Evidence review

Advice

Clinical and technical evidence
Costs and resource consequences
Strengths and limitations of the evidence

Evidence review

Clinical and technical evidence

Regulatory bodies

A search of the Medicines and Healthcare Products Regulatory Agency (MHRA) website revealed no manufacturer Field Safety Notices or Medical Device Alerts for the TaperGuard Evac oral tracheal tube. Two events with a TaperGuard device were identified from searches of the US Food and Drug Administration (FDA) database: Manufacturer and User Device Facility Experience (MAUDE). These reports related to endotracheal tubes but the brand of the device was not stated, so it is not clear whether these refer to the TaperGuard Evac oral tracheal tube. In 1 of the events (April 2014), when a nurse changed the tube, she found that the inflation line had been cut and was on the bed, near the patient's neck. The tube needed to be replaced but no additional harm to the patient was reported. In another event (September 2013), during mechanical ventilation an alarm related to leakage alerted the healthcare provider. The user reported that pretesting of the cuff had been performed, but that the balloon on the endotracheal tube appeared to be porous. A decision was made to extubate the patient and re‑intubate with a replacement tube.

Clinical evidence

A literature search identified 1 fully published randomised controlled trial (Mahmoodpoor et al. 2013) and 1 randomised controlled trial published in the form of a conference abstract only (Saito et al. 2013). Both compared the TaperGuard Evac oral tracheal tube (with subglottic secretion drainage) with conventional endotracheal tubes for mechanical ventilation in ICU patients.

One prospective controlled cohort study (Lorente et al. 2014) was also identified. This study compared 4 subglottic secretion management interventions in patients needing mechanical ventilation in an ICU. The 4 interventions included: standard tracheal tubes (Mallinckrodt Hi‑Lo tracheal tube, which has a cylindrical polyvinyl chloride (PVC) cuff but no subglottic drainage), with either continuous or intermittent control of cuff pressure; and the TaperGuard Evac oral tracheal tubes with subglottic drainage, with either continuous or intermittent control of cuff pressure. Two publications reporting the same case series study were identified (Suys et al. 2013; Spapen et al. 2013). The authors of this study investigated whether the use of the TaperGuard Evac oral tracheal tube for intermittent aspiration of subglottic secretions could cause tracheal damage.

A historical controlled study evaluated the use of an intervention bundle (that included the TaperGuard Evac oral tracheal tube) to prevent VAP compared with standard care without the intervention bundle (Pérez‑Granda et al. 2014).

None of these studies was conducted in the UK.

The Mahmoodpoor et al. (2013) trial (presented in tables 1 and 2) compared the impact of 3 different tracheal tubes on the prevention of VAP in critically ill patients. The types of tube were: the TaperGuard Evac oral tracheal tubes, which had a taper‑shaped cuff and subglottic secretion; the SealGuard tubes, which had a cylindrical/barrel‑shaped polyurethane (PU) cuff and a subglottic secretion suction port; and the Hi‑Lo tubes, which were standard tubes with a barrel shaped PVC cuff. It was not clear whether the Hi‑Lo tubes studied had subglottic secretion drainage. In the trial, 96 patients in the surgical ICU who were expected to need mechanical ventilation for more than 96 hours were assigned to have intubation using either the TaperGuard Evac (n=32), the SealGuard (n=32), or the Hi‑Lo tube (n=32). The ICU admission categories provided by the authors were 'surgery' for most patients or 'medical' for other patients. Further details regarding the admission category were not reported. During the 3‑day study period, no statistically significant differences were seen between the 3 groups of patients for mean cuff pressure, incidence of VAP, length of ICU stay, ICU mortality, use of prokinetic drugs or neuromuscular blocking drugs, and Richmond Agitation Sedation Scale.

The Saito et al. (2013) study (presented in table 3) was reported as a conference abstract only and therefore provided limited information. This was a randomised controlled trial comparing the TaperGuard Evac oral tracheal tube with the Hi‑Lo Evac tube in 289 adults who were expected to need mechanical ventilation for at least 48 hours. Both types of tube had subglottic suction drainage. The primary outcome was incidence of VAP. The incidence rate of microbiologically confirmed VAP was 21.7% (23/106) in the TaperGuard Evac group and 21.7% (23/106) in the Hi‑Lo Evac group (p=1.00). No statistically significant differences between groups were observed for time to VAP onset, duration of mechanical ventilation, length of ICU stay, and the rate of achieving appropriate cuff pressure. There was no statistically significant difference in the incidence of reintubation because of laryngeal oedema between the TaperGuard Evac group and the Hi‑Lo Evac group.

