Postoperative Complications: Recognize and Respond

Medical-Surgical · Perioperative / Pre & Post-Op·Updated 2026-10-28

What it is

After surgery, anesthesia, opioids, pain and immobility depress ventilation, the cough reflex, peristalsis, bladder tone and venous return. Those effects explain the classic complications: airway obstruction and atelectasis, paralytic ileus, urinary retention and venous thromboembolism (VTE). Most are prevented by the same care: pain control, deep breathing, early ambulation and close monitoring.

What the NCLEX focuses on

In the post-anesthesia care unit (PACU), airway patency comes first; the tongue is the most common cause of obstruction, and restlessness signals hypoxemia until proven otherwise.
Hemorrhage: rising heart rate, falling blood pressure, restlessness, low urine output and a saturated dressing; check under the client for pooled blood.
Atelectasis and pneumonia: diminished breath sounds, crackles and falling SpO2; prevented with incentive spirometry, coughing, turning and ambulation.
DVT: unilateral calf swelling, warmth and pain; pulmonary embolism: sudden dyspnea, pleuritic chest pain, tachycardia and anxiety.
Paralytic ileus: absent bowel sounds, distention and no flatus; passing flatus shows peristalsis has returned.
Wound infection appears 3 to 6 days after surgery; dehiscence and evisceration follow straining, coughing or vomiting and often begin with a sudden gush of serosanguineous drainage.
Malignant hyperthermia (volatile anesthetics, succinylcholine): rising end-tidal CO2, masseter and generalized muscle rigidity and tachycardia come first; high temperature is a late sign; dantrolene is the antidote.

Priority nursing actions

Maintain the airway: position the client side-lying or use a head tilt-chin lift until fully awake, and give prescribed oxygen for falling SpO2.
Check vital signs every 15 minutes at first, along with the dressing, drains and level of consciousness.
Control pain with prescribed analgesics so the client can cough, deep breathe and walk; monitor sedation level and respiratory rate with opioids.
Have the client use the incentive spirometer 10 times an hour while awake and ambulate early.
Apply prescribed sequential compression devices and give prescribed anticoagulant prophylaxis.
Track urine output, bladder distention, bowel sounds, temperature and the incision, and report findings outside the expected range.

Numbers to know

Value	Expected or target	Why it matters
Urine output	At least 0.5 mL/kg/hr	Less suggests hypovolemia or acute kidney injury
First void	Within 8 hours after surgery	Anesthesia and opioids cause retention; scan the bladder
Incentive spirometer	10 breaths every hour while awake	Reexpands alveoli and prevents atelectasis
Temperature	Up to 100.4 F (38 C) in the first 48 hours	Fever after 48 hours suggests wound, urinary or lung infection
Wound infection onset	3 to 6 days after surgery	Redness, warmth, purulent drainage and fever
PACU vital signs	Every 15 minutes at first	Early detection of bleeding and hypoventilation

Common exam traps

Choosing to push protruding bowel back into the wound or cover it with a dry dressing: wrong because it injures and contaminates the bowel; cover it with sterile saline-moistened dressings, place the client in low Fowler position with knees flexed, keep NPO and notify the surgeon.
Choosing to massage or walk a calf that is swollen, warm and painful: wrong because it can dislodge the thrombus; notify the provider.
Choosing to withhold prescribed opioids from a client who will not deep breathe because of pain: wrong because uncontrolled pain causes shallow breathing and atelectasis.
Choosing a pillow under the knees for comfort: wrong because it compresses the popliteal vessels and promotes VTE.
Choosing to offer a regular diet when bowel sounds are absent and the abdomen is distended: wrong because ileus requires NPO status and gastric decompression.

What to teach

Splint the incision with a pillow when coughing; use the incentive spirometer and walk several times a day.
Do ankle pumps, take the prescribed anticoagulant, and avoid crossing the legs or sitting for long periods.
Report redness, warmth, purulent drainage or opening of the incision, and fever of 100.4 F (38 C) or higher.
Call 911 for sudden shortness of breath or chest pain; report calf pain or swelling promptly.

Client handout: Recovering After Surgery at Home (nurse guide and printable patient handout).

Try 2 NCLEX-style questions on this topic

From the NCLEXPace question bank. Pick your answers, then check them inside NCLEXPace.

Question 1 · QID 0FED3A4F

A nurse discovers a postoperative client's abdominal wound has separated, with a loop of bowel visible through the opening. For each possible action, indicate whether it is appropriate or inappropriate.

	Inappropriate	Appropriate
Attempt to gently push the visible bowel back into the wound
Cover the area with a sterile saline-soaked dressing and notify the surgeon immediately
Apply a dry dressing and continue routine wound care
Document the finding and reassess at the next scheduled dressing change

Question 2 · QID E7D0AA28

A postoperative client reports new unilateral calf swelling, pain, and warmth. Which action is most appropriate?

Select the best answer.

A. Elevate the affected leg and continue close observation to determine whether the swelling and warmth improve with rest
B. Encourage short assisted walks to improve venous return and reassess the calf symptoms after activity
C. Apply gentle massage to the calf and elevate the extremity to improve local venous circulation and reduce pain
D. Notify the provider promptly, since this may indicate a deep vein thrombosis

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More tips on Medical-Surgical

Acute PancreatitisRecognize acute pancreatitis by pain and lipase, give fluids and pain control first, and catch hypocalcemia, shock and respiratory failure.Bowel Obstruction and NG Tube CareTell small from large bowel obstruction, spot strangulation early, and keep a decompression NG tube placed, patent and safe.Acute Kidney Injury vs Chronic Kidney DiseaseClassify AKI as prerenal, intrarenal or postrenal, follow its phases, and compare it with the staged, irreversible course of CKD.

Sources

Harding MM, Kwong J, Hagler D, Reinisch C. Lewis's Medical-Surgical Nursing: Assessment and Management of Clinical Problems. 12th ed. Elsevier; 2023.
Potter PA, Perry AG, Stockert PA, Hall AM. Fundamentals of Nursing. 10th ed. Elsevier; 2021.
Anderson DR, Morgano GP, Bennett C, et al. American Society of Hematology 2019 Guidelines for Management of Venous Thromboembolism: Prevention of Venous Thromboembolism in Surgical Hospitalized Patients. Blood Adv. 2019;3(23):3898-3944.

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