The word ‘triage’ originates from the French word ‘trier’ meaning ‘to sort’. The purpose of triage is to categorise and prioritise patients based on the severity of their condition, determined by a systematic evaluation of their clinical parameters, ensuring the most emergent are seen first (Covey, 2018).
Triage can be carried out over the phone, in the waiting room and also in hospitalised patients (Covey, 2018). On completion of a triage survey, veterinary nurses must be able to categorise patients as either unstable requiring immediate treatment or stable and able to wait. This article will discuss the method of performing a triage survey, what to do if a life-threatening abnormality is detected and how to categorise patients.
Telephone triage
Clients will typically call their veterinary clinic if they are concerned their pet has become unwell or injured. Triaging over the telephone determines if the pet requires immediate attention or if they can be offered a routine appointment (Covey, 2018). The drawback of telephone triage is that it isn't possible to physically assess the patient and a judgement is made from the information the owner provides. It is important to exercise caution when making a judgement based on information provided by the owner.
Acquiring a patient signalment (breed, age, sex, neuter status and known co-morbidities) can help to identify predisposed diseases. Asking clear and concise questions where possible will help to gather the relevant history in a timely manner. This is referred to as a ‘capsule history’. Some examples of clear and concise questions include ‘What are your main concerns?’ and ‘When did you first notice these signs?’, ‘What medications if any is the patient receiving?’ and ‘Has there been any access to toxins?’ (Covey, 2018). Although recent toxin ingestion may not be immediately life-threatening, advising urgent treatment and/or decontamination is necessary to prevent potential life-threatening consequences.
If the owner has serious concerns regarding their pets neurological, circulatory or respiratory status, it is important they seek immediate attention (Covey, 2018). Asking unnecessary questions will delay their arrival to the clinic. However, it is helpful to obtain further information about the patient's condition so that the clinical team can prepare the necessary equipment, such as stretchers, oxygen and crash kit, before the patient's arrival (Covey, 2018). If the pet has been involved in trauma, asking the owner if there are any obvious injuries, such as bleeding, wounds or fractures, will help the veterinary team to prepare for the patient's arrival. Owners should be given advice on how to safely transport the patient.
The use of closed questions that require a yes or no answer, including ‘Is the pet responsive to you?’, ‘Is the pet able to walk?’ and ‘Is the pet bleeding?’ can be useful to maintain control of the conversation if the pet owner is stressed or upset.
Questions that rapidly assess neurological, circulatory and respiratory status include ‘Is the pet acting normally at the moment?’, ‘Can they walk?’ ‘Do they respond as normal when you call their name?’ ‘Are they able to breathe easily?’. An estimated time of arrival should be obtained for all emergencies who are advised to present to the clinic immediately and the owner should be given the clinic address and postcode if they have not previously attended (Covey, 2018).
The triage survey and the primary survey
The triage survey is conducted when an emergency patient arrives at the clinic and starts with a focused survey of the major body systems, including the respiratory, circulatory and neurological systems. This involves a 60–90 second examination of the clinical parameters that yield the most important information. Evaluation of these parameters allows the veterinary nurse to identify life-threatening abnormalities and categorise patients as either stable or unstable (Covey, 2018). A capsule history is obtained at the same time the triage survey is being performed. A more detailed history can be obtained later once it is determined that there are no life-threatening abnormalities to attend to first (Jordan and Brainard, 2011; Brown and Drobatz, 2018).
Performing a triage survey in under 2 minutes can be achieved by assessing the six perfusion parameters. This involves assessing mentation and gait, heart rate, respiration, mucous membranes, capillary refill time and pulse quality. Assessment of these parameters broadly assesses the major body systems and the patient's perfusion status.
If a life-threatening abnormality is detected during the triage survey, the patient should be immediately taken to the treatment room for assessment by a veterinarian (Reineke, 2015). The veterinarian performs a primary survey, which, in addition to physical examination, may involve ordering point-of-care diagnostics, such as blood pressure, electrocardiogram, pulse oximetry, focused ultrasound assessment, and minimum database bloods (blood glucose, lactate and gases, electrolytes, and pack cell volume/total solids), all of which can be performed by registered veterinary nurses.