The Lorente et al. (2014) study (presented in tables 4 and 5) was a prospective controlled cohort study. It examined whether the joint use of VAP‑preventive interventions to avoid ventilator‑associated respiratory infection could reduce healthcare costs. The interventions investigated were the TaperGuard Evac oral tracheal tube with or without continuous control of endotracheal tube cuff pressure (CCCP), compared with the Hi‑Lo tracheal tube without subglottic drainage with or without CCCP. A total of 656 patients who needed mechanical ventilation during the 1‑year study period were included. Of these, 84 patients were treated with the TaperGuard Evac oral tracheal tube, 71 patients with the TaperGuard Evac oral tracheal tube with CCCP, 241 patients with the Hi‑Lo tracheal tube, and 260 patients with the Hi‑Lo tracheal tube with CCCP. There was statistically significant heterogeneity in the characteristics of patients treated in the 4 groups, including diagnostic group (for example cardiac surgery, cardiology, respiratory), type of ICU admission (for example postoperative, medical, and traumatic), cuff diameter, the Acute Physiology and Chronic Health Evaluation (APACHE)‑II score, duration of mechanical ventilation, and presence of respiratory infection before intubation. The incidence of ventilator‑associated respiratory infection was statistically significantly lower with the TaperGuard Evac plus CCCP than either with the Hi‑Lo without CCCP (3.77 compared with 20.62 per 1000 days of mechanical ventilation, p<0.001) or the Hi‑Lo plus CCCP methods (3.77 compared with 15.64 per 1000 days of mechanical ventilation, p=0.006). No statistically significant differences were found in the incidence of ventilator‑associated respiratory infection between the following comparisons: the TaperGuard Evac with CCCP compared with the TaperGuard Evac without CCCP; the TaperGuard Evac without CCCP compared with Hi‑Lo without CCCP; the TaperGuard Evac without CCCP compared with Hi‑Lo plus CCCP; and Hi‑Lo plus CCCP compared with Hi‑Lo without CCCP.

The Suys et al. (2013) study (presented in table 6) was a prospective case series investigating tracheal injury caused by intermittent subglottic secretion drainage using an automated cycle device in 6 consecutive patients who were intubated with the TaperGuard Evac endotracheal tube. After 24 hours of intubation, a CT scan of the neck showed entrapment of the posterior tracheal mucosa into the suction port orifice of the endotracheal tube in all patients. Bronchoscopy showed a diversity of tracheal mucosal lesions (maceration, erythema, linear erosion and ulceration) in the area next to the suction part of the endotracheal tube. Three patients had bedside percutaneous tracheostomy at 14, 16 and 17 days of ICU stay respectively. The same results were presented in a duplicate publication (Spapen et al. 2013).

A historical controlled study was identified (Pérez‑Granda et al. 2014) that evaluated the impact of an intervention bundle for the prevention of VAP over a 35‑month period in a major heart surgery ICU in Spain. The intervention bundle consisted of 4 measures including:

a specific training programme
aspiration of subglottic secretions using a TaperGuard Evac endotracheal tube over a 13‑month period
introduction of an inclinometer to improve the semi‑reclining position
reinforcement of oral care with chlorhexidine.

The primary end point was the reduction in the incidence rate of VAP from the 4 sequentially implemented measures. Data from 401 patients before implementing the bundle and from 1534 patients during the intervention bundle were collected. After implementing the intervention bundle, there was a statistically significant reduction in incidence rate of VAP (23.9 compared with 13.5 episodes per 1000 days of ventilation, p=0.005) and the mean number of days of mechanical ventilation/1000 days of stay (507 versus 375, p=0.001). The sequential application of preventive measures in time achieved a relative rate reduction of VAP of 41% (incidence rate ratio 0.41; 95% confidence interval [CI] 0.28 to 0.62). The mortality rates before and during the intervention were 13.0% and 10.2% respectively. VAP rate was reduced most significantly by training and using the inclinometer.

