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Abstract
Objective Binasal prongs are the most commonly used interface for the delivery of nasal positive airway pressure (CPAP) to preterm infants. However, they are associated with pressure-related nasal injury, which causes pain and discomfort. Nasal injury may necessitate a change in interface and occasionally damage is severe enough to require surgical repair. We aim to determine the incidence and risk factors for nasal injury in preterm infants, and to provide clinicians with strategies to effectively prevent and treat it.
Design We conducted a systematic search of databases including MEDLINE (PubMed including the Cochrane Library), EMBASE, CINAHL and Scopus. Included studies enrolled human preterm infants and were published prior to 20 February 2017.
Results Forty-five studies were identified, including 14 ra ndomised controlled trials, 10 observational studies, two cohort studies, eight case reports and 11 reviews. The incidence of nasal injury in preterm infants ranged from 20–100%. Infants born <30 weeks’ gestation are at highest risk. Strategies shown to reduce nasal injury included: nasal barrier dressings (2 studies, n=244, risk ratio (RD) −0.12, 95%, CI − 0.20 to −0.04), nasal high flow therapy as an alternative to binasal prong CPAP (7 studies, n=1570, risk difference (RD) −0.14, 95% CI −0.17 to −0.10), and nasal masks rather than binasal prongs (5 studies, n=544, RR 0.80, 95% CI 0.64 to 1.00).
Conclusions and relevance Nasal injury is common in preterm infants born <30 weeks’ gestational age receiving CPAP via binasal prongs. Larger randomised trials are required to fully evaluate strategies to reduce nasal injury.
- Preterm infant
- non-invasive respiratory support
- nasal injury
- injury prevention
- nursing care
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What is already known on this topic?
Binasal prongs are the most effective interface for CPAP delivery; however their use is associated with pressure-related nasal injury.
What this study adds?
Nasal masks and nasal barrier dressings may reduce nasal injury secondary to CPAP.
Nasal HF causes less nasal injury than CPAP.
Future large trials need standardised assessment of nasal skin integrity for proper evaluation of strategies to prevent nasal injury.
Introduction
Over the last 40 years, there has been an increased use of nasal continuous positive airway pressure (CPAP), which is the ‘gold standard’ form of non-invasive respiratory support to treat preterm infants.1 For effective delivery of nasal CPAP, tight fitting binasal prongs are required to maintain a constant airway pressure. However, the force applied to the delicate tissues of the nares and nasal septum can compromise skin integrity and cause nasal injury.2 3
Preserving the skin and mucosal membranes in preterm infants is important to protect against infection, and to avoid discomfort and nasal deformities. Due to immaturity, the nose of preterm infants can easily be injured, by even a short application of a nasal device.4
Nasal injury may cause pain and discomfort, necessitate change in respiratory therapy and sometimes require surgical intervention.5 6 Several sequelae have been reported, including hyperaemia, nasal snubbing and flaring (upturned nose and enlarged nares), scab formation and areas of necrosis.2 3
Proposed interventions for reducing nasal injury during nasal CPAP therapy include alternating using the binasal prongs with using a nasal mask, and using a nasal barrier dressing between the nares and binasal prongs.7 8 Nasal high flow (nHF) therapy, which uses smaller prongs, may be used as an alternative respiratory support mode to avoid injury. An alternative option discussed in the literature is the application of ointment before or after the occurrence of nasal injury.9
We conducted a systematic review to determine the incidence and risk factors for nasal injury in preterm infants, and the effectiveness of strategies to prevent and treat it.
Methods
This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.10 Randomised trials of interventions to prevent or treat nasal injury were identified and analysed using methods recommended in the Cochrane Handbook of Systematic Reviews of Interventions. Relevant articles were identified by searching electronic databases: MEDLINE (PubMed including the Cochrane Library), EMBASE, CINAHL and Scopus. The search strategy included the search terms: (Neonat*, Preterm, Infant*, Premature, Newborn) AND (respiratory support, cpap, ncpap, continuous positive airway pressure, nasal prong*) AND (nasal injur*, skin integrity, skin trauma, skin damage, pressure injury, nasal trauma or nasal injury or nose). The search was limited to studies conducted in humans and with full-text articles published in English.
Primary outcomes were (1) incidence, risk factors and timing of nasal injury; (2) strategies to prevent and treat nasal injury; and (3) sequelae of nasal injury. Studies were included if they reported one or more of the primary outcomes. The reference lists of reviewed articles were also screened for additional relevant articles. Studies were excluded if they did not report nasal injury secondary to non-invasive respiratory support (including CPAP, nHF and nasal intermittent positive pressure ventilation (NIPPV)).
