Lynn Bayne has no financial disclosures to make. · 2018-05-30 · 10/13/2012 1 Exploring the...

10/13/2012

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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.

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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

1867 1950 2001 2010

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

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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

N = 26 NICUs

NICUs Using RH

% 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), 535-540.

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Patterns of North American RH Use

From L. Bayne: http://www.surveymonkey.com/s/NF3C2DW

N = 907 NANN members

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), 535-540.

Profile of US NICUs using RH



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Is humidity in ANZ being used under protocol?

Protocol

Yes

77%

No

23%

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


Is humidity in North America being used under protocol?

From L. Bayne: http://www.surveymonkey.com/s/NF3C2DW N = 907 NANN members



Patterns of humidity use: Standalone protocol



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Patterns of humidity use: Type of protocol



How do RNs in ANZ drive RH implementation protocols?

Use Criteria

77%

23%

Gestational Age Birth Weight

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


0%

5%

10%

15%

20%

25%

30%

35%

Gestationalage

34%

19%

12%

8%

4%

< 28 weeks < 30 weeks

< 32 weeks < 34 weeks

< 37 weeks

0%

2%

4%

6%

8%

10%

12%

14%

16%

Birth weight

15%

8%

< 1000 grams < 1500 grams

ANZ RH use criteria: 77% GA vs. 23% BW

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How do RNs in North America drive RH implementation protocols?



North American use criteria: GA



North American use criteria: Weight



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How much RH do ANZ NICUs use?

8%

88%

4%

Initial RH

70-79% RH > 80% RH Unmeasured RH

N = 26 NICUs



How much RH do NICU RNs in North America use?



When are ANZ NICUs implementing RH?

N = 26 NICUs


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When do RNs in North America implement RH?


How long are ANZ NICUs using RH?


How long do RNs in North America use RH?



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When are ANZ NICUs

weaning RH?

0%

10%

20%

30%

40%

50%

60%

Time to weaning, %

8%

57%

23%

12%

No weaning < 7 days 7 to 14 days > 14 days

N = 26 NICUs


When do RNs in North America start to wean RH?



How do ANZ NICUs drive RH weaning protocols?

N = 26 NICUs



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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

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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?

From “Relative Humidity in Incubators” by E. Bardell, J. Freeman, E. Hey, (1968). Archives of Diseases in Childhood,

43, pp. 172-176..

Hypothetical NICU

NICU Room Temp = 27°C/81°F Ambient RH = 28%

As that air is entrained into the incubator and warmed…

X

…and the RH inside drops to 18%

From “Relative Humidity in Incubators” by E. Bardell, J. Freeman, E. Hey, (1968). Archives of Diseases in Childhood, 43, pp. 172-176. Reprinted by permission.

81°F/27°C, 28% RH

http://rds.yahoo.com/_ylt=A0PDoYAZdZdNSn4AtLyjzbkF/SIG=12e01sf87/EXP=1301800345/**http:/blog.girlsbydesign.com/wp-content/balance-scale.jpg

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•…the average BSA @ 24 weeks < 0.08 m2

• When 1 ml H2O evaporates/m2 of BSA = > 580 cals (0.58 kcals) literally sucked away from the baby!

–46.4 cals (0.0464 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 cm2 = 0.1 m2

Body surface area (BSA)

IWL/TEWL = heat loss = energy loss

The bottom line

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. 199-205. Reprinted by permission.

IWL not a major factor

> 2 kg

Rate of IWL

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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. 1-10. Reprinted by permission.

He

at

Lo

ss

He

at

Gain

0 Means Loss = Gain

Heat exchange

Heat Loss from

Evaporation (w/m2)


Heat exchange

Heat Supplied from

Convection (w/m2)

Heat exchange


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Clearly, heat loss from evaporation as RH from 20% to 60%

How much humidity?


