Lecture 23 11/8/24 Flashcards
What is dyspnea?
subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity
What are the signs of resp. distress?
-increased resp. rate
-increased resp. effort
-orthopnea/shortness of breath
-open mouth breathing
-cyanosis
-stridor
What are the characteristics of resp. distress in the ER?
-common cause of presentation
-life threatening
-patient and owner both in distress
What are the causes of resp. distress?
-hypoxemia resp. failure
-hypercapnic resp. failure
What are the hallmarks of hypoxemia?
-PaO2 less than 80 mmHg
-SpO2 less than 95%
What are the normal values for PaO2 and SpO2?
-PaO2 between 80 and 100 mmHg
-SpO2 greater than 95%
What are the life threatening values for PaO2 and SpO2?
-PaO2 less than 60 mmHg
-SpO2 less than 90%
What are the two forms of oxygen in the blood?
-dissolved in blood/PaO2
-carried by hemoglobin/SpO2 or SaO2
What are the characteristics of pulse oximetry?
-differential absorption of infrared light by oxygenated and deoxygenated hemoglobin
-red and infrared wavelengths of light used
-oxygenated hemoglobin absorbs more infrared light
What are the two types of pulse ox probes?
-transmissive probe
-reflectance probe
What are the characteristics of a transmissive pulse ox probe?
-most commonly used
-can be placed on lip. tongue, pinna, toe webbing, prepuce, or vulva
-challenging in awake patients
What are the characteristics of a reflectance pulse ox probe?
-often better tolerated
-must be used over a bony surface
-placed at the tail base, rib, metacarpal area, or metatarsal area
What can affect pulse ox?
-ambient light
-peripheral vasoconstriction
-darkly pigmented skin
-hypothermia/hypoperfusion
-anemia
-tachycardia
-hyperbilirubinemia
What are the limitations of pulse ox?
-poorly tolerated in awake patients
-must be over an area of pulsatile blood flow
-patient’s HR must match pulse ox reading
-abnormal Hb species
-carboxyhemoglobin
-methemoglobin
What are the characteristics of arterial blood gas?
-gold standard
-technically challenging and painful
-need special equipment to run samples
Which arterial sites are used to collect samples for arterial blood glass?
dogs:
-dorsal pedal
-femoral
-coccygeal
-sublingual
-dorsal auricular
cats:
-femoral
What is measured on an arterial blood gas?
-PaO2
-SaO2
-PaCO2
-pH
What are the characteristics of cyanosis?
-gray/blue discoloration of mucous membranes
-requires 5 mg/dL of deoxygenated hemoglobin to be visualized
-visualization can be affected by anemia, room lighting, and visual acuity
What can cause respiratory failure?
-failure to ventilate
-failure to maintain airway
-failure to oxygenate
What are the causes of hypoxemic resp. failure?
-pneumothorax
-hemothorax
-pleural effusion
-pneumonia
-pulmonary edema
-pulmonary contusions
-pulmonary thromboembolism
What are the characteristics of hypercapnic resp. failure?
-can be due to failure of the resp. center, diaphragm, intercostal muscles, or by airway obstruction
-results in partial pressure of CO2 (PaCO2) greater than 60 mmHg
What are the causes of hypercapnic failure?
-head trauma
-cervical spine disease
-lower motor neuron diseases
-laryngeal paralysis
-upper airway obstruction
-flail chest
What are the characteristics of oxygen?
-most important therapeutic drug
-widely available
-relatively inexpensive
-FiO2 of 21% in room air
-FiO2 of 100% in medical oxygen
What are the characteristics of medical oxygen?
-can cause oxygen toxicity
-may administer a lower conc. depending on route utilized
-should be humidify if used for more than a few hours
What are the characteristics of flow-by oxygen?
-provides 25-40% oxygen
-flow rate of 2 to 3 L a minute
-well tolerated
-can be used during initial patient treatment
What are the characteristics of mask oxygen?
-requires tight fitting mask held to patient’s face
-can provide 50-60% oxygen with high oxygen flow rates
-poorly tolerated
What are the characteristics of nasal oxygen?
-unilateral or bilateral
-easily placed
-can provide 30-70% FiO2
-50 to 150 ml/kg/min
Which tools can be used for oxygen administration?
-e-collar
-intratracheal oxygen
-nasal cannula
-oxygen cage
-intubation
What are the characteristics of sedation?
-alleviates anxiety
-excellent for cases with upper airway distress
-may be used with caution with lower airway disease
Which medications and admin routes are used for sedation?
butorphanol or acepromazine given IV, IM, or SQ
How is stress minimalized in animals undergoing resp. distress?
-minimize handling
-complete exam in stages
-wait to perform major diagnostics until patient is stable
-keep patient in quiet areas
What is thoracocentesis used for?
-relieve pleural effusion
-relieve pneumothorax
-diagnostic tool/fluid collection
What are the characteristics of intubation?
-ascertains patent airway
-provides immediate control of oxygenation and ventilation
-life saving
-done when patient is in overt resp. distress
What are the steps of tracheostomy?
-place patient in dorsal recumbency
-make a midline incision
-blunt dissection on midline
-incision into trachea
-stay sutures placed around dorsal and ventral aspects
-insert tube
Why do temporary tracheostomies require 24 hour nursing care?
-prone to obstruction with mucus
-cleaning needed around stoma site
-cuff needs deflated/reinflated every 4 hours
What are the characteristics of cricothyrotomy?
-incision made into cricothyroid membrane
–tracheostomy or ET tube is inserted directly into incision
-faster than tracheostomy
-less tissue dissection than tracheostomy
What are the characteristics of TFAST?
-focused assessment with sonography for trauma
-assess two sites on thorax
-assess chest tube site and pericardial site
Which sites are assessed with a Vet BLUE ultrasound?
-cranial
-middle
-perihilar
-caudal
What are the characteristics of thoracic radiographs?
-always indicated in any animal with trauma
-can be used to assess for diaphragmatic hernia and pneumothorax
What is the minimum data base?
-PCV
-total solids
-blood glucose
-lactate
Which advanced diagnostics are done in patients with resp. distress?
-CBC
-chem
-electrolytes
-urinalysis
Which diagnostics are done as indicated in resp. cases?
-bronchoscopy/tracheoscopy
-thoracic CT
-abdominal rads
-abdominal ultrasound
