5/3/2012. Goals and Objectives HFNC. High-Flow Oxygen Therapy: Real Benefit or Just a Fad?

Transcription

1 High-Flow Oxygen Therapy: Real Benefit or Just a Fad? Timothy R. Myers MBA, RRT-NPS Director, Women s & Children s Respiratory Care & Procedural Services and Pediatric Heart Center Rainbow Babies & Children s & MacDonald Hospital for Women Adjunct Faculty, Assistant Professor Department of Pediatrics, Case Western Reserve University Cleveland, Oh Goals and Objectives Discuss rationale and clinical advantages of utilizing high-flow oxygen with nasal cannulas (HFNC) Discuss the evidence and theories surrounding pharyngeal and distending pressures of HFNC Review the scientific evidenced of specific disease etiologies treated with HFNC Review the areas of caution and needs for future investigation necessary for HFNC 3 HFNC HFNC refers to the delivery of heated, humidified and blended oxygen/air via small caliber nasal cannula at flow rates of >1 l/min HFNC has been used: Pre/Post-extubation when CPAP may be technically difficult and/or lead to significant nasal trauma Longer-term support of CPAP-dependent patients with evolving or manifest chronic lung disease 4 1

2 Advantages of HFNC Heated, humidified high-flow nasal cannulas (HFNC/HHHFNC) have been incorporated into many ICU s: Ease of administration and management General perception of improved patient tolerance/comfort with minimal nasal trauma Patient outcomes are similar to those described with NCPAP use 5 Why it is Used Delivery of relatively high flows of heated and humidified gas via a nasal cannula in neonates (and others) has gained increasing acceptance in the treatment of respiratory conditions. de Klerk A. Adv Neonatal Care 2008; 8: Shoemaker MT et al. J Perinatol 2007; 27: Saslow JG et al. J Perinatol 2006; 26: Retrospective Comparison Assessed the frequency of usage, safety and clinical utility of HHFNC in two tertiary care hospitals and compare outcomes to a historical control group of premature infants on NCPAP Conclusions: HHFNC was well-tolerated by premature infants No apparent differences in adverse outcomes Additional research is needed to better define the utility and safety of HHFNC compared to NCPAP Shoemaker MT et al. Journal of Perinatology (2007) 27,

3 Australian and New Zealand NICUs Resp Support used to reduce nasal trauma (91%) provide continuous positive airways pressure (62%) easier application and care of the infant (86%) improved tolerance by the baby (84%) Post Extubation Hough JL Et al. J of Paediatrics and Child Health 48 (2012) Prevents Reintubation Compared 2 methods of delivering HFNC therapy, applied immediately after planned endotracheal extubations of 30 NICU patients Among NICU patients immediately following extubation, Vapotherm performed better than a standard HFNC in maintaining: Normal appearing nasal mucosa Lower respiratory effort score Averting reintubation Woodhead DD et al. J Perinatol Aug;26(8): HFNC is Equal to CPAP Outcomes Studies of Neonatal HFNC have demonstrated an effect comparable with nasal continuous positive airway pressure (CPAP) Saslow JG et al. Perinatol 2006; 26: Lampland AL etal. J Pediatr 2009; 154: Kubicka ZJ et al. Pediatrics 2008; 121:

4 Schematic of Trials Wilkinson DJ et al. Neonatology Today. 2008: 3(8) 11 Canadian Trial Compare feasibility CPAP support generated by HFNC with conventional CPAP for reintubation prevention in preterm infants < 1250 grams 40 neonates randomized 12 of 20 HFNC infants were reintubated compared to 3 of 20 using Infant Flow (< 0.003) HFNC had increased O 2 use with more apneas and bradycardias postextubation Campbell DM et al. J Perinatology (2006) 26, Adult ED Data Prospective, observational study in a university hospital s ED of 17 patients Patients with acute respiratory failure requiring > 9 L/min oxygen for ongoing clinical signs of respiratory distress despite oxygen therapy were included Dyspnea rated by Borg scale and visual analogue scale (VAS), respiratory rate (RR), and pulse oximetry (SpO 2 ) collected before and 15, 30, 60 min after beginning HFNC Lenglet H et al. Respir Care 2012; March 13 4

5 Adult ED Data Lenglet H et al. Respir Care 2012; March 14 HFNC in Acute Heart Failure The clinical profile of 5 patients with AHF due to acute pulmonary edema (APE) treated with a high-flow system via nasal cannulas with a builtin heated humidifier Clinical variables collected include dyspnea (modified Borg7 scale), blood oxygen saturation (SaO 2 ) measured by pulse oximeter, heart rate, respiratory rate, and systolic blood pressure Arterial gasometry was performed at 24 h after admission and 24 h after treatment with the HFT system Carratala Perales JM et al. Rev Esp Cardiol. 2011;64(8): HFNC in Acute Heart Failure Carratala Perales JM et al. Rev Esp Cardiol. 2011;64(8):

