Acute Management: CKD Patient on MHD - Post-AVF Surgery Presenting with Hypoxia, Tachycardia (HR 150), and Hypertension After Missed Dialysis Sessions

Clinical Picture

• Low SpO2 = pulmonary edema from volume overload
• HR 150 = compensatory sinus tachycardia (or possibly AF/flutter - must check ECG)
• High BP = volume-dependent hypertension in ESRD

STEP 1 - Immediate Priorities (Do Simultaneously)

STEP 2 - Medications

A. For Pulmonary Edema / Volume Overload

• Dose: Start IV NTG at 5-10 mcg/min, titrate up by 5 mcg/min every 3-5 min to reduce BP
• Acts as a venodilator reducing preload rapidly
• Also has coronary vasodilatory benefit if ACS is a trigger
• Rosen's Emergency Medicine recommends this as a cornerstone of therapy

• Dose: 60-100 mg IV
• Use even in anuric/oligouric ESRD - furosemide has short-lived vasodilatory action beyond diuresis
• Per Tintinalli: "Loop diuretics may aid even in those with minimal urine output because loop diuretics have short-lived vasodilatory actions"
• Doubles up as preload reducer

• If SpO2 not improving on high-flow O2, start BiPAP (IPAP 12-14, EPAP 5-8)
• Reduces work of breathing, improves oxygenation, decreases preload
• Avoids intubation in most cases

B. For Tachycardia (HR 150)

• If sinus tachycardia secondary to hypoxia/pain/anxiety: treat the cause (O2, fluid removal) - rate will come down
• If AF with rapid ventricular rate: rate control needed
• If AF: IV Metoprolol (2.5-5 mg IV, repeat every 5 min, max 15 mg) or IV Diltiazem (0.25 mg/kg IV over 2 min)
• Caution: avoid negative inotropes if LV function is poor (check echo first)
• If hyperkalemia-related arrhythmia: IV Calcium gluconate 10 mL of 10% stat (cardiac membrane stabilization)

C. For Hypertension

• 20 mg IV bolus, can repeat 40-80 mg every 10 min
• Good for ESRD - not renally cleared significantly
• Handles both tachycardia and hypertension

• 10-20 mg IV slowly
• Safe in renal failure
• Reduces afterload

• Long-acting calcium channel blockers are effective for volume-dependent hypertension

Avoid: ACE inhibitors/ARBs IV acutely if K+ unknown (risk of worsening hyperkalemia). Oral ACEI can be continued if already on it, but do not start fresh acutely until K+ confirmed safe.

STEP 3 - Definitive Treatment: Emergency Hemodialysis

"The most common problem requiring emergent dialysis, particularly in the patient with CKD, is pulmonary edema secondary to volume overload...Despite the effectiveness of temporizing measures, many of these patients require immediate dialysis."

• Set ultrafiltration target carefully - do NOT remove fluid too rapidly (risk of dialysis hypotension)
• Lower blood flow rate initially given tachycardia and hemodynamic instability
• Consider sodium profiling and cooling dialysate to improve hemodynamic tolerance
• Monitor BP, HR, SpO2 every 15-30 minutes throughout

STEP 4 - Post-AVF Surgery Precautions (Critical)

1. Do NOT use the new AVF arm for BP measurement - this is a hard rule. Use the contralateral arm.
2. Do NOT apply tourniquet or compression to the AVF arm.
3. Do NOT draw blood or place IV lines in the AVF arm unless absolutely no other option exists.
4. Check the AVF for thrill and bruit before and after dialysis - a lost thrill signals thrombosis.
5. The new AVF will NOT be mature - access for this emergency dialysis session will be via whatever existing access was used before (tunneled catheter or previous access site).
6. Protect the surgical site from bleeding, especially if anticoagulation (heparin) is used during dialysis - consider using minimal heparin or heparin-free dialysis (citrate anticoagulation or saline flushes).
7. Watch for high-output cardiac failure from the newly created AVF - this itself can worsen tachycardia and cardiac demand.

STEP 5 - Watch for and Treat Hyperkalemia

Summary Algorithm

Low SpO2 + HR 150 + High BP in MHD post-AVF

    ↓
Sit upright → O2 → ECG → K+ → Echo

    ↓
Treat hyperkalemia if present (Ca gluconate, insulin-dextrose)
    +
IV NTG / Furosemide 80-100mg IV for preload reduction
    +
BiPAP if SpO2 not improving
    +
IV Labetalol for BP + HR (if ECG confirms sinus tach or AF RVR)

    ↓
Initiate emergency HD - SLOW ultrafiltration
(Use existing catheter access, NOT new AVF)
    +
Protect AVF arm at all times
Monitor thrill/bruit before and after

Note: This patient needs immediate nephrologist involvement and likely cardiac monitoring in a step-down or ICU-level setting given post-surgical status and hemodynamic compromise. If tachycardia persists despite treating hypoxia and volume, a formal cardiological evaluation is warranted.

• Red alert at the top for missed dialysis presentation
• Three presenting symptom branches - hypoxia, tachycardia, hypertension
• Immediate simultaneous actions (ECG, O2, labs, echo)
• Hyperkalemia decision point with treatment protocol
• Pharmacotherapy - IV nitrates, furosemide, labetalol, BiPAP
• Emergency HD as definitive treatment with dialysis parameters
• AVF arm precautions (critical for your post-surgical patient)
• Ongoing monitoring reminders