Endotracheal tube cuff pressure in three hospitals, and the volume required to produce an appropriate cuff pressure

Association between septic shock and tracheal injury score in intensive care unit patients with invasive ventilation: a prospective single-centre cohort study in China

OBJECTIVES

There was no evidence regarding the relationship between septic shock and tracheal injury scores. Investigate whether septic shock was independently associated with tracheal injury scores in intensive care unit (ICU) patients with invasive ventilation.

DESIGN

Prospective observational cohort study.

SETTING

Our study was conducted in a Class III hospital in Hebei province, China.

PARTICIPANTS

Patients over 18 years of age admitted to the ICU between 31 May 2020 and 3 May 2022 with a tracheal tube and expected to be on the tube for more than 24 hours.

PRIMARY AND SECONDARY OUTCOME MEASURES

Tracheal injuries were evaluated by examining hyperaemia, ischaemia, ulcers and tracheal perforation by fiberoptic bronchoscope. Depending on the number of lesions, the lesions were further classified as moderate, severe or confluent.

RESULTS

Among the 97 selected participants, the average age was 56.6±16.5 years, with approximately 64.9% being men. The results of adjusted linear regression showed that septic shock was associated with tracheal injury scores (β: 2.99; 95% CI 0.70 to 5.29). Subgroup analysis revealed a stronger association with a duration of intubation ≥8 days (p=0.013).

CONCLUSION

Patients with septic shock exhibit significantly higher tracheal injury scores compared with those without septic shock, suggesting that septic shock may serve as an independent risk factor for tracheal injury.

TRIAL REGISTRATION NUMBER

ChiCTR2000037842, registered 03 September 2020. Retrospectively registered, https://www.chictr.org.cn/edit.aspx?pid=57011&htm=4.

Determining optimal cuff volume for cuffed endotracheal tubes commonly used in pediatric patients: A prospective observational study

OBJECTIVES

To determine an optimal cuff inflation volume to achieve safe cuff pressure (20-25 cmH2O) in cuffed endotracheal tubes (ETTs) with an inner diameter of 4.5, 5.0, and 5.5 mm, which are commonly used in pediatric anaesthesia clinical practice and to create a formula to determine the optimal cuff volume.

METHODS

This study was carried out between February and June 2021 in Ankara City Hospital, Ankara, Turkey. A total of 127 pediatric patients who were intubated with 4.5, 5.0 and 5.5 numbered cuffed ETTs were included in this study. The same brand of cuffed ETT was used for each patient. The diameter of the subglottic transverse airway was measured by ultrasound for selecting the appropriate tube. Cuff pressure was measured with a cuff manometer to ensure optimum cuff pressure (20-25 cmH2O).

RESULTS

We found out that the mean ideal cuff volume inflated for 4.5 size tube was 1.7±0.3 ml, 1.9±0.3 ml for 5.0 size tube, and 2.1±0.3 ml for 5.5 size tube. Additionally we developed the "endotracheal cuff volume (ml) = 1,027 x height (m) + 0,104 x subglottic transverse diameter (mm) - 0,0191" formula to predict the most suitable inflation volume for ETT cuffs.

CONCLUSION

In this study, we suggested the optimal cuff volume to inflate the cuffs of ETTs 4.5, 5.0, and 5.5, which are frequently used in pediatric anaesthesia practice, in the appropriate cuff pressure range.ClinicalTrials.gov ref. no.: NCT04948359.

Endotracheal Cuff-pressure Monitoring in ICU: A Standard of Care Yet to be Standardized, and Often Neglected

How to cite this article: Kumar AKA. Endotracheal Cuff-pressure Monitoring in ICU: A Standard of Care Yet to be Standardized, and Often Neglected. Indian J Crit Care Med 2024;28(1):8-10.

Pressure changes in the endotracheal tube cuff in otorhinolaryngologic surgery: a prospective observational study

Objective

Inflation of the endotracheal tube cuff is needed for providing ventilation. Cuff pressure should be maintained inside the appropriate range to prevent critical airway complications. The purpose of this study is to evaluate the pressure changes in the endotracheal tube cuff during otorhinolaryngologic surgery.

Design and method

This single-center observational study was conducted at Severance Hospital in Korea between April 2020 and November 2020. Patients aged >20 years scheduled to undergo otorhinolaryngological surgical procedures were enrolled. Patients undergoing planned tracheostomy and those who were slated for uncuffed endotracheal tube use were excluded. Intubation was performed after the induction of general anesthesia. A pressure transducer was connected to the pilot balloon of the endotracheal tube, and cuff pressure was continuously monitored until extubation. If the cuff pressure was not appropriate for more than 5 min, it was adjusted to the appropriate range by injecting or removing air. The percentage of time for which the cuff pressure remained within the appropriate range was calculated and defined as the time in the therapeutic range (TTR). The presumed cause for the rise or fall in cuff pressure was identified.

Results

In total 199 patients, alterations in cuff pressure outside the appropriate range occurred in 191 patients (96.0%). The mean TTR was 79.7% (SD 25.0%), and head and neck surgery had the lowest mean TTR of 69.0% compared to ear and nose surgeries (94.2 and 82.1%, respectively). Sixty-eight patients (34.2%) demonstrated inadequate endotracheal tube cuff pressure for more than 20% of the total anesthesia time. Twenty-six patients (13.1%) demonstrated optimal endotracheal tube cuff pressure for less than 50% of the total anesthesia time. The causative factors inducing inappropriate cuff pressure were found to vary, including positional changes, surgical procedure, anatomical manipulation, and anesthetic procedure.

Conclusion

In otorhinolaryngologic surgery, cuff pressure increased or decreased outside the appropriate range due to various factors. Therefore, we suggest close continuous monitoring of cuff pressure during anesthesia for otorhinolaryngologic surgery.

Clinical trial registration

clinicaltrials.gov, identifier NCT03938493.

Analysis of Risk Factors for Tracheal Stenosis Managed during COVID-19 Pandemic: A Retrospective, Case-Control Study from Two European Referral Centre

INTRODUCTION

Benign subglottic/tracheal stenosis (SG/TS) is a life-threatening condition commonly caused by prolonged endotracheal intubation or tracheostomy. Invasive mechanical ventilation was frequently used to manage severe COVID-19, resulting in an increased number of patients with various degrees of residual stenosis following respiratory weaning. The aim of this study was to compare demographics, radiological characteristics, and surgical outcomes between COVID-19 and non-COVID patients treated for tracheal stenosis and investigate the potential differences between the groups.

MATERIALS AND METHODS

We retrospectively retrieved electronical medical records of patients managed at two referral centers for airways diseases (IRCCS Humanitas Research Hospital and Avicenne Hospital) with tracheal stenosis between March 2020 and May 2022 and grouped according to SAR-CoV-2 infection status. All patients underwent a radiological and endoscopic evaluation followed by multidisciplinary team consultation. Follow-up was performed through quarterly outpatient consultation. Clinical findings and outcomes were analyzed by using SPPS software. A significance level of 5% (p < 0.05) was adopted for comparisons.

RESULTS

A total of 59 patients with a mean age of 56.4 (±13.4) years were surgically managed. Tracheal stenosis was COVID related in 36 (61%) patients. Obesity was frequent in the COVID-19 group (29.7 ± 5.4 vs. 26.9 ± 3, p = 0.043) while no difference was found regarding age, sex, number, and types of comorbidities between the two groups. In the COVID-19 group, orotracheal intubation lasted longer (17.7 ± 14.5 vs. 9.7 ± 5.8 days, p = 0.001), tracheotomy (80%, p = 0.003) as well as re-tracheotomy (6% of cases, p = 0.025) were more frequent and tracheotomy maintenance was longer (21.5 ± 11.9 days, p = 0.006) when compared to the non-COVID group. COVID-19 stenosis was located more distal from vocal folds (3.0 ± 1.86 vs. 1.8 ± 2.03 cm) yet without evidence of a difference (p = 0.07). The number of tracheal rings involved was lower in the non-COVID group (1.7 ± 1 vs. 2.6 ± 0.8 p = 0.001) and stenosis were more frequently managed by rigid bronchoscopy (74% vs. 47%, p = 0.04) when compared to the COVID-19 group. Finally, no difference in recurrence rate was detected between the groups (35% vs. 15%, p = 0.18).

