We recommend that ET cuff pressure be set and monitored with a manometer. We evaluated three different types of anesthesia provider in three different practice settings. 1996-2023, The Anesthesia Patient Safety Foundation, APSF Patient Safety Priorities Advisory Groups, Pulse Oximetry and the Legacy of Dr. Takuo Aoyagi, APSF Prevencin y Manejo de Fuegos Quirrgicos, APSF Prvention et gestion des incendies dans les blocs opratoires, Monitoring for Opioid-Induced Ventilatory Impairment (OIVI), Perioperative Visual Loss (POVL) Informed Consent, ASA/APSF Ellison C. Pierce, Jr., MD Memorial Lecturers, The APSF: Ten Patient Safety Issues Weve Learned from the COVID Pandemic, APSF Technology Education Initiative (TEI), Emergency Manuals Implementation Collaborative (EMIC), Perioperative Multi-Center Handoff Collaborative (MHC), APSF/FAER Mentored Research Training Grant, Investigator Initiated Research (IIR) Grants, Past APSF Consensus Conferences and Recommendations, Conflict in the Operating Room: Impact on Patient Safety Report from the ASA 2016 Annual Meetings APSF Workshop, Distractions in the Anesthesia Work Environment: Impact on Patient Safety. Nordin U, Lindholm CE, Wolgast M: Blood flow in the rabbit tracheal mucosa under normal conditions and under the influence of tracheal intubation. 9, no. B) Defective cuff with 10 ml air instilled into cuff. Lien TC, Wang JH: [Incidence of pulmonary aspiration with different kinds of artificial airways]. This study shows that the LOR syringe method is better at estimating cuff pressures in the optimal range when compared with the PBP method but still falls short in comparison to the cuff manometer. Free Respiratory Therapy Flashcards about RCP111 Spay/Neuter Patient Care: Inflating an Endotracheal Tube Cuff Endotracheal tube (ETT) insertion (intubation) PDF Improving Endotracheal Cuff Inflation Pressures - AANA Note: prolonged over-inflation of the cuff can cause pressure necrosis of the tracheal mucosa. Document Type and Number: United States Patent 11583168 . The patients were followed up and interviewed only once at 24 hours after intubation for presence of cough, sore throat, dysphagia, and/or dysphonia. For the secondary outcome, incidence of complaints was calculated for those with cuff pressures from 20 to 30cmH2O range and those from 31 to 40cmH2O. Methods With IRB approval, we studied 93 patients under general anesthesia with an ET tube in place in one teaching and two private hospitals. One study, for instance, found that cuff pressure exceeded 40 cm H2O in 40-to-90% of tested patients [22]. A systematic approach to evaluation of air leaks is recommended to ensure rapid evaluation and identification of underlying issues. El-Orbany M, Salem MR. Endotracheal tube cuff leaks: causes, consequences, and management. Similarly, inflation of endotracheal tube cuffs to 20 cm H2O for just four hours produces serious ciliary damage that persists for at least three days [16]. Advance the endotracheal tube through the vocal cords and into the trachea within 15 seconds. Charles Kojjo, Agnes Wabule, and Nodreen Ayupo were responsible for patient recruitment and data collection and analysis. None of the authors have conflicts of interest relating to the publication of this paper. However, increased awareness of over-inflation risks may have improved recent clinical practice. Endotracheal tubes | Anesthesia Airway Management (AAM) 10.1007/s001010050146. 1982, 154: 648-652. General anesthesia was induced by intravenous bolus of induction agents, and paralysis was achieved with succinylcholine or a non-depolarizing muscle relaxant. These included an intravenous induction agent, an opioid, and a muscle relaxant. Guidelines recommend a cuff pressure of 20 to 30 cm H2O. Bernhard WN, Yost L, Joynes D, Cothalis S, Turndorf H: Intracuff pressures in endotracheal and tracheostomy tubes. This however was not statistically significant ( value 0.052). PBP group (active comparator): in this group, the anesthesia care provider was asked to reduce or increase the pressure in the ETT cuff by inflating with air or deflating the pilot balloon using a 10ml syringe (BD Discardit II) while simultaneously palpating the pilot balloon until a point he or she felt was appropriate for the patient. This however was not statistically significant ( value 0.053) (Table 3). https://doi.org/10.1186/1471-2253-4-8, DOI: https://doi.org/10.1186/1471-2253-4-8. Because one purpose of our study was to measure pressure in the endotracheal tube cuff during routine practice, anesthesia providers were blinded to the nature of the study. The poster can be accessed by following the link: https://pdfs.semanticscholar.org/c12e/50b557dd519bbf80bd9fc60fb9fa2474ce27.pdf. 