Tracheal pressure and endotracheal tube obstruction can be detected by continuous cuff pressure monitoring: in vitro pilot study

Current state and influencing factors in airbag management among emergency department nurses: A multicenter study

BACKGROUND

The emergency department (ED) plays a critical role in establishing artificial airways and implementing mechanical ventilation. Managing airbags in the ED presents a prime opportunity to mitigate the risk of ventilator-associated pneumonia. Nonetheless, existing research has largely overlooked the understanding, beliefs, and practical dimensions of airway airbag management among ED nurses, with a predominant focus on intensive care unit nurses.

AIM

To investigate the current status of ED nurses' knowledge, beliefs, and practical behaviors in airway airbag management and their influencing factors.

METHODS

A survey was conducted from July 10^th to August 10^th, 2023, using convenience sampling on 520 ED nurses from 15 tertiary hospitals and 5 sary hospitals in Shanghai. Pathway analysis was utilized to analyze the influencing factors.

RESULTS

The scores for ED nurses' airway airbag management knowledge were 60.26 ± 23.00, belief was 88.65 ± 13.36, and behavior was 75.10 ± 19.84. The main influencing factors of airbag management knowledge included participation in specialized nurse or mechanical ventilation training, department, and work experience in the department. Influencing factors of airbag management belief comprised knowledge, department, and participation in specialized nurse or mechanical ventilation training. Primary influencing factors of airbag management behavior included knowledge, belief, department, participation in specialized nurse or mechanical ventilation training, and professional title. The belief in airbag management among ED nurses acted as a partial mediator between knowledge and behavior, with a total effect value of 0.513, and an indirect effect of 0.085, constituting 16.6% of the total effect.

CONCLUSION

ED nurses exhibit a positive attitude toward airbag management with relatively standardized practices, yet there remains room for improvement in their knowledge levels. Nursing managers should implement interventions tailored to the characteristics of ED nurses' airbag management knowledge, beliefs, and practices to enhance their airbag management proficiency.

Optimization of Endotracheal Tube Cuff Pressure by Monitoring CO2 Levels in the Subglottic Space in Mechanically Ventilated Patients: A Randomized Controlled Trial

BACKGROUND

Many of the complications of mechanical ventilation are related to inappropriate endotracheal tube (ETT) cuff pressure. The aim of the current study was to evaluate the effectiveness of automatic cuff pressure closed-loop control in patients under prolonged intubation, where presence of carbon dioxide (CO2) in the subglottic space is used as an indicator for leaks. The primary outcome of the study is leakage around the cuff quantified using the area under the curve (AUC) of CO2 leakage over time.

METHODS

This was a multicenter, prospective, randomized controlled, noninferiority trial including intensive care unit patients. All patients were intubated with the AnapnoGuard ETT, which has an extra lumen used to monitor CO2 levels in the subglottic space.The study group was connected to the AnapnoGuard system operating with cuff control adjusted automatically based on subglottic CO2 (automatic group). The control group was connected to the AnapnoGuard system, while cuff pressure was managed manually using a manometer 3 times/d (manual group). The system recorded around cuff CO2 leakage in both groups.

RESULTS

Seventy-two patients were recruited and 64 included in the final analysis. The mean hourly around cuff CO2 leak (mm Hg AUC/h) was 0.22 ± 0.32 in the manual group and 0.09 ± 0.04 in the automatic group (P = .01) where the lower bound of the 1-sided 95% confidence interval was 0.05, demonstrating noninferiority (>-0.033). Additionally, the 2-sided 95% confidence interval was 0.010 to 0.196, showing superiority (>0.0) as well. Significant CO2 leakage (CO2 >2 mm Hg) was 0.027 ± 0.057 (mm Hg AUC/h) in the automatic group versus 0.296 ± 0.784 (mm Hg AUC/h) in the manual group (P = .025). In addition, cuff pressures were in the predefined safety range 97.6% of the time in the automatic group compared to 48.2% in the automatic group (P < .001).

CONCLUSIONS

This study shows that the automatic cuff pressure group is not only noninferior but also superior compared to the manual cuff pressure group. Thus, the use of automatic cuff pressure control based on subglottic measurements of CO2 levels is an effective method for ETT cuff pressure optimization. The method is safe and can be easily utilized with any intubated patient.

CO2 driven endotracheal tube cuff control in critically ill patients: A randomized controlled study

Background

To determine the safety and clinical efficacy of an innovative integrated airway system (AnapnoGuard^™ 100 system) that continuously monitors and controls the cuff pressure (P_cuff), while facilitating the aspiration of subglottic secretions (SS).

