Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_2892_Библиотеки_им_академика_М_И_Перельмана
.pdf
This page intentionally left blank
https://t.me/medicina_free
CASE 38
https://t.me/medicina_free
A 70-year-old man comes to the office for his posthospitalization transition
of care (TOC) visit following a 2-day hospitalization for an uncomplicated
laparoscopic appendectomy that was done under spinal anesthesia by a local
surgeon. Last night, on his fourth postoperative day, the patient suddenly
developed a temperature of 102.5 °F (39.1 °C) accompanied by chills and vomiting.
Just before surgery, a urethral catheter had been placed, which was removed
24hours later, only to be replaced when he was unable to urinate on his own
on the second postoperative day. He was sent home with planned follow up
with the surgeon in 1 week, the urologist in 2 weeks, and a TOC visit with you
in 48 hours. He has a history of hypertension and benign prostatic hyperplasia
(BPH). Physical examination is unremarkable except for costovertebral angle
tenderness and suprapubic tenderness. He has no abdominal guarding or
rebound tenderness.
▶ What is the most likely cause of postoperative fever?
▶ What is the next diagnostic step?
▶ What is the most appropriate treatment at this time?
422 CASE FILES: FAMILY MEDICINE
https://t.me/medicina_free
ANSWERS TO CASE 38:
Postoperative Fever
Summary: A 70-year-old man presents with
A history of hypertension and BPH
Presentation for TOC appointment after laparoscopic appendectomy
Development of fever, chills, and vomiting on the fourth postoperative day
Physical examination showing costovertebral tenderness and suprapubic tenderness
A urethral catheter in place because of a problem in voiding
Most likely cause of postoperative fever: Urinary tract infection (UTI) with probable pyelonephritis.
Next diagnostic step: Urinalysis (UA) and urine culture; possible imaging to rule
out intra-abdominal abscess.
Treatment: Readmission and intravenous antibiotics.
ANALYSIS
Objectives
1. Identify the different causes of postoperative fever based on the timing of
onset, nature of surgery, and patient’s risk factors. (EPA 1, 2)
2. Understand the different clinical presentations that point to the etiology of
postoperative fever. (EPA 1, 2)
Considerations
Transition of care posthospital visits are evidence-based interventions to reduce
readmissions to hospitals. Hospitals with high readmission rates have lower
reimbursement and have readmission rates publicly seen on the Internet (https://
www.medicare.gov/hospitalcompare/search.html?). If patients are contacted
within 2business days and seen within 7 days in the outpatient primary care setting, not only are there fewer preventable readmissions, but there is also increased
reimbursement for primary care providers.
This 70-year-old man with history of hypertension and BPH is at high risk for
a UTI because he recently underwent a pelvic procedure under spinal anesthesia
and because he has urinary retention secondary to BPH. Also, the use of a urethral
catheter poses an additional risk for bacterial seeding of the urinary bladder. Suprapubic pain and costovertebral tenderness are physical findings suggestive of UTI,
most likely acute pyelonephritis. For those without a urethral catheter, symptoms
such as dysuria, urgency, and frequency are common.
A UTI is high on the list of causes of fever in the fourth postoperative day,
although it could also occur any time during the postoperative period. Less
likely could be intra-abdominal abscess, which is more common in laparoscopic
appendectomies. UA may detect the presence of bacteriuria, pyuria, nitrites, and
SECTION II: CLINICAL CASES 423
https://t.me/medicina_free
leukocyte esterase. Urine culture would determine the type of offending organism,
the most common of which are Escherichia coli, Proteus, Klebsiella, Staphylococcus
epidermidis, Pseudomonas, and Candida.
In this patient, the urethral catheter needs to be changed now and discontinued
as soon as he is able to void on his own. Symptomatic patients and those who are
at high risk for infection are usually treated with appropriate intravenous antibiotics according to the most likely pathogens. The antibiotics subsequently can be
adjusted based on culture results. Blood cultures should be ordered if sepsis from
a urinary tract source is suspected. Most importantly, it is crucial to address and
treat the cause of urinary retention (eg, BPH, kidney stone) to prevent recurrence
and avoid complications.