CONCLUSIONS

Obesity, a longer time of intubation, tracheostomy, re-tracheostomy, and longer decannulation time occurred more frequently in COVID-related tracheal stenosis. These events may explain the higher number of tracheal rings involved, although we cannot exclude the direct role of SARS-CoV-2 infection in the genesis of tracheal stenosis. Further studies with in vitro/in vivo models will be helpful to better understand the role of inflammatory status caused by SARS-CoV-2 in upper airways.

Objective and Subjective Evaluation of Endotracheal Tube Cuff Pressure between Different Levels of Anesthesia Experiences

Objective: After endotracheal intubation (ETI), the endotracheal tube cuff (ETTc) should be inflated at sufficient pressure to function, and high pressure should be avoided to prevent complications. In our study, the effect of professional experience on the estimation of ETTcP by palpation is investigated. Method: The study included 75 adult patients with physical status I-III of the American Society of Anesthesiology (ASA) scheduled for ETI. Anesthesia residents were divided into two groups of 20, each with 1 month to 1 year of experience (Group 1) and those with more than 4 years of experience (Group 2). After the ETI, one participant in both groups was asked to inflate the ETTc to an estimated 25 cm H2O by cuff palpation. Then the actual ETTcP was measured with a manometer. Results: The median ETTcP value was 42,00 cm H2O in Group 1 and 32,00 cm H2O in Group 2, (p=0.012). Although the data of both groups were significantly higher than the target value, the values obtained in Group 1 were further away from Group 2 (p&lt;0.001, p&lt;0.001). Conclusion: Professional experience has no effect on the correct estimation of the ETTcP. It is more convenient to measure the actual pressure to avoid undesirable effects of ETTcP outside the target.

Disposable Airway Pressure Manometers for Endotracheal Tube Cuff Inflation

This study aimed to assess the performance, accuracy, precision and repeatability of two single-use airway pressure manometers as a cost-effective alternative for inflation of endotracheal tubes with high-volume, low-pressure cuffs. The manometers were tested in a bench top model against a U-tube manometer. Eighteen units of each device were tested. Three consecutive measurements were performed at pressures of 20, 25 and 30 cmH₂O each. The mean ± SD of the recorded pressures and maximum deviation from the target pressures were calculated for each device and each target pressure. For device A, the mean ± SD pressures were 19.6 ± 0.7, 23.6 ± 0.8 and 28.3 ± 0.8 cmH₂O; for device B, the mean ± SD pressures were 19.3 ± 0.6, 24.3 ± 0.9 and 29.2 ± 0.67 cmH₂O for target pressures of 20, 25 and 30 cmH₂O, respectively. The bias for device A was -0.4, -1.4, and -1.7 cmH₂O and for device B, -0.7, -0.7, and -0.8 cmH₂O for target pressures of 20, 25, and 30 cmH₂O, respectively. Both devices showed results comparable to those reported for commercial cuff manometers. They represent inexpensive tools that provide clinically sufficient accuracy, precision and repeatability for ETT cuff inflation between pressures of 20 and 30 cmH₂O.

Airway injury from the presence of endotracheal tubes and the association with subglottic secretion drainage: a prospective observational study

PURPOSE

Laryngeal and tracheal injuries are known complications of endotracheal intubation. Endotracheal tubes (ETTs) with subglottic suction devices (SSDs) are commonly used in the critical care setting. There is concern that herniation of tissue into the suction port of these devices may lead to tracheal injury resulting in serious clinical consequences such as tracheal stenosis. We aimed to describe the type and location of tracheal injuries seen in intubated critically ill patients and assess injuries at the suction port as well as in-hospital complications associated with those injuries.

METHODS

We conducted a prospective observational study of 57 critically ill patients admitted to a level 3 intensive care unit who were endotracheally intubated and underwent percutaneous tracheostomy. Investigators performed bronchoscopy and photographic evaluation of the airway during the percutaneous tracheostomy procedure to evaluate tracheal and laryngeal injury.

RESULTS

Forty-one (72%) patients intubated with ETT with SSD and sixteen (28%) patients with standard ETT were included in the study. Forty-seven (83%) patients had a documented airway injury ranging from hyperemia to deep ulceration of the mucosa. A common tracheal injury was at the site of the tracheal cuff. Injury at the site of the subglottic suction device was seen in 5/41 (12%) patients. There were no in-hospital complications.

CONCLUSIONS

Airway injury was common in critically ill patients following endotracheal intubation, and tracheal injury commonly occurred at the site of the endotracheal cuff. Injury occurred at the site of the subglottic suction port in some patients although the clinical consequences of these injuries remain unclear.

Methods Used for Endotracheal Tube Cuff Inflation and Pressure Verification in Veterinary Medicine: A Questionnaire on Current Practice

Endotracheal intubation is a routine procedure in veterinary anaesthesia, yet no consensus guidelines exist for endotracheal tube (ETT) cuff inflation and pressure measurement. The aim of this study was to assess current practice of ETT cuff inflation and seal verification in veterinary medicine. An online questionnaire was distributed among veterinary professionals who administer anaesthesia, comprising six demographic and twelve ETT cuff-related questions per species. N = 348 questionnaires were completed. Cuff pressure was measured by 30% of respondents in cats, 32% in dogs and 9% in both farm animals and horses. Anaesthesia diplomates were not more likely to measure cuff pressure than others, except in cats (OR: 1.8; 95% CI: 1.1−2.9). The most frequently selected recommended range of cuff pressure was 20−30 cm H2O, regardless of species, although >30 cm H2O was selected significantly more often in horses compared to dogs, cats and farm animals. The preferred technique to verify cuff seal was minimal occlusive volume in dogs, cats and farm animals, whereas in horses, the preferred method was verification of normal capnogram waveform. ETT cuff pressure measurement remains uncommon in veterinary anaesthesia. The development of consensus recommendations for cuff inflation, including evidence-based target cuff pressure ranges for various species and different ETT models or materials, can help to improve practice.

The impact of esophageal device insertion on cuff pressure of endotracheal tube: a literature review and meta-analysis

The impact of intraoperative esophageal device insertion (EDI) on endotracheal tube (ET) cuff inflation pressure remains unclear. Electronic databases including Medline, Embase, Google scholar, Web of Science™ and Cochrane Central Register of Controlled Trials were searched for studies involving EDI after placement of ETs from inception to July 7, 2022. The primary outcome was risk of high cuff pressure, while the secondary outcomes were increases in cuff pressure following EDI. Difference between adults and children was investigated with subgroup analysis. There were ten eligible studies (observation study, n = 9, randomized controlled study, n = 1) involving a total of 468 participants. EDI notably increased the risk of high cuff pressure (n = 7, risk ratio: 12.82, 95% confidence interval: 4.9 to 33.52, subgroup analysis: p = 0.008). There were significant elevations in cuff pressure in adults and children both during (13.42 and 7.88 cmH₂O, respectively, subgroup analysis: p = 0.15) and after (10.09 and 3.99 cmH₂O, respectively, subgroup analysis: p = 0.0003) EDI. Our results revealed an over 12-fold increase in the risk of high endotracheal tube cuff pressure in patients, especially adults, receiving EDI under endotracheal anesthesia. There were significant increases in both adults and children despite a higher increase in the former after device insertion.

Comparative evaluation of three methods of endotracheal tube cuff inflation for adequacy of seal

Background and Aims

Intubation with cuffed endotracheal tube (ETT) is common in operation rooms, critical care, and emergency rooms. The pressure exerted by the cuff on the tracheal mucosa can lead to a reduction in blood flow to the tracheal wall and result in mucosal ischemia. There are many methods for ETT cuff inflation. Aim of the study was to compare the cuff pressures and volumes between the three methods of ETT cuff inflation.

Material and Methods

One hundred and twenty patients were randomized into three groups: Group SG (stethescope guided), group AL (audible leak), and group P (palpation). In group SG, the cuff was inflated by auscultating with the bell of the stethoscope over the thyroid cartilage for leak around cuff. In group AL, the cuff was inflated by listening for an audible leak around the cuff with observer's ear 5 cm away from the mouth of the patient. In group P, the cuff was inflated by palpating for a leak over the cricoid and trachea. The adequacy of the cuff seal was compared between the groups by assessing the volumes of additional air needed to stop the leak around the cuff as confirmed by supraglottic capnometry.

Results

The initial volumes needed to inflate the cuff were significantly more in the stethoscope (SG) and hearing (AL) groups than in the palpation (P) group (SG = 5.1 ± 1.4 ml, AL = 4.6 ± 1.6 ml, P = 3.1 ± 0.9 ml; SG and AL vs. P, P < 0.001). Additional cuff volumes required to achieve zero leak around cuff by supraglottic capnometry were 0.85 ± 1 ml in group SG, 1.3 ± 1.1 ml in group AL, and 2.237 ± 0.8 ml in group P (SG vs. P and AL vs. P; P < 0.001).