The titles and abstracts of all articles retrieved were screened independently by two investigators (DII and BJM) to assess the need for full-text review. Full-text articles were then assessed by all authors for inclusion, and grouped by primary outcome of interest. Disagreements were resolved via consensus of all authors.
Statistical analysis
Where randomised controlled trials (RCTs) were found, a pooled analysis was performed using the software and methodology of the Cochrane Collaboration (Revman, V5.3).10 Binary outcomes for individual RCTs are reported as risk ratio (RR) and risk difference (RD), number needed to treat (NNT) where applicable and presented as point estimate (95% confidence interval (CI)).
Risk of bias assessment
Risk of bias was assessed using the Cochrane Collaboration tool.10
Results
Search results
The final search was conducted on 20 February 2017 yielding 1304 articles. An additional 29 articles were identified from the reference lists of reviewed articles. Full-text reviews of 103 articles were conducted, of which 45 were included (figure 1).
Flow diagram showing results of search strategy.
Risk of bias within studies
No studies were excluded from meta-analysis due to high risk of bias. All studies were subject to performance and detection bias, as investigators of studies were not blinded to study intervention or to the outcome of nasal injury.
Incidence, risk factors and timing of nasal injury secondary to non-invasive respiratory support in preterm infants
Eleven studies evaluated the incidence, risk factors and timing of nasal injury in preterm infants receiving binasal non-invasive respiratory support (table 1).5 9 11–19 All assessments in these studies describe the severity of nasal injury as mild (stage I), moderate (stage II) and severe (stage III). Mild nasal injury is defined as persistent erythema or non-blanching hyperaemia around the nose, but with intact skin (figure 2A). Moderate injury includes bleeding, surficial ulcers or erosions, with partial thickness skin loss (figure 2B). Severe injury comprises excoriation or columella necrosis, with full thickness skin loss (figure 2C).
Details of studies reporting rates of nasal injury in infants receiving CPAP
Classification of nasal injury as described by Fischer et al 9: (A) stage I—persistent redness, (B) stage II—bleeding, superficial ulcers or erosions, (C) stage III—deep tissue injury. Reprinted with permission.
Infants born at <30 weeks’ gestation or with birth weight <1500 g are most at risk of developing skin breakdown (stage I or II nasal injury).14 17 19 20 Reported incidence of nasal injury in preterm infants receiving CPAP ranged from 20% to 100%; this wide range may be due to lack of standardised classification of nasal injury and varying gestational ages of the populations studied.9 19–21
Common risk factors described for nasal injury include the type of binasal prongs, and incorrect sizing and positioning of the prongs. In an RCT conducted by Rego and Martinez17 comparing Argyle (Covidien, Mansfield, USA) and Hudson (Hudson RCI, Research Triangle Park, North Carolina, USA) nasal prongs, Argyle prongs were more likely to cause nasal hyperaemia for infants weighing <1000 g. Fujii et al 13 noted that skin immaturity, incubator humidity and temperature, and the number of position changes were significant risk factors for infants who developed pressure-related injury.
The onset of nasal injury to the columella has been reported to occur within a mean of 2–3 days of CPAP commencement, with some cases occurring as early as 18 hours after commencement.7 9 15 18 Severe intranasal effects associated with CPAP treatment, including ulceration, granulation and vestibular stenosis have been reported within 9 days of CPAP commencement.
Strategies to prevent and treat nasal injury
Nasal barrier dressings
Two RCTs assessed the efficacy of the use of a nasal barrier dressing during CPAP, total 244 infants (table 2).7 8 Pooled analysis of these studies showed the use of a nasal barrier dressing significantly reduced the rate of nasal injury: RR, 0.29; 95% CI 0.12 to 0.69; RD, −0.12; 95% CI −0.20 to −0.04; number needed to treat (NNT), 9; 95% CI 5 to 25 (figure 3).
Details of randomised controlled trials included in pooled analysis
Rates of nasal injury in preterm infants when a nasal barrier dressing versus no nasal barrier dressing used during binasal continuous positive airway pressure (two studies).
