Postoperative complications can occur across several body systems. Common complications include surgical site infections (SSIs), wound dehiscence, hematomas, seromas, respiratory issues like hypoxemia and pneumonia, gastrointestinal complications like ileus and anastomotic leaks, delirium, deep vein thrombosis (DVT), urinary tract infections (UTIs), hypertension, hypotension, arrhythmias, and stroke. Close monitoring of vital signs and the surgical site are important to promptly identify and manage any complications in the postoperative period.

1. POST-OPERATIVE
COMPLICATIONS
Hadi Munib

2. Outline
• Introduction
• Common Complications
• Surgical Site Infections
• Wound Dehiscence, Hematomas and Seromas
• Gastrointestinal Complications
• Delirium
• DeepVenousThrombosis
• UrinaryTract Infection
• References

3. Introduction
• Surgical site infections (SSIs) alone affect >500,000 patients annually and are
associated a 2 to 11 times increase in the risk of postoperative mortality.
• Good communication among all providers caring or surgical patients is
fundamental.
• Patients should know about the complications before the procedure and a
consent form must be signed.
• The patient’s vital signs (including pulse, blood pressure and pulse oximetry
reading), level of consciousness, pain and hydration status are monitored in the
recovery room and supportive treatment is given.

4. Classification of postoperative
complications
• There are three common approaches for the classification of postoperative
complications of surgery:
• Linked to time after surgery:
• Immediate (within 6 h of procedure);
• Early (6–72 h);
• Late (>72 h).
• Generic and surgery specific.
• Clavian-Dindo: this system relates to surgical complications only and is used to
objectively and reproducibly measure the impact of the surgical complication on
the outcome of the procedure

5. Postoperative Bleeding
• All patients must have their vital signs (pulse rate, blood pressure, oximetry,
central venous pressure, if available, and urine output) monitored regularly.
• Dressings and drains should be inspected regularly in the first 24 hours after
surgery.
• If hemorrhage is suspected, blood samples should be taken for a full blood count,
coagulation profile and cross match.
• The decision about when to transfuse should be based on the individual patient
• In general, the accepted transfusion trigger is 75 g/L except in the presence of
known or suspected coronary artery disease when a higher trigger is acceptable.

6. Postoperative Pain
• Patients in this phase of care are often unable to verbalize pain due to effects of anesthesia
• Pain assessments are often based on other objective assessments such as blood pressure,
heart rate, respiratory rate and signs of agitation.
• The most commonly used intravenous opioids for postoperative pain are morphine,
hydromorphone (dilaudid), and fentanyl.
• Morphine is the standard choice for opiates and is widely used.
• Morphine has a rapid onset of action with peak effect occurring in 1 to 2 hours.
• Fentanyl and hydromorphone are synthetic derivatives of morphine and are more potent,
have a shorter onset of action, and shorter half-lives compared with morphine.

7. POSTOPERATIVE HYPERTENSION
• Cardiovascular Complications are the leading cause of death after 30-days of non-Cardiac
Surgeries
• Pain and elevated catecholamines can contribute to hypertension and tachycardia.
• β-blockers should be continued in the perioperative setting for patients who took them
preoperatively.
• Hypertension in the PACU is most commonly caused by pain and/or a history of
hypertension.
• Procedures such as carotid endarterectomy, require immediate and aggressive control of
systolic blood pressure regardless of etiology to avoid catastrophic vascular, cardiac, or
neurologic complications.
• For patients with pre-existing hypertension requiring medication, it is generally most
appropriate to gradually reintroduce the preoperative antihypertensive regimen with the
exception of diuretics in the immediate postoperative period.

8. POSTOPERATIVE HYPOTENSION
• Usually due to:
• Hypovolemia
• Narcotic and benzodiazepine administration
• Epidural anesthesia; Postoperative bleeding.
• Sepsis
• Arrhythmias
• Tension pneumothorax
• Pulmonary embolism
• Pericardial tamponade and anaphylaxis.

9. Postoperative Hypotension
• Postoperative hypotension can lead to end-organ dysfunction when
• Decreased urine output <0.5 mL/kg/h
• Decreased level of consciousness
• Myocardial ischemia
• Capillary refill >2 seconds
• In which it needs immediate management with fluid and may require the use of
vasopressors and inotropes.
• Invasive monitoring with a urinary catheter, central line, or arterial line should be
utilized if a patient remains hypotensive despite initial resuscitation with
crystalloid.

10. Postoperative Hypotension
• Epidural anesthesia can cause hypotension by blunting sympathetic tone and
decreasing vascular resistance.
• Treatment of epidural-related hypotension should include administration of a fluid
bolus.
• Temporarily holding the anesthetic infusion can also be helpful until euvolemia is
obtained.
• Treatment should be aimed at the cause.