APPROACH TO:
Postoperative Fever
DEFINITIONS
DRUG FEVER: Fever that coincides with the administration of a particular drug
and cannot otherwise be explained by clinical and laboratory findings. Resolution
of the fever occurs with discontinuation of the suspected drug. Drugs that are
usually implicated are beta-lactams, sulfa derivatives, anticonvulsants, allopurinol,
heparin, and amphotericin B.
SURGICAL SITE INFECTION (SSI): A concept introduced by the Centers for
Disease Control and Prevention and various consensus panels to replace the term
surgical wound infection. This refers to any infection that occurs in the site of surgery within 30 days of an operative procedure or within 1 year with implants. SSIs
are classified as superficial, deep, or organ/space infections. An SSI is a common
nosocomial infection.
CLINICAL APPROACH
Pathophysiology
Fever (defined as a temperature > 38 °C or 100.4 °F) is the most common postoperative complication, occurring in 50% of major surgeries in the immediate postoperative period. Tissue trauma during surgery stimulates an inflammatory response
that leads to release of pyrogenic cytokines (ie, interleukin, tumor necrosis factor,
interferons) from the tissues. In general, more extensive surgical procedures are
associated with more tissue trauma and a greater degree of fever response. Elevated
levels of bacterial endotoxins and exotoxins that are released from the endogenous
gut flora of the colon as a result of surgical complications also elicit the same inflammatory response. This reaction leads to elevation of the thermoregulatory set point
and production of fever. This explains why suppression of cytokine release by nonsteroidal anti-inflammatory drugs, steroids, or acetaminophen may alleviate fever
and enhance patient comfort.
424 CASE FILES: FAMILY MEDICINE
https://t.me/medicina_free
Table 38–1 • STRATEGIES TO REDUCE THE RISK OF POSTOPERATIVE FEVER
Preoperative Interventions
• Optimize nutritional status.
• Advise patient to stop smoking.
• Treat any existing active infections.
• Optimize management of existing medical conditions (eg, diabetes).
• Reduce dosage of immunosuppressive therapies (when indicated).
Perioperative Interventions
• Administer perioperative antibiotics.
• Use noninvasive ventilation.
• If intubation necessary, use pneumonia prevention protocols.
• Remove catheters, intravenous lines, tubes, and drains as soon as safe.
• Change lines after 72-96 h if they are still needed.
• DVT prophylaxis using early mobilization, sequential compression devices, subcutaneous
heparin, or low-molecular-weight heparin.
Abbreviation:DVT, deep venous thrombosis.
As an integral part of informed consent prior to surgery, patients need to be made
aware by the physician of the possibility of experiencing postoperative febrile episodes. In addition, adequate preoperative evaluation, which includes performing a
history and physical examination to identify risk factors, medications, nutritional
status, and comorbid conditions, is imperative to avoid possible life-threatening
situations during the perioperative period. Preoperative and perioperative strategies can be used to reduce the risk of developing a postoperative fever (Table 38–1).
Fortunately, postoperative fever typically resolves spontaneously and most of the
time does not necessarily indicate the presence of infection.
The etiology of postoperative fever could be infectious or noninfectious
(Tables 38–2 and 38–3). Most postoperative fevers are not infectious, but all
cases of fever require a thorough history and physical to rule out infectious
causes. The mnemonic “5 Ws” helps in remembering the most common causes of
postoperative fever in roughly the order of frequency: wind (pneumonia), water
(UTI), wound (SSI), walking (deep venous thrombosis [DVT]), and wonder
drugs (drug fever). When a surgical patient develops fever, the differential diagnosis and investigative methods are directed by the timing of the fever, the type of
surgery performed, the preexisting clinical conditions, and the presenting symptoms. Comorbid conditions that increase the risk for infectious postoperative
fevers include increasing age, frailty, smoking, diabetes, and immunosuppression.
A thorough physical examination should be initiated, followed by inspection of
the surgical site, a review of all medications, and a consideration of hospitalrelated causes (intravenous lines and catheters). In the absence of significant risk
factors and clear lack of clinical and physical signs of infection, laboratory tests
may not be required.
Fever Within 36 Hours Postsurgery
There are few causes of fever in the immediate postoperative period. Medications
and blood products are commonly associated with fevers immediately postoperative.
