Evidence review

Clinical and technical evidence

Regulatory bodies

A search of the Medicines and Healthcare Products Regulatory Agency website for manufacturer Field Safety Notices or Medical Device Alerts for this device revealed one advisory notice issued on 12 October 2010. The notice reported that, in an isolated incident, a LoTrach (that is, PneuX) tracheostomy tube migrated through its locking mechanism, which resulted in the loss of the patient's airway. It was stated that LoTrach tracheostomy tubes and endotracheal tubes of all sizes were potentially affected. The patient was re‑intubated and suffered no long‑term harm. No component failures were identified. No reports of adverse events were identified from a search of the US Food and Drug Administration (FDA) database: Manufacturer and User Device Facility Experience (MAUDE).

Clinical evidence

A literature search identified 3 published studies relevant to this briefing; 1 was a randomised controlled trial (Gopal et al. 2015) and 2 were retrospective cohort studies (Smith et al. 2014; Doyle et al. 2011). They are summarised in tables 1 to 6 of this briefing.

One study published as an abstract only was also identified to be relevant (Hodd et al. 2009). The study is summarised in table 7.

Four conference abstracts were also identified, 1 (Gopal et al. 2013) reporting the published Gopal et al. (2015) study, 1 (Smith et al. 2011) reporting the published Smith et al. (2014) study and 2 (Carter et al. 2009; Fletcher et al. 2009) reporting data from the published study by Doyle et al. (2011). None of the abstracts provided any additional information to the published papers, and so they were not summarised in the briefing.

One study, published as an abstract only (Crommett et al. 2013), used the PneuX system in 39 critically ill patients. The only outcome measured was the amount of secretions on the inner lumen of the PneuX endotracheal/tracheostomy tube. This study was not included in this briefing because it did not report patient outcomes.

The trial by Gopal et al. (2015) was a UK‑based, single‑centre randomised controlled trial comparing the PneuX system with a standard endotracheal tube in high‑risk adults having cardiac surgery. Each intubation group comprised 120 patients and the follow‑up period was 48 hours after extubation. The primary outcome measure was the incidence of VAP, confirmed using the Hospitals in Europe Link for Infection Control through Surveillance definition.

VAP incidence was significantly lower in the PneuX group than in the standard group (10.8% compared with 21%, p=0.03). The between‑group difference with 95% confidence intervals (CI) was not reported in the paper. These data were used to calculate an absolute risk difference of 10% (95% CI 1% to 19%), which equates to a number needed to treat of 10 (95% CI 5.3 to 100.0). There was no significant difference between the 2 groups in terms of length of ICU stay (p=0.2) and in‑hospital mortality (p=0.2). There were also no statistically significant differences between the 2 groups in terms of re‑exploration rates, intubation duration and cardiopulmonary bypass duration.

Smith et al. (2014) reported on a retrospective cohort study in an ICU in an NHS hospital trust, which included 48 patients who were intubated with the PneuX system during 2010. The follow‑up period was not specified but the primary outcome was incidence of VAP. The diagnosis of VAP was based on the recommendations of the American Thoracic Society and the Infectious Diseases Society of America 2005.

Three of the 48 patients in the study developed VAP (6.25%, 95% CI 1.3% to 17%). In these 3 patients, VAP was first identified on days 3, 7 and 9 after intubation. There was a 17% incidence of unplanned extubation, of which 5 incidents (10%) were classed as self‑extubation. The authors concluded that, compared with other published studies, there appeared to be a higher rate of unplanned extubations, mostly self‑extubations, raising concerns about patient safety. They suggested that further trials would be needed to determine the value of the system in clinical practice.

The study by Doyle et al. (2011) was a retrospective cohort study in a general ICU at a NHS hospital trust, which analysed 53 critically ill patients who sequentially were intubated with the PneuX system over 14 months. The primary outcome was incidence of VAP but the follow‑up period was not specified. VAP was diagnosed based on clinical suspicion, international consensus criteria or clinical pulmonary infection score. There were no VAP episodes while the PneuX endotracheal tube was in place. One patient needed re‑intubation following elective extubation, and developed VAP 2 days later while the conventional tube was in place. This gave a VAP rate in the 53 patients of 1.8%.

