489 THE FREQUENCY OF NASAL INJURY IN NEWBORNS DUE TO THE USE OF CONTINUOUS POSITIVE AIRWAY PRESSURE WITH PRONGS 1

Continuous positive airway pressure (CPAP) with prongs is the ventilatory support most used in newborns. Nasal injuries are complications that may arise due to the prolonged use of this device. This study aimed to determine the frequency of nasal injuries in newborns through the use of continuous positive airway pressure with prongs. A convenience sample composed of hospitalized newborns using prongs for more than two days was used. Data were collected through a structured form. Lesions were observed in all newborns, which were classified as: mild (79.6%), moderate (19.7%) and severe (0.7%). The conclusion is that the use of prongs for more than two days represents a risk factor for the lesions to develop.


INTRODUCTION
Pulmonary disorders represent an important cause of morbimortality in the neonatal period.
However, with the advancement of intensive therapy techniques better results are achieved in the treatment of these diseases and improved clinical development of newborns have been observed (1) .
Among the several types of ventilatory support for newborns aiming to improve the exchange of gases and reduce respiratory effort is the Continuous Positive Airway Pressure (CPAP).It is a mechanical ventilation in which positive transpulmonar pressure is continuously applied into the airways during a respiratory cycle so as to avoid the complete elimination of inspired gas and maintain functional residual capacity, increasing the intra-alveolar pressure and its stability, improving gases exchange and preventing the collapse of the airways during respiratory effort (2) .
To apply this pressure system, three components are essential: continuous flow of a heated and humidified gas mixture (compressed air and oxygen); a system connecting the device to the patient's airway such as facial masks, nasal prongs, nasopharyngeal or endotracheal tubes and a mechanism of positive pressure generation in the system (2)(3) .
A nasal prong is the most used device in connecting airways because it is a less invasive way of supplying CPAP (2) , it is available in different sizes and made of light and flexible material (3) .Despite its advantages, this device can harm the nostrils and cause discomfort and disfiguration in the long term (4) .
Research classifies nasal injuries caused by the use of prongs in three stages: mild, moderate and severe.
The mild stage is described as redness or nasal hyperemia; the moderate presents bleeding injuries and the severe stage refers to injuries with necrosis (5) .
Nasal lesions caused in newborns due to misuse of prongs vary from simple hyperemia of the nasal mucosa, bleeding, formation of crusts, and necrosis up to total destruction of the anterior part of the septum (columella) (6)(7) and nasal septum (5,8)   . The

METHOD
This is a quantitative, descriptive and crosssectional study (9) .It was carried out in the Neonatal Unit of Santa Monica Maternity, Macéio, AL, Brazil.A convenience sample was used (9) .The study included newborns hospitalized at the maternity's neonatal unit who underwent CPAP with prongs.
Newborns undergoing CPAP with prongs for less than two days were excluded from the sample.The sample size of 147 newborns was defined considering a 25% (8) frequency of nasal lesions caused by the use of CPAP with prongs; an absolute precision of 7% and 5% of significance level were considered.
The main researcher collected data between October 2007 and February 2008 until she reached the sample estimated for the study.The adults legally responsible for the newborns were approached weekly at the nursing wards where children were hospitalized and at the neonatal unit.Individuals were invited to voluntarily participate and allow the newborns' data to be collected and included in the study.
After the free and informed consent agreement was presented and read to the adults legally responsible for the newborns, data were collected through a form developed by the researcher.
Individuals were not evaluated twice.
To collect and establish lesions caused by the CPAP with prongs, the stage of lesions, use of protection, number and type of prongs used at the moment of data collection, the researcher had to take the prong out of newborns' nostrils for a brief moment, check their nostrils and immediately put it back after observation and collection of necessary data so as to avoid any alteration in newborns' general condition.
Another source of data collection was the individuals' files where complementary data were extracted from the neonatology charts, medical evolution records and nursing files.
After data collection, these were included and tabulated in an electronic spreadsheet.

RESULTS
We observed in the results that the gestational ages of 123 (83.7%) newborns out of 147 were below 37 weeks (2)   .
The type of prong used in all studied newborns was the Inca -Ackrad ® , and its size was In regard to the quality of gases (oxygen and compressed air) offered to these patients, we observed that all (100%) newborns in CPAP with prongs had humidifiers, though, only 127 (86.4%) were heated.

DISCUSSION
Nasal lesions in newborns caused by continuous positive airway pressure with prongs is a little discussed issue in the Brazilian literature.
However, research, especially international studies in the field, emphasizes that nasal complications secondary to prongs are present mainly in preterm and low-weight newborns due to their pulmonary immaturity and therefore need of CPAP very early on (7-8,10-11)   .This is confirmed in this study in which the age of 123 (83.7%) of newborns submitted to CPAP with prong was below 37 weeks and 51 (34.and large and the sizes for the Inca Ackrad ® type are: 7.5 and 9 for newborns below 700g, 10.5 for newborns between 701g and 1000g, 12 for newborns between 1001g and 1300g, and 15 for newborns above 1300g (2) .Some researchers consider that the ideal prong is the one not so large to the point it distends the nostrils and not so small to the point it lets extra space between the prong and nostrils (8)   .
As for its positioning, a well-positioned prong is that which does not deform the newborn's face and its bridge does not touch the nasal septum and does not allow the device to move inside the nostrils (8) .device and the nostrils and also encouraging air leakage (10)(11) .

