After hours we received a report that a CT scan shows an infrarenal (type B) aortic dissection, but the patient and emergency contact cannot be reached; what steps should we take?

Immediate Actions for Unreachable Patient with Infrarenal Aortic Dissection

You must immediately activate emergency medical services to perform a welfare check and transport the patient to the emergency department, while simultaneously notifying the on-call vascular surgery team, because infrarenal (Type B) aortic dissection requires urgent medical management to prevent life-threatening complications including rupture, organ malperfusion, and death. 1, 2

Step 1: Emergency Welfare Check and Patient Location

• Contact emergency medical services (EMS) or local police immediately to perform a welfare check at the patient's last known address. 1, 2
• Instruct EMS to transport the patient directly to the emergency department with lights and sirens if the patient is located and symptomatic. 3, 1
• Continue attempting to reach the patient and emergency contact by phone while EMS is en route. 1
• Document all attempts to contact the patient with timestamps in the medical record for medicolegal purposes. 1

Step 2: Simultaneous Surgical and Medical Team Notification

• Immediately notify the on-call vascular surgery team about the CT findings, even before the patient arrives, because infrarenal dissection may require urgent intervention if complicated. 3
• Alert the intensive care unit to prepare for admission, as all aortic dissections require ICU-level monitoring with invasive arterial line placement and continuous hemodynamic management. 1, 2
• Notify the emergency department attending physician to expect the patient and initiate the aortic dissection protocol upon arrival. 1, 2

Step 3: Review CT Imaging for High-Risk Features

While awaiting patient arrival, review the CT scan for indicators of emergency that mandate immediate intervention: 3

• Fluid extravasation into the pericardium, pleural space, or mediastinum—these findings indicate contained or impending rupture with mortality rates of 54% at 6 hours and 76% at 24 hours. 3
• Periaortic hematoma, which signals contained rupture requiring urgent treatment. 3
• Maximum aortic diameter ≥50 mm, which predicts complications. 3
• Progressive aortic wall thickness >11 mm or enlarging aortic diameter. 3
• Evidence of branch vessel compromise (renal, mesenteric, or iliac arteries), which causes multiorgan failure—a major cause of death after aortic dissection. 3
• Pleural or peritoneal effusions, particularly if increasing, which identify patients at highest risk of rupture. 3

Step 4: Prepare Immediate Medical Management Protocol

Upon patient arrival, initiate anti-impulse therapy within 20 minutes to prevent dissection propagation and rupture: 1, 2

First-Line Beta-Blockade (Mandatory First Step)

• Administer intravenous esmolol as the preferred agent: loading dose 0.5 mg/kg over 2-5 minutes, followed by continuous infusion starting at 0.10-0.20 mg/kg/min, titrating to maximum 0.3 mg/kg/min. 2
• Target heart rate ≤60 beats per minute BEFORE addressing blood pressure—this must be achieved first to reduce aortic wall shear stress by decreasing left ventricular ejection force (dP/dt). 1, 2, 4
• Alternative: labetalol (combined α/β-blocker) if esmolol is unavailable. 2

Sequential Blood Pressure Control (Only After Beta-Blockade)

• After achieving heart rate control, if systolic blood pressure remains >120 mmHg, add an intravenous vasodilator (nicardipine, sodium nitroprusside, or clevidipine) to achieve target systolic blood pressure 100-120 mmHg. 1, 2
• NEVER administer vasodilators before adequate beta-blockade—this causes reflex tachycardia, increases dP/dt, and can propagate the dissection or cause rupture. 1, 2, 4

Critical Monitoring Requirements

• Place invasive arterial line (preferably right radial artery) for continuous accurate blood pressure monitoring. 1, 2
• Measure blood pressure in both arms to exclude pseudo-hypotension from aortic arch branch obstruction. 1, 2, 4
• Continuous three-lead ECG monitoring. 1, 2
• Administer intravenous morphine for adequate analgesia to facilitate hemodynamic control. 2, 4

Step 5: Determine Intervention Threshold for Type B Dissection

Infrarenal (Type B) dissection is initially managed medically unless life-threatening complications develop: 3, 1, 4

Indications for Urgent Endovascular or Surgical Intervention

• Recurrent or refractory pain despite aggressive medical treatment. 3
• Difficult blood pressure control despite maximal medical therapy. 3
• Progressive aortic diameter enlargement or maximum diameter ≥50 mm. 3
• Recurrent or increasing pleural effusion. 3
• Detection of organ ischemia (bowels, kidneys, lower extremities) from branch vessel compromise. 3
• Periaortic hematoma indicating contained rupture. 3
• Intimal disruption with contrast enhancement on CT. 3

Medical Management for Uncomplicated Type B Dissection

• Initial medical therapy with careful surveillance is the standard approach for uncomplicated infrarenal dissection. 3, 1
• Repetitive imaging (CT or MRI) is required to monitor for complications. 3
• TEVAR (thoracic endovascular aortic repair) should be considered for complicated Type B dissection, with lower 30-day mortality (17-19%) compared to open surgery (25-33%). 3

Critical Pitfalls to Avoid

• Never delay medical management waiting for the patient to arrive—have the protocol ready to execute immediately upon arrival, as mortality increases 1-2% per hour in untreated patients. 5, 6, 7
• Never use vasodilators before beta-blockade—this is a Class III (harm) recommendation. 2, 4
• Never assume the patient is stable based on inability to reach them—infrarenal dissection can progress to rupture or organ malperfusion rapidly. 3, 5, 8
• Never rely solely on phone contact—physical welfare check is mandatory given the life-threatening nature of the diagnosis. 1
• Never delay imaging review—identifying high-risk features determines urgency of intervention. 3

Documentation and Medicolegal Considerations

• Document all attempts to contact patient with exact times and methods used. 1
• Document notification of EMS, vascular surgery, ICU, and emergency department with times. 1
• Document review of CT findings and presence or absence of high-risk features. 3
• Document the prepared management protocol to demonstrate readiness for immediate treatment upon patient arrival. 1, 2