Lynn Bayne has no financial disclosures to make.

Transcription

1 Exploring the Science Behind the Use of Humidity in the ELBW Lynn E. Bayne, PhD, NNP Christiana Care Health System Alfred I. dupont Hospital for Children Financial Disclosures Lynn Bayne has no financial disclosures to make. Learning Objectives At the end of this session, the attendee will be able to: Review the data on the global use of relative humidity (RH) patterns; Recognize how EHL influences total energy balance; Understand the climate changes in the microenvironment; Describe the relationship between transepidermal water loss (TEWL) and evaporative heat loss (EHL); and State 3 controversies in use of added RH. 1

2 Clinical Questions About RH? What are our US and global colleagues doing? If there such thing as too little RH? Is there such thing as too much RH? Is it better if the walls are wet? Is there a way to know if you have it just right How do you implement, maintain, and wean RH? What are the REAL hazards associated with RH? Patient Product RH Timeline Real Life You have a mom in active, preterm labor 24 6/7 weeks AGA, 740 gram male Baby is intubated, given surfactant in DR 2

3 Meanwhile...back in the NICU The team warms the microenvironment. A.W. adds a conductive blanket to the microenvironment. No humidity is added as Dr. S believes it causes infection! Objective #1: What are we doing with humidity? What do we think we know? Our Colleagues in ANZ NICUs Using RH % NICUs Using RH N = 26 NICUs From Variability in Incubator Humidity Practices in the Management of Preterm Infants by L. Sinclair, J. Crisp, and J. Sinn, Journal of Paediatrics and Child Health, 45 (2009),

4 Patterns of North American RH Use Profile of ANZ NICUs using RH N = 26 NICUs From Variability in Incubator Humidity Practices in the Management of Preterm Infants by L. Sinclair, J. Crisp, and J. Sinn, Journal of Paediatrics and Child Health, 45 (2009), Profile of US NICUs using RH 4

5 No 23% Is humidity in ANZ being used under protocol? Protocol Yes 77% N = 26 NICUs From Variability in Incubator Humidity Practices in the Management of Preterm Infants by L. Sinclair, J. Crisp, and J. Sinn, Journal of Paediatrics and Child Health, 45 (2009), Is humidity in North America being used under protocol? Patterns of humidity use: Standalone protocol 5

6 Patterns of humidity use: Type of protocol How do RNs in ANZ drive RH implementation protocols? Gestational Age Birth Weight 77% 23% N = 26 NICUs Use Criteria From Variability in Incubator Humidity Practices in the Management of Preterm Infants by L. Sinclair, J. Crisp, and J. Sinn, Journal of Paediatrics and Child Health, 45 (2009), ANZ RH use criteria: 77% GA vs. 23% BW 35% 30% 25% 20% 15% 10% 5% 0% 34% 19% 12% 8% 4% Gestational age < 28 weeks < 30 weeks < 32 weeks < 34 weeks < 37 weeks 16% 15% 14% 12% 10% 8% 8% 6% 4% 2% 0% Birth weight < 1000 grams < 1500 grams 6

7 How do RNs in North America drive RH implementation protocols? North American use criteria: GA North American use criteria: Weight 7

8 How much RH do ANZ NICUs Initial RH use? 70-79% RH > 80% RH Unmeasured RH 4% 8% 88% N = 26 NICUs From Variability in Incubator Humidity Practices in the Management of Preterm Infants by L. Sinclair, J. Crisp, and J. Sinn, Journal of Paediatrics and Child Health, 45 (2009), How much RH do NICU RNs in North America use? When are ANZ NICUs implementing RH? N = 26 NICUs From Variability in Incubator Humidity Practices in the Management of Preterm Infants by L. Sinclair, J. Crisp, and J. Sinn, Journal of Paediatrics and Child Health, 45 (2009),

9 When do RNs in North America implement RH? How long are ANZ NICUs using RH? From Variability in Incubator Humidity Practices in the Management of Preterm Infants by L. Sinclair, J. Crisp, and J. Sinn, Journal of Paediatrics and Child Health, 45 (2009), How long do RNs in North America use RH? 9