Prongs type Inca Ackrad
® were used in all studied newborns and the majority of them were smaller than the ideal size according to newborns weight at the time of the initial placement of the device.It is worth mentioning that in addition to a single type of prong, the quantity available was insufficient to meet the demand of newborns.These prongs were only disinfected before reuse and we observed that the exchange and sterilization of the system was not performed every two days as r e c o m m e n d e d i n t h e l i t e r a t u r e (8) .R o u t i n e disinfection of prongs available in the sector is probably wearing the material out and making it less flexible, which can also be a risk factor in the development of nasal lesions.It is urgent to provide prongs of different sizes and in quantity sufficient to appropriately meet the demand of this clientele with quality.
When the cap is larger than the newborn's head, it causes the tube to move and consequently it presses the prongs into the nostrils.Hence, it is advisable to ensure adequate cap sizes better suited to newborns' heads so that pressure on the nostrils is minimal (11) .
Another method to avoid such pressure is to wet the prongs in water or saline solution and bend it down so as to facilitate its adaptation in the nostrils (2,8) .Although this was not this study's objective, we also observed that the caps were of various sizes and often times they needed to be fixed with a common patch so as to adjust them to the newborns' heads.In the absence of caps, bandages were fixed around the head with patches with the same function: immobilizing the prongs.
Based on the above, we suppose that the formation of nasal lesions is related to health professionals inappropriately fixing the prongs into the newborns' nostrils.They introduce the entire prongs stems into the nostrils so that the bridge of this device is in direct contact with the columella.
Additionally, it is possible the prongs, smaller that the ideal size, cause the device to move inside the nostrils, clamping the septum.
Some health professionals spend 24 hours taking care of the details of the CPAP.They insert the prong very carefully so that the bridge does not touch the columella (11) and septum and also report that inserting it one or two millimeters is a l r e a d y s u f f i c i e n t t o p r o v i d e t h e d e s i r a b l e pressure (12) .Others affirm that harm in the nostrils' lateral walls and nasal septum can be avoided as long as the device is kept straight and does not pressure the nasal septum (13) .We observed in this s t u d y t h a t p r o n g s w e r e i n s e r t e d b e y o n d t h e recommended millimeters, the bridge touched the columella and septum so as to produce sufficient pressure to the CPAP system and impede air leakage.This practice probably encouraged early nasal lesions.
The literature indicates that resistance to the device is inversely proportional to its radius, that is, the larger the prong (larger diameter/ radius) the lower the resistance and, consequently, the better the pressure (11) .Prongs with the correct diameter reduce air leakage (13) and prevent harm in the nasal tissues (11) .
The frequency of nasal lesions caused by the use of CPAP with prong was 100%, contradicting the study hypothesis that the traction exerted by the tube weight jointly with the device is responsible for 25% of nasal lesions (8) .
Time was significant in relation to the evolution of stages of nasal lesions caused by the use of prongs, confirming the theory that the prolonged duration of CPAP with prongs is a risk factor for the development of nasal injuries and traumas (10) .
Aiming to alleviate and prevent lesions, nostrils are protected by adhesive tapes, such as c o m m o n p a t c h e s , h y p o a l l e r g e n i c t a p e s a n d hydrocolloid dressings (10)(11) , used to avoid direct friction between the prongs and the columella and septum.
The hydrocolloid is currently the most reported material used as a preventive measure (10) , especially in the international literature.Even though lesions are still observed with its use, they are presented in a smaller proportion.This fact makes clear that cost-benefit issues should be revaluated in the use of prongs.
Models of nasal protection used in the studied institution included: common dressings in form of patches (cut into strips and adhered to the columella) and in form of a pig snout, which covers both the columella and the nostrils edges.Among those using the pig snout type protection, one individual had a protection creatively devised by professionals, made of adhesive material to fix the  (2) .
Based on the above, we concluded that the frequency of lesions with the use of CPAP with prongs after a minimum period of two days was 100% and time was a risk factor for the development of lesions.
These events are distributed in Figure 1 showing that the longer the device is used, the more severe the lesions.Although experts affirm it is unlikely that the incidence of nasal lesions is reduced to zero despite prevention measures, risk factors can and should be minimized through the employment of correct device and technique.However, for the successful use of CPAP with prongs, much more than just material resources is necessary.The nursing team has to be constantly committed to adequate set up, to maintaining the system and especially to keeping surveillance on the newborns.
Trainings and educational programs are strategies that can improve care to newborns in CPAP with prongs, so as to make this practice safe and avoid complications as a consequence of its use.
Further studies in this line of research are needed so as to develop new devices and fixation methods that reduce nasal traumas.
The study was approved by the Research Ethics Committee at the State University of Health Sciences of Alagoas (UNCISAL) according to Resolution 196/ 96 of the National Health Council (Protocol 766/2007).
7%) presented low weight showing that lesions caused by the use of prongs more frequently compromise preterm newborns with low weight.Authors report that prongs are classified in three types: Hudson ® , Argyle ® Sherwood and Inca Ackrad ® , while the ideal size for each newborn depends on his(er) current weight.The Hudson ® type presents the following sizes: 0, 1, 2, 3, 4 and 5, which correspond to the following weights: less than 1000g, between 1000g and 1500g, between 1500 and 2000g, between 2000 and 3000g and above 3000g.The sizes for the Argyle ® Sherwood type are: extra small, small

Figure 1 -
Figure 1 -Stages of nasal lesions related to the duration of device use.Maceió, 2008

Table 1 -
Sample distribution regarding the stage of the nostrils.The one classified as severe presented necrosis in addition to bleeding and erosion.