Table 1 Overview of the Mahmoodpoor et al. (2013) trial

Study component	Description
Objectives/hypotheses	To compare the effect of different cuff materials (polyurethane) and shapes (cylindrical, conical) of tracheal tubes for mechanical ventilation on prevention of VAP in critically ill patients. The tubes being compared were the Hi‑Lo tubes (PVC, barrel), the Sealguard tubes (PU, cylindrical/barrel) and the TaperGuard tubes (PVC, cone/tapered).^a
Study design	Randomised controlled trial.
Setting	A 12‑bed surgical ICU in Tabriz, Iran. Follow‑up duration was 3 days.
Inclusion/exclusion criteria	All patients who were admitted to the ICU and expected to be under mechanical ventilation for more than 96 hours. Exclusion criteria were previous history of immunosuppression or pneumonia and intubation before admission to the ICU.
Primary outcomes	Cuff pressure manually monitored every 3 hours by a manometer and maintained between 20–30 mmHg by a nurse to reduce the risks of aspiration and tracheal mucous damage. Pressure more than 30 mmHg was considered as over‑inflation of the cuff and under 20 mmHg as under‑inflation.
Statistical methods	Data were analysed using SPSS. Variables were shown as mean ± standard deviation. Independent t‑test, Mann Whitney U‑test and chi‑square test were used for statistical analysis. A p value of less than 0.05 was considered significant.
Participants	Surgical ICU patients expected to need mechanical ventilation for more than 96 hours (n=96).
Results	There was no significant difference in mean cuff pressure between the 3 groups during 72 hours. Pneumonia was seen in 11 patients (34%) in the PVC group, 8 (25%) in the SealGuard group and 7 (21%) in the TaperGuard group. Changes in mean cuff pressure between SealGuard and PVC tubes and between the TaperGuard and PVC tubes did not show any significant difference. There was no significant difference in over‑inflation between the 3 groups.
Conclusions	The authors stated that the use of PU endotracheal tubes resulted in reducing VAP compared with endotracheal tubes with a PVC cuff. In PU tubes the TaperGuard had less incidence of VAP compared with the SealGuard tubes.
Abbreviations: ICU, intensive care unit; PU, polyurethane; PVC, polyvinyl chloride; VAP, ventilator‑associated pneumonia. ^a The authors recognised the material of the TaperGuard tube cuffs as PU; however, according to the manufacturer the TaperGuard tube cuffs are made of PVC rather than PU.

Table 2 Summary of the Mahmoodpoor et al. (2013) trial

	TaperGuard	SealGuard	Hi‑Lo	Analysis
Randomised	n=32	n=32	n=32
Efficacy	n=32	n=32	n=32
Outcomes
Mean cuff pressure (mmHg), mean±SD	24.10±0.49	24.07±0.48	24.20±0.47	NS
Incidence of VAP^a, % (n)	21% (7/32)	25% (8/32)	34% (11/32)	NS
Length of ICU stay^b	17 (13–31)	18 (12–33)	12 (8–22)	NS
ICU mortality^c	5	5	6	NS
Prokinetic drugs^c	2	2	3	NS
Neuromuscular blocking drugs^c	1	2	1	NS
Richmond Agitation Sedation Scale^d, mean±SD	−0.7±0.3	−0.65±0.4	−1.0±0.5	NS
Abbreviations: n, number of patients; NS, not statistically significant; SD, standard deviation; VAP, ventilator‑associated pneumonia. ^aPneumonia was defined based on clinical, radiological and laboratory findings based on clinical pulmonary infection score. ^bUnit was not reported. Presumably it was in hours. It was unclear whether the data reported were medians and those in the brackets were ranges. ^c Units of this measurement were not report. ^dNo further details were reported about the scale.

Table 3 Summary of the Saito et al. (2013) trial (based on abstract only)