Life-saving interventions are performed and therapies are administered including oxygen therapy, intravenous catheter placement and fluid resuscitation, once verbal permission has been granted by the owner (Reineke, 2015). Obtaining the patient's body weight before initiating treatment is recommended to ensure accurate dosages are administered, as well as, establishing a baseline weight for fluid balance assessment.
Patients that are deemed stable following the triage survey, may remain in the waiting room until the veterinarian becomes available (Covey, 2018). Clients should be informed to notify staff if they feel the condition has changed for the worse.
The major body systems
The major body systems include the neurological, cardiovascular and respiratory systems (Reineke, 2015). These systems are vital for maintaining perfusion (blood flow and oxygen delivery to the body's cells and tissues). A significant abnormality in one or more of these systems can compromise a patient and have life-threatening consequences.
Compromised patients who are in shock can compensate for a short amount of time, allowing them to maintain perfusion of vital organs. This compensatory state is referred to as ‘compensatory shock’. The compensatory responses commonly seen in patients in shock include increased heart rate (not in cats), increased respiration rate, pale mucous membranes, pro-longed capillary refill time and altered pulse quality (Boag, 2015). It is important to note that brick red mucous membranes and rapid capillary refill time may be seen in patients with distributive or septic shock.
Eventually a patient's ability to compensate to maintain perfusion will decrease and they will begin to decompensate. Signs of decompensated shock include, bradycardia, reduced respiratory rate, pale mucous membranes, delayed or absent capillary refill time and poor or absent pulses. If perfusion is not restored, tissue ischaemia (from circulatory collapse, hypoxaemia and/or poor microcirculatory blood flow) resulting from prolonged hypoperfusion can lead to mitochondrial dysfunction, reduction in cellular adenosine triphosphate and is thought to contribute to the development of organ dysfunction and/or failure (Silverstein, 2014)
The six perfusion parameter triage
Below is a summary of each perfusion parameter, how it is assessed and the potential abnormalities that can be present.
1. Mentation and ability to ambulate
Assessment of mentation provides information on each major body system, as appropriate mentation requires adequate cerebral blood flow, oxygen delivery and neurological function. Severe changes in a patient's mentation, such as stupor, coma, hyperexcitability and delirium or seizures should be addressed immediately and rapid treatment is required to prevent irreversible damage (Brown and Drobatz, 2018).
Types of altered mentation and their meaning:
- Hypersensitive: inappropriate alertness or over-reactivity to stimuli
- Dull: dulled level of alertness
- Obtunded: reduced level of alertness/consciousness but the patient can be roused
- Stuporous: unconscious but rousable with noxious stimuli
- Comatosed: unconscious and unable to rouse with noxious stimuli.
Gait
Although not necessarily immediately life-threatening, an abnormal gait can be suggestive of spinal cord injury or dysfunction. Patients who are suspected of having spinal cord dysfunction or injury should be prioritised over stable patients, as urgent treatment may be required to preserve spinal cord function (Covey, 2018). External assessment of patients involved in trauma should be performed by evaluating the entire animal for signs of bleeding (including from orifices), wounds and fractures (Reineke, 2015). Open fractures and/or wounds should be protected with sterile dressings to reduce contamination and risk of infection while the patient is being assessed and treated for life-threatening conditions. Analgesia should be prescribed by the veterinary surgeon for all patients in significant pain (Covey, 2018).
2. Heart rate
Evaluation of the heart rate and rhythm provides information on the cardiovascular system (Reineke, 2015). Assessment involves listening to the heart rate and rhythm with a stethoscope, while feeling for synchronous pulses. Abnormalities may include:
- Cardiac arrest: a life-threatening emergency that requires immediate cardiopulmonary resuscitation. Once identified cardiopulmonary resuscitation should begin immediately and the veterinarian must be alerted
- Tachycardia (heart rate >120 beats per minute (bpm) in dogs and >220 bpm for cats) (Newfield, 2018): patients that present to veterinary clinics are commonly tachycardic because of fear, stress or pain, which are not life-threatening abnormalities. Conditions, such as shock, cardiac disease or sepsis, may result in tachycardia, which is life-threatening. It is important that the triage nurse is able to accurately assess the other perfusion parameters and identify emergencies that are life-threatening (Reineke, 2015)
- Bradycardia (heart rate <60 bpm in dogs and <160 bpm for cats) (Newfield, 2018): the author recognises that there can be significant variations in normal heart rates in dogs, because of size and fitness status. Bradycardia is a common sign of shock in cats or may be associated with cardiac arrhythmias or electrolyte abnormalities, such as hyperkalaemia
- Pulse deficit: occurs when there are fewer pulses than the number of heartbeats
- Dull heart sounds: may be a sign of a pericardial effusion or pleural space disease
- Murmurs or arrhythmias: if detected during auscultation or ECG monitoring they should be reported to the veterinarian (Reineke, 2015).