11. Arrhythmias
• When they occur in the postoperative period, arrhythmias can cause hypotension,
myocardial ischemia and cardiac arrest.
• Tachycardia (sinus or supraventricular) may occur due to anxiety, pain, myocardial
ischemia or infarction, hypovolemia, sepsis or hypoxia in the postoperative period.
• Consideration should be given to correction of the underlying causes and rate controlled
with β-blockers, amiodarone or cardioversion, depending on the state of the patient.
• Sinus bradycardia may be normal in athletes but it may also be associated with hypoxia,
preoperative β-blockers, digoxin and increased intracranial pressure.
• Pharmacological options include glycopyrrolate or atropine intravenously.

12. Stroke
• Stroke is a recognized complication of carotid endarterectomy surgery both early
(secondary to emboli) and later (secondary to cerebral hyperperfusion syndrome).
• It is also a recognized consequence of both hypotension and hypertension.
• Thrombolysis may be indicated but the neurology and surgical teams must discuss
together the risks and benefits of such a treatment plan.

13. Immediate respiratory complications
AIRWAY
• Upper airway obstruction is one of the commonest immediate postoperative
complications and can be due to:
• Laryngospasm,
• Persisting relaxation of airway muscles
• Soft tissue oedema,
• Hematoma
• Vocal cord dysfunction or foreign body.

14. POSTOPERATIVE RESPIRATORY
INSUFFICIENCY
• Most patients will require some supplemental oxygen immediately after surgery.
• Dyspnea, tachypnea, wheezing, and signs of respiratory distress are not normal
postoperative signs and symptoms, and need to be addressed in the PACU.
• The causes and degree of risk to postoperative respiratory insufficiency are complex
and patient specific.
• All patients recovering from anesthesia require close monitoring o their respiratory
status, with personnel and equipment or reintubation readily available.

15. Postoperative Respiratory Insufficiency
• The primary factors that contribute to postoperative respiratory insufficiency
include:
• Use of general anesthesia
• Upper abdominal and thoracic surgeries
• Longer duration surgeries
• Use of endotracheal intubation
• Use of narcotics.

16. Hypoxemia
• This may occur as a consequence of:
• Acute pulmonary oedema (fluid overload, cardiac failure, postobstructive)
• Bronchospasm
• pneumothorax
• Aspiration
• Pulmonary embolism.
• De novo pneumonia is very unusual in the immediate postoperative period.
• Hypoxemia develops most quickly in patients with obstructive sleep apnea,
lung disease and obesity, who should therefore be closely observed.

17. Hypoxemia
• Patients with hypoxemia should be treated urgently.
• If the patient is breathing spontaneously, oxygen should be administered at
15 L/min using a non-rebreathing mask.
• A head tilt, chin lift or jaw thrust should relieve obstruction related to
reduced muscle tone.
• Suctioning of any blood or secretions and insertion of an oropharyngeal
airway may be needed.

18. RightTension
Pneumothorax

19. Pulmonary
Artery Blood
Embolism

20. Early and late postoperative pulmonary
complications
• Significant cause of postoperative
morbidity and mortality (between 5%
and 70%).
• Complications include:
• Fever (due to microatelectasis)
• Cough
• Dyspnea
• Bronchospasm
• Hypercapnoea
• Atelectasis
• Pneumonia
• Pleural effusion
• Pneumothorax
• Respiratory failure.

21. • Thoracic or abdominal surgery carries the highest risk.
• Risk Factors include
• Obese
• Smokers
• Chronic lung disease
• Obstructive sleep apnea
• Poor nutritional status.
• Can be identified preoperatively, facilitating the development of strategies that will
reduce the impact of surgery on the individual patient.
Early and late postoperative pulmonary
complications

22. Right upper lobe
atelectasis

23. Classical
Staphylococcus
Aureus Pneumonia

24. Low Urine Output
• Intravascular volume depletion may occur concurrently with pulmonary
edema due to increased vascular permeability associated with perioperative
inflammation
• Administration of diuretics or postoperative pulmonary edema can
exacerbate intravascular depletion, hypotension, and inadequate end-
organ perfusion.
• Postoperative oliguria (less than the equivalent of 0.5 cc/kg/h) requires
urgent evaluation.

25. POSTOPERATIVE NAUSEA ANDVOMITING
• Common.
• The causes are multifactorial.
• Prior history is the most significant risk factor
• Other risk actors include longer duration procedures, use of volatile
anesthetics (such as isoflurane), and procedures involving the inner ear,
eye, and abdominal viscera.
• Patients at moderate to high risk benefit from prophylactic antiemetics,
motility agents, or a scopolamine patch before emerging from anesthesia

26. POSTOPERATIVE FEVER
• About 40% of patients develop pyrexia after major surgery
• Low-grade fevers in the first 48 hours after surgery are a normal sequelae of
inflammation, atelectasis, or hematoma absorption following surgery, and usually
not from an infectious process.
• In the absence of any localizing signs or symptoms, self-limited fever within the first
48 hours postoperatively usually does not need infectious work-up.
• After 48 hours, temperatures greater than 38.5°C should prompt a complete fever
workup.
• In the postoperative patient, the surgical wound and site of venous access are
potential sources of infection and need to be carefully examined.