36, no. 87, no. Inflation of the cuff of . A critical function of the endotracheal tube cuff is to seal the airway, thus preventing aspiration of pharyngeal contents into the trachea and to ensure that there are no leaks past the cuff during positive pressure ventilation. muscle or joint pains. Water Cuff or Air Cuff? How To Tell The Difference - YouTube 21, no. 101, no. All authors read and approved the final manuscript. However, they have potential complications [13]. J. R. Bouvier, Measuring tracheal tube cuff pressurestool and technique, Heart and Lung, vol. Thus, appropriate inflation of endotracheal tube cuff is obviously important. Liu H, Chen JC, Holinger LD, Gonzalez-Crussi F: Histopathologic fundamentals of acquired laryngeal stenosis. 10, no. This cookie is installed by Google Analytics. The study groups were similar in relation to sex, age, and ETT size (Table 1). Endotracheal tube cuff pressure in three hospitals, and the volume required to produce an appropriate cuff pressure. Google Scholar. Our first goal was thus to determine if cuff pressure was within the recommended range of 2030 cmH2O, when inflated using the palpation method. These cookies do not store any personal information. While it is likely that these results are fairly representative, it is obvious that results would not be identical elsewhere because of regional practice differences. [21] found that the volume of air required to inflate the endotracheal tube cuff varies as a function of tube size and type. What are the . Dullenkopf A, Gerber A, Weiss M: Fluid leakage past tracheal tube cuffs: evaluation of the new Microcuff endotracheal tube. There was no correlation between the measured cuff pressure and the age, sex, height, or weight of the patients. Another study, using nonhuman tracheal models and a wider range (1530cmH2O) as the optimal, had all cuff pressures within the optimal range [21]. In contrast, newer ultra-thin cuff membranes made from polyurethane effectively prevent liquid flow around cuffs inflated only to 15 cm H2O [2]. In this cohort, aspiration had the second highest incidence of primary airway-related serious events [6]. There are a number of strategies that have been developed to decrease the risk of aspiration, but the most important of all is continuous control of cuff pressures. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. ETTs were placed in a tracheal model, and mechanical ventilation was performed. Interestingly, there was also no significant or important difference as a function of provider measured cuff pressures were virtually identical whether filled by CRNAs, residents, or attending anesthesiologists. Provided by the Springer Nature SharedIt content-sharing initiative. Every patient was wheeled into the operating theater and transferred to the operating table. At the hypobaric chamber at the RAAF base in Edinburgh several hundred air force pilots each year get to check out their reactions to depressurization and the effects of hypoxia. 1993, 104: 639-640. 6, pp. 139143, 2006. Previous studies have shown that the incidence of postextubation airway symptoms varies from 15% to 94% in various study populations [7, 9, 11, 27] and could be affected by the method of interview employed, such as the one used in our study (yes/no questions). PDF Tracheostomy Tube Reference Guide - UC Davis Chest. Product Benefits. Experienced emergency medicine physicians cannot safely inflate or estimate endotracheal tube cuff pressure using standard techniques. 965968, 1984. Manage cookies/Do not sell my data we use in the preference centre. Outcomes were compared by tube size, provider, and hospital with either an ANOVA (if the values were normally distributed) or the Kruskal-Wallis statistic (if the values were skewed). A limitation of this study is that cuff pressure was evaluated just once 60 minutes after induction of anesthesia. If the tracheal lumen is in the appropriate position (i.e., it has not been placed too deeply), bilateral breath sounds will. Cuffed Endotracheal Tubes Presentation | Operation Airway [21] observed that when the cuff was inflated randomly to 10, 20, or 30 cmH2O, participating physicians and ICU nurses were able to identify the group in 69% of the high-pressure cases, 58% of the normal pressure cases, and 73% of the low pressure cases. 795800, 2010. We also use third-party cookies that help us analyze and understand how you use this website. 