SECTION II: CLINICAL CASES 425
https://t.me/medicina_free
Table 38–2 • COMMON CAUSES OF POSTOPERATIVE FEVER
Approximate
Onset of Fever Infectious Noninfectious
Intraoperative up to
24 h after surgery
1 d to 1 wk from
surgery
1 to 4 wk after
surgery
> 1 mo after surgery Blood transfusion viral and parasitic
Preexisting infection
Bacteremia from urologic procedures
Intraperitoneal leak (up to 36 h)
Invasive soft-tissue infection
Toxic shock syndrome
UTI (often with indwelling urethral
catheters or following genitourinary
procedures)
Pneumonia (eg, ventilator-associated
or aspiration)
SSI
Catheter-related infection
Preexisting infection
Cellulitis
Viral upper respiratory tract infection
SSI
Pseudomembranous colitis
Antibiotic-associated diarrhea
(ie, Clostridium difficile)
Catheter-related infection (ie, central
venous catheters)
Device-related infections
Abscess
infections (ie, hepatitis, CMV, HIV,
toxoplasmosis,Plasmodium malariae,
babesiosis)
Infective endocarditis
Postpericardiotomy syndrome
(following cardiac surgery)
SSI
Device-related infections
Vascular graft infection
Surgical trauma
Medications
Blood products (at time of
transfusion)
Malignant hyperthermia
Acute myocardial infarction
Alcohol/drug withdrawal
Gout
Pancreatitis
Pulmonary embolism
Superficial vein thrombophlebitis
(often at intravenous line site)
Benign postoperative fever
(diagnosis of exclusion)
Medication toxicity
DVT
Pulmonary embolism
Thrombophlebitis (particularly in
those with impaired mobility)
Postpericardiotomy syndrome
Abbreviations: CMV, cytomegalovirus; DVT, deep venous thrombosis; SSI, surgical site infection; UTI, urinary tract
infection.
A rare but dangerous cause in this period is malignant hyperthermia, which is an
inherited disorder characterized by markedly elevated temperature, up to 104°F
(40 °C), typically within 30 minutes after induction of an inhalational anesthesia
(ie, halothane) or depolarizing muscle relaxant (ie, succinylcholine). A more common cause of immediate postoperative fever is bacteremia, which occurs more commonly in urologic procedures that involve instrumentation, such as transurethral
resection of the prostate. Gram-negative bacteria are the most common pathogen.
426 CASE FILES: FAMILY MEDICINE
https://t.me/medicina_free
Table 38–3 • OTHER CAUSES OF POSTOPERATIVE FEVER WITH VARIABLE
TIMING OF ONSET
Infectious Noninfectious
Abscess
Sinusitis
Otitis media
Parotitis
Meningitis
Acalculous cholecystitis
Osteomyelitis
Bacteremia
Empyema
Fungal sepsis
Hepatitis
Decubitus ulcers
Perineal infections
Peritonitis
Pharyngitis
Tracheobronchitis
Withdrawal reaction from drugs/alcohol
Subarachnoid hemorrhage
Bowel infarction
Pancreatitis
Hyperthyroidism/thyroid storm
Dehydration
Acute hepatic necrosis
Hypoadrenalism/Addisonian crisis/acute adrenal insufficiency
Neoplastic fever
Suture reaction
Systemic inflammatory response syndrome (SIRS)
Pheochromocytoma
Lymphoma
Hematoma
Seroma
Myocardial infarction/stroke
Gout/pseudogout
Transfusion reaction
Organ transplant–related infection
Neuroleptic malignant syndrome
Within 30 to 45 minutes, the patient develops chills and a temperature that could
exceed 104 °F (40 °C). Accompanying symptoms such as tachycardia, tachypnea,
oliguria, and hypotension are common.
If fever occurs within 36 hours postlaparotomy, there are two important infectious etiologies to keep in mind—bowel injury with leakage of gastrointestinal
contents into the peritoneum and invasive soft-tissue wound infection caused by
beta-hemolytic streptococci or Clostridium species. The former is accompanied by
hemodynamic instability. Much less common in this setting is toxic shock syndrome
caused by Staphylococcus aureus.