Conclusion

Out of the auscultation-guided, audible leak-guided, and palpation-guided methods of ETT cuff inflation, the auscultation-guided and audible leak-guided methods achieve significantly better tracheal seal than the palpation-guided method.

Post-COVID-19 airway stenosis treated by tracheal resection and anastomosis: a bicentric experience

Objective

The COVID-19 pandemic was an extraordinary challenge for the global healthcare system not only for the number of patients affected by pulmonary disease, but also for the incidence of long-term sequalae. In this regard, laryngo-tracheal stenosis (LTS) represents one of the most common complications of invasive ventilation.

Methods

A case series of patients who underwent tracheal resection and anastomosis (TRA) for post-COVID-19 LTS was collected from June 2020 to September 2021.

Results

Among 14 patients included, 50% had diabetes and 64.3% were obese. During intensive care unit stay, mean duration of orotracheal intubation (OTI) was 15.2 days and 10 patients (71.4%) underwent tracheostomy, which was maintained in 7 for an average of 31 days. According to the European Laryngological Society classification, 13 patients (92.9%) had a grade IIIa LTS and one a grade IIIa+. All patients underwent Type A TRA, according to the authors’ classification. No major perioperative complications were reported and at the last follow-up all patients were asymptomatic.

Conclusions

With the appropriate indications, TRA represents an effective treatment in post-COVID-19 LTS patients. Short OTI times and careful tracheostomy are required in order to reduce the incidence of airway injury.

Endotracheal tube cuff pressure during laparoscopic bariatric surgery: highs and lows

Background: Gastric calibration tubes (GCTs) are a unique component of bariatric surgery. This study aimed to assess changes in the endotracheal tube (ETT) cuff pressure during laparoscopic bariatric surgery.Methods: This was a prospective observational study consisting of 124 American Society of Anesthesiologists class I–III morbidly obese patients (body mass index > 40 kg/m2) undergoing elective laparoscopic bariatric surgery under general anesthesia. The baseline ETT cuff pressure was 28 cmH2O. Cuff pressure, peak airway pressure, and hemodynamic changes were observed during various steps of bariatric surgery. Immediate postoperative complications during the first 24 h were recorded. Results: ETT cuff pressure increased significantly from the baseline (28 cmH2O) after insertion of GCT (36.3 ± 7.3 cmH2O) and creation of carboperitoneum (33.3 ± 3.8 cmH2O). Cuff pressure decreased significantly on GCT removal (24.0 ± 3.0 cmH2O) and release of carboperitoneum (24.7 ± 3.0 cmH2O). Peak airway pressure increased from the initial baseline value of 25.1 ± 3.1 to 26.5 ± 4.5 after GCT insertion, creation of carboperitoneum (32.6 ± 4.4), attainment of reverse Trendelenburg position (32.3 ± 4.0), and subsequent return to supine position 32.5 ± 4.8.Conclusions: The endotracheal cuff pressure significantly varies during the intraoperative period. Routine monitoring and readjustment of cuff pressure are advisable in all laparoscopic bariatric surgeries to minimize the possibility of postoperative complications.

Knowledge and practice of tracheal tube cuff pressure monitoring: a multicenter survey of anaesthesia and critical care providers in a developing country

BACKGROUND

Tracheal tubes are routinely used during anaesthesia and in the intensive care unit. Subjective monitoring of cuff pressures have been reported to produce consistently inappropriate cuffs pressures, with attendant morbidity. But this practice of unsafe care remains widespread. With the proliferation of intensive care units in Nigeria and increasing access to surgery, morbidity relating to improper tracheal cuff pressure may assume a greater toll. We aimed to evaluate current knowledge and practice of tracheal cuff pressure monitoring among anaesthesia and critical care providers in Nigeria.

METHODS

This was a multicenter cross-sectional study conducted from March 18 to April 30, 2021. The first part (A) was conducted at 4 tertiary referral hospitals in Nigeria by means of a self-administered questionnaire on the various cadre of anaesthesia and critical care providers. The second part (B) was a nation-wide telephone survey of anaesthesia faculty fellows affiliated to 13 tertiary hospitals in Nigeria, selected by stratified random sampling.

RESULTS

Only 3.1% (6/196) of the care providers admitted having ever used a tracheal cuff manometer, while 31.1% knew the recommended tracheal cuff pressure. The nationwide telephone survey of anaesthesia faculty fellows revealed that tracheal cuff manometer is neither available, nor has it ever been used in any of the 13 tertiary hospitals surveyed. The 'Pilot balloon palpation method' and 'fixed volume of air from a syringe' were the most commonly utilized method of cuff pressure estimation by the care providers, at 64.3% and 28.1% respectively in part A survey (84.6% and 15.4% respectively, in the part B survey).

CONCLUSION

The use of tracheal cuff manometer is very limited among the care providers surveyed in this study. Knowledge regarding tracheal cuff management among the providers is adjudged to be fair, despite the poor practice and unsafe care.

Under- or overpressure: an audit of endotracheal cuff pressure monitoring at the tertiary care center

Background

Mechanical ventilation is a lifesaving intervention for critically ill patients but can produce the major complication of ventilator-associated pneumonia (VAP). Inappropriately inflated endotracheal tubes cause potential harm due to high or low pressure; this can be prevented through monitoring protocols.

Methods

A cross-sectional study of 348 cuff pressure readings was performed with intubated and mechanically ventilated patients to evaluate the exact proportion of patients in intensive care units (ICUs) where the cuff pressure is optimal and to identify the ICUs where device-based monitoring is available to produce a lower proportion of sub-optimal cuff pressure cases. Every three days, cuff pressure was assessed with a handheld cuff pressure manometer. The corresponding VAP rates of those ICUs were obtained from the hospital infection control department.

Results

Cuff pressure of 40.2% was the lower cutoff for the high category, that of optimal was 35.3%, and the highest cutoff of sub-optimal was 24.4%. This study also showed ICUs that had cuff pressure monitoring devices and protocols. Active measurement protocols had a higher proportion of optimal cuff pressure (58.5%) and a lower proportion of sub-optimal and high cuff pressure (19.5% and 22.0%) compared to ICUs with no device-based monitoring protocols. Furthermore, the VAP rate of ICUs exhibited a weak positive correlation with sub-optimal cuff pressure.

Conclusions

Device-based cuff pressure monitoring is essential in maintaining adequate cuff pressure but often is inadequate, resulting in high readings. Therefore, this study suggests that device-based cuff pressure monitoring be practiced.

Impact of endotracheal tube size and cuff pressure on tracheal and laryngeal mucosa of adult horses

OBJECTIVE

To assess the effects of two sizes of silicone endotracheal tubes with internal diameter 26 mm (ETT₂₆) and 30 mm (ETT₃₀) inflated to minimum occlusive volume on tracheal and laryngeal mucosa of adult horses anesthetized for 2 hours with isoflurane.

STUDY DESIGN

Prospective, randomized, blinded, crossover experimental study.

ANIMALS

A total of eight healthy adult mares.

METHODS

Upper airway endoscopy and ultrasound measurements of internal tracheal diameter were performed the day before anesthesia. Horses were anesthetized and orotracheally intubated with ETT₂₆ or ETT₃₀. Ease of intubation was scored. The cuff was inflated in 10 mL increments to produce a seal. Final volume of air used and intracuff (IC) pressure (measured by pressure transducer) were recorded. At the end of anesthesia, a manometer was used to measure IC pressure and these measurements compared against measurements from the pressure transducer. Laryngeal and tracheal mucosa were assessed via endoscopy and assigned a score 0-3 before anesthesia, and at 2 and 24 hours following extubation.

RESULTS

Data are from seven horses because one horse with laryngeal hemiplegia was excluded. Mean tracheal ultrasound measurement was 3.5 ± 0.4 cm. No significant differences were noted between endotracheal tube sizes for intubation score, IC pressures, inflation volumes or tracheal or laryngeal injury scores at any time point. IC pressure measured by manometer was slightly higher than that by transducer (+1.0 ± 2.8 mmHg).

CONCLUSIONS AND CLINICAL RELEVANCE

Results identified no clear advantage of one endotracheal tube size over the other in the population of horses studied, when endotracheal intubation is properly applied and IC pressure is carefully monitored. However, given that ETT₂₆ was associated with the highest observed IC pressures and the only observed incidents of tracheal circumferential erythema, the larger ETT₃₀ may be the better choice in most cases where tracheal size is sufficient.