6 Pressure 17 Pharyngeal Pressures Obtaining highly accurate pharyngeal pressure measurements over prolonged periods in preterm infants is difficult. Artifacts due to swallowing, movement, and secretions commonly rendered recordings uninterpretable However, satisfactory recordings are often possible when the infants are quiet 18 Evidence in the Literature Studies have shown HFNC pressure generated in the clinical setting is directly related to leak presence at nares and mouth Leak magnitude is related to: cannula size neonate s nares infant s mouth being opened or closed Kahn DJ et al. Pediatr Res. 2007;62(3): Kubicka ZJ et al. Pediatrics. 2008;121(1):

7 Pharyngeal Pressures Results show that the prong pressure is not all transmitted to the pharynx, but is more effectively transmitted when the mouth is actively closed. Considerable variation in pharyngeal pressure exists between infants with mouth closure. Predominantly due to variation in leak around the prongs at the nostrils 20 Pharyngeal Pressure Measured Pharyngeal pressures in 11 preterm infants, receiving binasal Hudson prong CPAP pressurized by bubbling bottles The mean pressure drop from the prongs to the pharynx was 3.2 (95% CI; 2.6 to 3.7) cmh 2 O with mouths open and 2.2 (1.6 to 2.8) cmh 2 O with mouths closed Mouth closure augments CPAP transmission DePaoli AG et al. Arch Dis Child Fetal Neonatal Ed 2005;90:F79 F81 21 Pharyngeal Pressure DePaoli AG et al. Arch Dis Child Fetal Neonatal Ed 2005;90:F79 F

8 Additional Comments HFNC and NCPAP are mechanistically similar modes of therapy PEEP generated by HFNC at a given flow rate depends on infant weight and nasal prongs size 1,2 HFNC has been shown to be an effective alternative to NCPAP in the treatment of apnea of prematurity 2 Minimal published research examining HFNC vs. NCPAP in treatment of neonatal RDS 3 1. Spence KL et al. J Perinatology 2007;27: Sreenan C et al. Pediatrics 2001;107: Campbell DM et al. J Perinatology 2006;26: HFNC: CPAP? To evaluate relationship between device, intraprong, and proximal airway pressures with flow values in a neonatal/pediatric test lung model, using two humidified, HFNC Flow values between 0 L/min and 12 L/min with an FiO 2 of 0.21 at a temperature of 37 degrees C and 100% humidity Hasan RA et al. Pediatr Crit Care Med Mar HFNC--CPAP All 3 pressures increased with increasing flows with both devices, irrespective of leak. With minimal leak, Fisher-Paykel device generated > pressures than Vapotherm for flows of < 8 L/min Trend reversed at higher flows due to pressure release feature of the Fisher-Paykel Under minimal leak, intraprong pressure values varied between 22% and 27% (F-P) and 20% and 32% (Vapotherm) corresponding device pressure Hasan RA et al. Pediatr Crit Care Med Mar

9 HFNC -- CPAP Proximal airway pressure was reduced by 20% to 30% relative to the intrapong pressure values with the two devices Device pressure essentially unaffected by nares-prong leaks or mouth leak. Intraprong pressure and proximal airway pressure reduced substantially with increased nares or mouth leak Hasan RA et al. Pediatr Crit Care Med Mar HFNC Tidal Volumes CONCLUSIONS: Clinically important pressures were not generated by high flows with a standard nasal cannula. The differences in spontaneous VT across all flows were negligible. Volsko TA et al. Respir Care 2011;56(12): Leaks decrease Pressure 28 9

10 Distending Pressure Locke et al demonstrated HFNC s in newborns can result in inadvertent PEEP leading to altered breathing strategy Lampland et al demonstrated in vitro that no leak present within HFNC system can increase pressure that can rupture humidifier outcome with a perfect seal is dramatic, obtaining a perfect seal in the clinical setting is unlikely. high pressure in the clinical setting (eg, barotrauma) may be evident long before a perfect seal has been obtained. Locke RG et al Pediatrics. 1993;91(1): Lampland AL et al J Pediatr. 2009;154(2): Linear Regression of Flow Versus Pressure Wilkinson DJ etal. J Perinatol 2008: 28(1): Inadvertent Pressure Frey B et al. Eur J Pediatr. 2001:

11 Study from Iran Amoozegar, et al. J. Arab Neonatal Forum 2006; 3: Children with respiratory distress treated with HFNC Reviewed records of 46 patients treated with HFNC and estimated the modified COMFORT score, the respiratory clinical scale, and the oxygen saturation level Study indicated that HFNC improved respiratory scale score,oxygen saturation, and the patient's COMFORT scale. Its mechanism of action is application of mild positive airway pressure and lung volume recruitment. Spentzas t etal. J Intensive Care Med Sep-Oct;24(5): High-Flow in ARF To compare the comfort of oxygen therapy via high-flow nasal cannula (HFNC) versus via conventional face mask in patients with acute respiratory failure. Acute respiratory failure was defined as blood oxygen saturation < 96% while receiving a fraction of inspired oxygen > 0.50 via face mask. Rocho O et al. Respir Care 2010;55(4):