1995, 44: 186-188. Endotracheal intubation: Purpose, Procedure & Risks - Healthline For example, Braz et al. A caveat, though, is that tube sizes were chosen by clinicians in our study and presumably matched patient size; results may well have differed if tube size had been randomly assigned. The allocation sequence was generated by an Internet-based application with the following input: nine sets of unsorted sequences, each containing twenty unique allocation numbers (120). 8, pp. The entire process required about a minute. All patients received either suxamethonium (2mg/kg, max 100mg to aid laryngoscopy) or cisatracurium (0.15mg/kg at for prolonged muscle relaxation) and were given optimal time before intubation. Endotracheal Tube Cuff - an overview | ScienceDirect Topics On the other hand, overinflation may cause catastrophic complications. Anesthetic officers provide over 80% of anesthetics in Uganda. High-volume low-pressure cuffed endotracheal tubes (ETT) are the standard of airway protection. 2, p. 5, 2003. This is used to present users with ads that are relevant to them according to the user profile. At the time of the intervention, the study investigator retrieved the next available envelope, which indicated the intervention group, from the next available block envelope and handed it to the research assistant. By using this website, you agree to our Managing endotracheal tube cuff pressure at altitude: a comparison of 154, no. 1990, 44: 149-156. Cuff Pressure Measurement Check the cuff pressure after re-inflating the cuff and if there are any concerns for a leak. Young, and K. K. Duk, Usefulness of new technique using a disposable syringe for endotracheal tube cuff inflation, Korean Journal of Anesthesiology, vol. W. N. Bernhard, L. Yost, D. Joynes, S. Cothalis, and H. Turndorf, Intracuff pressures in endotracheal and tracheostomy tubes. Cuff pressure adjustment: in both arms, very high and very low pressures were adjusted as per the recommendation by the ethics committee. Because cuff inflation practices are likely to differ among clinical environments, we evaluated cuff pressure in three different practice settings: an academic university hospital and two private hospitals. If using a neonatal or pediatric trach, draw 5 ml air into syringe. Animal data indicate that a cuff pressure of only 20 cm H2O may significantly reduce tracheal blood flow with normal blood pressure and critically reduces it during severe hypotension [15]. The study would be discontinued if 5% of study subjects in one study group experienced an adverse event associated with the study interventions as determined by the DSMB, or if a value of <0.001 was obtained on an interim analysis performed halfway through patient accrual. We recognize that people other than the anesthesia provider who actually conducted the case often inflated the cuffs. B) Defective cuff with 10 ml air instilled into cuff. However, this could be a site-specific outcome. Incidence of postextubation airway complaints in the study population. However, a major air leak persisted. The AAFP recommends inflating the cuff using air in 0.5-mL increments from a 3-mL syringe until no leak can be heard when the rebreathing bag is squeezed and the pressure in . Smooth Murphy Eye. Endotracheal intubation: MedlinePlus Medical Encyclopedia leaking cuff: continuous air insufflation through the inflation tubing has been describe to maintain an adequate pressure in the perforated cuff; . Cuff pressures less than 20cmH2O have been shown to predispose to aspiration which is still a major cause of morbidity, mortality, length of stay, and cost of hospital care as revealed by the NAP4 UK study. Informed consent was sought from all participants. N. Lomholt, A device for measuring the lateral wall cuff pressure of endotracheal tubes, Acta Anaesthesiologica Scandinavica, vol. The pressures measured were recorded. 3 1985, 87: 720-725. supported this recommendation [18]. H. M. Kim, J. K. No, Y. S. Cho, and H. J. Kim, Application of a loss of resistance syringe for obtaining the adequate cuff pressures of endotracheal intubated patients in an emergency department, Journal of the Korean Society of Emergency Medicine, vol. Analytics cookies help us understand how our visitors interact with the website. Low pressure high volume cuff. P. Biro, B. Seifert, and T. Pasch, Complaints of sore throat after tracheal intubation: a prospective evaluation, European Journal of Anaesthesiology, vol. Continuous data are presented as the mean with standard deviation and were compared between the groups using the t-test to detect any significant statistical differences. 1). Bunegin L, Albin MS, Smith RB: Canine tracheal blood flow after endotracheal tube cuff inflation during normotension and hypotension. 