Acquired tracheoesophageal fistula in a pregnant patient with COVID-19 pneumonia on prolonged invasive ventilation

A previously healthy pregnant woman was diagnosed with COVID-19 pneumonia and was subsequently intubated. Throughout the course of her illness, the patient was treated for recurrent bouts of pneumonia. A high-resolution chest and neck CT scan confirmed the presence of a tracheoesophageal fistula (TEF), which may have been caused by the presence of the overinflated endotracheal cuff, prolonged steroid use, hypoxic injury and possible direct injury of the tracheal mucosa from COVID-19 itself. A temporising procedure, involving tracheostomy with an extended-length tracheal tube, was performed. Unfortunately, the patient succumbed to infection prior to definitive repair. This case highlights the importance of keeping a high index of suspicion for tracheal injury in patients who experience prolonged periods of intubation. It also underlies the high morbidity and mortality rate associated with TEF, although being a rare disease.

Endotracheal Tube Cuff Pressure - Comparison of the Two Filling Methods - Simulated Test

INTRODUCTION

Tracheal intubation is the optimal method for opening up airways. Performed correctly, it prevents stomach contents from entering the respiratory tract and allows asynchronous cardiopulmonary resuscitation (CPR) to be conducted during sudden cardiac arrest. An important element of correct intubation is proper inflation of the endotracheal tube cuff. Research has shown that when medical personnel use the palpation technique, the cuff is usually inflated incorrectly. This can result in numerous health complications for the patient.

METHODS

This research was conducted in 2020 on a group of paramedics participating in the 15th International Winter Championship of Medical Rescuers in Bielsko-Biala (Poland). The aim of the research was to assess two methods of inflating the endotracheal tube cuff. Method A involved inflating the cuff using a syringe and assessing the pressure in the control cuff using the palpation technique. Method B involved inflating the cuff using a manometer. During the inflation, both the cuff inflation pressure and the time required to complete the procedure were recorded. Analysis was also conducted on whether completion of certified Advanced Life Support (ALS) and Advanced Cardiovascular Life Support (ACLS) training had any influence on the effectiveness of the inflation procedure.

RESULTS

The research showed that paramedics using Method B significantly more often inflated the endotracheal tube cuff to the correct pressure than those using Method A. However, when Method B was used, the procedure took longer to conduct. The study also showed that completion of certified ALS or ACLS training did not have a significant influence on proper inflation of the cuff. Those who had completed certified training courses took significantly longer to inflate the endotracheal tube cuff when using Method A.

CONCLUSIONS

Inflation of the endotracheal tube cuff by use of a syringe, followed by the palpation technique for assessing the inflation of the cuff balloon, is ineffective. Paramedic teams should be equipped with manometers to be used for inflating the endotracheal tube cuff.

Changes in the Bronchial Cuff Pressure of Left-Sided Double-Lumen Endotracheal Tube by Lateral Positioning: A Prospective Observational Study

Proper bronchial cuff pressure (BCP) is important when using a double-lumen endotracheal tube (DLT), especially in thoracic surgery. As positional change during endotracheal tube placement could alter cuff pressure, we aim to evaluate the change in BCP of DLT from the supine to the lateral decubitus position during thoracic surgery. A total of 69 patients aged 18–70 years who underwent elective lung surgery were recruited. BCP was measured at a series of time points in the supine and lateral decubitus positions after confirming the DLT placement. The primary outcome was change in the initial established BCP (BCPi), which is the maximum pressure at which the BCP did not exceed 40 cmH₂O without air leak in the supine position, after lateral decubitus positioning. As the primary outcome, the BCPi increased from 25.4 ± 9.0 cmH₂O in the supine position to 29.1 ± 12.2 cmH₂O in the lateral decubitus position (p < 0.001). Out of the 69 participants, 43 and 26 patients underwent surgery in the left-lateral decubitus position (LLD group) and the right-lateral decubitus position (RLD group) respectively. In the LLD group, the BCPi increased significantly (p < 0.001) after lateral positioning and the beginning of surgery and the difference value, ∆BCPi, from supine to lateral position was significantly higher in the LLD group than in the RLD group (p = 0.034). Positional change from supine to lateral decubitus could increase the BCPi of DLT and the increase was significantly greater in LLD that in RLD.

Prehospital Intubations Are Associated with Elevated Endotracheal Tube Cuff Pressures: A Cross-Sectional Study Characterizing ETT Cuff Pressures at a Tertiary Care Emergency Department

INTRODUCTION

Emergency Medical Services (EMS) providers are trained to place endotracheal tubes (ETTs) in the prehospital setting when indicated. Endotracheal tube cuffs are traditionally inflated with 10cc of air to provide adequate seal against the tracheal lumen. There is literature suggesting that many ETTs are inflated well beyond the accepted safe pressures of 20-30cmH2O, leading to potential complications including ischemia, necrosis, scarring, and stenosis of the tracheal wall. Currently, EMS providers do not routinely check ETT cuff pressures. It was hypothesized that the average ETT cuff pressure of patients arriving at the study site who were intubated by EMS exceeds the safe pressure range of 20-30cmH2O.

OBJECTIVES

While ETT cuff inflation is necessary to close the respiratory system, thus preventing air leaks and aspiration, there is evidence to suggest that over-inflated ETT cuffs can cause long-term complications. The purpose of this study is to characterize the cuff pressures of ETTs placed by EMS providers.

METHODS

This project was a single center, prospective observational study. Endotracheal tube cuff pressures were measured and recorded for adult patients intubated by EMS providers prior to arrival at a large, urban, tertiary care center over a nine-month period. All data were collected by respiratory therapists utilizing a cuff pressure measurement device which had a detectable range of 0-100cmH2O and was designed as a syringe. Results including basic patient demographics, cuff pressure, tube size, and EMS service were recorded.

RESULTS

In total, 45 measurements from six EMS services were included with ETT sizes ranging from 6.5-8.0mm. Mean patient age was 52.2 years (67.7% male). Mean cuff pressure was 81.8cmH2O with a range of 15 to 100 and a median of 100. The mode was 100cmH2O; 40 out of 45 (88.9%) cuff pressures were above 30cmH2O. Linear regression showed no correlation between age and ETT cuff pressure or between ETT size and cuff pressure. Two-tailed T tests did not show a significant difference in the mean cuff pressure between female versus male patients.

CONCLUSION

An overwhelming majority of prehospital intubations are associated with elevated cuff pressures, and cuff pressure monitoring education is indicated to address this phenomenon.

Utility of Endotracheal Tube Cuff Pressure Monitoring in Mechanically Ventilated (MV) Children in Preventing Post-extubation Stridor (PES)

Objective

To study if protocolized monitoring of endotracheal tube (ETT) cuff pressure every 6 hours is better than adjusting endotracheal tube cuff inflation by the only bedside clinical assessment.

Materials and methods

This was a single-center prospective randomized controlled study done between July 1, 2017 and March 31, 2019. Children between 1 month and 18 years, intubated with cuffed ETT by our trained doctors were included. After obtaining consent, patients were randomized into two groups, standard group (SG) and cuff pressure monitoring group (MG). Sample size was calculated with 80 patients in each group with a power of 80%, significance level (alpha 0.05 and beta 0.2). In the SG, ETT cuff inflation was adjusted by clinical assessment (bedside minimal leak technique and monitoring the percentage of leak displayed on ventilator display) at 6 hours interval. In the MG, cuff pressures were monitored by the device every 6 hours to maintain between 20 and 25 mm Hg.

Results

Out of 543 mechanically ventilated children during the study period, 266 were eligible and randomized for study. During the study, 89 patients died and 17 were left against medical advice, leaving 80 patients in each group. Incidence of post-extubation stridor (PES), re-intubation rate, ventilator-associated pneumonia (VAP) rate, ventilator days, and length of pediatric intensive care unit (PICU) stay were analyzed and found no advantage of protocolized monitoring of cuff pressures in the reduction of any of the above variables.

Conclusion

Our findings if confirmed by large multicentric studies can bring an end to routine ETT cuff pressure measurements and emphasize more on clinical assessment. Clinical trial registry (CTRI/2019/05/019098).

Indian Journal of Critical Care Medicine (2021): 10.5005/jp-journals-10071-23737

How to cite this article

Shaikh F, Janaapureddy YR, Mohanty S, Reddy PK, Sachane K, Dekate PS, et al. Utility of Endotracheal Tube Cuff Pressure Monitoring in Mechanically Ventilated (MV) Children in Preventing Post-extubation Stridor (PES). Indian J Crit Care Med 2021;25(2):181–184.

