VNJ Volume 39 (6) December 2024 | Page 35

Plus-Hex CLINICAL

Table 1 . Comparison of oxygen supplementation methods . Normal room air provides approximately 21 % inspired oxygen [ 12 , 17 ] .

Method of oxygen delivery Suggested oxygen flow rate

Approximate inspired oxygen concentration (%)

detect hypoxaemia is poor [ 19 ] . Furthermore , pulse oximetry readings can be impaired by pigmented skin , hypoperfusion or patient movement . Arterial blood gas analysis is the gold standard method of assessing lung function , as it measures PaO 2 and PaCO 2

[ 2 ]

. However , it is not available in many practices ; it is also invasive and technically challenging . Additionally , arterial blood sampling and arterial catheter placement can be stressful and painful , and it is important to minimise stress in patients with respiratory difficulties to avoid exacerbating their condition . If the patient remains obtunded , it may be possible to take an arterial sample without increasing stress , but , as mentation improves , the benefits may no longer outweigh the increased risk to the patient .

When a patient has already displayed hypocapnia , the VN could consider using capnography to measure end-tidal carbon dioxide , which is a less accurate but more available way of assessing ventilation [ 12 ]. However , this is reliable only when used in conjunction with an endotracheal tube , which would necessitate anaesthesia or severe obtundation . Capnography may be used with a nasal catheter , but readings may be unreliable as the patient may breathe through its mouth , especially if it is panting . The VN should also recheck the patient ' s respiratory rate and effort , and auscultate the thorax to monitor for deterioration or improvement in clinical signs . If the patient ' s hypoxia and dyspnoea improve , the VN can consider weaning it on to room air , under guidance from the attending veterinary surgeon ( VS ) [ 20 ] .

Humidification should be considered when using longterm oxygen therapy , due to the risk of drying and irritation of the mucous membranes and decreased mucociliary clearance [ 2 ] . If using an oxygen kennel , the VN can bubble the oxygen through a container of sterile water to provide some moisture . Ice packed around the container will keep it cool and help prevent the kennel overheating [ 21 ] . Nebulisation with saline is another consideration that can be easily implemented by the VN . This produces small saline droplets , which can enter the lower airways to humidify and loosen respiratory secretions [ 4 , 22 ] . Ackerman [ 22 ] suggests using the nebuliser every 4 hours for 15 – 20 minutes each time . The VN can also perform coupage after nebulisation , for around 10 minutes . Rapid , sharp percussions of the chest using cupped hands creates vibrational energy , which helps to loosen secretions and stimulates the cough reflex [ 23 ] . Rosewell [ 24 ] suggests that coupage should be instigated from the point of diagnosis of aspiration pneumonia ; however , there is currently a lack of evidence to support its use in veterinary patients [ 25 ] .

Neurological monitoring

Status epilepticus is defined as a seizure lasting longer than 5 minutes . Prolonged seizure activity can cause neuronal cell death , leading to neurological impairment [ 26 ] . This patient had been given antiepileptic drugs and was obtunded . Monitoring seizure patients requires intensive nursing care . One study suggests that seizuring patients should be frequently reassessed as changes in neurological status can be rapid [ 27 ] . Kwiatkowska et al . [ 28 ] studied dogs admitted to hospital for seizure evaluation and found that 50 % had another seizure while hospitalised . The VN can use an objective scoring system , such as the modified Glasgow Coma Scale ( Table 2 [ 29 ] , page 36 ), to monitor neurological status . The scale assesses motor activity , brainstem reflexes and level of consciousness , and provides a total score out of 18 . The score provides an indication of the severity of a patient ' s neurological status , with lower scores indicating the possibility of a poorer prognosis . Furthermore , serial monitoring can be used to assess improvement or progression . This should be used as part of the routine monitoring of patient parameters . If the patient seizures again , further veterinary intervention may be required .

The VN can also provide a seizure pack on the patient ' s kennel , containing appropriate antiepileptic drugs , syringes and needles ; this saves time and is easy to use if the patient has another seizure . It should be noted that benzodiazepines should not be pre-drawn into syringes , as they can bind to plastic . Additionally , environmental stimuli such as light and noise should be reduced , as these can trigger further seizure activity [ 30 ] .

Volume 39 ( 6 ) • December 2024

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