175183, 2010. (Cuffed) endotracheal tubes seal the lower airway of at the cuff location in the trachea. The patient was maintained on isoflurane (11.8%) mixed with 100% oxygen flowing at 2L/min. This website uses cookies to improve your experience while you navigate through the website. chest pain or heart failure. This type of aneroid manometer is nearly as accurate as a mercury manometer, but easier to use [23]. Google Scholar. Listen for the presence of an air leak around the cuff during a positive pressure breath. Used by Google DoubleClick and stores information about how the user uses the website and any other advertisement before visiting the website. On the other hand, Nordin et al. Endotracheal tube system and method - Viren, Thomas J. We included ASA class I to III adult patients scheduled to receive general anesthesia with endotracheal intubation for elective surgical operation. Our study set out to investigate the efficacy of the loss of resistance syringe in a surgical population under general anesthesia. In an experimental study, Fernandez et al. PDF ENDOTRACHEAL INTUBATION ADULT PERFORMANCE CRITERIA EMS Policy No. 2545 An intention-to-treat analysis method was used, and the main outcome of interest was the proportion of cuff pressures in the range 2030cmH2O in each group. Lomholt N: A device for measuring the lateral wall cuff pressure of endotracheal tubes. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. SP oversaw day-to-day study mechanics, collected data on many of the patients, and wrote an initial draft of manuscript. 32. 2013 Aug;117(2):428-34. doi: 10.1213/ANE.0b013e318292ee21. Morphometric and demographic characteristics of the patients were similar at each participating hospital (Table 1). The authors wish to thank Ms. Martha Nakiranda, Bachelors of Arts in Education, Makerere University, Uganda, for her assistance in editing this manuscript. The end of the cuff must not impinge the opening of the Murphy eye; it must not herniate over the tube tip under normal conditions; and the cuff must inflate symmetrically around the ETT.1 All cuffs are part of a cuff system consisting of the cuff itself plus . In addition, over 90% of anesthesia care at this hospital was provided by anesthetic officers and anesthesia residents during the study period. However, these are prohibitively expensive to acquire and maintain in many operating theaters, and as such, many anesthesia providers resort to subjective methods like pilot balloon palpation (PBP) which is ineffective [1, 2, 1620]. Inflate the cuff of the endotracheal tube with sufficient air to seal the area between the trachea and the tube. The cuff is inflated with air via a one-way valve attached to the cuff through a separate tube that runs the length of the endotracheal tube. The cookie is used to store and identify a users' unique session ID for the purpose of managing user session on the website. Also to note, most cuffs in the PBP group were inflated to a pressure that exceeded the recommended range in the PBP group, and 51% of the cuff pressures attained had to be adjusted compared with only 12% in the LOR group (Table 2). Note correct technique: While securing the ET tube with one hand, inflate the cuff with 5-10 cc's of air. 2001, 137: 179-182. ETT exchange could pose significant risk to patients especially in the case of the patient with a difficult airway. A) Dye instilled into the normal endotracheal tube travels all the way to the cuff. Pediatr Pathol Lab Med. Endotracheal intubation is a medical procedure in which a tube is placed into the windpipe (trachea) through the mouth or nose. The cookie is used to determine new sessions/visits. Printed pilot balloon. To achieve the optimal ETT cuff pressure of 2030cmH2O [3, 8, 1214], ETT cuffs should be inflated with a cuff manometer [15, 16]. A total of 178 patients were enrolled from August 2014 to February 2015 with an equal distribution between arms as shown in the CONSORT diagram in Figure 1. Related cuff physical characteristics, Chest, vol. Sanada Y, Kojima Y, Fonkalsrud EW: Injury of cilia induced by tracheal tube cuffs. Alternative, cheaper methods like the minimum leak test that require no special equipment have produced inconsistent results. If pressure remains > 30 cm H2O, Evaluate . M. L. Sole, X. Su, S. Talbert et al., Evaluation of an intervention to maintain endotracheal tube cuff pressure within therapeutic range, American Journal of Critical Care, vol. 5, pp. Anesth Analg. This cookies is set by Youtube and is used to track the views of embedded videos. 513518, 2009. [22] observed cuff pressure exceeding 40 cm H2O in 91% of PACU patients after anesthesia with nitrous oxide, 55% of ICU patients, and 45% of PACU patients after anesthesia without nitrous oxide. The pressure reading of the VBM was recorded by the research assistant. 