Nursing care
Mastectomy Care: the nurse's role, start to finish
Written and reviewed by Dana Whitfield, RN, MSN · 6 min read · Updated September 2026
Short answer
Mastectomy care nursing centres on protecting the affected arm for life: no blood pressure readings, blood draws or injections on that side, plus lymphoedema precautions, drain management, and early detection of seroma, haematoma and infection. Pre-op teaching, positioning to reduce shoulder and lymphatic strain, and structured discharge education complete the picture.
What the procedure achieves
A mastectomy removes breast tissue, and depending on the type, some or all of the underlying muscle, skin and axillary lymph nodes. It is performed for invasive or in-situ breast cancer, for BRCA-positive risk reduction, or occasionally for recurrent benign disease that has failed conservative management. Simple, modified radical and radical mastectomy differ mainly in how much axillary and muscular tissue is taken, which in turn determines how aggressive the post-operative arm precautions need to be.
The nurse's role is not confined to the operating list. It spans the full arc from diagnosis through to survivorship: supporting a patient processing a cancer diagnosis and body-altering surgery, coordinating with the surgical and oncology teams, and setting up the lifelong self-monitoring habits the patient will need long after discharge. Sentinel lymph node biopsy or full axillary dissection, done at the same time, is what drives the single most important nursing instruction on this page: protecting the ipsilateral arm.
Pre-procedure nursing responsibilities
Baseline assessment should include bilateral arm circumference and range of motion, documented before surgery so that any post-operative swelling can be measured against a true baseline rather than guessed at. Confirm consent, mark the correct side with the surgeon, and review allergies, anticoagulant use and cardiac history, since many patients are older and carry comorbidities that affect anaesthesia planning.
Psychological preparation matters as much as the physical checklist. Many patients are frightened of disfigurement, of the cancer diagnosis itself, or of how a partner will respond, and a nurse who asks directly about these fears before surgery builds the trust needed for honest post-operative reporting of pain or mood changes. Reinforce what reconstruction options were discussed, if any, and correct any misunderstanding about the extent of surgery planned. Confirm NPO status, mark the affected side clearly with a wristband alert, and notify every team member that no blood pressure cuff, IV line, venepuncture or injection should go on that arm, starting now, not just after surgery.
Equipment and positioning
The affected arm is elevated on a pillow post-operatively to promote venous and lymphatic drainage, and the patient is positioned semi-Fowler's to reduce tension on the incision and ease breathing. Avoid restrictive clothing, jewellery, and any tourniquet or blood pressure cuff on the surgical side; use the contralateral arm for all vital signs, blood draws and IV access, and label the bed and chart clearly so every subsequent clinician respects this.
Surgical drains, usually closed-suction Jackson-Pratt type, are placed to prevent fluid accumulation in the dead space left by tissue removal and are secured to the patient's gown, never to the bed rail, to avoid accidental traction. Have equipment ready for drain output measurement and a wristband or bed sign reading 'no BP, no needles, this arm' before the patient leaves recovery. Compression garments are not routinely required immediately post-op but may be introduced later if lymphoedema risk is high.
Complications and early signs
Watch first for haematoma and active bleeding: firm swelling, ecchymosis, or drain output that suddenly increases or turns frankly bloody warrants prompt surgical review. Seroma, a collection of serous fluid under the flap, is common even with a functioning drain and presents as a soft, fluctuant swelling; most resolve with continued drainage or aspiration rather than reoperation.
Infection shows as increasing redness, warmth, fever or purulent drain output, usually emerging several days after discharge rather than on the ward, which is exactly why discharge teaching on site care matters. Lymphoedema is the complication with the longest tail: it can appear weeks, months or years later as arm heaviness, tightness or visible swelling, and once established it is managed, not cured, which is why prevention through lifelong precautions is emphasised from day one rather than treated as an inpatient concern only.
Post-procedure care
Assess the surgical site and drain output at each round, recording colour, consistency and volume, and report output that stays above roughly 30 mL in 24 hours or that changes character, since this often signals a complication rather than normal healing. Encourage early, gentle shoulder mobilisation as directed by the surgical team, generally starting with passive range of motion and progressing to active exercises once the surgeon clears it, to prevent frozen shoulder without disrupting the flap.
Continue strict avoidance of blood pressure cuffs, venepuncture and injections on the affected side throughout the admission, and hand this instruction to every new shift and every consulting team, since lapses tend to happen precisely when care is transferred between providers. Manage pain with the prescribed regimen and monitor for signs of anxiety or low mood, since body image distress often surfaces once the dressing is first changed and the incision is seen.
What to teach before discharge
Teach drain care in concrete, repeatable steps: how to empty and measure output, how to strip the tubing if it clots, when to call the surgical team, and what output threshold typically signals it is time for drain removal. Reinforce wound care, showering guidance once cleared, and signs of infection to report immediately rather than wait out.
The lymphoedema precautions are the piece patients most often forget, because nothing hurts and nothing looks wrong in the moment. No blood pressure readings, blood draws or injections in the affected arm, ever, not just during this admission. Avoid tight sleeves, jewellery, heavy lifting and cuts or burns on that side, use gloves for gardening or washing up, and treat any scratch promptly. These precautions are lifelong, not a temporary recovery-phase rule, and framing them that way is what prevents a patient quietly abandoning them once they feel well again.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our med-surg practice questions are the closest set to what this page covers.
One question from the med-surg set
A client with chronic obstructive pulmonary disease has an oxygen saturation of 88% on 2 L/min via nasal cannula and is alert with no distress. What should the nurse do first?
Rationale
In COPD a saturation of 88–92% is the therapeutic target, not an emergency, and this client is alert with no distress. The first action is the independent nursing intervention that is least invasive and most likely to help: sit them up and reassess. Turning the oxygen up to 6 L/min risks blunting the hypoxic drive, and calling rapid response or drawing an ABG escalates ahead of an assessment you have not finished.
Answer: B
Common questions
Why can't you take blood pressure on the mastectomy side?
Axillary lymph node removal disrupts lymphatic drainage on that side, and any pressure, needle stick or constriction raises the risk of triggering or worsening lymphoedema. This precaution applies to blood pressure cuffs, venepuncture, IV cannulation and injections, and it is permanent, not just for the hospital stay.
How much drain output is normal after a mastectomy?
Output is usually highest in the first 24 to 48 hours and tapers over days to about 20 to 30 mL or less per 24 hours, which is typically the threshold surgeons use to consider drain removal. A sudden increase in volume, or output turning frankly bloody or cloudy, should be reported rather than assumed normal.
Is lymphoedema preventable after mastectomy?
Risk can be reduced but not eliminated, since it depends partly on how much lymphatic tissue was removed. Consistent precautions, avoiding trauma, infection and constriction on the affected arm, and prompt treatment of any injury on that side, meaningfully lower the risk over a lifetime.
When can a patient start moving the arm after mastectomy?
Gentle passive range of motion is often started within a day or two under surgeon guidance, progressing to active exercises as healing allows. Full overhead reaching is usually delayed until the surgeon confirms the flap and drains support it, since early aggressive movement can increase seroma risk.
What are the early signs of a mastectomy site infection?
Look for increasing redness, warmth or swelling around the incision, fever, and drain fluid that becomes cloudy or foul-smelling. These signs often appear after discharge, which is why wound and drain teaching before leaving hospital is essential.
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