From “Transepidermal Water Loss in Newborn Infants: Relationship to Gestational Age” by K. Hammarlund, G. Sedin

(1979). Acta Paediatrica Scandanivica, 68, pp. 795-801. Reprinted by permission.

Rate of evaporation

Objective #4: So how much RH should we be using?

How should we wean RH? What are the TRUE risks?

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From “Measurements of Transepidermal Water Loss in Newborn Infants” by G. Sedin, K. Hammarlund, G.

Nilsson, et al: (1985). Clinics in Perinatology, 12, pp. 79-96. Reprinted by permission.

A developmental argument in use of RH

Effect of high vs moderate RH

From “Ambient Humidity Influences Skin Maturation in Extremely Preterm Infants” by J.Agren, G Sjors, and G.Sedin (PAS 2005): 57: 2600.

N=22 All nursed @ 85% RH

x 7 days

N=22 11 nursed @ 75% RH 11 nursed @ 50% RH



Delayed keritinization of stratum corneum with

prolonged exposure to higher levels?

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Should the microenvironment be able to offer RH while protecting skin

integrity & promoting fluid & electrolyte balance?

A prospective study…

• Patient population < 30-32 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



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Impact of RH on Skin Condition



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%)



Impact on fluid balance



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Is there an impact of RH on total fluids and sodium balance @ high vs. moderate levels?


Is Dr. S’s concern for infection unfounded?

We know these organisms love H2O!

Pseudomonas aeruginosa

Escherichcia coli

Candida albicans

Serratia marcescens

L. Biagotti and L. Lynam (2001).

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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


We know that the infections in 1960’s were related to RH use!

• Infections Were Real!!! • Why?

–Device side •Temperature of H2O 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

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

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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



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65% RH, % No added humidity, %

P value

Confirmed sepsis < 14 days

50 31 0.43

Confirmed sepsis > 14 days

22 26 0.94

Confirmed sepsis or sepsis evaluation > 3 days

37 52 0.68

NEC 20 23 0.90

Remember that prospective study?

Non-Humidified Incubators

Humidified Incubators

p value

Number of patients 151 194

Max fluid rate (ml/kg/day) 196.2+43.7 days 174.9+27.1 <0.0001*

Avg fluid rate (ml/kg/day) 139.8+14.2 133.2+7.9 <0.0001*

Days to return to BW 12.4+6.0 11.4+5.6 0.118

Phototherapy days 9.0+5.4 6.9+4.1 <0.001*

Indocin prophylaxis (%) 37(24.5%) 31(15.9%) 0.048*

PDA (%) 29(19.2%) 36(18.5%) 0.879

Confirmed bacterial sepsis (%) 38(25.8%) 31(15.9%) 0.043*

Fungemia (%) 1(0.6%) 1(0.5%) 0.125

BPD (%) 5(3.3%) 10(5.1%) 0.405

Mortality (%) 12(7.9%) 7(3.6%) 0.80

Abu-sultaneh et.al, PAS 2008

And a retrospective study!

In Summary….

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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. 1-10. 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. 1-10.

Patterns of humidity use: Special precautions



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Patterns of humidity use: This is what worries me…



What is the scientific basis for use of humidity?

• On whom? – < 30-32 weeks gestation

• How long? – Has been used up to 30-32 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!

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Questions?

Questions? http://www.surveymonkey.com/s/NF3C2DW

Case study A, revisited

•DOB was 1/2011 –24 6/7 week AGA male

•Humidity started at 30% –Baseline @ 12h, Na 136 –1/22 Na+ @ 151, TF @ 173 ml/k/d –1/23 Na+ @ 149, RH d/c at 1500 –1/24 Na+ @ 148, TF @ 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?

http://www.surveymonkey.com/s/NF3C2DW

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Baby B—Do I need RH?

Baby C—Is it enough RH?

Baby D – How long?

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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! [email protected]

[email protected]

[email protected]

mailto:[email protected]



Lynn Bayne has no financial disclosures to make. · 2018-05-30 · 10/13/2012 1 Exploring the...

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