Protocol in depth Asthma/COPD.

Transcription

1 Protocol in depth Asthma/COPD

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3 Asthma/COPD Narrowing of airways (an H4 histamine response causing inflammation and mucous production), leading to wheezing on inspiration and exhalation. This narrowing leads to breathing difficulty due to increased resistance, specifically on exhalation (normally a passive process) which now requires energy and muscle to accomplish leading to fatigue; this can be seen on waveform capnography.

4 Asthma/COPD Since these are inflammatory processes, airway size dramatically effects symptom presentation; minor inflammation in small airways significantly increases resistance and decreases air flow capacity. Larger airways are less susceptible. This is why children outgrow asthma: the inflammation is still intermittently present, but goes unnoticed. Similarly, aging reduces muscle tone that keeps airways open (leading to smaller airways), and the susceptibility returns.

5 Asthma, COPD Exacerbation Any irritant that comes in contact with airway tissues can lead to a histamine response in airways. Frequently... Environmentally allergies (dust, pollen, animals) Pollution Physical exertion Infection or other sickness Systemic allergic reaction (anaphylaxis)

6 Assessments Work of breathing History Lung sounds Wave form capnography SpO2 Events leading

7 Physical Assessment Level of consciousness Distress level (speaking in full sentences or 1 word at a time) Skin conditions Respiratory rate and volume Heart rate and rhythm Lung sounds: wheezing on inhalation, exhalation, or both? Adequate air volume movement? Are they the same in all four fields?

8 Cardiac Asthma Pathology of CHF even though you hear wheezing, it's still caused by pulmonary edema (bronchodilator use in pulmonary edema leads to worsening of condition) Conditions pointing to cardiac wheezing (CHF) instead of asthma History of CHF without COPD/Asthma Peripheral edema Differing lung sounds in different lung fields (Lungs sound worse in lower lobes because of gravity) EtCO2 hypercarbic, with normal wave form Hypertension

9 Not Sure? If you're not sure, consider CPAP. CPAP improves COPD, asthma, and CHF.

10 Treatments For Asthma We do not currently have the equipment to administer nebulized medications while on CPAP

11 Albuterol Adernergic Beta2 agonist Causes smooth muscle relaxation, resulting in dilation of bronchial passages, vasodilation in muscle and liver, relaxation of uterine muscle, release of insulin, and contraction of the heart muscle. Side Effects: tremors, anxiety, restlessness, palpitations, tachycardia, HTN, Contraindications: tachydysrhythmia, hypersensitivity. (Tachycardia is sometimes listed as a contraindication. However, frequent users of albuterol rarely suffer drastic heart rate incrases, and as such this does not pose as great of a risk)

12 Albuterol, cont'd Labetalol (being a beta blocker) reduces the effectiveness of Albuterol. Administration of Labetalol in asthmatic patients, who use nebulized medications frequently, can lead to bronchoconstriction and respiratory distress. Efficacy of Albuterol will be reduced in patients taking oral beta blockers Albuterol can be administered in dosages up to 20 mg for hyperkalemia, to reduce potassium levels.

13 Ipratropium Bromide (Atrovent) Anticholinergic (like Atropine) Inhibits interaction of acetycholine at receptor sites on bronchial smooth muscle, inhibiting mucous production and causing bronchodilation. Side Effects: N/V, coughing, headache, tachycardia, dry mouth, blurred vision Contraindications: Hypersensitivity to ipratopium, atropine, soybean protein, peanuts

14 Racemic Epinephrine Racemic Epi is an isomer of Epinephrine it is made of the same molecules, but is structurally different. (Specifically a 1:1 mixture of two isomers, L-isomer and D-isomer) Racemic Epi shares the same mechanisms and properties as Epinephrine Alpha and Beta agonist (causing vasoconstriction, tachycardia, bronchodilation) Racemic Epi has less Alpha properties, leading to less tachycardia and vasoconstriction

15 Racemic Epinephrine, cont'd Racemic Epinephrine should be administered if a nebulizer of albuterol/atrovent yields no therapeutic results. For EMT-B's, it is the 2 nd line drug if first administration of Albuterol/Atrovent is not effective. Be sure to dilute Racemic Epi in 2.5ml saline prior to administration

16 CPAP Since we are currently unable to administer bronchodilators via CPAP, it should be used when all nebulizer medication options have been exhausted. Should we become able to administer nebulized medication with CPAP, it can be applied immediately with first round of medication.