Study component	Description
Objectives/hypotheses	To determine whether an endotracheal tube with tapered‑type cuff (the TaperGuard Evac) can reduce the incidence of VAP compared with the spindle type Hi‑Lo Evac tubes.
Study design	Single‑centre, randomised controlled trial.
Setting	Data not available from the abstract.
Inclusion/exclusion criteria	Data not available from the abstract.
Primary outcomes	VAP incidence (microbiologically confirmed, based on semiquantitative bronchoalveolar lavage fluid culture of 3+ or phagocytosis on Gram staining).
Statistical methods	Data not available from the abstract.
Participants	Adult patients (≥18 years) expected to need mechanical ventilation for at least 48 hours.
Results	The rate of microbiologically confirmed VAP was 21.7% (23/106) in the TaperGuard Evac group and 21.7% (23/106) in the Hi‑Lo Evac group (p=1.00). No significant differences between groups were observed for time to VAP onset, duration of mechanical ventilation, and ICU stay. The rate of achieving appropriate cuff pressure was 83.2% (332/1974)^a for the TaperGuard Evac tubes and 82.4% (328/1867)^a for the Hi‑Lo Evac tubes (p=0.549). There was no significant difference in the incidence of reintubation because of laryngeal oedema between the TaperGuard Evac group and the Hi‑Lo Evac group (11.5% [6/52] versus 2.0% [1/49]; p=0.113).
Conclusions	The authors concluded that differences in cuff type and shape under identical conditions of cuff pressure control have no influence on the incidence of VAP.
Abbreviations: ICU, intensive care unit; n, number of patients; VAP, ventilator‑associated pneumonia. ^a There is a discrepancy between the reported rate and the reported percentage.

Table 4 Overview of the Lorente et al. (2014) study

Study component	Description
Objectives/hypotheses	To determine whether the joint use of VAP preventive measures (the TaperGuard Evac oral tracheal tube with or without CCCP; the Hi‑Lo tracheal tube without subglottic drainage, with or without CCCP) to avoid VARI could reduce health care costs.
Study design	Prospective controlled cohort study.
Setting	A 24‑bed medical‑surgical ICU of the University Hospital of the Canary Islands and a 650‑bed tertiary hospital in Tenerife, Spain over a 1‑year period. Follow‑up duration was presumably until discharge from the unit.
Inclusion/exclusion criteria	Patients in ICU needing mechanical ventilation.
Primary outcomes	Main outcomes included incidence of respiratory infection (including pneumonia or tracheobronchitis, diagnosed by an expert panel blinded to the type of endotracheal tube and cuff pressure system using predefined criteria), daily healthcare costs, and cost of antimicrobial agents.
Statistical methods	Qualitative variables were reported as frequencies and percentages, and were compared using the chi‑square test or Fisher's exact test as appropriate. Quantitative variables are reported as mean±SD and were compared using ANOVA. Poisson regression analysis for unconditional maximum likelihood inference with exact p values was used to compare respiratory infections per 1000 days of mechanical ventilation and daily healthcare costs between pairs of groups. Bonferroni correction was applied to correct for multiple testing. The probability of remaining free of VARI was plotted using the Kaplan–Meier method, and comparisons between groups were done using the log‑rank test. A p value of <0.05 was considered statistically significant. Statistical analyses were performed using SPSS and StatXact.
Participants	Patients in ICU needing mechanical ventilation (n=656), including: 84 on the TaperGuard Evac oral tube 71 on the TaperGuard Evac oral tube with CCCP 241 on Hi‑Lo tracheal tube 260 on Hi‑Lo tracheal tube with CCCP.
Results	The incidence of VARI was lower in the TaperGuard Evac oral tracheal tube with CCCP group, compared with the Hi‑Lo tube group (p<0.001), the Hi‑Lo tube with CCCP group (p=0.006), and the TaperGuard Evac oral tracheal tube group (p=0.008). Daily healthcare costs were also lower in the TaperGuard tube with CCCP group compared with the Hi‑Lo tube group (p<0.001), the Hi‑Lo tube with CCCP group (p<0.001), and the TaperGuard group (p<0.001).
Conclusions	The authors concluded that the combined use of the TaperGuard and CCCP reduced the incidence of VARI and saved healthcare costs.
Abbreviations: ANOVA, analysis of variance; CCCP, continuous control of endotracheal tube cuff pressure; ICU, intensive care unit; n, number of patients; SD, standard deviation; VAP, ventilator‑associated pneumonia; VARI, ventilator‑associated respiratory infection.