Effect of Tracheal Suctioning on Cuff Pressure in Mechanically Ventilated Patients: a Quasi-Experimental Study

BACKGROUND

Endotracheal tube cuff pressure must be kept in an optimal range, but it might change during some nursing procedures. If the cuff pressure gets outside the normal range, it can cause mucosal damage, insufficient ventilation, and microaspiration. This study aimed to determine the effect of endotracheal suctioning on cuff pressure in patients during mechanical ventilation.

MATERIALS AND METHODS

This is a quasi-experimental study utilizing repeated measures with a within-subject design. Using a simple convenience sampling method, 61 patients were studied during intubation on mechanical ventilation. Baseline cuff pressure was adjusted to 25 cm H ₂ O. Then, at 15, 30, and 60 minutes' intervals, cuff pressures were measured once without suctioning and again after suctioning.

RESULTS

The results showed a significant change in the mean endotracheal tube cuff pressure during suctioning (p<0.001, d=7.47). During suctioning, cuff pressure exceeded the normal range in 64% of the patients. After suctioning, although endotracheal tube cuff pressure decreased in both conditions, it decreased more significantly (F (2.17, 260.55)=238.19, p<0.001, ν=0.665, d=1.37) in the suctioning condition.

CONCLUSION

The results suggest that endotracheal tube cuff pressure increases suddenly and briefly during suctioning, but within 60 minutes after suctioning, it becomes more reduced in suctioning conditions than without suctioning. Therefore, patients are at risk of mucosal damage and microaspiration after and during suctioning, respectively. It is suggested that nurses use continuous cuff pressure regulation methods to prevent potential risks.

Does the endotracheal tube cuff pressure increases with transesophageal probe insertion?

Context:

The cuff pressure (CP) of the endotracheal tube (ETT) exceeding 30 cm of H₂O results in reduced perfusion of lateral mucosa of trachea leading to complications. As the posterior tracheal wall is in contact with the esophagus, there is a possibility that the insertion of transesophageal echo (TEE) probe may compress the tracheal wall and increase CP.

Aims:

This study was aimed to assess the impact of TEE probe insertion on CP in adults undergoing cardiac surgery.

Settings and Design:

Prospective observational study of 65 patients at tertiary care level hospital.

Subjects and Methods:

After balanced general anesthesia, patients were intubated with high volume low-pressure ET.TEE probe was then inserted with gentle jaw thrust. CP was measured by standard invasive pressure monitoring device at four points: T1 at baseline before TEE probe insertion; T2 maximum CP noted at TEE probe insertion; T3 at 5 min post TEE probe insertion; and T4 at post-TEE exam.

Statistical Analysis Used:

CP was compared between pairs of time points (T1 vs. T2; T1 vs. T3; and T1 vs. T4) using Mann-Whitney U test. Factors predicting CP >30 cm of H₂O at T4 were assessed by backward stepwise regression.

Results:

CP (mean ± S.D.) at T1, T2, T3, and T4 was 22 ± 3, 38 ± 10, 30 ± 6, and 30 ± 7, respectively. CP increased significantly from T1 to T2 (P < 0.001), T1 to T3 (P < 0.001), and T1 to T4 (P < 0.001). There were 26 patients (40%) with CP >30 cm of H₂O at end of TEE exam (T4). On multivariate analysis baseline, CP (T1) >20 cm of H₂O was significantly associated with CP >30 cm of H₂O at end of TEE exam with Odd's Ratio (OR) of 8.5 (1.76–41.06, P = 0.008).

Conclusions:

To conclude, the CP increases significantly with TEE probe insertion in 40% of patients exceeding a safe limit of 30 cm of H₂O. The monitoring and optimization of CP is advisable.

What is the Adequate Cuff Volume for Tracheostomy Tube? A Pilot Cadaver Study

OBJECTIVE

To determine the patterns of tracheostomy cuff pressure changes with various air inflation amounts in different types of tracheostomy tubes to obtain basic data for appropriately managing long-term tracheostomy.

METHODS

We performed tracheostomy on a 46-year-old male cadaver. Three types of tracheostomy tubes (single-cuffed, double-cuffed, and adjustable flange), divided into 8 different subtypes based on internal tube diameters and cuff diameters, were inserted into the cadaver. Air was inflated into the cuff, and starting with 1 mL air, the cuff pressure was subsequently measured using a manometer.

RESULTS

For the 7.5 mm/14 mm tracheostomy tube, cuff inflation with 3 mL of air yielded a cuff pressure within the recommended range of 20-30 cmH2O. The 7.5 mm/24 mm tracheostomy tube showed adequate cuff pressure at 5 mL of air inflation. Similar values were observed for the 8.0 mm/16 mm and 8.0 mm/27 mm tubes. Double-cuffed tracheostomy cuff pressures (7.5 mm/20 mm and 8.0 mm/20 mm tubes) at 3 mL air inflation had cuff pressures of 18-20 cmH2O at both the proximal and distal sites. For the adjustable flange tracheostomy tube, cuff pressure at 6 mL of cuff air inflation was within the recommended range. Maximal cuff pressure was achieved at inflation with almost 14 mL of air, unlike other tube types.

CONCLUSION

Various types of tracheostomy tubes showed different cuff pressures after inflation. These values might aid in developing guidelines For patients who undergo tracheostomy and are discharged home without cuff pressure manometers, this standard might be helpful to develop guidelines.

Frequency and characterization of the use of cuffed tracheal tubes in neonatal and pediatric intensive care units in Brazil

Objective

To identify the neonatal, pediatric and mixed (neonatal and pediatric) intensive care units in Brazil that use cuffed tracheal tubes in clinical practice and to describe the characteristics related to the use of protocols and monitoring.

Methods

To identify the intensive care units in Brazil, the Ministry of Health’s National Registry of Health Facilities was accessed, and information was collected on 693 registered intensive care units. This was an analytical cross-sectional survey conducted through electronic questionnaires sent to 298 neonatal, pediatric and mixed intensive care units in Brazil.

Results

This study analyzed 146 questionnaires (49.3% from neonatal intensive care units, 35.6% from pediatric intensive care units and 15.1% from mixed pediatric intensive care units). Most of the participating units (78/146) used cuffed tracheal tubes, with a predominance of use in pediatric intensive care units (52/78). Most of the units that used cuffed tracheal tubes applied a cuff pressure monitoring protocol (45/78). The use of cuff monitoring protocols was observed in intensive care units with a physical therapy service exclusive to the unit (38/61) and in those with a physical therapist present 24 hours/day (25/45). The most frequent cause of extubation failure related to the use of cuffed tracheal tubes in pediatric intensive care units was upper airway obstruction.

Conclusion

In this survey, the use of cuffed tracheal tubes and the application of a cuff pressure monitoring protocol was predominant in pediatric intensive care units. The use of a monitoring protocol was more common in intensive care units that had a physical therapist who was exclusive to the unit and was present 24 hours/day.

Comparison of four inflation techniques on endotracheal tube cuff pressure using a feline airway simulator

OBJECTIVES

The aim of this study was to compare four inflation techniques on endotracheal tube cuff (ETC) pressure using a feline airway simulator.

METHODS

Ten participants used four different endotracheal cuff inflation techniques to inflate the cuff of a low-pressure, high-volume endotracheal tube within a feline airway simulator. The simulator replicated an average-sized feline trachea, intubated with a 4.5 mm endotracheal tube, connected to a circle breathing system and pressure-controlled ventilation with oxygen and medical air. Participants inflated the ETC: by pilot balloon palpation (P); by instilling the minimum occlusive volume (MOV) required for loss of airway leaks during mechanical ventilation; until a passive release of pressure with use of a loss-of-resistance syringe (LOR); and with use of a syringe with a digital pressure reader (D) specifically designed for endotracheal cuff inflation. Intracuff pressure was measured by a manometer obscured to participants. The ideal pressure was considered to be between 20 and 30 cmH2O. Data were analysed by Shapiro-Wilk, Kruskal-Wallis and χ2 tests, as appropriate.

RESULTS

Participants were eight veterinarians and two veterinary nurses with additional training in anaesthesia. Measured median intracuff pressures for P, MOV, LOR and D, respectively, were 25 cmH2O (range 4-74 cmH2O), 41 cmH2O (range 4-70 cmH2O), 31 cmH2O (range 18-64 cmH2O) and 22 cmH2O (range 20-30 cmH2O). D performed significantly better (P <0.001) than all other techniques, with no difference between the other techniques.

