P.M.C. Nair, V.G. Reddy
and S. Jaya
From the Division of
Neonatology, Department of Child Health and Department of
Anesthesiology, Sultan Qaboos University, Muscat, Oman.
Correspondence to: Dr.
P.M.C. Nair, Consultant, Department of Child Health, Sultan Qaboos
University Hospital, Post Box-38, Al-khod-123, Muscat, Sultanate of
Oman.
E-mail: [email protected]
Manuscript received:
March 21, 2001, Initial review completed: May 3, 2001;
Revision accepted: March
6, 2002.
We present our
experience with nasal CPAP (continuous positive airway pressure) with
Benveniste’s valve in 66 neonates. Failure rate was only 10.7%. The
complications were few with this valve assembly. Babies could be
nursed better, moved about and breast fed while on CPAP.
Key Words:
Benveniste’s valve, CPAP, Newborn.
Endotracheal intubation
and mechanical ventilation is the gold standard in the management of
acute respiratory failure. But it is not without complications. The
complications range from acute pharyngeal and laryngeal injury, vagal
stimulation, apnea and bradycardia, larnygeal edema, pneumothorax,
atelectasis, introduction of nosocomial infection to late complications
like stricture and subglottic stenosis. Hence non-invasive ventilation
is gaining more acceptance recently(1). We present our experience with
the use of non-invasive ventilation using CPAP (continuous positive
air-way pressure) in neonates with moderate respiratory distress
admitted in the neonatal intensive care unit of the Sultan Qaboos
University Hospital, over a period of 2 years and 3 months.
Subjects and Methods
We used a discontinuous
system of nasal CPAP using Dameca Benveniste’s valve (jet assembly)
and Argyle silastic nasal prongs, secured in place by a knitted bonnet (Fig.
1). Smaller size nasal prongs were used for smaller babies. The
positive pressure was generated by a narrow stream of warmed humidified
air/oxygen mixture generated by an Ohmeda Air/Oxygen Mixer and directed
against the breathing hole in the jet device. The jet assembly consists
of a straight nozzle and a curved tube co-axially positioned by means of
a ring in such a way that a jet of gas from the nozzle will hit the
inlet opening of the collecting tube which is connected to the nasal
prongs. This gas from the jet is inspired while expired gas is vented to
the surrounding atmosphere. Flows ranging from 4 to 20 L/min served to
generate pressure in the infant’s upper airway between zero and 13 cm
of water (Table I). Standard indications were used for starting
and discontinuing CPAP in neonates with moderate respiratory distress.
Results
One hundred and twenty one babies out of
589 (20.54%) required respiratory support during the study period. Of
these, 66 babies (54.5%) were put on nasal CPAP. The details of cases
and duration of CPAP are given in Table II. None of the cases
required sedation, analgesia or paralysis, which helped in better
observation and mother-infant bonding. Because we were using the special
type of discontinuous system of CPAP babies could be moved about, breast
fed and even bathed, while still on CPAP.
