of acidosis (bicarbonate 7 mEq/L) and week-long dyspnea indicate failed outpatient compensation 1.
• Do not assume the patient is stable because she is conscious – altered mental status may develop rapidly with worsening acidosis 2.
• Do not restrict oxygen therapy even in the setting of potential chronic CO2 retention – hypoxemia is more immediately life-threatening 1.
• Do not use dopamine to "protect" renal function – it is ineffective and potentially harmful 1.