CONCLUSIONS AND RELEVANCE

Use of D for cuff inflation achieved optimal cuff pressures. There may be high operator-dependent variability in the cuff pressures achieved with the use of P, MOV or LOR inflation techniques. As such, a cuff manometer is recommended when using any of these techniques.

Long-term intubation and high rate of tracheostomy in COVID-19 patients might determine an unprecedented increase of airway stenoses: a call to action from the European Laryngological Society

INTRODUCTION

The novel Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2, may need intensive care unit (ICU) admission in up to 12% of all positive cases for massive interstitial pneumonia, with possible long-term endotracheal intubation for mechanical ventilation and subsequent tracheostomy. The most common airway-related complications of such ICU maneuvers are laryngotracheal granulomas, webs, stenosis, malacia and, less commonly, tracheal necrosis with tracheo-esophageal or tracheo-arterial fistulae.

MATERIALS AND METHODS

This paper gathers the opinions of experts of the Laryngotracheal Stenosis Committee of the European Laryngological Society, with the aim of alerting the medical community about the possible rise in number of COVID-19-related laryngotracheal stenosis (LTS), and the aspiration of paving the way to a more rationale concentration of these cases within referral specialist airway centers.

RESULTS

A range of prevention strategies, diagnostic work-up, and therapeutic approaches are reported and framed within the COVID-19 pandemic context.

CONCLUSIONS

One of the most important roles of otolaryngologists when encountering airway-related signs and symptoms in patients with previous ICU hospitalization for COVID-19 is to maintain a high level of suspicion for LTS development, and share it with colleagues and other health care professionals. Such a condition requires specific expertise and should be comprehensively managed in tertiary referral centers.

Measuring endotracheal tube intracuff pressure: no room for complacency

Tracheal intubation constitutes a routine part in the care of critically ill and anaesthetised patients. Prolonged use of endotracheal with inflated cuff is one of the major multifactorial causes of complications. Both under-inflation and over-inflation of cuff are associated with complications. Despite known problems, regular measurement of cuff pressure is not routine, and it is performed on an ad hoc basis.

Does endo-tracheal tube clamping prevent air leaks and maintain positive end-expiratory pressure during the switching of a ventilator in a patient in an intensive care unit? A bench study

Objectives

When patients with acute respiratory distress syndrome are moved out of an intensive care unit, the ventilator often requires changing. This procedure suppresses positive end expiratory pressure and promotes lung derecruitment. Clamping the endotracheal tube may prevent this from occurring. Whether or not such clamping maintains positive end-expiratory pressure has never been investigated. We designed a bench study to explore this further.

How the study was done

We used the Elysee 350 ventilator in ‘volume controlled’ mode with a positive end-expiratory pressure of 15 cmH2O, connected to an endotracheal tube with an 8 mm internal diameter inserted into a lung model with 40 ml/cmH2O compliance and 10 cmH2O/L/s resistance. We measured airway pressure and flow between the distal end of the endotracheal tube and the lung model. We tested a plastic, a metal, and an Extra Corporeal Membrane Oxygenation clamp, each with an oral/nasal, a nasal, and a reinforced endotracheal tube. We performed an end-expiratory hold then clamped the endotracheal tube and disconnected the ventilator. We measured the change in airway pressure and volume for 30 s following the disconnection of the ventilator.

Results

Airway pressure decreased thirty seconds after disconnection with all combinations of clamp and endotracheal tube. The largest fall in airway pressure (-17.486 cmH₂O/s at 5 s and -18.834 cmH₂O/s at 30 s) was observed with the plastic clamp combined with the reinforced endotracheal tube. The smallest decrease in airway pressure (0 cmH₂O/s at 5 s and -0.163 cmH₂O/s at 30 s) was observed using the Extra Corporeal Membrane Oxygenation clamp with the nasal endotracheal tube.

Conclusions

Only the Extra Corporeal Membrane Oxygenation clamp was efficient. Even with an Extra Corporeal Membrane Oxygenation clamp, it is important to limit the duration the ventilator is disconnected to a few seconds (ideally 5 s).

Subjective method for tracheal tube cuff inflation: performance of anesthesiology residents and staff anesthesiologists. Prospective observational study

Background and objectives

Poor monitoring of tracheal tube cuff pressure may result in patient complications. The objective method of using a manometer is recommended to keep safe cuff pressure values (20‒30 cm H₂O). However, as manometers are not readily available, anesthesiologists use subjective methods. We aimed to assess appropriateness of a subjective method for attaining cuff pressure and the expertise level of manometer handling among anesthesiology staff and residents in a university teaching hospital.

Methods

Prospective observational study, recruiting participants that performed tracheal intubation and the subjective method for tube cuff inflation. Patients with difficult airway, larynx and trachea anatomic abnormality and emergency procedures were not included. Up to 60 minutes after tracheal intubation, an investigator registered the cuff pressure using an aneroid manometer (AMBU®) connected to the tube pilot balloon.

Results

Forty-seven anesthesiologists were included in the study – 24 residents and 23 staff. Mean (SD) and medians (IQR) measured in cmH₂O were, respectively, 52.5 (27.1) and 50 (30‒70). We registered 83% of measurements outside the recommended pressure range, with no difference between specialists and residents. The level of expertise with the objective method was also similar in both groups. Pressure adjustments were performed in 76.6% of cases.

Conclusion

The subjective method for inflating the tracheal tube cuff resulted in a high rate of inadequate cuff pressures, with no difference in performance between anesthesiology specialists and residents.

[Subjective method for tracheal tube cuff inflation: performance of anesthesiology residents and staff anesthesiologists. Prospective observational study]

BACKGROUND AND OBJECTIVES

Poor monitoring of tracheal tube cuff pressure may result in patient complications. The objective method of using a manometer is recommended to keep safe cuff pressure values (20-30 cm H₂O). However, as manometers are not readily available, anesthesiologists use subjective methods. We aimed to assess appropriateness of a subjective method for attaining cuff pressure and the expertise level of manometer handling among anesthesiology staff and residents in a university teaching hospital.

METHODS

Prospective observational study, recruiting participants that performed tracheal intubation and the subjective method for tube cuff inflation. Patients with difficult airway, larynx and trachea anatomic abnormality and emergency procedures were not included. Up to 60 minutes after tracheal intubation, an investigator registered the cuff pressure using an aneroid manometer (AMBU®) connected to the tube pilot balloon.

RESULTS

Forty-seven anesthesiologists were included in the study - 24 residents and 23 staff. Mean (SD) and medians (IQR) measured in cm H₂O were, respectively, 52.5 (27.1) and 50 (30-70). We registered 83% of measurements outside the recommended pressure range, with no difference between specialists and residents. The level of expertise with the objective method was also similar in both groups. Pressure adjustments were performed in 76.6% of cases.

CONCLUSION

The subjective method for inflating the tracheal tube cuff resulted in a high rate of inadequate cuff pressures, with no difference in performance between anesthesiology specialists and residents.

Acquired Non-malignant Cervical Trachea-Esophageal Fistula: A Case Series

Acquired non-malignant trachea-esophageal fistula (TEF) of cervical oesophagus is rare. Surgical closure of fistula is the standard treatment of choice. Our experience in management of such cases is presented. Five cases of acquired cervical TEF of varying etiology were retrospectively analysed. Two patients had history of migrated endoluminal stent. All the patients were treated by trans-cervical repair with muscle interposition. Tracheal Stenosis in two patients was managed concurrently. Successful repair was achieved in four cases. One patient with chronic obstructive pulmonary disease and active leprosy has residual fistula. Of the two patients with tracheal stenosis correction one was decannulated 6 month later and second has stent in situ. Post-operative vocal cord palsy occurred in one patient. Transcervical repair with muscle interposition is treatment of choice in cases of acquired nonmalignant cervical tracheoesophageal fistulas. Endoluminal stents have high tendency to migrate and are not recommended.