Discussion
CPAP effectively splints the chest wall;
keeps the collapsible airways patent, thus reducing upper airway
resistance and occlusion, thereby preventing obstructive apneas and
atelectasis. The question of which strategy is best in initial treatment
of pre-term
Table I-Flow Guide for Continuous Positive Airway Pressure
Flow (L/min)
|
Positive end expiratory
Pressure (cm of water)
|
2
|
0
|
5
|
0.5
|
8
|
2
|
10
|
3
|
12
|
4
|
14
|
6
|
16
|
8.5
|
18
|
11
|
20
|
13
|
Table II-Nasal CPAP with Benveniste’s Valve: Details of Cases ( n = 66)
Diagnosis
|
Number
of cases
|
Median
birth weight
(range) in g
|
Mean
gestation
(range) in
wk
|
Median
age at
start
of CPAP
(range)
in hr
|
Median
duration
of CPAP
(range)
in hr
|
Complications
(n)
|
CPAP
failure
(n)
|
RDS (n=46)
|
4
|
820(750-999)
|
26(25-27)
|
1/2 hr (0-4)
|
120 (100-210)
|
IVH (grade3) 1
|
1
|
|
|
|
|
|
|
ROP (stage3) 1
|
|
13
|
1120(1000-1249)
|
28(27-29)
|
1/2 hr (0-6)
|
124 (100-168)
|
Sepsis –1
|
1
|
|
12
|
1310(1250-1449)
|
30(29-31)
|
1 hr (0-8)
|
96 (80-180)
|
ROP (stage 3)–1
|
--
|
|
9
|
1630(1500-1749)
|
32 (31-33)
|
1 hr (0-7)
|
72 (60-200)
|
Sepsis –1
|
1
|
|
8
|
1820(1750-1999)
|
34 (33-37)
|
3 hr (1-8)
|
120 (100-240)
|
Sepsis –1
|
2
|
Birth asphyxia
|
6
|
2800 (2500 & above)
|
38 (36-40)
|
4 hrs (1-12)
|
72 (60-140)
|
|
1
|
Pneumonia
|
4
|
1750 (1500-3000)
|
34 (32-38)
|
72 hrs (10-120)
|
96 (72-168)
|
|
1
|
Sepsis
|
3
|
1800 (1500-2500)
|
34 (32-38)
|
80 hrs (24-120)
|
120 (100-250)
|
|
|
Aspiration
|
2
|
2800 (2500 & above)
|
38 (36-40)
|
72 hrs (24-178)
|
48 (30-72)
|
|
|
Others
|
5
|
3000 (2500 & above)
|
38 (36-40)
|
42 hrs (20-168)
|
42 (24-120)
|
|
|
IVH-Intraventricular hemorrhage; ROP - Retinopathy of prematurity; CPAP - Continuous Positive Airway Pressure.
infants has always been
debated (2-4). We used a special type of CPAP device, namely Dameca
Benveniste valve (jet assembly) (Denmark)(5) and Argyle silastic nasal
prongs. The device functions as a respiratory valve with no moving
parts. The Benveniste’s valve is light-weight (5 g), easy to apply,
safe, autoclavable and reusable. It is a discontinuous system at the
region of the ring. The gap (ring) across which the jet passes acts as
pop-off valve in the circuit and also helps to remove excess water of
condensation and does away with any expiratory tubings. Thus the
pressure generated is constant and well controlled with less chance for
complications like overdistension and pneumothorax. Uncontrolled CPAP
can cause over-distension of the lungs, carbon dioxide retention, air
leaks and pneumothorax which may precipitive a periventricular
hemorrhage and later peiventricular leucomalacia (PVL)(6-10). The tight
head bandages used to hold the face masks/nasal prongs in place may
cause intra-cerebellar hemorrhage(7-8). Prolonged use of CPAP has been
reported to cause nasal excoriation, trauma and damage to the septal
mucosa (8,9,11-13). In our study, none of these complications occurred.
Fig. 1. Baby with
respiratory distress syndrome on nasal CPAP (Benveniste’s valve) and
Argyle silastic nasal prongs, secured with a knitted bonnet.
With all CPAP devices
some air may get into the gut and cause gastric distension. To prevent
this, an open-ended oro-gastric tube may be kept in-situ. There is
usually no need for sedation, analgesia or paralysis and hence better
observation for infection and other diseases are possible. Another
advantage of this system is the flexibility/mobility which permits all
nursing procedures easily, nursing in prone position or kangaroo method,
breast feeding or even bathing. The overall failure rate is among the
lowest reported with any CPAP system(7-11).
Contributors:
PMCN conducted the study and wrote the paper. He shall act as guarantor
for the study. VGR coordinated the study. JS participated in the data
collection and also helped in drafting the paper.
Funding: None.
Competing interests:
None stated.
|
Key
Messages |
| •
Non-invasive ventilation using the discontinuous system of Nasal
CPAP (Benveniste’s valve) is effective in neonates with moderate
respiratory distress. |
