D r. Ella Rokosh Assist a n t C linical RESCUE Professor D iv ision of C r it ical C ar e Me dicin e BIPAP University of Albe r t a

Transcription

1 RESCUE BIPAP Dr. Ella Rokosh Assistant Clinical Professor Division of Critical Care Medicine University of Alber ta

2 OBJECTIVES Review types of acute respiratory failure commonly seen in emergency department (ER) Become familiar with types of non-invasive ventilation (NIV) commonly available in ER and their benefits in acute respiratory failure Explore indications for different modes and settings of NIV in case by case basis Learn about contraindications and complications of NIV

3 RESPIRATORY FAILURE Type 1: hypoxic CHF pneumonia PE Some AECOPD Type 2: hypercarbic AECOPD obesity hypoventilation syndrome/sleep apnea syndromes drug overdose Large percentage of patients presenting to ER are in acute respiratory failure

4 CASE 1 55 year old man with a history of HTN and DM Presents to ER with acute SOB Unable to speak in full sentences, hx of PND, orthopnea On exam, BP 125/80, HR 125 reg, RR30, O2 saturation 80% on RA On exam bibasilar crackles, elevated JVP, moderate leg edema Bloodwork shows wbc of 12, Hb 125, normal electrolytes but Cr elevated at 150 ABG 7.38/38/50/23/80 What do you do?

5 CASE 2 78 year old woman with history of smoking and asthma Presents with 2-3 day history of progressively increasing shortness of breath associated with increased sputum production On Symbicort and Spiriva at home, has been using Ventolin 3-4 times daily the last 2 days On exam, BP 150/90, HR 150. RR 35, saturation 82% on RA Chest sounds very diminished throughout, wheeze, accessory muscle use, speaks in 1-2 word sentences Bloodwork shows wbc of 15, Hb 115, normal electrolytes and creatinine ABG 7.21/65/45/25/82%

6 NON-INVASIVE POSITIVE PRESSURE VENTILATION (NIPPV) For number of decades shown to be of benefit in acute respiratory failure Prevention of intubation and its complications in 60% of patients if used correctly: VAP pneumothorax tracheomalacia Deconditioning, oversedation Reasons to implement NIPPV: Treatment of acute respiratory failure in ER Initial alternative to intubation to see if it can be avoided Ceiling of ventilatory support for patients who would not benefit from intubation

7 NIPPV Nasal or full face interface with a tight seal PEEP (EPAP) and PSV (IPAP) Pressures required differ depending on type of respiratory failure Less expensive that a ventilator, easier to administer Shortens ICU stay by about 2 days Reduces ICU mortality be about 17%

8 NIPPV MASKS

9 NIPPV EPAP provides steady pressure throughout the respiratory cycle Recruitment manouver, thus minimizing shunts Avoidance of dynamic hyperinflation/airway collapse in expiration Decreased preload and afterload Maximized gas transfer Positive pressure transmitted to left ventricle, increasing cardiac output Increased lung compliance IPAP provides extra support during inspiration Decreases work of breathing Increases oxygen exchange Helps in ventilation

10 CASE 1 55 year old man with a history of HTN and DM Presents to ER with acute SOB Unable to speak in full sentences, hx of PND, orthopnea On exam, BP 125/80, HR 125 reg, RR30, O2 saturation 80% on RA On exam bibasilar crackles, elevated JVP, moderate leg edema Bloodwork shows wbc of 12, Hb 125, normal electrolytes but Cr elevated at 150 ABG 7.38/38/50/23/80 What do you do?

11 CASE 1 Dx is: CHF Treatment: oxygen, diuretics, narcotics, nitrates and NIPPV

12 NIPPV IN CHF Well studied, shown benefit CPAP or BIPAP, no difference in outcomes Effects of NIPPV: PEEP or EPAP open de-recruited alveoli improving shunt also effect on the heart pump via increased intrathoracic pressure decreased preload and afterload Lung water pushed out Patients usually respond quickly with decreased RR and HR Need for frequent assessment initially to ensure appropriate response to treatment: Decreased RR and HR Comfort Cooperation

13 CPAP EPAP expiratory positive airway pressure continuous pressure throughout the respiratory cycle essentially a recruitment manouver Start with CPAP of 4-10 cm H2O, there should be no need for major adjustments Effective within 1-2 hours and often not needed again as long as adjunctive treatment IF CPAP fails, could try BiPAP Shown decrease in intubation rates from 28% to 6.7% Shown decrease in mortality from 25% to 5.5%

14 CASE 2 78 year old woman with history of smoking and asthma Presents with 2-3 day history of progressively increasing shortness of breath associated with increased sputum production On Symbicort and Spiriva at home, has been using Ventolin 3-4 times daily the last 2 days On exam, BP 150/90, HR 150. RR 35, saturation 82% on RA Chest sounds very diminished throughout, wheeze, accessory muscle use, speaks in 1-2 word sentences Bloodwork shows wbc of 15, Hb 115, normal electrolytes and creatinine ABG 7.21/65/45/25/82%

15 CASE 2 Dx: TX: AECOPD MDI or nebulized ventolin, atrovent, pulmicort, supplemental oxygen, po or iv steroids and antibiotics and NIPPV

