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37 Cardiopulmonary Resuscitation 371

apex of the heart to avoid the phrenic nerve and the sac As the PCA period increases, focus should be directed
VetBooks.ir is then reflected dorsally to the base of the heart. The at preventing or minimizing secondary organ damage
and neuroprotection. The routine use of corticosteroids,
heart should be compressed from the apex to the base at
a rate of 100–120 compressions per minute. This can be
mended. If evidence of increased intracranial pressure is
done with one or two hands, depending on patient size. hyperosmotic fluids, and anticonvulsants is not recom-
In some patients, the descending aorta can be briefly present then treatment with mannitol or hypertonic
(10–15 minutes) cross‐clamped to help direct blood flow saline is warranted. Should generalized seizures develop
to the cerebral and coronary circulation. then appropriate treatment with an anticonvulsant
If ROSC is achieved, the patient should be maintained should be started. Prophylactic treatment with anticon-
in an anesthetized state while a thoracostomy tube is vulsant medications may be considered in animals dem-
placed and the thoracotomy site is closed. Volatile gas onstrating global cerebral signs (coma, compulsion) in
anesthetics have profound vasodilator effects and may the postarrest period. The use of corticosteroids has not
be detrimental to a recently resuscitated patient. All been documented to improve outcome and their use
efforts should be made to avoid hypotension and total IV should be restricted to animals with a clear indication
anesthesia may be the best option during this time. due to the potential for severe adverse effects.
Prophylactic antibiotics should be considered for Induction of mild therapeutic hypothermia is rapidly
patients that have undergone open chest CPR due to the becoming the standard of care in human PCA manage-
likelihood of contamination. ment. Its use has been described in the veterinary litera-
ture but is not widespread at this time. Due to the risks
associated and the technical difficulty of safely inducing
Postresuscitation Care and maintaining appropriate hypothermia, it is not cur-
rently recommended. If, however, mild hypothermia
Despite initial reported ROSC rates of 35–45% in veteri- develops spontaneously, the patient should not be
nary medicine, survival to discharge rates range from 2% aggressively warmed; rather, the return to normothermia
to 10%. This highlights the need for continued aggressive should be gradual (0.25–0.5 °C/h).
critical care following ROSC. Initial postcardiac arrest
(PCA) care should focus on preventing rearrest, specifi-
cally targeting hemodynamic stability and pulmonary/ Discontinuing CPR
respiratory function. Specific goals of hemodynamic sta-
bilization should include normalization of central venous The decision to terminate CPR generally lies with the
oxygen saturation, central venous pressure, cardiac out- clinician. When making the decision to withhold or
put, arterial blood pressure, and arterial oxygen content. terminate CPR, several factors should be considered
IV fluid therapy should be judicious and efforts should be including the inciting cause of the arrest, interval from
made to prevent overresuscitation. Ventilatory function onset of arrest to initiation of CPR, duration of CPR,
may be altered in PCA patients with resultant hyper‐ or and long‐term prognosis associated with the underly-
hypoventilation. Ventilation should be assessed and ing disease process. Although no definitive guidelines
positive pressure ventilation should be provided as exist, continuing efforts for 15–20 minutes is reasona-
needed to maintain normocapnia (PaCO 2 35–45 mmHg). ble, after which time the likelihood of a good neuro-
Supplemental oxygen or mechanical ventilation is used logic outcome is exceedingly small and CPR can be
as needed to maintain normoxemia (PaO 2 90–100 mmHg). discontinued.