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250 Section IV: Postoperative Care and Rehabilitation

require assisted ventilation, and can be used in recumbent patients urination may develop between 4 and 6 weeks. Voluntary urination
to try to limit thoracic congestion and development of aspiration in the thoracolumbar spinal patient is typically possible if the
pneumonia [36]. patient retains or regains voluntary motor function; many patients
remain nonambulatory for a variable period of time after regaining
motor and voluntary urinary function.
Mechanical Ventilation
Mechanical ventilation of neurological patients can be required Indwelling Catheterization
prior to surgery, particularly in dogs with high cervical lesions Indwelling urinary catheters are recommended for the intracranial
(discs, tumors, and luxations/fractures) or in patients that have patient or the tetraparetic or paraparetic patient with no loss of
intracranial disease that is affecting respiratory function. Indications nociception or voluntary motor function in the immediate postop-
for mechanical ventilation include the lack of spontaneous respira- erative period until the change in neurological status and potential
tion due to the location of the cervical lesion, to prevent hypercap- for recovery can be evaluated. In cases where the patient is experi-
nia in intracranial disease, to minimize cerebral edema, and in encing pain and is finding it difficult to express urine in the imme-
patients that have developed aspiration pneumonia and have diate postoperative period, the use of an indwelling urinary catheter
reduced oxygenation. Triggers on blood gas analysis for mechanical to prevent over‐distension, overflow incontinence, and urine scald-
ventilation are Pao below 60 mmHg or Paco above 60 mmHg ing is also recommended. The average time a urinary catheter can
2
2
[37]. In cases of intracranial disease, hyperventilation and reduc- remain in place prior to development of a UTI has been shown to be
tion of CO to around 35 mmHg is often indicated to minimize approximately 3 days [39,40].
2
changes in intracranial pressure. If mechanical ventilation is If possible, antibiotics should be avoided in patients while the
required, positive end‐expiratory pressure (PEEP) should be catheter is in place and the urine should be cultured around 24
avoided as it may lead to increases in intracranial pressure due to hours following removal of the catheter to determine if a UTI is
impaired venous outflow secondary to increased intrathoracic present. If an infection is suspected during catheterization, appro-
pressure [38]. priate antibiotics are selected based on bacterial culture and sensi-
The prognosis for patients that require mechanical ventilation tivity. In the guidelines developed for managing UTIs in dogs and
depends on the underlying pathology, the type of surgical proce- in cats, it is recommended to remove the urinary catheter whenever
dure performed, and the development of ventilator‐associated com- possible if infection has developed and to culture the urine via cys-
plications such as pneumonia and sepsis. tocentesis [41]. Prophylactic use of antibiotics is not recommended
while the catheter is in place [41].
Indwelling urinary catheters should be placed using aseptic tech-
Bladder Management nique (catheter, gloves, lubricant, etc.). The vulva or prepuce should
One of the most important aspects of managing the neurological be prepared with an aqueous chlorhexidine solution or soap to limit
patient is management of the urinary bladder. Voluntary bladder retrograde introduction of bacteria during catheter placement.
control will depend on the neurological status of the patient at the Some clinicians perform a complete surgical clip and preparation of
time of presentation or postoperatively. If bladder function is not the perivulvar or peripreputial region prior to placing a urinary
adequately managed, the patient is likely to develop a UTI, detrusor catheter. Following placement, the sterile closed collection system
atony, and also severe and debilitating skin lesions secondary to should be kept as clean as possible (e.g., off the ground while allow-
urine scalding that can lead to sepsis. There are several alternatives ing for drainage by gravity) (Figure 28.4). The urinary catheter, plus
to physically and medically manage the urinary bladder for both or minus vulva or prepuce, should be wiped every 8 hours with an
the short‐ and long‐term neurology patient. aqueous chlorhexidine solution and the urine collection system
should be replaced every 48 hours until the catheter is removed
Urinary Catheters [37,42].
Urinary catheters can be indwelling or placed intermittently. The
decision to place a urinary catheter is based on the preoperative Intermittent Catheterization
neurological status of the patient and can also be dependent on the Intermittent catheterization can be used to manage the urinary
gender and demeanor of the patient. The greatest risk associated bladder and can be taught to an owner if manual expression is not
with urinary catheterization is the development of UTIs, which can tolerated in male patients. This is not typically a viable option in a
ultimately lead to pyelonephritis. However, this risk is also present female patient due to the increased difficulty of catheterization
if the patient is allowed to develop overflow incontinence. The risk without sedation. The frequency of catheterization depends on
of developing UTIs has been found to be unrelated to the use of whether the patient is on intravenous fluids and whether corti-
indwelling or intermittent catheterization, but rather is related to costeroids or mannitol are being administered. With the owners
the duration of catheter placement or urinary dysfunction [39]. following aseptic technique, it is recommended catheterization
Dogs that are nonambulatory have been shown to be twice as likely be performed three to four times per day using a sterile catheter
to develop a UTI [12]. The development of UTIs has also been each time.
reported in a population of dogs with indwelling urinary catheters
in an intensive care setting [40]. In this study, female dogs had an Manual Bladder Expression
overall higher incidence of UTIs than male dogs, with an increased Intermittent bladder expression can be performed for short‐ or
risk of infection after 3 days of catheterization [40]. long‐term management of the neurological patient that does not
For patients without nociception preoperatively and postopera- have voluntary urination. If the patient is receiving intravenous
tively, and which may never fully regain voluntary urination, blad- fluids, this may need to be as frequently as every 3–4 hours to
der expression is required and the owners need to be taught this ensure that there is no over‐distension of the bladder or overflow
technique. In some of the nociception‐negative patients, reflex of urine that could cause urine scalding. If the patient is not