16 BIPAP Shown very effective in AECOPD Decreases incidence of intubation by nearly 65% if done right Decreases in-hospital mortality by 55% Better that CPAP because of the IPAP component (inspiratory positive airway pressure) Similar benefits as CPAP but also supports inspiratory effort and increases volumes, so better rest, decreased respiratory rate (important in AECOPD)and improved ventilation Even if patient quite obtunded, short trial of BIPAP may result in increased LOC and avoidance of intubation Usually not a quick fix, though, unlike CPAP in CHF In meta-analysis, shown that mean use was 8 hrs/day for about 4 days

17 BIPAP How to use: start with EPAP 8-10 and IPAP of 6-10 and adjust based on patient response these patients might need higher EPAP because of air-trapping and autopeep Again, frequent monitoring needed to make sure the settings are appropriate Breath triggering RR and HR Decreased RR especially important in this patient population to resolve air trapping Patient comfort ABG s to assess CO2 effect and normalization of ph

18 CONTRAINDICATIONS TO NIPPV Diminished LOC/coma/unresponsiveness Hemodynamic instability Risk of aspiration Ileus Bowel obstruction Recent/active vomiting Impending cardiac arrest Refractory or very severe hypoxia Copious secretions Facial trauma/surgery/upper airway edema Lack of airway protection, ie.: absent gag/cough reflex Untreated pneumothorax

19 CONTRAINDICATIONS TO NIPPV Relative contraindications: Lack of patient cooperation, anxiety, claustophobia High risk of pneumothorax Severe comorbidities Also consider severity of illness, if the patient will need continuous NIPPV for days, he/she will not be able to cough effectively or eat and may end up with skin breakdown over nose, cheeks, forehead Pneumonia unless code status is no intubation ARDS, if severe, as will require prolonged and continuous BIPAP

20 CASE 3 65 year old male with hx of ALS Presents with dyspnea and inability to manage secretions or lie flat No prodrome of infection No bulbar findings Physical exam normal other that loss of muscle mass and fasciculations Bloodwork normal

21 CASE 3 Dx: neuromuscular failure Tx: BIPAP can be used here quite successfully to support neuromuscular respiratory insufficiency start with low EPAP, around 4 and little IPAP, around 8 patients are weak and cannot tolerate high pressures as a rule, Need low EPAP as might have difficulties breathing out against higher pressures Need increased trigger sensitivity

22 Does the patient require immediate intubation? yes intubate no Would NIPPV be the ceiling of treatment? yes Consider trial of NIPPV if no contraindications no Is NIPPV contraindicated? yes intubate no Consider intubation yes High APACHE score? High CO2? Very low ph? no AECOPD Cause of ARF? Acute CHF other BIPAP, EPAP 10 IPAP 5-10 over 1 hr Consider NIPPV CPAP 4-10 Consider switching to a different method of ventilation no Subjective/physiologic improvement in first hour? yes Continue NIPPV and wean as tolerated

23 PROPORTIONAL ASSIST VENTILATION More physiologic Uses flow assist and volume assist Ventilator evaluates patient on breath by breath basis re compliance and resistance Ventilator senses respiratory distress by the flow demand by patient Set to proportionately help with flow and volume Comparable to BIPAP in small studies, maybe better tolerated Better at coordinating respiratory cycle Senses flow demand better, easier to trigger Usually set at 100% assist then weaned

24 SUMMARY Acute respiratory failure is frequently seen in ER Depending on the type of acute respiratory failure, different NIPPV modalities may be used NIPPV very beneficial in reduction of in-hospital mortality and intubation rates Need to understand the indications and contraindications for NIPPV Need to reassess the patient frequently early on in the treatment to assure appropriateness of settings and/or abort trial in favor of intubation

25 BIBLIOGRAPHY 1. Bolton R, Bleetman A. Non-invasive ventilation and continuous positive pressure ventilation in emergency depar tments: where are we now? Emerg Med J 2008; Sarasin F, Jolliet P, Indication a la ventilation non invasive (VNI) dans les ser vices d urgence. Revue Medicale Suisse 2005; Yosefy C,et al. BIPAP ventilation as assistance for patients presenting with respirator y distress in the depar tment of emergency medicine. Am J Respir Med 2003;2(4): Cross A M, et al. Non -invasive ventilation in acute respirator y failure :a randomized comparison of continuous positive air way pressure and bi -level positive air way pressure. Emerg Med J 2003;20: Keenan S, et al. Does noninvasive positive pressure ventilation improve outcome in acute hypoxemic respirator y failure? A systematic review. Crit Care Med 2004 Vol. 32 No. 12; Quon B, et al. Contemporar y management of acute exacerbations of COPD. CHEST 2008 Vol. 133 No. 3; Tsai C et al. comparative ef fectiveness of noninvasive ventilation vs invasive mechanical ventilation in chronic obstructive pulmonar y disease patients with acute respirator y failure. J of Hosp Med 2013;8 (4): Gay P, Hess D, Hill N. Noninvasive proportional assist ventilation for acute respirator y insuf ficiency. Comparison with pressure support ventilation. Am J Respir Crit Care Med 2001;164: