Nursing care
Perioperative Complications, explained for the bedside and the exam
Written and reviewed by Dana Whitfield, RN, MSN · 5 min read · Updated September 2026
Short answer
Perioperative complications are the adverse events that can occur before, during or after surgery, ranging from atelectasis and haemorrhage to malignant hyperthermia. Malignant hyperthermia is the one to know cold: it is rare, it escalates within minutes of triggering anaesthetic agents, and dantrolene is the only drug that reverses it.
The idea in one paragraph
Perioperative complications span three phases: preoperative, intraoperative and postoperative. Each phase carries its own risk profile. Preoperatively, the concern is undiagnosed comorbidity and inadequate consent or NPO status. Intraoperatively, the concern is airway compromise, haemorrhage and anaesthetic reaction. Postoperatively, the concern shifts to atelectasis, wound infection, venous thromboembolism and paralytic ileus.
One complication sits apart from the rest because of its speed and mortality: malignant hyperthermia. It is a pharmacogenetic reaction to volatile anaesthetics and succinylcholine, and it is not something a nurse manages by watching and waiting. It is a call-for-help, stop-the-drug, give-dantrolene event.
Why it matters clinically
Malignant hyperthermia is rare, occurring in roughly 1 in 5,000 to 1 in 100,000 anaesthetic exposures depending on the population, but untreated mortality has historically approached 70%. With early recognition and dantrolene, mortality drops to under 5%. That gap is the entire clinical argument for vigilance: the difference between a fatal event and a survivable one is how fast the team acts.
The other perioperative complications matter because they are common and preventable with good nursing care. Atelectasis and VTE account for a large share of postoperative morbidity, and both respond to simple, repeatable interventions. Malignant hyperthermia matters because it is uncommon but unforgiving, and no amount of good positioning or incentive spirometry substitutes for recognising it in the first few minutes.
How to apply it at the bedside
For malignant hyperthermia, the trigger is exposure to a volatile anaesthetic gas or succinylcholine, and the earliest sign is often a rising end-tidal CO2 that does not match the ventilator settings, followed by masseter muscle rigidity, tachycardia and a rapid temperature climb that can exceed 40°C. The nursing response is to stop the triggering agent, hyperventilate with 100% oxygen, and prepare dantrolene sodium for immediate IV administration, reconstituted per protocol and given until symptoms resolve.
For the broader category, apply routine but non-negotiable measures. Preoperatively, verify consent, confirm NPO status and screen for personal or family history of anaesthetic complications, since malignant hyperthermia has a genetic component. Postoperatively, get patients coughing, deep breathing and mobilising early to prevent atelectasis and VTE, and monitor surgical sites and vital signs on a schedule rather than only on request.
Where students get it wrong
Students often confuse malignant hyperthermia with a simple postoperative fever and reach for antipyretics or a cooling blanket alone. Malignant hyperthermia is a hypermetabolic crisis, not an infection, and it needs dantrolene, not paracetamol. Waiting for a confirmatory blood gas before acting is also a common error; the diagnosis is clinical and time-critical, so treatment starts on suspicion.
A second common mistake is treating all perioperative complications as equally urgent, which flattens the priority list. A patient with mild postoperative nausea and a patient with rigid jaw muscles and a spiking temperature are not the same acuity, and an exam question that buries the malignant hyperthermia clue in a longer vignette is testing whether the student notices it.
Worked examples
A patient two hours into a laparoscopic procedure develops a heart rate of 140, muscle rigidity and a temperature of 39.8°C rising fast. The correct first action is to notify the anaesthesia provider and prepare to discontinue the triggering agent, not to administer a fever-reducing medication. Dantrolene is drawn up and given per the malignant hyperthermia protocol while the team cools the patient with ice packs and cold IV fluids.
A separate, more routine example: a postoperative patient on day two has not ambulated, reports calf tenderness, and has shallow breathing on auscultation. This is a VTE and atelectasis picture, not malignant hyperthermia, and the response is early mobilisation, incentive spirometry and notifying the provider about the calf finding for possible Doppler ultrasound.
How the exam tests it
NCLEX items on this topic usually present a vignette with vital sign trends and ask for the priority nursing action, using Maslow or an ABC framework to rank interventions. Malignant hyperthermia questions typically give a cluster of clues, rigidity, tachycardia, rising temperature intraoperatively, and expect the test-taker to select stopping the anaesthetic and preparing dantrolene over generic cooling measures.
Distractor answers often include reasonable-sounding but wrong choices: administering acetaminophen, applying a cooling blanket alone, or simply increasing IV fluids without addressing the trigger. The correct answer will almost always name dantrolene or discontinuing the causative agent when malignant hyperthermia is described, because those are the interventions that change the outcome.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our reduction of risk potential practice questions are the closest set to what this page covers.
One question from the reduction of risk potential set
Four hours after a cardiac catheterization via the right femoral artery, the nurse notes the client's right dorsalis pedis pulse is now faint and the foot is cool and pale. What is the nurse's priority action?
Rationale
A pulse that was present and is now faint, with a cool, pale extremity distal to the puncture site, is arterial occlusion until proven otherwise — a limb-threatening complication that needs the provider now. Documenting and rechecking wastes the window, warming treats the symptom and masks the change, and asking the client to move the ankle neither restores flow nor gives you new information.
Answer: C
Common questions
What is the antidote for malignant hyperthermia?
Dantrolene sodium is the specific treatment. It works by inhibiting calcium release from skeletal muscle, which halts the hypermetabolic reaction. It is given IV and reconstituted per the malignant hyperthermia protocol, continuing until symptoms resolve.
How soon after anaesthesia exposure can malignant hyperthermia occur?
It typically appears within the first hour of exposure to a triggering agent but can also develop later in the postoperative period. Rising end-tidal CO2, tachycardia and muscle rigidity are usually the earliest signs, ahead of the temperature spike.
What is the single most important nursing action for suspected malignant hyperthermia?
Notify the anaesthesia provider and stop the triggering agent immediately, then prepare to administer dantrolene. Delaying treatment while waiting for confirmatory tests significantly worsens outcomes.
How do I tell malignant hyperthermia apart from a normal postoperative fever on an exam question?
Look for the timing and the cluster of signs. A vignette set intraoperatively or immediately postoperatively with muscle rigidity, tachycardia and rapidly rising temperature points to malignant hyperthermia, whereas a low-grade fever on postoperative day two or three is more likely atelectasis or infection.
Are all patients equally at risk for malignant hyperthermia?
No. Risk is higher with a personal or family history of the condition or of unexplained anaesthesia-related deaths, and with certain muscular conditions. Preoperative screening for this history is a key nursing responsibility before surgery involving volatile anaesthetics or succinylcholine.
More on reduction of risk potential