Small Animal Surgical Emergencies. Группа авторов

1 Triage and Initial Stabilization of the Emergency Small Animal Surgical Patient

       Dana Clarke

       University of Pennsylvania, School of Veterinary Medicine, Philadephia, PA, USA

Introduction

      One of the most challenging aspects of emergency medicine is being presented with patients who have a variety of clinical signs and disease severities to assess, prioritize, stabilize, and provide with definitive care. The veterinary clinician is reliant on information provided by the client, their physical assessment, and initial diagnostics to determine severity of illness and injury, and therefore, urgency of care. Efficient identification and treatment of respiratory, cardiovascular, urinary, and neurologic derangements is essential for successful patient outcomes. When emergency surgical intervention is required, it is crucial to appropriately stabilize the patient for anesthesia without unduly delaying surgical care.

Triage and Initial Assessment

      Triage is an essential tool in the setting of emergency medicine to assess and prioritize critically ill patients [1, 2]. This is particularly true of patients that may require emergency surgical intervention, as the time to provide appropriate stabilizing care and definitive surgical therapy likely impacts patient outcome.

In many veterinary hospitals, nurses obtain pertinent historical information and perform a basic assessment to determine whether the patient needs immediate further evaluation or is stable enough to be seen in turn. In general, over‐triage is preferred to under‐triage in veterinary medicine, as the severity of signs presented by the patient and observed by the pet owner may not be fully appreciated by untrained individuals. Triage and training systems in patient assessment are used routinely in human emergency medicine. A variety of triage systems exist for human patients, which when combined with education of the medical staff on the system's guidelines for prioritizing medical care, reduces inconsistencies in decision‐making [3]. In veterinary medicine, no uniformly accepted triage system exists. Veterinary healthcare professionals therefore use historical information and intuition to make rapid decisions regarding the need for immediate care and order in which patients will be seen. The animal trauma triage (ATT) score was developed retrospectively and assessed prospectively to help to classify and prognosticate for a heterogenous patient group. For each patient, six categories are assessed (perfusion, cardiac, respiratory, skeletal, neurologic, and eye/muscle/integument) and scored from 0 to 3, with 0 being unaffected or only slightly affected to 3 indicating severe injury. The six scores are added together with a maximum possible score of 18. In both the retrospective and prospective populations, the mean ATT score of survivors was significantly lower than non‐survivors and for each one‐point increase in ATT, the likelihood of survival decreased 2.3–2.6 times [4]. Another veterinary triage system, adapted from the Manchester triage system, uses a five‐category system using color‐coding to indicate urgency. Examples of “red” emergencies (those which need to be seen immediately) include severe respiratory distress, decompensated shock, life‐threatening hemorrhage, and active seizures. Very urgent emergencies, including moderate respiratory distress, evidence of aortic thromboembolism, and urethral obstruction, were classified as “orange.” Urgent emergencies, such as mild hemorrhage, moderate dehydration and open fracture were classified as “yellow,” while non‐urgent disease processes such as localized inflammation, soft‐tissue swelling, stranguria and recent isolated seizure were classified as “green” [5]. The study determined that the use of a veterinary triage list by nurses upon triage corresponded better to retrospectively reviewed patient status than when individual judgment and intuition upon triage were employed [5]. Multicenter, prospective evaluation of this veterinary triage list is warranted to determine whether patient care is improved and time to be seen can be better estimated.

      Irrespective of the need for a formal veterinary triage system, a brief, but thorough physical exam remains the gold standard for recognizing critical patient status. The initial triage assessment includes visual examination and assessment of four key body systems: cardiovascular, respiratory, neurologic, and urinary [6, 7]. Information regarding the patient's mentation and responsiveness, as well as respiratory rate and effort, are obtained quickly on brief visual exam, often before performing any parts of a physical examination. Thoracic and cardiac auscultation with concurrent pulse palpation and a more thorough assessment of neurologic status, if indicated, follows visual examination. After cardiovascular, respiratory, and neurologic status is determined, if the patient is stable enough for further evaluation, urinary triage can be performed. Any significant pain must be addressed urgently to improve patient comfort and so that the effects of pain do not alter interpretation of cardiovascular and respiratory findings. Additionally, aggression should not be considered a sign of patient stability, as many scared and stressed patients will be aggressive in the face of severe shock.

Respiratory Assessment

Before any physical examination, all patients should have their respiratory rate, effort, noise, and pattern observed from afar. If a patient is showing any changes in respiratory pattern or effort, oxygen supplementation should be provided immediately. If there is any respiratory compromise, the patient should be presumed to be in hypoxemic shock until proven otherwise and oxygen supplementation should be provided. Further respiratory triage involves auscultation of the upper airway, trachea, and thorax. During abbreviated thoracic auscultation, emphasis should be placed on determining heart rate, rhythm, the presence of murmur(s) or arrhythmia(s), and lung sounds in all lung fields. Visual and auditory assessment of respiratory pattern and noise combined with thoracic auscultation should help localize the anatomic origin of the respiratory distress. The impact of pain, stress, and anxiety on respiratory rate and effort should not be underestimated (Figure 1.1).

      If respiratory noise is localized to the upper airway, diseases associated with an upper airway obstruction, including laryngeal paralysis, laryngeal collapse, brachycephalic airway disease, tracheal collapse, the presence of a tracheal, laryngeal, or pharyngeal mass, and the presence of a foreign body should be ruled out. See Chapter 28 for stabilization of the patient with upper airway obstruction.