Bi-national survey of intraoperative cuff pressure monitoring of endotracheal tubes and supraglottic airway devices in operating theatres

Correct intracuff pressure of endotracheal tubes and supraglottic airway devices is required to avoid complications such as sore throat, dysphagia and dysphonia, while maintaining an adequate airway seal. However, intracuff pressure monitoring of airway devices during general anaesthesia may not receive the attention it deserves. The aim of this survey was to investigate the current practice regarding intraoperative cuff pressure monitoring in hospitals across Australia and New Zealand. An online ten-question survey was disseminated by the Australian and New Zealand College of Anaesthetists Clinical Trials Network to a randomised selection of 1000 Australian and New Zealand College of Anaesthetists Fellows working in private and public hospitals of varying sizes. There were 305 respondents in total, but not all respondents answered all questions. In total, 67 of 304 respondents (22.0%) did not have access to a cuff pressure manometer at their main site of work, and of these, 30 (9.9%) expressed that they would like access to one in their daily practice. Of 288 respondents, 122 (40.0%) reported that they used cuff pressure monitoring as part of their routine practice, but 95 (33.0%) measured the cuff pressure at induction only. For supraglottic airway devices, only 44 of 250 respondents (17.6%) aimed for a cuff pressure of 40–60 cmH2O. Of 255 respondents, 101 (39.6%) aimed for a cuff pressure of 20–30 cmH2O for endotracheal tubes. These findings indicate that educational programmes are required to increase the availability and use of cuff pressure monitoring devices for both endotracheal tubes and supraglottic airway devices across Australia and New Zealand.

Evaluating the Knowledge of Endotracheal Cuff Pressure Monitoring Among Critical Care Providers by Palpation of Pilot Balloon and By Endotracheal Tube Cuff Manometer

Introduction Mishandled endotracheal cuff pressure may either make ventilation difficult or cause damage to the airway. Therefore, the aim of this audit was to assess the knowledge about endotracheal cuff pressure monitoring with a manometer and manual palpation of pilot balloon among critical care providers. Methods This audit includes 150 critical care providers having experience of handling endotracheal tube (ETT) cuff at critical care area of National Institute of Cardiovascular Diseases (NICVD), Karachi from April 2017 to June 2017. Knowledge about endotracheal cuff pressure monitoring with the manometer and deleterious effects of mishandled ETT cuff was assessed using a self-reported questionnaire. Enrolled healthcare providers were asked to palpate the patient and cuff pressure was recorded and categorized. Results Out of 150 participants, 66 (44.0%) were doctors. Only 46 (30.67%) participants had prior knowledge about ETT cuff manometer and 110 (73.33%) had never used a manometer. Similarly only 42 (28.0%) had knowledge of hazardous effects of mishandled ETT cuff. Kappa coefficient of 0.155 with p=0.015 showed significant yet low agreement between participant prediction and the actual amount of air in cuff balloon. Agreement level was comparatively higher for staff as compared to doctors with a Kappa coefficient of 0.210 (p=0.018) vs. 0.133 (p=0.099). Conclusion In this study of knowledge and practice of ETT tube cuff pressure monitoring, we observed low levels of knowledge (30.67%), poor adherence to standard practice (73.33%) and were able to demonstrate poor agreement (Kappa coefficient 0.155; p=0.015) between the palpation method and cuff manometer measurements for assessing cuff pressure.

Subglottic perioperative airway-tube inflation via randomized evaluation with variable syringe size (Spair-Tire) study

INTRODUCTION

Risks of endotracheal tube cuff (ETTC) over inflation must be balanced with the need to achieve a minimum pressure of 20 cm H₂ O. Methods have been developed to estimate adequate ETTC pressurization but do not provide accurate endotracheal tube cuff pressure (ETCP) measurements. Hence, different sized syringes may play a role in determining ETCP.

OBJECTIVES

Determine optimal syringe size for recommended ETCP.

METHODS

Two hundred patients were randomized to use of either a 10-mL syringe (standard syringe) or a 5-mL syringe (study group) for ETTC inflation. Following the insertion of the endotracheal tube, the ETTC was inflated per the attending anesthesiologist. Within 10 minutes of intubation, ETCP was measured with a hospital-provided manometer.

RESULTS

The percentage of in range cuff pressures for the 5-mL group was 10.53% and 6.78% for the 10-mL group. 84.21% (n = 64) of the study group and 91.53% (n = 54) of the control group had cuff pressures exceeding 30 cmH₂ O. Although our study did not demonstrate that syringe size was predictive of ideal cuff pressure ranges, the average cuff pressure for the 5-mL group was 55.8 cm H₂ O versus 68.8 cm H₂ O in the 10-mL group.

CONCLUSION

Although both 5- and 10-mL syringes resulted in elevated cuff pressures after intubation, 5-mL syringes resulted in a lower degree of elevation. Use of a 5-mL syringe should be considered when inflating the endotracheal cuff to possibly reduce patient harm secondary to elevated cuff pressures. Further studies assessing smaller syringe sizes to reduce cuff pressures are warranted.

Effect of lateral positioning on the bronchial cuff pressure of a left-sided double-lumen endotracheal tube during thoracic surgery: study protocol for a prospective observational study

INTRODUCTION

Correct pressure is important when using a double-lumen endotracheal tube (DLT), especially in thoracic surgery. An inadequate bronchial cuff pressure (BCP) can cause air leak and interfere with visualisation of the surgical field, whereas an excessive pressure BCP can lead to cuff-related complications. Based on several reports that cuff pressure could alter after a positional change when using an endotracheal tube, we hypothesise that a change from the supine position to the lateral decubitus position, which is essential for thoracic surgery, would affect the BCP of the DLT.

METHODS AND ANALYSIS

This prospective, single-centre, observational study will enrol 74 patients aged 18-70 years undergoing elective lung surgery from September 2018 to April 2019. The primary outcome will be the change in the 'initially established BCP' (maximum BCP not exceeding 40 cm H₂O with no air leak in the supine position) after lateral decubitus positioning. BCP and air leak will be assessed in each patient position during inflation of the cuff with air in 0.5 mL increments from 0 to 3 mL. Secondary outcomes will include the incidence of BCP exceeding 40 cm H₂O after the initial established value and that of a change in the smallest bronchial cuff volume without air leak after a change to the lateral position. The relationship between the change in BCP and airway pressure, compliance and body mass index after lateral positioning will be investigated.

ETHICS AND DISSEMINATION

The study will be conducted in accordance with the Declaration of Helsinki and supervised by the Daegu Catholic University Medical Center institutional review board (study approval number CR-18-111). All patients will receive information about the study and will need to provide written informed consent before enrolment. The results will be presented at an international meeting and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT03656406; Pre-results.

Comparison of tracheal tube cuff pressure with two technique: fixed volume and minimal leak test techniques

Introduction: There is a correlation between endotracheal cuff pressure and airway complication; therefore, cuff pressure measurement is of an essential importance. The gold standard technique is measuring the cuff pressure by a calibrated manometer. However, there are several methods that injects air into balloon pilot and measures the cuff pressure. The aim of this study is to compare the tracheal cuff pressure measurement by two methods: fixed volume and minimal leak test (MLT). Methods: This descriptive study was performed at the emergency department on 110 patients. Patients were randomized into two groups. For one group, fixed volume technique and for the other group MLT was used. Results: Mean cuff pressure was 46.07±23.54 cmH2O in the fixed volume group and 33.72±9.14 cmH2O in the MLT group (P=0.05) which is significantly higher in the fixed volume group (P=0.028). In addition, 56.4% and 78.2% of the subjects had normal cuff pressure in the fixed volume group and MLT group, respectively; indicating a significantly higher rate in MLT group (P=0.025). Conclusion: Both techniques cause above normal intracuff pressure; however, MLT produces more acceptable pressure than fixed volume. It seems that the volume of 10 cc produces high pressures; therefore, fixed values may yield more appropriate results in lower volumes.

Aspects of in vivo endotracheal tube intracuff pressure in cats

OBJECTIVES

To determine the endotracheal tube cuff pressure produced with two inflation techniques, in two brands of endotracheal tube in cats. To determine the inspiratory pressure which produces an audible leak when the intracuff pressure is 30 cmH₂O.

STUDY DESIGN

Prospective, clinical, randomized study.

ANIMALS

A total of 40 client-owned healthy adult cats.

METHODS

Following induction of anaesthesia, endotracheal intubation was performed with a Parker Flex-Tip PFLP (Parker; n = 20) or Flexicare VentiSeal (Flexicare; n = 20) endotracheal tube. For each cat, the endotracheal tube cuff was inflated using two methods, minimum occlusive volume (MOV) and pilot balloon palpation (PBP). Intracuff pressure was recorded. Cuff pressure was then set at 30 cmH₂O and the pressure within the breathing system when a manual breath first caused an audible leak was measured.