Two non-randomised studies were reviewed. Badr et al 22 conducted a retrospective comparative study to investigate the use of a polyvinyl chloride foam septum protector, NeoSeal (Neotech, California, USA), in 101 preterm infants with average gestational age of 32 weeks. The application of NeoSeal significantly reduced rates of nasal injury: 3/51 (6%) vs 12/50 (24%), p=0.01, compared with historical controls. Collins et al 23 compared two nasal dressings in 132 preterm infants born at <32 weeks’ gestation receiving either nHF or CPAP. One was a hydrocolloid material, Cannulaide (Beevers Manufacturing, Oregon, USA), fitted over the nose and upper lip during CPAP and nHF. The other dressing was a Velcro-coated hydrocolloid material ‘Sticky Whiskers’ (Beevers Manufacturing, Oregon, USA), which covered only the upper lip, and was designed to secure nHF or CPAP prongs in place. There was no difference in mean nasal injury score between infants receiving CPAP plus Cannulaide (9.5) and CPAP plus Sticky Whiskers (14.4), p=0.06.
Nasal HF as an alternative form of non-invasive respiratory support to CPAP
Nasal HF is an increasingly popular mode of non-invasive respiratory support that is used as an alternative to CPAP in preterm infants. It requires smaller prongs that do not need to be firmly affixed into the nares. It is perceived by clinicians and parents to be a more comfortable interface than CPAP.
Seven randomised studies comparing nHF with CPAP reported the incidence of nasal injury as a secondary outcome (table 2).24–30 Pooled analysis of these studies found that nHF was associated with a significantly reduced rate of nasal injury: RD, −0.14; 95% CI −0.17 to −0.10, RR, 0.46; 95% CI 0.37 to 0.58; NNT 7; 95% CI 6 to 10 (figure 4).
Incidence of nasal injury in infants receiving CPAP versus those receiving nasal high flow (seven studies). CPAP, continuous positive airway pressure; NIPPV, nasal intermittent positive pressure ventilation.
Two studies24 25 compared nHF with CPAP (or NIPPV) as primary respiratory support, and four studies compared nHF with CPAP as postextubation support.26 28–30 Yoder et al 27 compared nHF with CPAP as either primary or postextubation support.
The seven studies enrolled infants with a wide range of gestational ages and non-invasive respiratory support devices; classification of nasal injury was not standardised. A high degree of heterogeneity (I2=93%) was noted (figure 4); therefore, the pooled data should be interpreted with caution. Despite these limitations, there is an overall reduction in the rate of nasal injury in preterm infants receiving nHF compared with CPAP.
Nasal masks versus binasal prongs for CPAP delivery
Five studies were identified that compared the rate of nasal injury in preterm infants receiving CPAP via nasal mask with those receiving CPAP via short binasal prongs (table 2).20 31–34 Pooled analysis showed a borderline reduction in the rate of nasal injury in those receiving mask CPAP: RR, 0.80, 95% CI 0.64 to 1.00; RD, −0.07; 95% CI −0.13 to 0 (figure 5).
Incidence of nasal injury in infants receiving continuous positive airway pressure via nasal mask versus via binasal prongs (five studies).
Yong et al 20 noted that the distribution of the nasal injuries between the mask and prong groups was different; the mask group had crusting and/or excoriation of the nasal septum, narrowing of the nasal passages or sustained redness on the base of the nasal septum, whereas the prong group had injuries on the medial aspect of the nostrils, or bleeding or narrowing of the nasal passages.
Alternating CPAP interfaces
Some studies suggest that systematic rotation between these two nasal interfaces can help reduce pressure on delicate areas such as the nasal septum and nares, particularly in infants with birth weight <1500 g.20 34 35 Fischer et al 9 alternated therapy between nasal prongs and masks every 4–6 hours. Xie et al 7 used nasal prongs or masks alternatively every 6 hours if an infant presented with mild or moderate nasal injury.
Ointments
The use of epidermal growth sprays, hirudoid cream and dexpanthenol/mupirocin ointment to treat and repair nasal skin breakdown7 33 has been discussed. Paraffin oil has also been used around the nostrils before inserting binasal prongs, possibly to reduce friction between the plastic prongs and skin.7
Sequelae of nasal injury
Sepsis
Skin and mucosal damage compromises the first line of defence against the entry of bacteria. In a case–control study, Graham et al 36 described an association between CPAP and Gram-negative sepsis. Other reports suggest that infants with nasal injury due to CPAP have a higher incidence of nosocomial bacterial infections between days 2 and 7 of life, caused by coagulase-negative staphylococcal sepsis.37–39 However, RCTs included in this review did not report the incidence of bacterial infections during CPAP.