27. SURGICAL SITE INFECTION
• Account for approximately 30% of nosocomial infections and are the most
common infections after surgery.
• Associated with a 7-Day increased length of stay.
• Classified as
• Superficial; Infections involving the skin and subcutaneous tissues.
• Deep; Involve the Fascia or the Muscles below
• Organ space infections; Involve organs below the muscular and cutaneous layers

29. Surgical Site Infections
• Wound infections
• Despite the most rigorous aseptic technique, all wounds are contaminated to
some degree and have some risk of infection.
• Even “clean” wounds have a 1.5% risk of infection.
• Wound infections commonly occur between 5 and 10 days after an operation.
• Antibiotics are not necessary for simple wounds that have been drained.
• Deep space infections usually require drainage; antibiotics alone are insufficient.

30. Surgical Site Infections
• Risk factors for wound infection are patient and operation dependent.
• Patient related risk actors include:
• Large body habitus
• Diabetes
• Disability
• Immunosuppression
• Malnutrition
• Smoking

31. Surgical Site Infections
• Operative Risk Factors include:
• Certain operations, such as those involving the colon or small bowel, are
higher risk than others.
• Operating room conditions
• Surgical technique (eg, laparoscopic or open)
• Administration of antibiotic prophylaxis
• Hypoxia or hypotension during the procedure.

32. Surgical Site Infections
• Prophylactic antibiotics are very effective at reducing the risk of SSIs
• They should be administered within 1 hour of incision and continued for no
more than 24 hours after surgery.
• In the event of significant contamination in the OR, wounds may be left open
and managed with delayed primary closure or wet to dry dressings.

33. Surgical Site Infections
• The hallmarks of a wound infection are
• FEVER
• PAIN/TENDERNESS
• PURULENT DRAINAGE
• The typical presentation is between 5 and 10 days postoperatively.
• Clostridial necrotizing wound infection should be suspected when a patient has a very
high fever in the immediate postoperative period; immediate surgical evaluation and
drainage.

34. Surgical Site Infections
• Deep space infections occur in enclosed spaces with some degree of isolation from
blood supply, making them relatively impervious to antibiotics.
• Such infections usually require drainage either percutaneously or in the operating
room.
• Anastomotic leaks typically occur between postoperative days 5 and 7 and should
be suspected in surgical patients with tachycardia, abdominal pain, fever, and
elevated white count.
• These leaks can often be managed with percutaneous drainage, but inability to
control the infection may require operative drainage

38. Wound Dehiscence, Hematomas and Seromas
• Wounds typically heal to a maximum of 80% of the tensile strength within 6 weeks
among healthy, well-nourished patients.
• Most surgeons restrict postoperative activities to avoid stress on the wound for 4 to 6
weeks.
• Wounds that have been closed primarily should be kept clean, dry and well covered
for 48 hours post-surgery.
• Dry, sterile wound dressing should be kept for the second post-operative day;
Showering.

39. Wound Dehiscence
• It is the disruption of any layer of the surgical wound.
• This rare complication results from increased pressure on the wound and can arise due to a
variety of reasons.
• May need a return into the operation room
• Poor wound healing often leads to dehiscence.
• Malnutrition, liver disease, diabetes, immunosuppression, and chronic steroid use inhibit
normal wound healing and are risk factors.
• Most common layers involved; Skin and Fascia
• Sudden release of serosanguinous fluid of the wound is usually the first sign of Dehiscence

41. Wound Dehiscence
• Management depends on: Size, location and patient’s condition
• Fascial dehiscence; separation of the deepest layer of the abdominal wall;
typically requires urgent closure in the operating room.
• In the most severe cases, dehiscence leads to extrusion of intra-abdominal
contents (eg, evisceration).
• Evisceration is a surgical emergency that requires immediate return to
operating room.

42. Hematomas
• More common
• Can be caused either by inadequate hemostasis during surgery or disruption of
hemostasis Postoperatively
• Risk factors include bleeding disorders and anticoagulant use.
• Can result in; wound elevation, pressure, pain, dehiscence, and infection.
• Management; depending on the size and location;
• Watchful waiting to re-exploration in the OR.
• Hematomas following neck exploration may rapidly compromise the airway in the
postoperative period.

