Chapter 44 Postoperative Fever (Case 29)
Postoperative context: A 52-year-old female presents with fever on postoperative day 3 after small bowel resection for obstruction with reanastomosis.
| Drug-induced fever | Deep venous thrombosis (DVT) | Blood product reaction |
Think of five common causes of postoperative fever—(“the 5 W’s”):
| Wind | Atelectasis, pneumonia |
| Wound | Surgical site infection |
| Water | UTI |
| Walking | DVT, PE, phlebitis at IV site |
| Wonder drug | Drug reactions |
PATIENT CARE
Clinical Thinking
• Look first for life-threatening problems that might need rapid tx such as necrotizing SSIs, which are diagnosed by careful wound inspection.
History
• Onset and duration of fever are most important. Associated symptoms (e.g., pain, dyspnea, cough, and diarrhea) may give clues and will direct your workup.
• Fever on POD #5 to #10 may indicate an SSI, an intra-abdominal abscess, or an anastomotic leak in GI tract surgery.
Tests for Consideration
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| Clinical Entities | Medical Knowledge |
|---|---|
| Atelectasis | |
| PΦ | Atelectasis is one of the most common causes of fever during PODs #1 and #2. Hypoinflation of alveoli may occur with mechanical ventilation during surgery and poor respiratory effort afterward. |
| TP | The patient often has fine bibasilar crackles on physical examination and poor clearance of respiratory tract secretions. X-rays may be negative unless the problem is severe. Those |
| patients at increased risk include smokers, chronic pulmonary disease patients, the obese, and patients with upper abdominal or chest incisions. | |
| Dx | CXRs are not highly sensitive for atelectasis. Fevers are low grade and should clear with incentive spirometry, upright positioning, increased ambulation, and inhalers to help clear secretions. If fever and respiratory symptoms continue, pneumonia must be considered. See Sabiston 15, Becker 10. |
| Pneumonia | |
| PΦ | Pneumonia is an infectious inflammation of alveoli with accumulation of exudate caused by bacteria, viruses, or fungi. |
| TP | Manifestations are productive cough, chest pain, and fever. Aspiration pneumonia is a chemical pneumonitis often related to difficult intubation or vomiting. Bacterial pneumonia can also result from poor pulmonary ventilation and/or secretion clearance. |
| Dx | Pneumonia is diagnosed by hx, physical examination, and CXR. Sputum or blood cultures may identify the organism. |
| Tx | Treat with appropriate antibiotics and respiratory support. Bronchoscopy and bronchoalveolar lavage may be indicated in severe cases. See Sabiston 15, 59; Becker 5, 10. |
| Urinary Tract Infection | |
| PΦ | UTIs tend to occur slightly later in a typical postoperative course (usually POD #4 and beyond), but can appear at any time. They are common in patients who have had a Foley catheter in place pre-or postsurgery. For this reason, urinary catheters are removed as soon as possible after surgery. |
| TP | Symptoms of dysuria and frequency are not always present. |
| Dx | U/A (looking for WBCs) and urine cultures should be part of any postoperative fever workup. |
| Tx | Tx depends on the specific organism. See Becker 10. |
| Surgical Site Infection | |
| PΦ/TP | Wound infection typically manifests itself on PODs #4 to #6. Risk factors include abdominal or emergency surgery, significant dead space within the wound, hematoma, tissue ischemia, foreign bodies, diabetes, morbid obesity, and malnutrition. |
| Dx | The surgical wound should be inspected daily for erythema, drainage, and increased tenderness. A wound infection in the deeper tissue planes may not manifest externally. |
| Tx | If infection is strongly suspected, the wound should be opened, cleaned, and packed with gauze. Wound infection and wound complications are considered in greater detail in Chapter 46, Wound Complications (Case 31). See Sabiston 14, 15; Becker 10. |
| Line-Related Infection | |
| PΦ/TP | IV sites can become erythematous, indurated, and tender. This local reaction may be due to inflammation and/or infection. Simple noninfectious phlebitis is benign and should resolve with removal of the catheter. An infectious process is of greater concern as IV lines have direct access to the circulation, especially central IV lines in the subclavian and internal jugular veins. Skin bacteria (Staphylococcus and Streptococcus) are the most commonly associated organisms. |
