21.2 Respiratory Distress and Mediastinal Mass

CPHON TCO V.E.2 tests respiratory distress from an anterior mediastinal mass and superior vena cava (SVC) syndrome as oncologic emergencies. The leukemia and lymphoma chapters already named T-cell acute lymphoblastic leukemia (T-ALL), T-lymphoblastic lymphoma, and Hodgkin lymphoma as mass owners and taught “do not sedate casually.” This section is the first-hour airway: do not lay the child flat, do not sedate without an airway plan, get tissue from the safest site, and nurse SVC obstruction as venous and airway failure, not as “the child looks puffy.”

A 15-year-old who coughs and turns dusky when the stretcher flattens, a 10-year-old with facial swelling and dilated chest-wall veins, and a toddler with a teratoma who stridors on the scanner table are the same emergency. Domain IV respiratory effects (bleomycin, radiation pneumonitis) are not this chapter. A mediastinal mass is mechanical compression until proven otherwise.

Who has an anterior mediastinal mass

The anterior mediastinum sits behind the sternum, in front of the heart and great vessels. In pediatric hematology/oncology the mass is usually T-ALL, T-lymphoblastic lymphoma, Hodgkin lymphoma, or a germ-cell tumor / teratoma. Other anterior lesions exist; those four are the CPHON list. The mass compresses the trachea and main bronchi and can obstruct the SVC. Children’s airways are more compressible than adults’. Loss of sitting muscle tone—sleep, opioids, or sedation—lets the mass fall onto the airway. The result is cannot intubate, cannot ventilate.

What you see: orthopnea (cannot lie flat), cough that worsens supine, stridor or wheeze that is positional, anxiety, sitting forward or refusing the stretcher, facial or neck swelling, plethora (red-blue fullness of the face), dilated chest-wall and neck veins, headache, and sometimes syncope. A sitting room-air saturation of 97% does not prove a safe supine anesthetic. Ask the child to recline only if a team is ready to sit them up immediately. If they refuse or desaturate, believe them.

A 14-year-old with a two-week cough, night sweats, and a “full face” who will not recline for a chest radiograph is a mediastinal-mass patient, not a stubborn teenager. A preschooler who is comfortable only in a parent’s lap, leaning forward, may not have the words orthopnea; the position is the finding.

Do not lay flat; do not sedate without a plan

Two hard rules:

1. Do not force a supine position for comfort, for a “quick computed tomography (CT),” or to make the radiology table happy. Image upright or in the position of comfort when the scanner and the radiologist can accommodate it. Some children tolerate a slight recline or a lateral position; none should be dropped flat because the protocol says “supine, arms up.”
2. Do not sedate for CT or biopsy without an airway plan. Pediatric anesthesia, oncology, and often otolaryngology or critical care share the plan: upright or lateral positioning, spontaneous ventilation, possible awake fiberoptic strategies, and a ready intensive-care bed. Neuromuscular blockade removes the last muscle tone holding the airway open. A “short propofol nap” in a procedure unit is a documented path to arrest.

If the child is crashing—severe stridor, rising carbon dioxide, unresponsive orthopnea, or SVC with altered mentation—the team may start corticosteroids or emergency radiation before a perfect tissue diagnosis. That is a team decision. Steroids and radiation can blur histology, especially in lymphoma and leukemia. A dead child has no histology. The nurse’s job is to escalate, keep the child upright, support oxygen, and not block prephase therapy because “we do not have a biopsy yet.” Prephase is not a nurse solo order and not a reason to skip every attempt at a safer specimen if the child is still stable enough to give one.

Tissue from the safest site

Diagnosis should not require a general anesthetic through a compressed airway if another specimen exists:

• Peripheral-blood flow cytometry if circulating blasts (classic T-ALL).
• Pleural-fluid cytology and flow (common with T-lymphoblastic lymphoma).
• The most accessible peripheral node under local anesthesia or the lightest sedation that anesthesia will still call safe.
• Bone marrow if it can be done without flattening the child.
• Only then a carefully planned mediastinal or other central biopsy with a full airway plan.

Do not send this child to an off-site outpatient biopsy mill. Do not insist on a “better” mediastinal core when pleural fluid already shows T-lymphoblasts. Do not schedule “just a quick sedated CT to map the mass” as if mapping were more important than the airway.

SVC syndrome nursing

SVC syndrome is obstruction of venous return from the head, neck, and arms. Findings are facial swelling, plethora, upper-body venous distention, conjunctival fullness, headache, visual change, and risk of cerebral edema or thrombosis. Airway compression often travels with it. This is not steroid moon face on day 0 of therapy and not ordinary allergic periorbital puffiness.

Nursing cluster:

• Elevate the head of the bed. Never Trendelenburg “to help the line” or to make a central-line insertion more convenient.
• Keep the child in position of comfort, usually sitting.
• Avoid unnecessary upper-extremity venipuncture and central lines on the obstructed side when another site exists; lower-extremity or uninvolved access as the team directs. Do not place a large-bore catheter into an already obstructed cava as a reflex “access for the crash.”
• Monitor airway, mental status, swelling, and urine output.
• Treat the mass—steroids, radiation, chemotherapy per protocol—once a safe specimen exists or the crash pathway is invoked.
• Watch for thrombosis; anticoagulation is a team decision, not a nurse-initiated default.

A 16-year-old with Hodgkin lymphoma whose collar no longer closes, whose eyelids are puffy, and whose chest wall shows a ladder of veins has SVC syndrome. Sit the child up, notify immediately, protect the airway plan, and do not send the child down the hall supine for “a quick port placement” before the mass is addressed.

The CPHON product is a child who stayed sitting, a CT that was not forced supine under propofol, a diagnosis from pleural fluid rather than a heroic mediastinoscopy, and an SVC face that was recognized as venous obstruction rather than allergy or steroid effect before the first dose.