Abstract
Summary
Continuous positive airway pressure (CPAP) is a valuable tool in managing infants requiring respiratory support. This article highlights a simple and economical alternative model to administer nasal CPAP using an infant feeding tube.
Nasal continuous positive airway pressure (CPAP) is a non-invasive method of administering constant distending pressure to support spontaneously breathing infants with lung disease. It has been found to cause fewer adverse effects associated with traditional neonatal ventilation (for example, oxygen toxicity, barotrauma, chronic lung disease). 1 They primarily act by preventing bronchio-alveolar collapse during expiration, recruitment of surfactant-deficient and collapsed alveoli that subsequently increase functional residual capacity and decrease the effort of breathing. 1 Numerous devices are being developed and modified to deliver CPAP. Currently used devices are: nasal prongs; bi-nasal pharyngeal tubes; endotracheal tubes; naso-endotracheal tubes; pressurized plastic bags; head box enclosures; and tight-fitting face masks. 2
Infant feeding tubes (IFTs) are nasogastric tubes used for feeding infants. They can also be used to administer CPAP in infants. IFTs inserted nasally up to nasopharynx and externally fixed can be connected directly to a wall-mounted oxygen flow meter with a humidifier. The distance between the tip of the nose and the tragus roughly corresponds to the distance that the IFS should be inserted nasally. A continuous flow of humidified gas at a set pressure of 3–8 cm of H2O can be connected to the proximal end of the IFT. 3 The amount of oxygen: air mixture can be adjusted according the requirements.
This set-up is a simple and effective method for delivering nasopharyngeal CPAP.
No documented data are currently available regarding the efficacy of this model. In our experience, IFT is a safe alternative way to provide CPAP and is extensively used in many resource-limited hospitals in India. They are cheaper than all other methods.
The major disadvantages of this technique are an inability to measure the delivered pressure or fraction of inspired oxygen (Fio2) and difficulty in deciding how much flow would be enough for each individual case. The only parameter that can be controlled is the flow of oxygen which we usually tend to maintain at between 2–6 L/min. It is estimated that an inspired flow of 5 cm H2O results in nasal pharyngeal distending pressure of approximately 2–3 cm H2O. 4 Many factors, such as air leak, mouth opening and a diameter of IFT, can affect the delivered pressure. An in-depth knowledge of the possible complications are mandatory before using this model. Nasal mucosal damage and bleeding can occur during the insertion of IFTs. A lack of proper heating and humidification can lead to hypothermia and inspissations of airway secretions. This can be avoided by using heated humidifiers and periodic gentle suctioning. The inadvertent administration of excessive airway pressure or prolonged therapy can lead onto stomach distension, aspiration, hyperinflation and pulmonary air leaks. However, gastric decompression and careful monitoring can prevent these complications.
This model can be helpful in resource-limited setups, emergencies, neonatal transport and when no other conventional nasopharyngeal CPAP delivery devices are available. This simple and cheap alternative CPAP delivery method deserves further evaluation and modification through trials in order to determine flow mechanics, efficacy and safety.