Atelectasis, Pneumonia, and UTI
Within the first 48 to 72 postoperative hours, atelectasis (partial collapse of periph-
eral alveoli) causes 90% of pulmonary complications of surgery, particularly following abdominal and thoracoabdominal procedures. Contrary to popular belief, its
close association with early postoperative fever is probably coincidental. The alveolar collapse is compounded by the loss of functional residual capacity in almost
all patients and 50% reduction of vital capacity intraoperatively. Chest x-ray may
reveal discoid infiltrate and an elevated hemidiaphragm. Although fever is not
likely a consideration, hypoxemia, pneumonia, and scarring that can lead to bronchiectasis can be a consequence of atelectasis.
SECTION II: CLINICAL CASES 427
https://t.me/medicina_free
Postoperative Pneumonia. Instructing the patient on deep inspiration and coughing, the use of incentive spirometry, and the provision of adequate pain control
can facilitate the opening of the alveoli. Without resolution of atelectasis, pneumo-
nia may ensue. Patients who are on mechanical ventilators are at highest risk for
pneumonia (ventilator-associated pneumonia). Fever associated with productive
cough, pulmonary crackles, worsening oxygenation, elevation of white blood cells
(WBCs), positive sputum culture, and new infiltrates in chest x-ray are the usual
indicators of pulmonary infection. Postoperative pneumonia is typically polymicrobial. Enterobacteriaceae and S. aureus or Enterobacteriaceae and streptococci are
common bacterial combinations. Appropriate use of broad-spectrum intravenous
antibiotic therapy is the treatment.
Aspiration Pneumonia. Aspiration as the possible cause of pneumonia should
be suspected in the elderly, those who reside in a nursing home, and those with
neurologic dysphagia, compromised cough reflex, altered mentation, endotracheal
intubation, and gastroesophageal reflux disease. Antibiotics are typically given following a witnessed aspiration and discontinued after 48 to 72 hours with no development of infiltrates. Gram-negative coverage is required for aspiration pneumonia,
with the current agents of choice being piperacillin/tazobactam, meropenem, or
cefipime, often with additional gram-negative coverage if there are higher rates of
antibiotic resistance or additional risk factors. Vancomycin can be considered to
cover for methicillin-resistant S. aureus (MRSA).
Urinary Tract Infection. It is also around this time that a UTI should be enter-
tained as part of the differential diagnosis. Mild UTIs can be treated with similar
agents or with a third-generation cephalosporin or fluoroquinolone. The patient
with persistent fever 5 to 7 days after surgery needs to have a thorough examination
of the operative site to check for signs of infection, which include erythema, pain,
local edema, and purulent discharge.
Surgical Site Infections
Surgical site infections have markedly decreased through wide practice of aseptic technique and team-based perioperative management protocols. Patients at
high risk of wound infection are those who underwent lengthy surgical procedure,
received blood transfusion, are malnourished, are immunosuppressed, and have
diabetes mellitus. Prophylactic antibiotics should be given within 1 hour before
surgery and discontinued within 24 hours after surgery to lower the risk of SSIs.
Skin site infections may be treated with oxacillin or with vancomycin if MRSA is
common in the institution or environment. Deep abdominal infections are often
treated with a cephalosporin, such as cefoxitin, or a combination of fluoroquinolone plus metronidazole to cover anaerobic, enterococci, and enteric gram-negative
bacilli infections.
Drug Fevers
Drug fevers are often associated with rash and/or lupus-like syndromes. They also
may have renal, liver, lung, joint, or hematologic dysfunction associated with the
drug toxicity. The risk of developing drug fever correlates with the number of
drugs prescribed. Antimicrobial agents account for roughly one-third of all cases.
428 CASE FILES: FAMILY MEDICINE
https://t.me/medicina_free
Common antimicrobial agents associated with drug fever include minocycline,
cephalosporins, fluoroquinolones, sulfonamides, and penicillins. Unfractionated
heparin, which is common in the hospital setting for DVT prophylaxis, is another
medication associated with drug fever. Drug fever typically resolves within 72 to
96 hours after discontinuation of the offending agent.