10 When are ANZ NICUs weaning RH? 60% 57% 50% 40% N = 26 NICUs From Variability in Incubator Humidity Practices in the Management of Preterm Infants by L. Sinclair, J. Crisp, and J. Sinn, Journal of Paediatrics and Child Health, 45 (2009), % 23% 20% 10% 8% 12% 0% Time to weaning, % No weaning < 7 days 7 to 14 days > 14 days When do RNs in North America start to wean RH? How do ANZ NICUs drive RH weaning protocols? N = 26 NICUs From Variability in Incubator Humidity Practices in the Management of Preterm Infants by L. Sinclair, J. Crisp, and J. Sinn, Journal of Paediatrics and Child Health, 45 (2009),

11 When drives RNs in North America to wean RH? Patterns of humidity use: Other interventions Objectives #2 and #3: Heat balance and physiology The role of the device and trying to achieve balance 11

12 It s all about the heat balance Skin Integrity = IWL/TEWL RW heater power or air temperature from convective incubator What happens to humidity when air inside is warmed? Hypothetical NICU NICU Room Temp = 27 C/81 F Ambient RH = 28% As that air is entrained into the incubator and warmed X From Relative Humidity in Incubators by E. Bardell, J. Freeman, E. Hey, (1968). Archives of Diseases in Childhood, 43, pp and the RH inside drops to 18% 81 F/27 C, 28% RH From Relative Humidity in Incubators by E. Bardell, J. Freeman, E. Hey, (1968). Archives of Diseases in Childhood, 43, pp Reprinted by permission. 12

13 Body surface area (BSA) the average 24 weeks < 0.08 m 2 When 1 ml H 2 O evaporates/m 2 of BSA = > 580 cals (0.58 kcals) literally sucked away from the baby! 46.4 cals ( kcals) Clinician can t write enough fluid or calories to offset fluid/energy losses! Devices can t heat enough to offset losses without potential skin damage! 1000 cm 2 = 0.1 m 2 The bottom line IWL/TEWL = heat loss = energy loss Rate of IWL IWL not a major factor > 2 kg From Fluid, Electrolyte and Glucose Management in the Very Low Birthweight Infant by S. Baumgart, C. Langman, R. Sosulski, (1982). Clinical Pediatrics, 21(4), pp Reprinted by permission. 13

14 Heat Loss 10/13/2012 Heat exchange 0 Means Loss = Gain Heat Gain From Heat Loss from the Skin of Preterm and Fullterm Newborn Infants During the First Weeks After Birth by K. Hammarlund, B. Stromberg, G. Sedin (1986).Biology of the Neonate, 50, pp Reprinted by permission. Heat exchange Heat Loss from Evaporation (w/m 2 ) From Heat Loss from the Skin of Preterm and Fullterm Newborn Infants During the First Weeks After Birth by K. Hammarlund, B. Stromberg, G. Sedin (1986).Biology of the Neonate, 50, pp Reprinted by permission. Heat exchange Heat Supplied from Convection (w/m 2 ) From Heat Loss from the Skin of Preterm and Fullterm Newborn Infants During the First Weeks After Birth by K. Hammarlund, B. Stromberg, G. Sedin (1986).Biology of the Neonate, 50, pp Reprinted by permission. 14

15 How much humidity? Clearly, heat loss from evaporation as RH from 20% to 60% From Heat Loss from the Skin of Preterm and Fullterm Newborn Infants During the First Weeks After Birth by K. Hammarlund, B. Stromberg, G. Sedin (1986).Biology of the Neonate, 50, pp Reprinted by permission. Rate of evaporation From Transepidermal Water Loss in Newborn Infants: Relationship to Gestational Age by K. Hammarlund, G. Sedin (1979). Acta Paediatrica Scandanivica, 68, pp Reprinted by permission. Objective #4: So how much RH should we be using? How should we wean RH? What are the TRUE risks? 15

