What lab results should nurses immediately notify doctors about, even at night?

Critical Laboratory Values Requiring Immediate Physician Notification

Nurses should immediately notify physicians of abnormal laboratory values that indicate life-threatening conditions requiring urgent intervention, including severe electrolyte abnormalities, critical blood counts, significant coagulation disorders, and signs of sepsis or organ failure, regardless of the time of day.

Hematology Parameters

• Complete Blood Count (CBC):

  • White Blood Cell (WBC) count: ≥14,000 cells/mm³ or <1,500 cells/mm³ 1
  • Hemoglobin: <7 g/dL or acute drop >2 g/dL
  • Platelets: <20,000/mm³ or acute drop >50%
  • Presence of blast cells or significant left shift (>6% bands) 1

• Coagulation Studies:

  • INR >5.0 or rapid increase in patients on anticoagulants
  • PTT >100 seconds
  • Fibrinogen <100 mg/dL 1

Chemistry Parameters

• Electrolytes:

  • Potassium: <2.5 mmol/L or >6.0 mmol/L
  • Sodium: <120 mmol/L or >160 mmol/L
  • Calcium (ionized): <0.75 mmol/L or >1.6 mmol/L 1
  • Magnesium: <1.0 mg/dL or >4.5 mg/dL
  • Phosphorus: <1.0 mg/dL

• Glucose: <40 mg/dL or >500 mg/dL

• Acid-Base Parameters:

  • pH: <7.2 or >7.6
  • Bicarbonate: <10 mEq/L or >40 mEq/L
  • Lactate: >4 mmol/L 1

• Cardiac Markers:

  • Troponin: Any new significant elevation 1

• Renal Function:

  • Creatinine: Acute increase >1.0 mg/dL from baseline
  • BUN: >100 mg/dL

Microbiology Results

• Blood Cultures:

  • Any positive blood culture result 1
  • Gram stain results from positive blood cultures 1
  • Identification of critical pathogens (e.g., MRSA, VRE, CRE)

• Other Cultures:

  • Positive CSF cultures
  • Group A Streptococcus in sterile sites
  • Neisseria meningitidis from any site

Arterial Blood Gas Results

• PaO2: <50 mmHg on room air or significant decrease on oxygen therapy
• PaCO2: >60 mmHg (unless chronic) or acute increase >15 mmHg
• pH: <7.2 or >7.6 1

Vital Signs Requiring Immediate Notification

• Temperature: >101°F (38.3°C) or <96°F (35.6°C) 1
• Heart rate: <40 or >130 beats per minute
• Respiratory rate: <8 or >25 breaths per minute 1
• Blood pressure: Systolic <90 mmHg or >200 mmHg; Diastolic >110 mmHg
• Oxygen saturation: <90% despite supplemental oxygen 1
• Glasgow Coma Scale: Drop of ≥2 points

ECG Findings

• New ST-segment elevation or depression >2mm 1
• New onset of life-threatening arrhythmias
• New complete heart block or high-degree AV block

Implementation Considerations

1. Communication Protocol:

   • Use SBAR (Situation, Background, Assessment, Recommendation) format when notifying physicians
   • Document time of notification and physician response
   • Implement closed-loop communication to confirm understanding

2. Timing of Notification:

   • Critical results should be reported within 60 minutes of availability 1
   • Life-threatening results (e.g., severe hyperkalemia, critical hypoglycemia) should be reported immediately

3. Common Pitfalls to Avoid:

   • Failing to recognize trends (e.g., gradually worsening renal function)
   • Not considering the clinical context when interpreting lab values
   • Delaying notification due to fear of disturbing physicians at night
   • Assuming another team member has already notified the physician

4. Special Considerations:

   • For patients with chronic conditions, notification thresholds may need adjustment (e.g., COPD patients with chronic hypercapnia)
   • In patients with multiple abnormalities, prioritize the most life-threatening condition
   • Consider the rate of change in values, not just absolute numbers

By following these guidelines, nurses can ensure timely intervention for critical laboratory abnormalities, potentially preventing adverse outcomes and improving patient safety. Remember that these values represent general guidelines and may need to be adjusted based on institutional protocols and individual patient circumstances.