12 High-Flow in ARF The total gas flow administered was higher with the HFNC than with the facemask (30 [ ] L/min vs 15 [12 20] L/min, P <.001). The HFNC was associated with less dyspnea (3.8 [ ] vs 6.8 [ ], P.001) and mouth dryness (5 [2.3 7] vs 9.5 [8 10], P <.001), and was more comfortable (9 [8 10]) versus facemask [ ], P <.001). Rocho O et al. Respir Care 2010;55(4): High-Flow in ARF 36 High-Flow in ARF HFNC was associated with higher PaO 2 (127 [83 191] mm Hg vs 77 [64 88] mm Hg, P = 0.002) and lower respiratory rate (21 [18 27] breaths/min vs 28 [25 32] breaths/min, P < 0.001), but no difference in PaCO 2. Conclusion: HFNC was better tolerated and more comfortable than face mask HFNC was associated with better oxygenation and lower respiratory rate. Rocho O et al. Respir Care 2010;55(4):

13 Adult High Flow: Is it CPAP? The aim of this study was to quantify the airway pressure effect associated with NHF in an adult patient cohort Parke R et al. Br J Anaesth 2009; 103: Adult High Flow: Is it CPAP? Significantly higher nasopharyngeal airway pressures recorded with mouth closed position compared with mouth open [2.7 (1.04) vs 1.2 (0.76) cmh2o (P<0.001)] Nasopharyngeal pressures with NHF (mouth open or mouth closed) significantly higher than those with a facemask (P< 0.001) No significant difference in nasopharyngeal airway pressure with facemask mouth open [0.11 (0.39) cmh 2 O] and facemask mouth closed [0.2 (0.63) cmh 2 O] (P>0.5) Parke R et al. Br J Anaesth 2009; 103: A Nursing Perspective: Healthy Adults Studies of paediatric patient using HFNC have been shown to have similar efficacy as nasal continuous positive airway pressure (CPAP). Although the degree of positive pressure and the effect of different flow rates on positive pressure generation have not been well defined or studied in the adult intensive care population Groves N et al. Australian Critical Care (2007) 20,

14 A Nursing Perspective: Healthy Adults Conclusion: This study has demonstrated that HFNC therapy is associated with the generation of significant positive airway pressure in volunteers In conclusion there is a degree of CPAP generated with the HFN therapy, which is flow dependent and also dependent on whether the person is breathing with mouth open or closed Groves N et al. Australian Critical Care (2007) 20, CPAP vs HFNC Randomized, open label, controlled trial 60 Preterm infants born at 28 weeks gestation clinically stable on NCPAP of 5 cmh 2 O with FiO2 < 0.30 for at least 24h randomly assigned to one of 2 groups The no-nc group were kept on NCPAP until they were on FiO 2 =0.21 for 24 h, and then were weaned off NCPAP without NC Nc group weaned off NCPAP when FiO 2 was 0.30 to NC (2 L/min) followed by gradual weaning from oxygen Abdel-Hady H et al. Early Human Dev 87 (2011) CPAP vs HFNC Abdel-Hady H et al. Early Human Dev 87 (2011)

15 Cautions The paucity of scientific, RCT evidence would support a cautious approach to the use of HFNC - particularly in those who are most at risk of harm (the smallest infants) HFNC may deliver elevated pharyngeal pressures in ELBW infants, it would be prudent to limit flows used in such infants Wilkinson DJ et al. Neonatology Today. 2008: 3(8) 44 Cautions HHFNC provides inconsistent and relatively unpredictable positive airway pressure Concerns regarding infection risks (past?) Caution should be exercised in the use of HHFNC in neonates (eg. relatively lower flows in larger neonates) until further evidence is available to clearly delineate its role, as well as to support its safety and efficacy. Klerk A. Adv Neonatal Care Apr;8(2): Questions of HFNC Randomized, controlled trials are not readily available to help guide therapy Key concerns regarding use of HFNC therapy in the neonates are: No standard exists for measuring pressure delivery (CPAP-generated) when an HFNC is being used Potential for increased risk for infection with the use of HFNC devices Lack of pressure monitoring is a well-known limitation of HFNC therapy 46 15

16 Questions to be Answer A need for more research to guide decisions about HFNC HFNC should be compared in a scientifically robust way with existing means of support (for example CPAP) Questions of efficacy and safety will only be answered by large randomized controlled trials. Wilkinson DJ et al. Neonatology Today. 2008: 3(8) 47 16