Casefiles 2: postop fever/acute respiratory insufficiency Flashcards
what should be at the top of our differential diagnosis if there is persistent ileus and fevers 7 days post abdominal operation?
intra-abdominal (deep surgical space) infection
many clinicians arbitrarily define fever as oral temperature higher than ?
38.0 to 38.5°C (100.4-101.3° F)
secondary peritonitis etiology
spillage of endogenous microbes into the peritoneal cavity following visceral perforation
need source control and antimicrobial therapy
tertiary peritonitis etiology
diminished host peritoneal response. Very often in these cases, low virulence or opportunistic pathogens such as Staphylococcus epidermis, Enterococcus faecalis, or Candida species are identified.
The approach to a febrile postoperative patient who has undergone abdominal surgery is to presume that there is ? until proven otherwise.
an intra-abdominal or surgical site related infectious complication
Several factors can influence the effectiveness of the host response to an infection:
1) the size of the microbial inoculum;
(2) the timing of diagnosis and treatment;
(3) the inhibitory, synergistic, or cumulative effects of microbes on the growth of other microbes;
(4) effectiveness of the host peritoneal defense.
Dual-Agent Therapy for intra-abdominal infections
- 2nd or 3rd gen cephs (cephtetan, cefoxitin, ceftriaxone, cefotaxime, cefepime) + metronidazole or clindamycin
- FQs (ciprofloxacin, levofloxacin, gatifloxacin) + metronidazole or clindamycin
- Aminoglycoside** + metronidazole or clindamycin
Aminoglycosides should be used with caution in whom?
older patient or patients with compromised renal functions; close monitoring of levels is needed to avoid harm
With the availability of many newer, effective antibiotics against Gram-negative organisms, aminoglycosides are rarely used as first-line therapy
Single-Agent Therapy for treatment of mild or moderate infections such as perforated appendicitis in healthy individuals
Cefoxitin, cefotetan, ceftriaxone, ampicillin-sulbactam (Unasyn)
Single-Agent Therapy for treatment of severe infections or infections in immunocompromised hosts
imipenem-cilastatin (Primaxin), meropenem, ertapenem, tigecycline, piperacillin-tazobactam (Zosyn), ticarcillin-clavulanate (Timentin)
What is the most common cause of fever in a patient during the first 24 hours following surgery?
Atelectasis
A diagnosis of acute lung injury (ALI) requires the respiratory insufficiency to be acute in onset (such as in this patient), associated with a ?
PaO2/FiO2 less than 300, nonsegmental infiltrates on CXR, and with a pulmonary capillary wedge pressure (PCWP) that is less than 18 mm Hg
atelectasis
collapse of alveolar units occurs in patients undergoing general anesthesia, which causes a reduction in functional residual capacity that is further reduced because of incisional pain.
may progress to obstruction and inflammation, leading to larger airway obstruction and segmental collapse.
Most patients only have a low-grade fever and mild respiratory insufficiency.
ARDS is a severe form of ALI where the PaO2/FiO2 is less than ?
- decreased oxygen exchange and decreased pulmonary compliance.
- injury to the pulmonary endothelial cells with intense inflammatory responses.
Associated with the inflammatory changes in ARDS are ?
These changes manifest clinically as ?
interstitial and alveolar edema, loss of type II pneumocytes, surfactant depletion, intra-alveolar hemorrhage, hyaline membrane deposition, and eventual fibrosis.
severe hypoxia, decreased pulmonary compliance, and increase in dead space ventilation.
Ventilator bundle
strategies for mechanically ventilated patients
(1) elevation of head of bed; (2) stress ulcer prophylaxis; (3) DVT prophylaxis; (4) daily sedation interruption; (5) daily assessment of readiness for weaning and removal from ventilatory support.
The inability to maintain PaO2 of ? or an oxygen saturation of ? with a supplemental nonrebreathing O2 mask indicates significant alveolar-arterial (A-a) gradient, suggesting that mechanical ventilation should be instituted
60 mm Hg
91%
Acute lung injury and ARDS are associated with increases in ? as there is significant ventilation and perfusion (V/Q) mismatches occurring in various parts of the lungs
dead-space ventilation
Positive pressure ventilation can produce a variety of injuries that are known as ?
