Page 362 - Clinical Small Animal Internal Medicine

330 Section 4 Respiratory Disease

secondary infection, hemorrhage, residual or continuous postthoracotomy patient. Serosanguinous pleural effu-
VetBooks.ir pneumothorax, seroma formation, sternal osteomyelitis, sion (PCV <25% of peripheral PCV) is a common and
expected occurrence with an indwelling thoracostomy
pyrexia, iatrogenic chylothorax, fibrosing pleuritis, sur-
gical dehiscence, and ipsilateral thoracic limb lameness
pleural PCV exceeds peripheral PCV by 25% and war-
(lateral thoracotomy). Crystalloid fluid therapy, ano- tube(s). However, hemothorax is diagnosed when the
rexia, vasculitis, and postoperative inflammation can rants immediate investigation. When the volume of tho-
contribute to peripheral edema formation. racic hemorrhage exceeds 10 mL/kg, autotransfusion
The most common complication involving the thora- should be considered.
costomy tube is improper placement. Insufficient subcu- Proper postoperative incisional care can reduce
taneous tunnel formation with large‐bore thoracostomy patient discomfort and surgical inflammation while
tubes can lead to continuous air leakage and pneumo- minimizing risk of infection. During the initial postop-
thorax. The thoracostomy tube percutaneous insertion erative period, the thoracotomy incision as well as
site should be inspected carefully when continuous thoracostomy tube insertion site(s) should be covered
pneumothorax is observed. Continual pleural effusion with an impermeate adhesive dressing. This provides a
may be primary or secondary in origin, depending on the seal preventing air leakage with resultant pneumotho-
etiology requiring thoracotomy. Pyothorax, chylothorax, rax while protecting against environmental contamina-
and neoplastic effusion represent sources of continual tion. Cold and warm compresses following surgery can
pleural effusion during the postoperative period. Pleural reduce incisional pain, swelling, and inflammation.
drainage is important to maintain proper ventilatory Cold compresses are usually applied during the imme-
function as well as oxygenation. However, excessive diate postthoracotomy period for 24–48 hours, with
pleural effusion can lead to significant systemic protein warm compresses used thereafter.
and fluid loss with subsequent intravascular volume An elevation in body temperature above normal in any
depletion. Vasculitis and surgical inflammation are con- postoperative patient warrants immediate concern and
tributors to this protein‐losing pleuropathy and third investigation. Hyperthermia may be secondary to
spacing, which may encourage perpetual effusion. decreased heat dissipation (inability to pant due to pain,
Resolution of the underlying disease process will likely excessive cage bedding), pharmacologic (mu opioid use
terminate the cause of effusion. in cats), or pain induced. Postthoracotomy pyrexia may
Infection is an undesirable complication in any post- be observed with infection, inflammation, or neoplasia.
operative patient. Preoperative infection may be present Indwelling catheter sites should be inspected for
in some patients, such as pyothoraces, in which septic hyperemia, warmth or discomfort upon palpation.
effusion necessitated surgical intervention. Continual Thoracostomy tube insertion sites should also be inter-
monitoring of thoracic fluid cytology and cell counts aids rogated in a similar fashion. Complete blood count and
in determining resolution of pyothorax. Responsible thoracic radiographs may also be considered when an
antimicrobial administration is of paramount impor- obvious etiology of pyrexia cannot be determined from
tance in the care of critically ill patients. A full discussion physical examination.
on this topic can be found elsewhere. Generally speak- Surgical reexploration is rarely necessary following
ing, clinicians should be familiar with antibiotic sensitiv- thoracotomy, but is required for continuous pneumo-
ity patterns of common bacterial isolates from their thoraces or hemothoraces that do not respond to medi-
hospitals and deescalate coverage to single‐agent therapy cal management. Pneumothoraces, which fail to seal
as soon as possible. Infection may be introduced intratho- despite continuous active suction, are an indication for
racically via the thoracostomy tube or surgical incision. prompt reexploration to evaluate the pulmonary paren-
This may be due to bacterial contamination associated chyma (bullae or pneumatocele rupture) and previous
with prolonged surgical exposure, improper handling of surgical sites (complete or partial lobectomy). Chronic
the thoracostomy tube, or bacterial invasion of the thora- pleural effusion, despite prior thoracotomy, may also
costomy tube insertion site and/or surgical incision. necessitate a second surgery due to fibrosing pleuritis
Appropriate samples should be obtained for bacterial or restrictive fibrin plaque formation on the surface of
culture and antimicrobial susceptibility testing when the visceral pleura of the lung. Decortication may be
infection is suspected. necessary if significant inelastic fibrin plaque forma-
Proper intraoperative hemostasis ensures minimal tion has occurred restricting lung expansion. For per-
postoperative hemorrhage, therefore significant petual pleural effusion, pleurodesis may also be
hemorrhagic pleural effusion is not expected in the considered.