81
Continous End-Tidal CO? (Ρ^ΦΟΟ?) Monitoring in Respiratory Distress Syndrome .
S. Sun, T.J. Wei, A. Bautista, E. de la Cruz
Continuous end-tidal C 2 monitoring has not been widely used in neonatal respiratory care mainly because of technical difficulty arising from large instrumental dead space relative to small air way and tidal volume of newborns, especially preterm infants. Recently this problem has been overcome by using a minimal dead space ET tube adapter and a high flow sampling rate (150 ml/min). The purpose of this study is to evaluate the relationship between end-tidal C 2 and arterial C 2 tension (PaCC^) in non-distressed newborns as well as newborn infants suffering from respiratory distress syndrome.
Material & Method. Study I. Eleven infants (age 1-14 days, GA 26-40 wks, B . W . 760-4120 gm) considered to have no major respiratory disease were studied during spontaneous breathing.
A Foregger End-Tidal CU2 monitor was used to follow PETC02 continuously via a sampling tube placed at the posterior nasopharynx through a nostril. Arterial PC 2 was determined by IL 813 blood gas analyzer. Study II. Twenty-one patients (age 3-14 days, GA 26-42 wks, B . W . 700-3460 gms ) were studied.
Pjj»rpC02 was monitored via ET tube during mechanical ventilation one day prior to extubation. Study III. Using the same procedure as that of Study II, we further studied Alveolar-arterial PC02 difference (AaDC02=PaC02-PEco2' in 14 neonates being mechanically ventilated because of respiratory distress
syndrome. (Mean GA 30.4 wk, range 28-35 wks, mean BW 1370 gm, range 830-2420 gm Age 0-8 days). Relationship between 1). fraction inspired U2 (FiU2) and AaDC02 2 ) . peak inspiratory pressure ( P I P ) and AaDCU2 3 ) . AaDC02 and duration of mechanical ventilation (IMV) were studied.
Results: Study I: correlation between PETCU2 obtained via nasopharynx in normal infants and PaCU2 was extremely good.
Linear regression analysis revealed a relationship of PaC02=l-00 χ PE TC02+3.22, correlation coefficient r=0.932 and P <0.001.
Study II: See figure I. Study III, see figures 2 , 3 , and 4.
Conclusion: End-tidal C02 correlates very well with
in normal and near normal lungs of preterm as well as term newborn infants. 2. The severer the RDS, the greater the AaDC02, 3. The greater the AaDC02/ the higher the Fi02 requirement, 4. The greater the AaDC02r the higher PIP is needed to ventilate the patient, 5. The greater the AaDC02r the longer the duration of mechanical ventilation, 6. When AaDC02 is less than 5, the patient is ready to be extubated. End tidal C02 monitoring is non-invasive, it reduces the loss of blood due to frequent blood gas samplings, it helps monitor PCU2 continuously and it proves to be an important asset in the respiratory care of the newborn infant.
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PETC02 (PAC02) VS. PoC02 IN NEWBORNS
PE TC02VIAETTUBE ΔπΠηπ. νς FiO. IN TRDS BEFORE SUCCESSFUL EXTUBATION -
660
600
540
480 i
~λ 42°
360
300
240
179
r 100
PT 21
GA 26-42(m33) wks
" BW 700-3460 Im1821)gms . 89 AGE 3 -14 DAY
78
• ** yS 68
• · jr
·· jr · jS
— · s' «-Γ*• c »CC» · 21 ^
.ccP-
- EECC'C
c/
E.~~ ·
^ NO. STUDY 62
" . * * y = 0.82X + 10.43 36
y -· 0.896
p = < o.ooi 25 Τ Ι ι Ι ι Ι ι 1 . Ι ι 1 15
ρ · · C
PT 14 · C /r
- GA 28-35 (m 30 4) wks / BW 830- 2420 (m 1370) gms E/ AGE 0-8 DAY /
ccX
C· · / ·
— /
• V ^
' ' /
&' ·
.c c^.
g -· . ·
£' NO. STUDY 79
* * ^S * y : 1-97X -»- 15.29
>ίί V ^ y = 0.862 CC/ft C«C· p = < 0.001 (2 TAIL) 9C I . ι ι l ι Ι ι Ι ι 1 234 36.3 492 620 ?49 87.8 3.4 10.4 173 24.3 31.2 38.2
PeTC02 (lorr) . AaDC02 (totr) PoC02 = 0.8PEC02+lO FjQ = 1 g? AflDCO + ^ ^
AaDC02 VS. IMV DAYS IN IRDS AaDCO, VS. PIP IN IRDS
36
30
25 i
^<NI
1 2 °
15
10 7
_ · 60 PT 14
GA 28-35 (m30.4) wks 53 8W 830-2420 (m 1370) gms
—
47
• . ^r
^^ 41 o^ . 1^r · 35
^S Q_
Ο · °~
S^ 28 .X C
- / ' ^ 22 l/^ . * y s 0.12X + 2.26
* y= 0.567 I6
P = < 0 . 0 5 ( 2 T A I L )
Τ ι Ι ι Ι ι Ι ι Ι , Ι , I 10
PT 14 * GA 28-35 (m 30 4) wks
BW 830-2420 (m 1370) gms £ AGE 0-8 DAY /*
• / /
• c. ^
~ · ·· c
>^cc
~~ · c *xc Λ ·
CExE
C · C'E · ·
• c · xci€ c ··
- · .C^EtS
c* c^c * ** ** N0- STUOY 69 c^ * y = 0.81X + 16.4
c · · y = 0.805 P = <0.001 (2 TAIL) T l t ι , ι , ι , ι , ι , 2 3 4 5 6 7 8 3.8 11.6 19.4 27.2 35.0 42.8
IMV (DAYS) AaDC02 (torr) IMV DAYS -- 0.12 AaOC02 + 2 PIP = 0.81 AoDC02 + 16.4
Address: S. Sunr MD Associate Professor of Pediatricst UMD-New Jersey Medical School, Children's Hospital of New Jersey, 15 South 9th Street/ Newark, New Jersey 07107. USA
