3.1 Medical Emergencies & Critical Findings

A sonographer works alone with patients for extended periods, often in dimly lit rooms with the patient partially disrobed and sometimes medically fragile. The American Registry of Radiologic Technologists (ARRT) expects you to recognize an emergency early, initiate the correct first response, and summon help without abandoning the patient. The universal first steps in any emergency are the same: stop the examination, assess responsiveness and breathing, activate the emergency response system (call the facility's code number or 911), and remain with the patient.

Allergic Reactions: Contrast and Latex

Anaphylaxis is a rapid, systemic hypersensitivity reaction that can kill within minutes. In sonography the two classic triggers are ultrasound contrast agents (sulfur hexafluoride or perflutren microspheres used in echocardiography and contrast-enhanced ultrasound) and latex (transducer covers, gloves, probe sheaths used for endocavitary work).

Reactions follow a spectrum:

Epinephrine (adrenaline) is the first-line drug for anaphylaxis, typically 0.3-0.5 mg of 1:1000 solution intramuscularly into the anterolateral thigh in adults. Antihistamines are adjuncts only. Patients with a known latex allergy must be scheduled first in the day when possible, examined with latex-free equipment, and flagged in the chart; the exam order and allergy history should be verified before any contrast or endocavitary study.

Cardiac and Respiratory Arrest

The chain of survival begins with recognition: an unresponsive patient who is not breathing normally (or only gasping/agonal respirations) is in cardiac arrest. Current adult basic life support (BLS) guidelines:

• Activate emergency response and get an automated external defibrillator (AED)
• Begin cardiopulmonary resuscitation (CPR): compressions at 100-120 per minute, depth at least 2 inches (5 cm) but not more than 2.4 inches (6 cm), full chest recoil, minimal interruptions
• Compression-to-ventilation ratio of 30:2 for a single rescuer
• Apply AED pads (right upper chest, left lateral apex) as soon as available; shock when advised; resume compressions immediately after

For respiratory arrest with a pulse, give rescue breaths at about 1 breath every 6 seconds (10 per minute) and recheck the pulse every 2 minutes. Know where your department's crash cart and AED live before you ever need them.

Physical Injury, Trauma, and Falls

Trauma patients arriving for focused assessment with sonography for trauma (FAST) exams may have unstable spine injuries - move them only with proper support and log-roll technique, and never remove cervical immobilization without an order. Within the department, falls are the most common injury: keep the stretcher low, side rails up when unattended, brakes locked, and assist weak or sedated patients during transfers. If a patient falls, do not move them; assess, call for help, and file an incident report.

Mental Health Crisis

Signs of escalation include agitation, pacing, clenched speech, and verbal threats. Respond with a calm, low voice, non-threatening body position, an unobstructed exit path for yourself, and clear simple choices. Do not argue, touch unexpectedly, or turn your back. A patient expressing suicidal intent must not be left alone - summon help and maintain observation until trained staff take over.

Seizures and Diabetic Reactions

During a tonic-clonic (grand mal) seizure: lower the patient to a safe surface, protect the head, loosen restrictive clothing, roll to the side when convulsions stop, and time the seizure. Never restrain the limbs and never place anything in the mouth - the tongue-biting airway object is a myth that causes dental and airway trauma. Call for help for any seizure lasting more than 5 minutes, repeated seizures, or a first-known seizure.

Hypoglycemia (blood glucose below about 70 mg/dL) presents with sweating, tremor, confusion, irritability, and pallor - dangerous because fasting patients are common in abdominal imaging. A conscious hypoglycemic patient receives 15-20 g of fast oral carbohydrate (juice, glucose gel, regular soda), rechecked in 15 minutes. Hyperglycemia develops more slowly with thirst, frequent urination, fruity breath (ketoacidosis), and deep rapid breathing. Never give oral intake to an unresponsive patient - that is a call for help and parenteral glucose or glucagon by medical staff.

Recognizing Deterioration and Communicating Critical Findings

Trends matter more than single values: a rising pulse with falling blood pressure, decreasing oxygen saturation, new confusion, or decreasing responsiveness are red flags. When you encounter a critical finding - suspected ruptured ectopic pregnancy with free intraperitoneal fluid, a large aortic aneurysm, absent fetal cardiac activity, testicular torsion without flow - the sonographer's legal and ethical duty is:

1. Do not render a verbal diagnosis to the patient, but do not send the patient home either
2. Contact the interpreting physician (radiologist or ordering provider) directly and immediately
3. Document the finding, the time of communication, who was notified, and the response/instructions received
4. Follow the chain of communication upward until a responsible physician accepts the information

Verbal critical-value reports should be read back to confirm accuracy, and every contact is recorded in the patient's record.