1999, 117: 243-247. It would thus be helpful for clinicians to know how much air must be injected into the cuff to produce the minimum adequate pressure. Notes tube markers at front teeth, secures tube, and places oral airway. This was a randomized clinical trial. CAS M. H. Bennett, P. R. Isert, and R. G. Cumming, Postoperative sore throat and hoarseness following tracheal intubation using air or saline to inflate the cuffa randomized controlled trial, Anesthesia and Analgesia, vol. Airway 'protection' refers to preventing the lower airway, i.e. Endotracheal Tube Cuff Inflation Pressure Varieties and Response to Abstract: An endotracheal tube includes a main tubular portion including a distal end and a proximal end opposite the distal end, the main tubular portion including a central lumen at least in part defined by a wall of the main tubular portion; a . In this case, an air leak was audible from the patients oropharynx, which led the team to identify the problem quickly. The cookie is set by Google Analytics. Article 2, pp. The distribution of cuff pressures achieved by the different levels of providers. recommended selecting a cuff pressure of 25 cmH2O as a safe minimum cuff pressure to prevent aspiration and leaks past the cuff [17]; Bernhard et al. Currently, in critical care settings, patients are intubated with ETT comprising high-volume low-pressure cuffs. This cookie is set by Google Analytics and is used to distinguish users and sessions. Necessary cookies are absolutely essential for the website to function properly. 111115, 1996. Cuff pressure can be easily measured with a small aneroid manometer [23], but this device is not widely available in the United States. Compliance of the cuff system was evaluated by linear regression of measured cuff pressure vs. measured cuff volume. The difference in the incidence of sore throat and dysphonia was statistically significant, while that for cough and dysphagia was not. Using a laryngoscope, tracheal intubation was performed, ETT position confirmed, and secured with tape within 2min. statement and Tracheal tubes explained simply. - How Equipment Works Secures tube using commercially approved tube holder. If the silicone cuff is overinflated air will diffuse out. Volume + 2.7, r2 = 0.39. All patients with any of the following conditions were excluded: known or anticipated laryngeal tracheal abnormalities or airway trauma, preexisting airway symptoms, laparoscopic and maxillofacial surgery patients, and those expected to remain intubated beyond the operative room period. However, less serious complications like dysphagia, hoarseness, and sore throat are more prevalent [911]. Nor did measured cuff pressure differ as a function of endotracheal tube size. Cuff pressure is essential in endotracheal tube management. This cookies is installed by Google Universal Analytics to throttle the request rate to limit the colllection of data on high traffic sites. All patients who received nondepolarizing muscle relaxants were reversed with neostigmine 0.03mg/kg and atropine 0.01mg/kg at the end of surgery. Up to ten pilots at a time sit in the . The cuff was then briefly overinflated through the pilot balloon, and the loss of resistance syringe plunger was allowed to passively draw back until it ceased. Fernandez R, Blanch L, Mancebo J, Bonsoms N, Artigas A: Endotracheal tube cuff pressure assessment: pitfalls of finger estimation and need for objective measurement. In general, the cuff inflates properly for adults, but physicians often over-inflate the cuff during . We also appreciate the statistical analysis by Gilbert Haugh, M.S., and the editorial assistance of Nancy Alsip, Ph.D., (University of Louisville). Misting can be clearly seen to confirm intubation. The incidence of postextubation airway complaints after 24 hours was lower in patients with a cuff pressure adjusted to the 2030cmH2O range, 57.1% (56/98), compared with those whose cuff pressure was adjusted to the 3040cmH2O range, 71.3% (57/80). Correspondence to APSF President Robert K. Stoelting, MD: A Tribute to 19 Years of Steadfast Leadership, Immediate Past Presidents Report Highlights Accomplishments of 2016, Save the Date! However, the performance of the air filled tracheal tube cuff at altitude has not been studied in vivo. At the University of Louisville Hospital, at least 10 patients were evaluated with each endotracheal tube size (7, 7.5, 8, or 8.5 mm inner diameter [Intermediate Hi-Lo Tracheal Tube, Mallinckrodt, St. Louis, MO]); at Jewish Hospital, at least 10 patients each were evaluated with size 7, 7.5, and 8 mm Mallinckrodt Intermediate Hi-Lo Tracheal Tubes; and at Norton Hospital, 10 patients each were evaluated with size 7 and 8-mm Mallinckrodt Intermediate Hi-Lo Tracheal Tubes. Measured cuff volumes were also similar with each tube size. We tested the hypothesis that the tube cuff is inadequately inflated when manometers are not used. Your trachea begins just below your larynx, or voice box, and extends down behind the . 