17 COPD & Oxygen Can you kill a COPD patient with oxygen?

18 COPD & Oxygen Only if you hit them with the cylinder. Hard.

19 COPD & Oxygen Hypoxic drive, where a lack of oxygen causes respiration (rather than arterial hypercarbia like in most people) is present in less than 5% of COPD patients. Many in EMS believe high administration of high flow O2 will lead to apnea. This is unfounded for the periods of time a patient is with EMS (this process takes over 24 hours). The danger of excessive oxygen administration is that it may lead to bradypnea, which causes hypercarbia. Any provider can monitor and prevent that by assuring the patients respiratory rate is >12.

20 COPD & Oxygen, cont'd Hypercapnia is unlikely to manifest itself in the ambulance, even during extended journeys. Should bradypnea occur before arrival at hospital, this is far more likely to be due to exhaustion than hypercapnia Singer M, Bellingan G. Reply to Denniston et al. Clin Med (2)184.

21 Intermediate Treatments

22 More Albuterol If the first nebulizer was not sufficiently effective, but provided some relief (patient improvement, but some distress is still present), continue with additional Albuterol until symptoms resolve. If no improvement occurred with initial nebulizer treatment, move to Racemic Epi.

23 IV Fluid Bolus If the absence of pulmonary edema can be assured, a fluid bolus of 20ml/kg can improve patient condition. Patients experiencing Asthma/COPD have increased work of breathing, leading to dehydration Mucous viscosity is reduced by fluid administration, making removal easier and treatments more effective. (dry mucous is much more difficult for the body to clear)

24 Intubation Intubation in Asthma/COPD patients should be an action of last resort, to protect a patients airway only, or for a patient in respiratory arrest/failure. While conscious, a patient can provide both inhalation and exhalation effort. BVM ventilations can only provide inhalation. This can be seen in a capnography waveform.

25 This same waveform can be seen in conscious patients The shark-fin waveform demonstrates how exhalation occurs slowly initially, then increases as further effort occurs. The elevated and increasing baseline shows CO2 retention.

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27 Solu-Medrol Methylprednisolone corticosteroid used to decrease inflammation. Changes the immune response Even though onset is rapid, changes in patient condition only occur after immune system response has changed, and is typically several hours. Solu-Medrol changes immune response, and should be used in caution in patients with active infection.

28 Solu-Medrol Patients taking Solu-Medrol at home can have acute changes to BGL. This is especially problematic in diabetics, and can lead to significant hyperglycemia if not properly monitored. Patients may not know about this effect, and since Solu-Medrol is usually taken for a short duration, symptoms may not be noticed leading to I didn't have a problem last time I took this!

29 Terbuatline Beta2 agonist. Side effects similar to other Beta2 agonists. When administered SQ, onset occurs within 15 minutes. Can also be administered via nebulizer.

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31 Magnesium Sulfate Magnesium prevents or controls convulsions by blocking neuromuscular transmission and decreasing the amount of acetylcholine liberated at the end plate by the motor nerve impulse. Magnesium is said to have a depressant effect on the central nervous system a smooth muscle relaxer that decreases CNS impulses that maintain muscle tone (this causes broncohodilation). This can cause hypotension by decreasing vascular resistance.

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33 Magnesium Sulfate, cont'd Administration of Rocuronium (or any other non-depolarizing neuromuscular blockade) after Magnesium Sulfate significantly increases the duration of action of Rocuronium, by as much as factor of two to eight. Depolarizing neuromuscular blocking medications (e.g. Succinylcholine) are not affected in the same way. In fact, MgSO4 is frequently used to prevent fasciculations related to Succinylcholine.

34 RSI Intubation of asthmatics is rarely warranted or advised, for the reasons listed earlier. With no ability to administer bronchodilators in-line to intubated patients, we can only provide ventilatory support, we cannot improve air movement. RSI will likely require calling for orders.

35 RSI, cont'd IV mag sulfate can still improve wheezing, but should be used cautiously with Rocuronium. Instead, consider orders for IM/SQ epi (similar dosages to anaphylaxis) or epi drip (2-4 mcg/minute) Or continue with Mag sulfate and request orders for sedation (Ativan, Valium, Fentanyl, etc) in place of rocuronium.

36 Epi Drip Place 1mg Epi in 1 liter of saline with 10gtts drip set. For 2 mcg/minute, 20 drops per minute For 3 mcg/minute, 30 drops per minute For 4 mcg/minute, 40 drops per minute Place 1mg Epi in 250 cc bag with 60gtts For 2 mcg/minute, 30 drops per minute For 3 mcg/minute, 45 drops per minute For 4 mcg/minute, 60 drops per minute

37 Questions?