Abscess
Purulent drainage and fluctuant appearance indicate the presence of an abscess,
which requires incision and drainage. When cellulitis is confirmed, treatment with
an antibiotic is warranted. Gram-positive bacteria, such as S. aureus, S. epidermidis
(especially with implants or devices), Streptococcus pyogenes, and Enterococcus,
are important pathogens. Fungal etiology should not be ruled out in patients with
severe comorbid conditions. On rare occasions, deep abscesses produce fever 10 to
15 days after surgery. A high level of suspicion leads to diagnostic imaging, such as
computed tomographic (CT) scan of the body region most likely to be infected,
which depends on the location of the surgery. Interventional radiology specialists
can be called upon for radiologically guided drainage of the abscess, which is the
definitive treatment. Antibiotics should include coverage for gram-negative enteric
bacilli and anaerobes, especially when intra-abdominal or pelvic infections are suspected. Gallium scans may be helpful in finding sites of infection in patients without localizing symptoms and workup.
Line-Associated Infection
An intravascular catheter or line-associated infection needs to be entertained when
the patient has had intravenous devices for 3 days or more, even when the site
appears clean. Any unnecessary lines should be discontinued, as they are potential
sites of infection. The catheter tip should be cultured to reveal an offending organism that would direct treatment.
Deep Venous Thrombosis
Fever caused by a DVT usually occurs 1 to 4 weeks postoperatively. Half of the
time, patients with DVT are asymptomatic. Common complaints are unilateral
leg swelling, tenderness, pain, and warmth. The Homan sign (pain in the calf
on foot dorsiflexion) is demonstrated in some cases. When possible, surgical
patients are encouraged to ambulate early; otherwise, subcutaneous heparin or
low-molecular-weight heparin are useful prophylactic measures. If the patient is
at high risk for bleeding, intermittent pneumatic compression devices can help.
Diagnosis is made by risk stratification, laboratory testing, and duplex ultrasound.
Patients who develop pulmonary embolism (PE) usually have a concomitant DVT.
The treatment of DVTs and PE is initiated with low-molecular-weight heparin or
unfractionated heparin, followed by oral anticoagulation.
SECTION II: CLINICAL CASES 429
https://t.me/medicina_free
Types of Surgery and Associated Complications
The type of surgery provides a clue regarding the associated risks of fever-associated
surgical morbidity. In general, due to less tissue trauma, laparoscopic surgery comparatively causes fewer cases of fever than open surgery. Pleural effusion develops
in all patients undergoing cardiothoracic surgery, and 5% of those patients acquire
pneumonia. Particularly unique to abdominal surgery is deep abdominal abscess
and pancreatitis. Obstetric and gynecologic surgery could be complicated by postpartum endometritis/deep pelvic abscess, necrotizing fasciitis, and pelvic thrombophlebitis. SSI is the most common infectious cause of fever in orthopedic surgery.
Prostatic and perinephric abscesses are more commonly seen in urologic procedures. Arterial embolization, or “blue toe” syndrome due to emboli from an infected
vascular graft, can occur following vascular surgery, especially in grafts involving the
groin and the legs. Endovascular aortic aneurysm repair may be complicated by
“postimplantation syndrome” characterized by self-limited fever, elevated C-reactive
protein levels, leukocytosis, and negative blood cultures. Patients undergoing genitourinary procedure are at greater risk of having a UTI. Meningitis is a common
cause of fever following a neurosurgical procedure. Neurosurgery patients, who are
usually immobilized and less aggressively anticoagulated to avoid brain hemorrhage, have the highest incidence of DVT.
CASE CORRELATION
See Case 24 (Pneumonia), Case 44 (Cerebrovascular Accident/Transient
Ischemic Attack), and Case 48 (Fever and Rash).
COMPREHENSION QUESTIONS
38.1 A 60-year-old man with a diagnosis of adenocarcinoma of the colon under-
went a left hemicolectomy with primary anastomosis. Thirty hours after
surgery, he was found to have a fever of 102 °F (38.8 °C), blood pressure of 90/60 mm Hg, heart rate of 140 beats/min, respiratory rate of
24 breaths/min, and low urine output. Physical examination showed diffuse abdominal tenderness. The surgical site is clean and without redness.
UA was negative, and the complete blood count showed a WBC count of
11,000cells/mm3. Which of the following is the most likely cause of this
patient’s fever?
A. Pneumonia
B. Intraperitoneal leak from bowel injury
C. Surgical site infection
D. Deep tissue abscess
Соседние файлы в папке Библиотека им академика М.И. Перельмана