1993, 76: 1083-1090. Striebel HW, Pinkwart LU, Karavias T: [Tracheal rupture caused by overinflation of endotracheal tube cuff]. American Society of Anesthesiology, Committee of Origin: Committee on Quality Management and Departmental Administration (QMDA). 408413, 2000. Surg Gynecol Obstet. Standard cuff pressure is 25mmH20 measured with a manometer. Only 27% of pressures were within 2030 cmH2O; 27% exceeded 40 cmH2O. After deflating the cuff, we reinflated it in 0.5-ml increments until pressure was 20 cmH2O. 28, no. 1990, 18: 1423-1426. There was a linear relationship between measured cuff pressure (cmH2O) and volume (ml) of air removed from the cuff: Pressure = 7.5. non-fasted patients, Size: 8mm diameter for men, 7mm diameter for women, Laryngoscope (check size the blade should reach between the lips and larynx size 3 for most patients), turn on light, Monitoring: end-tidal CO2 monitor, pulse oximeter, cardiac monitor, blood pressure, Medications in awake patient: hypnotic, analgesia, short-acting muscle relaxant (to aid intubation), Pre-oxygenate patient with high concentration oxygen for 3-5mins, Neck flexed to 15, head extended on neck (i.e. PM, SW, and AV recruited patients and performed many of the measurements. It is however possible that these results have a clinical significance. Routine checks of the ETT integrity and functionality before insertion used to be the standard of care, but the practice is becoming less common, although it is still recommended in current ASA guidelines.1. Article The Human Studies Committee did not require consent from participating anesthesia providers. V. Foroughi and R. Sripada, Sensitivity of tactile examination of endotracheal tube intra-cuff pressure, Anesthesiology, vol. These cookies will be stored in your browser only with your consent. With IRB approval, we studied 93 patients under general anesthesia with an ET tube in place in one teaching and two private hospitals. 2003, 38: 59-61. At this point the anesthesiology team decided to proceed with exchanging the ETT, which was successful. Previous studies suggest that the cuff pressure is usually under-estimated by manual palpation. Aire cuffs are "mid-range" high volume, low pressure cuffs. Anesth Analg. laryngeal mask airway [LMA], i-Gel), How to insert a nasopharyngeal airway (NPA), Common hypertensive emergencyexam questions for medical finals, OSCEs and MRCP PACES, Guedel Airway Insertion Initial Assessment of a Trauma Patient, Haemoptysis case study with questions and answers, A fexible plastic tube with cuff on end which sits inside the trachea (fully secures airway the gold standard of airway management), Ventilation during anaesthetic for surgery (if muscle relaxant is required, long case, abdominal surgery, or head positing may be required), Patient cant protect their airway (e.g. 1977, 21: 81-94. Fred Bulamba, Andrew Kintu, Arthur Kwizera, and Arthur Kwizera were responsible for concept and design, interpretation of the data, and drafting of the manuscript. In case of a very low pressure reading (below 20cmH, https://pdfs.semanticscholar.org/c12e/50b557dd519bbf80bd9fc60fb9fa2474ce27.pdf. On the other hand, high cuff pressures beyond 50cmH2O were reduced to 40cmH2O. The data collected including the number visitors, the source where they have come from, and the pages visited in an anonymous form. 12, pp. However, there was considerable patient-to-patient variability in the required air volume. The loss of resistance syringe was then detached, the VBM manometer was attached, and the pressure reading was recorded. Remove the laryngoscope while holding the tube in place and remove the stylet from the tube. If the patient is able to talk, the cuff is not inflated adequately (air is vibrating the vocal cords). Part 1: anaesthesia, British Journal of Anaesthesia, vol. The mean volume of inflated air required to achieve an intracuff pressure of 25 cmH2O was 7.1 ml. 70, no. Endotracheal tube system and method . 21, no. 4, no. A) Normal endotracheal tube with 10 ml of air instilled into cuff. AW contributed to protocol development, patient recruitment, and manuscript preparation. This method is cheap and reproducible and is likely to estimate cuff pressures around the normal range. Figure 1. We recommend the use of the cuff manometer whenever available and the LOR method as a viable option.