Methods

This was a prospective, single centre, open-label, randomized, controlled feasibility and safety trial. The primary endpoint of the study was the rate of device related adverse events (AE) and serious AE (SAE) as a result of using AnapnoGuard (AG) 100 during mechanical ventilation. Secondary endpoints were: (1) mechanical complications rate (2) ICU staff satisfaction; (3) VAP occurrence; (4) length of mechanical ventilation; (5) length of Intensive Care Unit stay and mortality; (6) volume of evacuated subglottic secretions.

Sixty patients were randomized to be intubated with the AG endotracheal-tube (ETT) and connected to the AG 100 system allowing P_cuff adjustment and SS aspiration; or with an ETT combined with SS drainage and P_cuff controlled manually.

Results

No difference in adverse events rate was identified between the groups. The use of AG system was associated with a significantly higher incidence of P_cuff determinations in the safety range (97.3% vs. 71%; p<0.01) and a trend to a greater volume of aspirated SS secretions: (192.0[64–413] ml vs. 150[50–200], p = 0.19 (total)); (57.8[20–88.7] ml vs. 50[18.7–62] ml, p = 0.11 (daily)). No inter-group difference was detected using AG system vs. controls in terms of post-extubation throat pain level (0 [0–2] vs. 0 [0–3]; p = 0.7), hoarseness (42.9% vs. 75%; p = 0.55) and tracheal mucosa oedema (16.7% vs. 10%; p = 0.65).

Patients enrolled in the AG group had a trend to reduced VAP risk of ventilator-associated pneumonia(VAP) (14.8% vs. 40%; p = 0.06), which were more frequently monomicrobial (25% vs. 70%; p = 0.03).

No statistically significant difference was observed in duration of mechanical ventilation, ICU stay, and mortality.

Conclusions

The use AG 100 system and AG tube in critically ill intubated patients is safe and effective in P_cuff control and SS drainage. Its protective role against VAP needs to be confirmed in a larger randomized trial.

Trial registration

ClinicalTrials.gov NCT01550978. Date of registration: February 21, 2012.

Cuff pressure monitoring by manual palpation in intubated patients: How accurate is it? A manikin simulation study

BACKGROUND

Endotracheal intubation (ETI) for mechanical ventilation has a central role in the Intensive Care Unit (ICU). ETI is one of the main risk factors for the development of ventilator-associated pneumonia (VAP) as its presence reduces the natural defences of the upper airway and allows the micro-suction of secretions in the airways. In order to minimise such complications, it is fundamental to maintain a suitable pressure inside the tube cuff.

AIM AND SCOPE

The main objective of the present study is to evaluate the effectiveness and reliability of palpation method, performed with the operators fingers, for detecting the tube cuff pressure.

RESULTS

The study was performed using a manikin to test the pressure of the ETT cuff, on a sample constituted by nurses employed in three Italian ICU from two different Umbrian hospitals. From a total of 68 participants, detection by palpation method revealed to be not correct in 68% of cases; in particular, only 10% of respondents can correctly detect a pressure in the recommended range (20-30cmH₂O) using palpation. Moreover it was possible to highlight that the participation in emergency courses has a positive effect on the correct measurement of cuff pressure using the palpation method (V=0.501).

CONCLUSIONS

The study, in agreement with the literature, confirms the thesis that the palpation method is inadequate to determine an estimate of the pressure existing inside the cuff.

Detection of endobronchial intubation by monitoring the CO2 level above the endotracheal cuff

Early detection of accidental endobronchial intubation (EBI) is still an unsolved problem in anesthesia and critical care daily practice. The aim of this study was to evaluate the ability of monitoring above cuff CO2 to detect EBI (the working hypothesis was that the origin of CO2 is from the unventilated, but still perfused, lung). Six goats were intubated under general anesthesia and the ETT positioning was verified by a flexible bronchoscope. The AnapnoGuard system, already successfully used to detect air leak around the ETT cuff, was used for continuous monitoring of above-the-cuff CO2 level. When the ETT distal tip was located in the trachea, with an average cuff pressure of 15 mmHg, absence of CO2 above the cuff was observed. The ETT was then deliberately advanced into one of the main bronchi under flexible bronchoscopic vision. In all six cases the immediate presence of CO2 above the cuff was identified. Further automatic inflation of the cuff, up to a level of 27 mmHg, did not affect the above-the-cuff measured CO2 level. Withdrawal of the ETT and repositioning of its distal tip in mid-trachea caused the disappearance of CO2 above the cuff in a maximum of 3 min, confirming the absence of air leak and the correct positioning of the ETT. Our results suggest that measurement of the above-the-cuff CO2 level could offer a reliable, on-line solution for early identification of accidental EBI. Further studies are planned to validate the efficacy of the method in a clinical setup.