3. Respiratory rate and effort
Evaluation of respiration provides information on the respiratory and cardiovascular systems, and is achieved by assessment of the respiratory rate, effort and pattern, as well as auscultation of the lung fields.
Severe and/or prolonged respiratory distress can result in hypoperfusion from hypoxia, respiratory muscle fatigue and eventual respiratory arrest (Reineke, 2015). Abnormalities may include:
- Apnoea is a life-threatening emergency that requires immediate intervention, such as endotracheal intubation and manual ventilation
- Tachypnoea (increased respiratory rate >40 bpm) (Reineke, 2015) can be a sign of respiratory compromise, but can also be a sign of excitement, fear, pain, shock or anaemia. Tachypnea that is secondary to respiratory compromise will be typically accompanied by increased respiratory effort (Reineke, 2015)
- Bradypnoea (decreased respiratory rate) or respiratory depression warrants further assessment as it may be life-threatening
- Dyspnoea or respiratory distress is life-threatening and requires rapid intervention, such as oxygen therapy and sedation. Common signs of dyspnoea include open-mouth breathing (especially in cats) and orthopnea, which is the abduction of the elbows and extension of the head and neck to minimise chest compression, and allow recruitment of the accessory muscles to facilitate respiration (Waddell and King, 2018). These patients benefit from oxygen supplementation prior to handling and assessment, as even minor manipulations can lead to a respiratory or cardiac arrest (Jordan and Brainard, 2011)
- Abnormal respiratory patterns may include increased inspiratory effort indicating upper-airway obstruction, increased expiratory effort indicating small-airway obstruction or both; paradoxical breathing, which is recognised as a lack of synchronous movement of the thoracic and abdominal walls, causing caudal intercostal and abdominal muscles to collapse inwards during inspiration (Reineke, 2015; Waddell and King, 2018)
- Audible respiratory noises (stertor or stridor) are indicative of upper-airway obstruction and require immediate assessment (Reineke, 2015)
- Abnormal lung sounds such as pulmonary crackles and wheezes
- Absent lung sounds could indicate lung collapse, consolidation or pleural space disease (Holgate, 2008; Sharpe, 2015).
4. Mucous membranes
Evaluation of the mucous membranes provides information on the cardiovascular and respiratory systems and is achieved by assessing the colour. Normal mucous membranes can vary from pale to darker pink in colour and are moist to the touch (Jordan, 2011). Abnormalities may include:
- Pale/white mucous membranes may be a sign of vasoconstriction (Boag, 2015) and/or hypoperfusion, hypothermia or anaemia (Jordan and Brainard, 2011)
- Brick red mucous membranes may be a sign of vasodilation. Common causes of vasodilation include inflammation, infection or hyperthermia. Cherry-red mucous membranes can occur as a result of carbon monoxide poisoning (Jordan and Brainard, 2011)
- Icteric mucous membranes are associated with increased levels of circulating bilirubin, which may result from liver disease, haemolysis or biliary tract obstruction
- Cyanotic mucous membranes are a sign of late or severe hypoxaemia (low blood oxygen levels)
- Brown or muddy mucous membranes are a sign of paracetamol toxicity, which causes methaemoglobin formation (Jordan and Brainard, 2011). Unlike haemoglobin, methaemoglobin binds so tightly to oxygen molecules that it does not release them to the body's cells and tissues. This results in tissue hypoxia and discoloured mucous membranes
- Dry/tacky mucous membranes are a common sign of dehydration or may be normal in a healthy panting dog.
5. Capillary refill time
Capillary refill time is used to assess peripheral perfusion of the tissues and provides information on the cardiovascular system. Assessment involves putting light pressure on the mucous membranes with a fingertip, and then counting the time it takes for the colour to return when the pressure is removed (Jordan, 2011). Normal capillary refill time is 1–2 seconds.