16 A developmental argument in use of RH From Measurements of Transepidermal Water Loss in Newborn Infants by G. Sedin, K. Hammarlund, G. Nilsson, et al: (1985). Clinics in Perinatology, 12, pp Reprinted by permission. Effect of high vs moderate RH N=22 All 85% RH x 7 days N= % RH 11 50% RH From Ambient Humidity Influences Skin Maturation in Extremely Preterm Infants by J.Agren, G Sjors, and G.Sedin (PAS 2005): 57: Effect of high vs moderate RH Delayed keritinization of stratum corneum with prolonged exposure to higher levels? From Ambient Humidity Influences Skin Maturation in Extremely Preterm Infants by J.Agren, G Sjors, and G.Sedin (PAS 2005): 57:

17 Should the microenvironment be able to offer RH while protecting skin integrity & promoting fluid & electrolyte balance? A prospective study Patient population < weeks GA, 1200 grams Randomized to 1 of 2 groups 40 infants enrolled to the humidity group (65%) 3 died during data collection 40 infants, case controlled to the no added humidity (control) group (~20% RH) 4 died during data collection Nonthermoregulatory of Supplemental Microenvironment Humidity in Premature Infants, Locke et.al, Abstract A prospective study Primary Hypotheses Skin Integrity Infants nursed in 65% RH incubators will have better skin integrity scores compared to those infants receiving routine care Serum Sodium Values Infants nursed in 65% RH incubators will have more days with serum sodium values between 135 and 145 meq compared to those infants receiving routine care Nonthermoregulatory of Supplemental Microenvironment Humidity in Premature Infants, Locke et.al, Abstract 17

18 Impact of RH on Skin Condition Nonthermoregulatory of Supplemental Microenvironment Humidity in Premature Infants, Locke et.al, Abstract Impact on Na + Infants in the humidity group spent a greater proportion of time with normal serum sodium values (p = 0.04): Humidity group: 81% (+ 19%) Non-humidity group: 64% (+ 21%) Nonthermoregulatory of Supplemental Microenvironment Humidity in Premature Infants, Locke et.al, Abstract Impact on fluid balance Nonthermoregulatory of Supplemental Microenvironment Humidity in Premature Infants, Locke et.al, Abstract 18

19 Effect of high vs moderate RH Is there an impact of RH on total fluids and sodium high vs. moderate levels? From Ambient Humidity Influences Skin Maturation in Extremely Preterm Infants by J.Agren, G Sjors, and G.Sedin (PAS 2005): 57: Is Dr. S s concern for infection unfounded? We know these organisms love H 2 O! Candida albicans Pseudomonas aeruginosa Serratia marcescens Escherichcia coli L. Biagotti and L. Lynam (2001). 19

20 We know that the infections in 1960 s were related to RH use! Infections Were Real!!! Why? Baby side Frontiers of viability pushed (32-34 weeks) Antibiotics less available Clinical side Neonatology not formalized as a discipline Pseudomonas aeruginosa L. Biagotti and L. Lynam (2001). We know that the infections in 1960 s were related to RH use! Infections Were Real!!! Why? Device side Temperature of H 2 O bath Psychophilic (-15ºC-10ºC) Mesophilic (10ºC-50ºC) Thermophilic (50ºC - 70ºC) Method of humidity delivery Liquid Nebulized Uncontrolled levels of RH Use of wristlets? No standard cleaning cycle L. Biagotti and L. Lynam (2001). Pseudomonas aeruginosa 1970 s and 1980 s Infection Rates Decreased! Why Baby side Gowns and glove use started Antibiotic use Handwashing techniques Clinical side Neonatology became formalized as a discipline Humidity abandoned in North America One week cleaning cycle Device side No real changes in equipment 20