Nasal deformities
Six case reports and one case–control study have reported long-term nasal deformities in infants who received CPAP/NIPPV support.5 6 18 40–43 While the majority of nasal injury resolves when CPAP is discontinued, long-term functional difficulties or permanent distortion occasionally occurs. Severe nasal deformities may require surgical intervention in order to improve functional and cosmetic outcomes.6 Nasal injuries persisting beyond the newborn period include nostril asymmetry, columella asymmetry, nasal tip deviation or collapse, lack of nasal projection and nasal airway obstruction.6 Long-term functional or cosmetic impairments due to nasal injury secondary to CPAP are not well documented. There are no cohort studies reporting the incidence of long-term impairments and the rate of these problems is uncertain.
Discussion
Nasal injury remains a common problem in very preterm infants receiving non-invasive respiratory support.44–47 Majority of the reported cases of nasal injury are mild (stage I) and occur in more immature infants. The main concerns related to nasal injury are infant discomfort, requirement for a change in the mode of respiratory support, potential for sepsis and risk of long-term nasal deformity.
The main underlying mechanism of nasal injury related to CPAP appears to be pressure generated on the columella by tight-fitting binasal prongs.44 Prior to 30 weeks’ gestation, the epidermal skin layer and stratum corneum are fragile and poorly defined, increasing the preterm infants’ risk for pressure-related skin breakdown.48 Relieving the pressure is key to healing and prevention. Correct sizing of binasal prongs is crucial as prongs that are too small for the nares are likely to have excessive movement, damaging the internal nares, while prongs that are too large may cause nasal flaring.12 15 Even with highly skilled nursing care, involving monitoring of the skin and correct positioning of the binasal prongs, it can be difficult to prevent nasal injury, particularly in very preterm or very low birth weight infants.
From this review, three main preventative strategies appear useful: the use of nasal barrier dressings, nHF as an alternative form of support to CPAP and the use of nasal masks rather than binasal prongs for CPAP delivery.
Nasal barrier dressings seem to be effective in reducing nasal injury secondary to CPAP. Although significant reductions in rates of nasal injury were shown when either a silicon gel sheeting or hydrocolloid ‘moustache’ dressing protected the nares, the best type of dressing has not been identified. The application of a physical barrier has also been shown to decrease the severity of nasal injury, as it relieves excessive pressure exerted by binasal prongs. Xie et al 7 noted that a nasal dressing created a better seal in the nares during CPAP delivery, particularly in infants with larger nares, which potentially could be an additional advantage of such dressings. However, the effectiveness of nasal dressings in very small infants remains unclear.
Nasal HF significantly reduces rates of nasal injury compared with CPAP in preterm infants.24–30 49 The popularity of nHF is increasing, but it may not replace the use of CPAP in preterm infants. There is some evidence that nHF is not as efficacious in some very preterm infants with moderate or severe lung disease.24
Nasal mask CPAP may reduce rates of nasal injury compared with binasal prongs. However, short binasal prongs are the most popular CPAP interface, with more evidence of efficacy than nasal masks.50 Masks and binasal prongs cause nasal injury in different sites. Alternating interfaces may be a helpful nursing strategy to allow for shorter intervals of constant pressure against the delicate nasal septum, forehead and nares.
This review has several limitations. Some studies enrolled preterm infants greater than 32 weeks’ gestation who are less likely to develop nasal injury. There is inconsistent grading of nasal injury and different preventative techniques used in study protocols, such as ointments for infants randomised to the control group and included RCTs were not blinded to interventions.
Conclusions
Preterm infants born at <30 weeks’ gestation are most susceptible to nasal injury secondary to CPAP. The use of nasal barrier dressings and nasal masks as an alternative to binasal prongs may be effective interventions to reduce nasal injury. Nasal HF causes less nasal injury than CPAP, but it may not provide sufficient respiratory support for the smallest, sickest preterm infants. Further trials in this population that include a blinded, standardised assessment of nasal skin integrity are required to determine whether these strategies are effective in clinical practice.
References
Footnotes
Contributors DII and BJM performed the systematic search. All authors reviewed full-text articles for inclusion. DII prepared the first draft of the paper; this and all subsequent drafts were reviewed and revised by all authors. All authors approved the final version submitted.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
Correction notice This paper has been amended since it was published Online First. The article type has been changed from Leading article to Original article.
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