Abnormalities may include:
- A rapid capillary refill time (less than 1 second) indicates an increase in blood flow to the tissues. Increased blood flow may result from vasodilation, which can occur because of inflammation, infection or hyperthermia (Jordan and Brainard, 2011)
- A delayed capillary refill time (greater than 2 seconds) indicates reduced blood flow and potentially poor peripheral perfusion of those tissues (Jordan and Brainard, 2011)
The capillary refill time should be evaluated in conjunction with mucous membrane colour (Jordan and Brainard, 2011):
- Brick red mucous membranes with a rapid capillary refill time are commonly observed during the compensatory phases of shock or seen with systemic inflammation
- Pale mucous membranes with a delayed capillary refill time is a sign of poor perfusion and potentially decompensating shock
- Pale mucous membranes with a normal capillary refill time (1–2 seconds) may be an indicator of low red blood cells levels (anaemia) (Jordan and Brainard, 2011).
6. Pulse quality
Assessment of pulse quality is determined by palpation of the pulses and provides information on the cardiovascular system. Changes in systolic or diastolic blood pressure (or both) may be represented by changes to the pulse quality (Jordan and Brainard, 2011).
During an assessment the pulse amplitude (height) and duration (width) are palpated. There are several terms used to describe pulse quality. A bounding pulse describes a pulse that is tall and narrow. A weak or thready pulse describes a pulse that is short and narrow (Hansen, 2009). Absent pulses in a single limb, or both hind limbs, may be a sign of an arterial thromboembolism (Jordan and Brainard, 2011).
Categorising patients
Once all perfusion parameters have been assessed patients can be assigned an appropriate triage level. A number of triage scoring systems are available, which are validated for use in humans, some of which have been adapted to suit veterinary patients (Covey, 2018). Many triage systems, including the Manchester Triage Scale (Reineke, 2015), use a five-level structure (eg level 1: resuscitation; level 2: emergent; level 3: urgent; level 4: less urgent; and level 5: nonurgent). Each level is associated with a wait time, except level 1, which requires immediate assessment by a veterinarian (Covey, 2018).
The Animal Trauma Triage (ATT) scoring system was the first veterinary triage system available. Although initially designed for research, the ATT scoring system is useful in identifying veterinary trauma patients that require rapid medical or surgical intervention (Ash et al, 2018). Six physical examination findings (perfusion, cardiac, respiratory, eye/muscle/skin, skeletal and neurologic) are scored from 0–3. Patients with higher scores would receive treatment quicker than those with lower scores. The ATT has been shown to predict survival time with patients scoring higher being less likely to survive than those with lower scores.
In more recent years, a colour-coded veterinary scoring system called the Veterinary Triage List (VTL) has been developed for categorising emergency veterinary patients. The VTL was modified from the Manchester Triage Scale and it categorises veterinary emergencies into colours and wait times (ie, red: immediate; orange: 15 minutes; yellow: 30–60 minutes; green: 120 minutes) (Ruys et al, 2012; Reineke, 2015).
General practice clinics may benefit from a simple traffic light system, whereas bigger hospitals will likely require a levelled system.
Secondary survey
The primary survey continues until the patient is stabilised or no life threatening problems are identified and then a secondary survey is performed by the veterinarian. This involves a full physical assessment of the patient and obtaining a detailed history from the owner. The purpose of the secondary survey is to identify concurrent problems that were not assessed during the primary survey (Poli, 2021).
Conclusions
Triage involves performing professional nursing assessments and making critical decisions. The role carries a wealth of responsibility and as such sufficient training should be provided to ensure triage nurses are competent identifying which patients require treatment first, and which patients can safely wait.
KEY POINTS
- Triage can be used over the phone, in the waiting room and also in hospitalised patients.
- The purpose of the triage survey is to identify life-threatening abnormalities so that therapies can be initiated as early as possible.
- A triage survey is a 60–90 second evaluation of the clinical parameters that yield the most important information.
- The major body systems are vital for maintaining perfusion of cells and tissues. A significant abnormality in one or more of these systems can compromise a patient and have life-threatening consequences.
- The veterinarian performs a primary survey and orders life-saving interventions which are administered to patients who have a life-threatening conditions.
- A secondary survey is performed by the veterinarian once the patient is stabilised which identifies abnormalities that were not assessed during the primary survey.