| Dx/Tx | If line sepsis is suspected, all IV lines should be changed to new sites. Catheters tips should be cultured, and blood cultures drawn. The best prevention against catheter infections is strict adherence to sterile technique whenever central lines are inserted or manipulated. See Sabiston 14, 15; Becker 10. |
| Intra-abdominal Abscess/Anastomotic Leak | |
| PΦ | In the realm of general surgery, intra-abdominal abscess usually occurs either when there has been gross contamination of the abdominal cavity by the initial disease process (e.g., perforated viscus) or when there has been contamination related to the nature of the surgery performed (e.g., colectomy). When a patient has undergone a bowel anastomosis, anastomotic leak must always be considered. Anastomotic leaks usually manifest themselves after the 4th postoperative day. |
| TP | The typical patient has fever, leukocytosis, increasing abdominal tenderness (unexplained by the recent incision), persistent ileus, and abdominal distention. |
| Dx | If abscess or anastomotic leak is suspected, CT scan of the abdomen and pelvis is the best diagnostic test and should be performed urgently. Always consider that what appears to be a presentation of shortness of breath may represent sepsis due to an anastomotic leak. |
| Tx | Whereas an intra-abdominal abscess may be treated with percutaneous drainage under CT guidance, anastomotic leaks almost always require prompt return to the operating room. |
| Deep Venous Thrombosis | |
| PΦ | DVT is often related to venous stasis from immobility in the perioperative period. The deep veins of the lower limbs and pelvis are the most commonly affected. |
| TP | The most common sign is limb swelling. Other clues are tenderness, pain, and erythema. Homan’s sign (pain in the calf upon dorsiflexion of the ankle) tends to be an inconsistent finding. |
| Dx | The key to dx is to pay attention to risk factors: prior hx of DVT, obesity, immobility, pelvic and orthopedic procedures, cancer, hypercoagulable state, and peripheral venous disease. Doppler ultrasonography is the best test for dx. |
| Tx | Tx of DVT necessitates anticoagulation intravenously (heparin), usually followed by oral warfarin tx. Patients with recurrent PEs and lower extremity DVT already on prophylaxis or those with contraindications to anticoagulation need an IVC filter. See Sabiston 15, 68; Becker 36. |
| Blood Product Reaction | |
| TP | Febrile nonhemolytic transfusion reaction: most common adverse reaction to a blood transfusion. Presents as fever and dyspnea 1 to 6 hours following transfusion; clinically benign, no lasting side effects. |
| Acute hemolytic reaction: a true emergency usually caused by administration of the wrong unit to the wrong patient (see the M & M box, Case 27) when RBCs are destroyed by host antibodies; presents as fever, chills, back pain, and myoglobinuria leading to acute renal failure. | |
| Anaphylactic reaction: severe allergic reaction can occur (patients usually have an unknown IgA deficiency) at a rate of 1 per 30,000–50,000 transfusions. | |
| Transfusion-associated acute lung injury (TRALI) is a syndrome of acute respiratory distress often associated with fever, noncardiogenic pulmonary edema, and hypotension. Symptoms are mild to life-threatening, but most patients recover fully within 2–3 days; mortality rate can be as high as 10%. | |
| Dx | Dx is by suspicion based on recent transfusion and exclusion of other common causes of postoperative fever. |
| Tx | Tx is immediate cessation of blood product delivery and supportive care |
| Drug-Induced Fever | |
| PΦ | Fever after drug administration can be caused by systemic hypersensitivity or by local inflammation at the injection site (phlebitis, abscess). Drugs or their delivery systems may contain pyrogens or microbial contaminants. Certain drugs may specifically produce fever (e.g., thyroxine), limit heat dissipation, or alter thermoregulation (e.g., phenothiazines, antihistamines). Fever is most often associated with antimicrobials (beta-lactam antibiotics), antihypertensives (methyldopa), antiarrhythmics (procainamide), and antiepileptic drugs (phenytoin). |
| TP | Fever may occur days after a drug has been administered and may last for days after the drug has been discontinued. Rash and eosinophilia occur in only a small percentage of cases. |
| Dx | The dx of drug-induced fever is a dx of exclusion and is established by a temporal relationship between drug initiation and fever. |
| Tx | Tx is cessation of drug administration. See Sabiston 15. |