The abstract by Hodd et al. (2009) reported a retrospective cohort study in an ICU at a NHS hospital trust. The electronic medical records of all ICU patients intubated with the PneuX system over 2006–09 (185 intubations) were analysed. The primary outcome was the incidence of unplanned extubations. There was 1 unplanned extubation (self‑extubation) during that period, resulting in an incidence of 0.1% (1.02 unplanned extubations per 1000 intubation days).

Recent and ongoing studies

No ongoing or in‑development trials on the PneuX system for patients in ICU at risk of VAP were identified.

Costs and resource consequences

No published evidence was identified on the direct costs and resource consequences related to using the PneuX system in preventing VAP. If the PneuX system reduced the incidence of VAP, then resources related to the treatment of VAP and VAP‑related emergency department, ICU and hospital stay could be saved. According to the manufacturer, 3 NHS hospitals are currently using the PneuX system.

One abstract (Carter et al. 2009) reported the same data as the published paper by Doyle et al. (2011). No cases of VAP were seen in the 58 patients with the PneuX system in place. On an intention‑to‑treat basis the VAP rate was 1.8%, because 1 patient who needed reintubation with a conventional endotracheal tube developed VAP while the tube was in place. With a 10–20% expected incidence of VAP, the authors extrapolated that 5–10 episodes of VAP were expected in this study.

The authors stated that the price of the PneuX system was $250 (approximately £160) per patient, making a total cost per year of $11,400 (approximately £7480) in their institution; for comparison, other researchers have estimated that treating a single case of VAP costs around $10,019 (approximately £6490).

Gopal et al. (2015) cited a review paper that puts the cost of VAP treatment in the USA at around $40,000 (approximately £25,900) per patient. The authors then stated that in their study, there were 12 fewer patients with VAP in the PneuX group than in the standard endotracheal tube group. This was equal to a potential cost saving of $480,000 (approximately £310,750). The authors estimated that, assuming using PneuX costs $100 (approximately £65) per patient, about 4800 patients could have been intubated using the PneuX system with at least a halving of the VAP rate. The cost of the PneuX system assumed by the authors is considerably lower than the current list price, so these results should be interpreted with caution.

Strengths and limitations of the evidence

The evidence is based on 3 published studies and 1 study available as an abstract.

The VAP diagnosis criteria used varied across the studies where the incidence of VAP was assessed. The follow‑up period was reported in only 1 study (Gopal et al. 2015).

The Gopal et al. (2015) study was a single‑centre randomised controlled trial. The trial may have been subject to a number of known sources of potential bias. The treatment assignment method using a computer‑generated randomisation software program was appropriate, but it was unclear whether the random allocation of the treatments was concealed. A sample size calculation was done and the recruited number of patients in each group was sufficient. However, it was unclear whether a blinding method was applied to the treatments, for example to blind the outcome assessors, or those who analysed the data. Performance bias was minimised because other than the treatments being compared, patients in both groups received the same care, with both groups having routine respiratory care in the ICU as per the NHS ventilator care bundle and the same routine gastric stress ulcer prophylaxis. The patients included in this study were high‑risk patients (over 70 years old or with impaired left ventricular ejection fraction of less than 50%) having elective and urgent cardiac surgery. This patient group may not be fully representative, being a specific subgroup of the patient population for whom the use of the PneuX system is intended. Because this was a single and relatively small study, the estimates of the effectiveness of the PneuX system are imprecise.

In the study by Smith et al. (2014) the patients were recruited using consecutive sampling, because it included all patients who met the inclusion criteria during the study period. In the study by Doyle et al. (2011) inclusions were sequential patients who had the PneuX system for mechanical ventilation during the study period. However, because both studies had a non‑comparative single‑cohort, the observed VAP rate with the PneuX system was not compared to that with an alternative tube. As such, conclusions regarding the comparative effectiveness of the PneuX system cannot be drawn from these studies.

One study published as an abstract only (Hodd et al. 2009) provided limited information in terms of study methods, characteristics and results, making it hard to judge the quality of the evidence in the abstracts.

All 4 studies were UK‑based. Their results are likely to be generalisable to the UK healthcare settings.

Three authors of the Gopal et al. (2015) study received a grant from the distributor of the PneuX system to present the data following the completion of the study. The PneuX system used in the Smith et al. (2014) study was provided by the manufacturer. In the Doyle et al. (2011) study, 1 author is the inventor of the PneuX system and is a minor shareholder in the intellectual property ownership of the PneuX system and tracheal seal monitor. In the past this author received funding and consultancy fees from the manufacturer.