VILI (ventilator-induced lung injury)
? is one of the leading contributors to respiratory distress in the surgical patient
Excess fluid administration
Failure to terminate fluid resuscitation in patients with hemorrhagic shock and septic shock has been demonstrated to increase the pulmonary-related morbidity and mortality in ventilated patients.
post-op fever etiologies based on timing
during: malignant hyperthermia right after: bacteremia POD1: atelectasis POD2: pneumonia POD3: UTI POD5: DVT/PE POD7: cellulitis POD10-14: abscess
workup for atelectasis in patient 7 days post colectomy for adenocarcinoma
Provide supplemental oxygen therapy, obtain venous duplex scan of the lower extremities and CT angiography of the chest, consider empiric heparin therapy until the results of imaging studies are obtained
(she is high risk for PE)
Diagnostic bronchoscopy with bronchoalveolar lavage is indicated in the evaluation of ?
an immunocompromised patient with acute respiratory distress with bilateral pulmonary infiltrates
What would most likely differentiate ARDS from cardiogenic pulmonary edema?
pulmonary artery catheter to get PA pressure and PCWP
-helps determine the pt’s LV EDP
if the PCWP is less than 18 mm Hg, the diagnosis of ARDS is more likely, if greater cardiogenic pulmonary edema more likely
ALI secondary to forced inspiration against a closed or narrowed airway can result in ?
how to treat?
“negative pressure pulmonary edema”
often self-limiting with supportive care that includes mechanical ventilation and judicious fluid management
occult pneumothorax
seen on CT scan but not visualized by CXR
pulmonary contusion
lung parenchymal injury that occurs most commonly after high-energy blunt trauma to the chest
associated with rib fractures or flail chest involving the overlying chest wall
susceptible to capillary leakage and secondary inflammatory injuries, which can be made worse by pulmonary edema; therefore, avoid excessive fluid administration
flail chest
rib fractures that occur in more than one location, leading to that chest wall segment to move independently from the rest of the chest during respiration.
what is the is currently the “gold standard” for the detection of blunt thoracic aortic injuries?
CT angiogram (CTA)
tension pneumo treatment
Tube thoracostomy
Needle decompression
hemothorax treatment
Tube thoracostomy resuscitation
Possible exploration, repair
cardiac tamponade treatment
Decompression (open, needle)
Exploration repair
treatment for blunt cardiac injury
Supportive care (inotropes); operative repair for cardiac rupture
air emboli treatment
Exploration, repair
treatment for injury to great vessels
Exploration, repair or repair via endovascular approach
What are the leading causes of early death associated with blunt chest injuries?
Tension pneumothorax, massive hemothorax, blunt cardiac injury, and thoracic aortic disruption
consider the possibility of the possibility of a major tracheobronchial injury if pneumothorax patient experiences what?
persistent large air leak and/or failure of lung re-expansion with the chest tube attached to suction
Patients who are hemodynamically unstable with large hemothoraces and no other sources of blood loss should undergo ? for control of bleeding.
thoracotomy
also: strong considerations for surgical treatment should also be given to patients with greater than 1500 mL of initial output with chest tube placement and patients with greater than 200 mL/h bloody output for 4+ hrs
The spectrum of blunt cardiac injury (BCI) encountered in clinical practices can range from self-limiting ?
how to manage?
sinus tachycardia, SVT, and ventricular arrhythmias (rare)
EKG, if new EKG abnormalities should undergo monitoring for cardiac rhythm or pump abnormalities for 24 hours
if the initial ECG is normal and a serum troponin I is less than 0.4 ng/mL, the patient with suspected BCI can be safely discharged from the emergency center
what is the leading cause of death from blunt trauma? the #2 cause?
traumatic brain injury
traumatic rupture of the aorta (TRA)
traumatic rupture of the aorta (TRA) on CXR
but actually…
left apical cap, mediastinal widening, obscured aortic knob, widening of the paravertebral stripe, downward deviation of the left mainstem bronchus, rightward deviation of the NG tube, and opacification of the aorto-pulmonary window
gold standard for TRA dx
CTA
Management choices for TRAs include ?
mainly determined by ?
conservative treatment, thoracic endovascular aortic repairs (TEVARs), and open repairs
the patient’s clinical conditions, aortic injury type and severity, as well as patient co-morbidities and associated injuries
All patients with TRAs should be initially managed with ?
controlled hypotension to maintain a systolic BP of 100 mm Hg until definitive repair or continued medical therapy is instituted
traumatic aortic rupture diagnosis and treatment
dx: CT angiography, TEE, aortography (much less commonly used)
tx: Urgent repair by either open repair or endovascular repair
what used to be the cornerstone of flail chest management but now is no longer applied routinely except when patients develop respiratory failure and need mechanical ventilatory support?.
PEEP
If suspect PTX and following chest tube placement the breath sounds improve and blood pressure remain low, the next step would be to perform a ? to determine if intra-abdominal hemorrhage is the cause of the hypotension
focused abdominal sonography for trauma (FAST)