43. Hematomas
• Precipitating factors include:
• Abrupt increases in intrathoracic pressure from coughing
• Emesis;Vomiting
• Valsalva maneuvers; moderately forceful attempted exhalation against a
closed airway, usually done by closing one's mouth, pinching one's nose
shut while expelling air out as if blowing up a balloon
• Treatment; emergent evacuation of the hematoma prior to reintubation.

45. Seromas
• Collections of serous fluid that form after procedures involving disrupted
lymphatic flow and raised skin flaps.
• Generally the result of a normal physiologic response to anatomic dead
space.
• Their incidence is dependent on the anatomic location of the wound
• Procedures associated; inguinal hernia repair, groin exploration, and
mastectomy.
• Suction drains may be left in place at the end of the procedure to increase
tissue apposition and remove fluid.

46. Seromas
• Compression dressings can also reduce the risk of seroma formation.
• Seromas may increase the risk for wound disruption and infection but are usually
nothing more than a nuisance.
• Management may be expectant or include serial aspirations.
• Rarely, return to the OR is indicated to ligate contributing lymphatics.

47. DeepVenousThrombosis and Pulmonary Embolus
• Venous thromboembolism (VTE) is a leading cause of preventable death in the
postoperative setting.
• Surgical patients are at high risk forVTE due to the surgical procedure itself as well as
induction of general anesthesia, which results in prolonged immobility, hypercoagulability,
and endothelial damage.
• Patients with known hyper- coaguable states, priorVTE, and malignancy are at especially
high risk.
• High-risk surgical procedures include orthopedic surgery, trauma, and neurosurgical
treatment of head injury and brain tumors.
• Prophylaxis starts with the application of pneumatic compression devices and subcutaneous
heparin 2 hours prior to anesthetic induction.

48. DeepVenousThrombosis and Pulmonary Embolus
• Unless there are clear contraindications, such as increased bleeding risk, patients
should receive pharmacologic prophylaxis and pneumatic boots throughout and
perioperative period.
• Pulmonary embolus (PE) still causes considerable mortality in hospitalized
patients.
• PE should be suspected in all surgical patients presenting with symptoms of
dyspnea, tachycardia, and hypoxemia.
• The decision to start anticoagulation should be made with the operating surgeon,
while pending further diagnostic testing.

50. UrinaryTract Infections
• Most common after vaginal or urologic surgery and any surgery with the use of
indwelling catheters.
• Women and obese patients are at highest risk.
• The most common pathogens are Escherichia coli, Staphylococcus saprophyticus,
and Proteus mirabilis.
• Hospitalized and immunosuppressed patients are also susceptible to Klebsiella,
Proteus vulgaris, Candida albicans, and Pseudomonas.
• The standard for prevention is the removal of indwelling catheters within 48 hours
of insertion.

51. UrinaryTract Infections
• The need for continued urinary catheterization should be assessed at least daily to
prevent needless prolongation of catheter placement and increased risk of
catheter-associated UTI.

52. Post-Operative Urinary Retention
• Postoperative is common but rarely prolonged.
• Common risk factors include; male sex, prostatic enlargement, epidural/spinal/prolonged
anesthesia, use of antihistamines or narcotics, and pelvic/perineal procedures.
• An overdistended bladder (>500 mL) and disruption of the neural pathways that control
voiding impairs urinary contraction and micturition.
• Prophylactic catheterization in the operating room is recommended or any procedure lasting
more than 3 hours
• Also when interruption of the sacral plexus is anticipated (eg, abdominoperineal resection).

53. Post-Operative Urinary Retention
• If a catheter is not present, patients should be encouraged to void soon after the procedure.
• If the patient has not voided for more than 6 hours, it is appropriate to evaluate retention
with a bedside ultrasound; or an in-out catheter may be used to determine the extent of
retention.
• The treatment for bladder distention is intermittent catheterization along with mitigation
of any contributing factors.
• Some patients may have prolonged urinary retention in the postoperative period (>48
hours).
• Appropriate pharmacologic treatment should be initiated and an indwelling Foley catheter
should be placed.
• Some may require subsequent outpatient urologic follow-up or a void trial after discharge

54. Acute Kidney Injury
• According to national guidance (National Institute for Health and Care Excellence,
NICE) based on several definitions, acute kidney injury can be detected by the
following criteria:
• A rise in serum creatinine of 26 μmol/L or greater within 48 hours;
• a ≥50% rise in serum creatinine known or presumed to have occurred within the past
7 days;
• A fall in urine output to less than 0.5 mL/kg/h for more than 6 hours in adults and
more than 8 hours in children and young people;
• A ≥25% fall in estimated glomerular filtration rate in children and young people
within the past 7 days.

55. References
• Principles and Practice of Hospital Medicine; Chapter 45: Postoperative
Complications
• Bailey and Love Short Practice of Surgery; Chapter 20: Postoperative Care

56. THANKYOU