21 1970s and 1980s Humidity re-introduced at a therapy Why Baby side Surfactant pushed frontier Difficult for warmers and incubators to counterbalance heat losses Clinical side Focus on growth and relationship to heat balance renewed Device side Water baths can be heated Gaseous method of water vapor delivery Wristlets replaced by air curtains and plexiglas portholes 1990 s and beyond Humidity re-introduced at a therapy Why Baby side Surfactant pushed frontier Difficult for warmers and incubators to counterbalance heat losses Clinical side Focus on growth and relationship to heat balance renewed Device side Water baths can be heated Gaseous method of water vapor delivery Wristlets replaced by air curtains and plexiglas portholes Remember that prospective study? Primary hypothesis infection Infants nursed in 65% RH incubators will have lower rates of late onset infection compared to those infants receiving routine care Nonthermoregulatory of Supplemental Microenvironment Humidity in Premature Infants, Locke et.al, Abstract 21

22 Remember that prospective study? Confirmed sepsis < 14 days Confirmed sepsis > 14 days Confirmed sepsis or sepsis evaluation > 3 days 65% RH, % No added humidity, % P value NEC And a retrospective study! Non-Humidified Incubators Humidified Incubators Number of patients Abu-sultaneh et.al, PAS 2008 p value Max fluid rate (ml/kg/day) days <0.0001* Avg fluid rate (ml/kg/day) <0.0001* Days to return to BW Phototherapy days <0.001* Indocin prophylaxis (%) 37(24.5%) 31(15.9%) 0.048* PDA (%) 29(19.2%) 36(18.5%) Confirmed bacterial sepsis (%) 38(25.8%) 31(15.9%) 0.043* Fungemia (%) 1(0.6%) 1(0.5%) BPD (%) 5(3.3%) 10(5.1%) Mortality (%) 12(7.9%) 7(3.6%) 0.80 In Summary. 22

23 Benefits of humidity Decreased TEWL Improved fluid and electrolyte balance Possible reduction in BPD, PDA, IVH Improved thermal stability Enhanced energy balance Enhanced skin integrity From Heat Loss from the Skin of Preterm and Fullterm Newborn Infants During the First Weeks After Birth by K. Hammarlund, B. Stromberg, G. Sedin (1986).Biology of the Neonate, 50, pp From Kim et.al, 2007 PAS Abstract, Improved Management and Growth by Using Advanced Humidified Incubators in ELBW. Risks of RH Infection Uncontrolled applications Excessive amount/higher than required Failure to clean per manufacturers instructions Failure to use universal precautions when filling Failure to remove water source after therapy completed Mesophilics love 10 to 50 C Water bath will assume room temperature Failure to clean microenvironment between uses or in recommended cycles Other hazards Temperature instability with microenvironment disruption Obstructed patient view (rainout) Water intoxication Inability to attach other monitoring equipment Minimum adhesive/lead use in our future? From Heat Loss from the Skin of Preterm and Fullterm Newborn Infants During the First Weeks After Birth by K. Hammarlund, B. Stromberg, G. Sedin (1986).Biology of the Neonate, 50, pp Patterns of humidity use: Special precautions 23

24 Patterns of humidity use: This is what worries me What is the scientific basis for use of humidity? On whom? < weeks gestation How long? Has been used up to weeks gestation globally No safety data for use beyond the first one to two weeks of life How much? Up to 85% for first week of life in ELBW, then consider weaning to 50% How to wean humidity? How to individualize protocol based on evidence? DO YOU KNOW YOUR GRAM NEG/FUNGAL RATES? Skin damage is a lifelong deformity BSIs can kill! PDA is not a benign surgery! 24

25 Questions? Questions? Case study A, revisited DOB was 1/ /7 week AGA male Humidity started at 30% 12h, Na 136 1/22 Na 151, 173 ml/k/d 1/23 Na 149, RH d/c at /24 Na 148, 180 ml/kg/d 30% RH restarted Was 30% helpful or worthless? 1/25 Na 152 RH increased to 50%, Then what happened????? How does this device impact the picture? What happens when you add this to the mix? 25

26 Baby B Do I need RH? Baby C Is it enough RH? Baby D How long? 26

27 Baby E Is it time to wean RH? What happens you take this away from this to the mix? And the baby s temperature is increasing? Do you wean the k-pad or the RH? THE END! Lbayne@christianacare.org Lbayne@nemours.org Lynn.LynamBayne@gmail.com 27