RESULTS

PBP pressure was lower for Parker (36 ± 13 cmH₂O) compared with Flexicare (45 ± 13 cmH₂O, p = 0.048). MOV pressure was not different between tube types (56 ± 28 versus 66 ± 25 cmH₂O for Parker and Flexicare, respectively, p = 0.247). MOV produced a higher pressure than PBP for Parker (56 ± 28 versus 36 ± 13 cmH₂O, p = 0.001) and Flexicare (66 ± 25 versus 45 ± 13 cmH₂O, p = 0.007). When intracuff pressure was set at 30 cmH₂O, 95% of cats did not develop an audible leak until the inspiratory pressure was greater than 10 and 12 cmH₂O for Parker and Flexicare tubes, respectively.

CONCLUSIONS

PBP produced lower cuff pressures than MOV, although both techniques produced a cuff pressure above that at which mucosal blood flow is believed to be restricted. A cuff pressure of 30 cmH₂O may be sufficient to prevent audible leak in most cats if respiratory pressures are kept at 10-12 cmH₂O or below.

CLINICAL RELEVANCE

To ensure a safe endotracheal tube cuff pressure, use of a specifically designed pressure gauge is recommended.

Comparison of endotracheal tube cuff pressure changes using air versus nitrous oxide in anesthetic gases during laparoscopic abdominal surgeries

Background and objectives

The purpose of this study was to compare the endotracheal tube cuff pressure changes during laparoscopic surgeries using air versus nitrous-oxide in anesthetic gas mixture; and to observe the incidences of postoperative sore throat, hoarseness and dysphagia.

Methods

Total 100 patients scheduled for elective laparoscopic abdominal surgery were allocated into two groups. Group A (n = 50) received air while Group N (n = 50) received nitrous-oxide in anesthetic gas mixture. After endotracheal intubation, cuff was inflated with air to achieve sealing pressure. Cuff pressure at baseline (sealing pressure), 30 min, 60 min and 90 min was recorded with a manometer. Incidence of sore throat, hoarseness and dysphagia was noted at the time of discharge from post-anesthesia care unit and 24 h after extubation.

Results

Cuff pressure increased from baseline in both the groups. The increase in cuff pressure in Group N was greater than that in Group A at all time points studied (p < 0.001). Within Group A, cuff pressure increased more at 90 min than at 30 min (p < 0.05). Within Group N, increase in cuff pressure was more at each time point (30, 60 and 90 min) than its previous time point (p < 0.05). The incidence of sore throat in post-anesthesia care unit was higher in Group N than in Group A.

Conclusion

Use of nitrous-oxide during laparoscopy increases cuff pressure resulting in increased incidence of postoperative sore throat. Cuff pressure should be monitored routinely during laparoscopy with nitrous-oxide anesthesia.

[Comparison of endotracheal tube cuff pressure changes using air versus nitrous oxide in anesthetic gases during laparoscopic abdominal surgeries]

BACKGROUND AND OBJECTIVES

The purpose of this study was to compare the endotracheal tube cuff pressure changes during laparoscopic surgeries using air versus nitrous-oxide in anesthetic gas mixture; and to observe the incidences of postoperative sore throat, hoarseness and dysphagia.

METHODS

Total 100 patients scheduled for elective laparoscopic abdominal surgery were allocated into two groups. Group A (n=50) received air while Group N (n=50) received nitrous-oxide in anesthetic gas mixture. After endotracheal intubation, cuff was inflated with air to achieve sealing pressure. Cuff pressure at baseline (sealing pressure), 30min, 60min and 90min was recorded with a manometer. Incidence of sore throat, hoarseness and dysphagia was noted at the time of discharge from post-anesthesia care unit and 24h after extubation.

RESULTS

Cuff pressure increased from baseline in both the groups. The increase in cuff pressure in Group N was greater than that in Group A at all time points studied (p<0.001). Within Group A, cuff pressure increased more at 90min than at 30min (p<0.05). Within Group N, increase in cuff pressure was more at each time point (30, 60 and 90min) than its previous time point (p<0.05). The incidence of sore throat in post-anesthesia care unit was higher in Group N than in Group A.

CONCLUSION

Use of nitrous-oxide during laparoscopy increases cuff pressure resulting in increased incidence of postoperative sore throat. Cuff pressure should be monitored routinely during laparoscopy with nitrous-oxide anesthesia.

Comparison of the Force Required for Dislodgement Between Secured and Unsecured Airways

INTRODUCTION

Airway device placement and maintenance are of utmost importance when managing critically ill patients. The best method to secure airway devices is currently unknown.

STUDY OBJECTIVE

We sought to determine the force required to dislodge 4 types of airways with and without airway securing devices.

METHODS

We performed a prospective study using 4 commonly used airway devices (endotracheal tube [ETT], laryngeal mask airway [LMA], King laryngeal tube [King], and iGel) performed on 5 different mannequin models. All devices were removed twice per mannequin in random order, once unsecured and once secured as per manufacturers' recommendations; Thomas Tube Holder (Laerdal, Stavanger, Norway) for ETT, LMA, and King; custom tube holder for iGel. A digital force measuring device was attached to the exposed end of the airway device and gradually pulled vertically and perpendicular to the mannequin until the tube had been dislodged, defined as at least 4 cm of movement. Dislodgement force was reported as the maximum force recorded during dislodgement. We compared the relative difference in the secured and unsecured force for each device and between devices using a random-effects regression model accounting for variability in the manikins.

RESULTS

The median dislodgment forces (interquartile range [IQR]) in pounds for each secured device were: ETT 13.3 (11.6, 14.1), LMA 16.6 (13.9, 18.3), King 21.7 (16.9, 25.1), and iGel 8 (6.8, 8.3). The median dislodgement forces for each unsecured device were: ETT 4.5 (4.3, 5), LMA 8.4 (6.8, 10.7), King 10.6 (8.2, 11.5), and iGel 3.9 (3.2, 4.2). The relative difference in dislodgement forces (95% confidence intervals) were higher for each device when secured: ETT 8.6 (6.2 to 11), LMA 8.8 (4.6 to 13), King 12.1 (7.2 to 16.6), iGel 4 (1.1 to 6.9). When compared to secured ETT, the King required greater dislodgement force (relative difference 8.6 [4.5-12.7]). The secured iGel required less force than the secured ETT (relative difference -4.8 [-8.9 to -0.8]).

CONCLUSION

Compared with a secured device, an unsecured airway device requires only half the force to cause airway dislodgement. The secured King had the highest dislodgement force relative to the other studied devices.

Achieving the Recommended Endotracheal Tube Cuff Pressure: A Randomized Control Study Comparing Loss of Resistance Syringe to Pilot Balloon Palpation

BACKGROUND

Both under- and overinflation of endotracheal tube cuffs can result in significant harm to the patient. The optimal technique for establishing and maintaining safe cuff pressures (20-30 cmH2O) is the cuff pressure manometer, but this is not widely available, especially in resource-limited settings where its use is limited by cost of acquisition and maintenance. Therefore, anesthesia providers commonly rely on subjective methods to estimate safe endotracheal cuff pressure. This study set out to determine the efficacy of the loss of resistance syringe method at estimating endotracheal cuff pressures.

METHODS

This was a randomized clinical trial. We enrolled adult patients scheduled to undergo general anesthesia for elective surgery at Mulago Hospital, Uganda. Study participants were randomized to have their endotracheal cuff pressures estimated by either loss of resistance syringe or pilot balloon palpation. The pressures measured were recorded.

RESULTS

One hundred seventy-eight patients were analyzed. 66.3% (59/89) of patients in the loss of resistance group had cuff pressures in the recommended range compared with 22.5% (20/89) from the pilot balloon palpation method. This was statistically significant.

CONCLUSION

The loss of resistance syringe method was superior to pilot balloon palpation at administering pressures in the recommended range. This method provides a viable option to cuff inflation.

Case Series of Inflation Pressures of the Endotracheal Tube Cuffs among Intubated Patients at an Accident and Emergency Department in Hong Kong

Despite the frequent use of endotracheal tubes in daily practice of emergency medicine, not much emphasis has been put on the measurement of cuff pressure. We attempted to conduct a case series study of prospectively recruited patients to illustrate the risk of inappropriate cuff inflation without manometry. It was found that the pilot balloon palpation was an inaccurate method to estimate cuff under- or over-inflation, with large discrepancies when compared with an objective measure. Such discrepancies might be independent of doctors' and nurses' working experience in airway management. Use of an aneroid manometer remains an economical and cost-effective way to obtain an instantaneous yet reasonably reliable result and should become a routine in emergency departments.