Casefiles 2: postop fever/acute respiratory insufficiency

Question 1

what should be at the top of our differential diagnosis if there is persistent ileus and fevers 7 days post abdominal operation?

Answer 1

intra-abdominal (deep surgical space) infection

Question 2

many clinicians arbitrarily define fever as oral temperature higher than ?

Answer 2

38.0 to 38.5°C (100.4-101.3° F)

Question 3

secondary peritonitis etiology

Answer 3

spillage of endogenous microbes into the peritoneal cavity following visceral perforation
need source control and antimicrobial therapy

Question 4

tertiary peritonitis etiology

Answer 4

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.

Question 5

The approach to a febrile postoperative patient who has undergone abdominal surgery is to presume that there is ? until proven otherwise.

Answer 5

an intra-abdominal or surgical site related infectious complication

Question 6

Several factors can influence the effectiveness of the host response to an infection:

Answer 6

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.

Question 7

Dual-Agent Therapy for intra-abdominal infections

Answer 7

• 2nd or 3rd gen cephs (cephtetan, cefoxitin, ceftriaxone, cefotaxime, cefepime) + metronidazole or clindamycin
• FQs (ciprofloxacin, levofloxacin, gatifloxacin) + metronidazole or clindamycin
• Aminoglycoside** + metronidazole or clindamycin

Question 8

Aminoglycosides should be used with caution in whom?

Answer 8

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

Question 9

Single-Agent Therapy for treatment of mild or moderate infections such as perforated appendicitis in healthy individuals

Answer 9

Cefoxitin, cefotetan, ceftriaxone, ampicillin-sulbactam (Unasyn)

Question 10

Single-Agent Therapy for treatment of severe infections or infections in immunocompromised hosts

Answer 10

imipenem-cilastatin (Primaxin), meropenem, ertapenem, tigecycline, piperacillin-tazobactam (Zosyn), ticarcillin-clavulanate (Timentin)

Question 11

What is the most common cause of fever in a patient during the first 24 hours following surgery?

Answer 11

Atelectasis

Question 12

A diagnosis of acute lung injury (ALI) requires the respiratory insufficiency to be acute in onset (such as in this patient), associated with a ?

Answer 12

PaO2/FiO2 less than 300, nonsegmental infiltrates on CXR, and with a pulmonary capillary wedge pressure (PCWP) that is less than 18 mm Hg

Question 13

atelectasis

Answer 13

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.

Question 14

ARDS is a severe form of ALI where the PaO2/FiO2 is less than ?

Answer 14

200. • decreased oxygen exchange and decreased pulmonary compliance.
     • injury to the pulmonary endothelial cells with intense inflammatory responses.

Question 15

Associated with the inflammatory changes in ARDS are ?

These changes manifest clinically as ?

Answer 15

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.

Question 16

Ventilator bundle

strategies for mechanically ventilated patients

Answer 16

(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.

Question 17

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

Answer 17

60 mm Hg

91%

Question 18

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

Answer 18

dead-space ventilation

Question 19

Positive pressure ventilation can produce a variety of injuries that are known as ?

Answer 19

VILI (ventilator-induced lung injury)

Question 20

? is one of the leading contributors to respiratory distress in the surgical patient

Answer 20

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.

Question 21

post-op fever etiologies based on timing

Answer 21

during: malignant hyperthermia
right after: bacteremia
POD1: atelectasis
POD2: pneumonia
POD3: UTI
POD5: DVT/PE
POD7: cellulitis
POD10-14: abscess

Question 22

workup for atelectasis in patient 7 days post colectomy for adenocarcinoma

Answer 22

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)

Question 23

Diagnostic bronchoscopy with bronchoalveolar lavage is indicated in the evaluation of ?

Answer 23

an immunocompromised patient with acute respiratory distress with bilateral pulmonary infiltrates

Question 24

What would most likely differentiate ARDS from cardiogenic pulmonary edema?

Answer 24

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

Question 25

ALI secondary to forced inspiration against a closed or narrowed airway can result in ?
how to treat?

Answer 25

“negative pressure pulmonary edema”

often self-limiting with supportive care that includes mechanical ventilation and judicious fluid management

Question 26

occult pneumothorax

Answer 26

seen on CT scan but not visualized by CXR

Question 27

pulmonary contusion

Answer 27

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

Question 28

flail chest

Answer 28

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.

Question 29

what is the is currently the “gold standard” for the detection of blunt thoracic aortic injuries?

Answer 29

CT angiogram (CTA)

Question 30

tension pneumo treatment

Answer 30

Tube thoracostomy

Needle decompression

Question 31

hemothorax treatment

Answer 31

Tube thoracostomy resuscitation

Possible exploration, repair

Question 32

cardiac tamponade treatment

Answer 32

Decompression (open, needle)

Exploration repair

Question 33

treatment for blunt cardiac injury

Answer 33

Supportive care (inotropes); operative repair for cardiac rupture

Question 34

air emboli treatment

Answer 34

Exploration, repair

Question 35

treatment for injury to great vessels

Answer 35

Exploration, repair or repair via endovascular approach

Question 36

What are the leading causes of early death associated with blunt chest injuries?

Answer 36

Tension pneumothorax, massive hemothorax, blunt cardiac injury, and thoracic aortic disruption

Question 37

consider the possibility of the possibility of a major tracheobronchial injury if pneumothorax patient experiences what?

Answer 37

persistent large air leak and/or failure of lung re-expansion with the chest tube attached to suction

Question 38

Patients who are hemodynamically unstable with large hemothoraces and no other sources of blood loss should undergo ? for control of bleeding.

Answer 38

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

Question 39

The spectrum of blunt cardiac injury (BCI) encountered in clinical practices can range from self-limiting ?
how to manage?

Answer 39

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

Question 40

what is the leading cause of death from blunt trauma? the #2 cause?

Answer 40

traumatic brain injury

traumatic rupture of the aorta (TRA)

Question 41

traumatic rupture of the aorta (TRA) on CXR

but actually…

Answer 41

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

Question 42

gold standard for TRA dx

Answer 42

CTA

Question 43

Management choices for TRAs include ?

mainly determined by ?

Answer 43

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

Question 44

All patients with TRAs should be initially managed with ?

Answer 44

controlled hypotension to maintain a systolic BP of 100 mm Hg until definitive repair or continued medical therapy is instituted

Question 45

traumatic aortic rupture diagnosis and treatment

Answer 45

dx: CT angiography, TEE, aortography (much less commonly used)
tx: Urgent repair by either open repair or endovascular repair

Question 46

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?.

Answer 46

PEEP

Question 47

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

Answer 47

focused abdominal sonography for trauma (FAST)