Table 5 Summary of the Lorente et al. (2014) study

	TaperGuard + CCCP	TaperGuard	Hi‑Lo + CCCP	Hi‑Lo	Analysis
n	n=71	n=84	n=260	n=241
Selected outcome
VARI per 1000 days of MV	3.77	14.93	15.64	20.62	The TaperGuard + CCCP vs Hi‑Lo: p<0.001
					The TaperGuard + CCCP vs Hi‑Lo + CCCP: p=0.006
					The TaperGuard + CCCP vs TaperGuard: p=0.008^a
					The TaperGuard vs Hi‑Lo: p=0.36
					The TaperGuard vs Hi‑Lo + CCCP: p=0.99
					Hi‑Lo + CCCP vs Hi‑Lo: p=0.44
Abbreviations: CCCP, continuous control of endotracheal tube cuff pressure; MV, mechanic ventilation; n, number of patients; SSD: subglottic secretion drainage; VAP, ventilator‑associated pneumonia. VARI, ventilator‑associated respiratory infection; vs, versus. ^a According to Bonferroni correction, all p values <0.008 were considered statistically significant.

Table 6 Summary of the Suys et al. (2013) study

Study	Study characteristics
Suys et al. (2013); Spapen et al. (2013)	Study design	A prospective case series
	Objective	To investigate whether intermittent subglottic secretion drainage, using an automated cycle device, could cause tracheal injury.
	Setting	Intensive care unit in the University Hospital, Vrije Universiteit Brussel, Belgium.
	Population	6 consecutive patients, intubated with the TaperGuard Evac endotracheal tube.
	Intervention	Intubation with the TaperGuard Evac endotracheal tube. Before the CT scan was performed, patients were curarised and intermittent subglottic secretion drainage was applied.
	Outcome measures	A high‑resolution CT scan of the neck after 24 hours to measure tracheal injury.
	Findings	CT imaging showed entrapment of the posterior tracheal mucosa into the suction port orifice of the endotracheal tube in all patients. Bronchoscopy revealed a diversity of tracheal mucosal lesions (maceration, erythema, linear erosion, and ulceration) in the area adjacent to the suction part of the endotracheal tube. Three patients had bedside percutaneous tracheostomy at 14, 16 and 17 days of ICU stay respectively.
Abbreviations: CT, computerised tomography; n, number of patients; ICU, intensive care unit; VAP, ventilator‑associated pneumonia.

Recent and ongoing studies

One randomised controlled trial (reported to have completed in June 2014) comparing the TaperGuard tracheal tube with the Hi‑Contour Brandt endotracheal tube for postoperative pneumonia in patients after aortic surgery was identified in the preparation of this briefing (ClinicalTrials.gov identifier: NCT01457248). It was not clear whether the TaperGuard tubes studied were the TaperGuard Evac tubes. Results of this trial had not been published at the time of preparing this briefing.

Costs and resource consequences

The study by Pérez‑Granda et al. (2014) included an assessment of the financial impact of a bundle of measures to reduce VAP, including the use of the TaperGuard Evac oral tracheal tube. The authors reported that implementing this care bundle reduced the cost of antimicrobial therapy from €70,612 to €52,775/1000 days of stay, p=0.10, which is equivalent to a reduction from £55,996 to £41,851 (exchange rate at December 2014).

Strengths and limitations of the evidence

Two randomised controlled trials were available, 1 fully published (Mahmoodpoor et al., 2013) and the other as a conference abstract only (Saito et al. 2013). Both studies, particularly the Saito et al. abstract, reported limited information on the methods used on which to estimate the quality of these studies. For example, there was no information on the randomisation methods, sample size calculation and the methods of detecting VAP used in the studies. The authors of the Mahmodpoor et al. trial recognised the small sample size as a limitation of the study. Also, the follow‑up duration in the Mahmodpoor trial was 3 days; thus, any VAP incidence occurring due to prolonged mechanical ventilation beyond 3 days would not be observed.

In the prospective controlled cohort study (Lorente et al., 2014) comparison groups were defined by the types of endotracheal tubes that the patients had for mechanical ventilation, and there was statistically significant heterogeneity in many aspects of the patient characteristics between the comparison groups, including APACHE‑II score, duration of mechanical ventilation and respiratory infection. This may affect the comparability between the groups and introduce bias in the results.

Another available study was a case series of only 6 patients (Suys et al., 2013), which added no evidence on the efficacy but only information on the safety of the TaperGuard Evac oral tracheal tube.

None of the studies identified using the TaperGuard Evac oral tracheal tube were conducted in the UK and so the generalisability of these results to the NHS is unclear.

Overall, the evidence identified was sparse and of limited quality that does not allow firm conclusions to be drawn on the potential of the TaperGuard Evac oral tracheal tube to reduce the incidence of VAP or other respiratory infections.