Anesthetists were blinded to study purpose. 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. To detect a 15% difference between PBP and LOR groups, it was calculated that at least 172 patients would be required to be 80% certain that the limits of a 95%, two-sided interval included the difference. These cookies will be stored in your browser only with your consent. The exact volume of air will vary, but should be just enough to prevent air leaks around the tube. This is the routine practice in all three hospitals. . Note correct technique: While securing the ET tube with one hand, inflate the cuff with 5-10 cc's of air. PubMed B) Dye instilled into the defective endotracheal tube stops at the entrance of the pilot balloon tubing into the main tubing (arrow in Figure 2A and 2B). Cite this article. C) Pressure gauge attached to pilot balloon of normal cuff reading 30 mmHg with cuff inflated. L. Zuccherelli, Postoperative upper airway problems, Southern African Journal of Anaesthesia and Analgesia, vol. Acta Anaesthesiol Scand. California Privacy Statement, Br Med J (Clin Res Ed). 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 . Another study, using nonhuman tracheal models and a wider range (1530cmH2O) as the optimal, had all cuff pressures within the optimal range [21]. 21, no. We recommend the use of the cuff manometer whenever available and the LOR method as a viable option. 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 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. Martinez-Taboada F. The effect of user experience and inflation technique on endotracheal tube cuff pressure using a feline airway simulator. Independent anesthesia groups at the three participating hospitals provided anesthesia to the participating patients. The manual method used a pressure manometer to adjust pressure at cruising altitude and after landing. The loss of resistance syringe was then detached, the VBM manometer was attached, and the pressure reading was recorded. BMC Anesthesiology There were no statistically significant differences in measured cuff pressures among these three practitioner groups (P = 0.847). 443447, 2003. Curiel Garcia JA, Guerrero-Romero F, Rodriguez-Moran M: [Cuff pressure in endotracheal intubation: should it be routinely measured?]. 48, no. Only two of the four research assistants reviewed the patients postoperatively, and these were blinded to the intervention arm. 1: anesthesia resident; 2: anesthesia officer; 3: anesthesia officer student; 4: anesthesiologist. 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. Lien TC, Wang JH: [Incidence of pulmonary aspiration with different kinds of artificial airways]. February 2017 Zhonghua Yi Xue Za Zhi (Taipei). Your trachea begins just below your larynx, or voice box, and extends down behind the . Inflation of the cuff of . ismanagement of endotracheal (ET) tube cuff pressure (CP), defined as a CP that falls outside the recommended range of 20 to 30 cm H 2 O, is a frequent occur-rence during general anesthetics, with study findings ranging from 55% to 80%.1-4 Endotra-cheal tube cuffs are typically filled with air to a safe and adequate pressure of 20 to 30 cm H 2 It is thus essential to maintain cuff pressures in the range of 2030 cm of H2O. 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. A) Normal endotracheal tube with 10 ml of air instilled into cuff. To achieve the optimal ETT cuff pressure of 2030cmH2O [3, 8, 1214], ETT cuffs should be inflated with a cuff manometer [15, 16]. 154, no. Distractions in the Operating Room: An Anesthesia Professionals Liability? There was a linear relationship between measured cuff pressure (cmH2O) and volume (ml) of air removed from the cuff: Pressure = 7.5. 4, pp. Our primary outcomes were 1) measured endotracheal tube cuff pressures as a function of tube size, provider, and hospital; and 2) the volume of air required to produce a cuff pressure of 20 cmH2O as a function of tube size. Approved by the ASA House of Delegates on October 20, 2010, and last amended on October 28, 2015. Chest. 2003, 38: 59-61. Air leaks are a common yet critical problem that require quick diagnosis. Part of supported this recommendation [18]. The patients were followed up and interviewed only once at 24 hours after intubation for presence of cough, sore throat, dysphagia, and/or dysphonia. 775778, 1992. 2, p. 5, 2003. The difference in the number of intubations performed by the different level of providers is huge with anesthesia residents and anesthetic officers performing almost all intubation and initial cuff pressure estimations. In most emergency situations, it is placed through the mouth. 6, pp. Although the ETT pilot balloon was noted to be appropriately tense to the touch, a small amount of air was added to the cuff. Striebel HW, Pinkwart LU, Karavias T: [Tracheal rupture caused by overinflation of endotracheal tube cuff]. The data were exported to and analyzed using STATA software version 12 (StataCorp Inc., Texas, USA). The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2253/4/8/prepub. A syringe attached to the third limb of the stopcock was then used to completely deflate the cuff, and the volume of air removed was recorded. (Cuffed) endotracheal tubes seal the lower airway of at the cuff location in the trachea. 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). These data suggest that tube size is not an important determinant of appropriate cuff inflation volume. In contrast, newer ultra-thin cuff membranes made from polyurethane effectively prevent liquid flow around cuffs inflated only to 15 cm H2O [2]. D) Pressure gauge attached to pilot balloon of defective cuff with reading of 30 mmHg with cuff not appropriately inflated. Cookies policy. After induction of anesthesia, a 71-year-old female patient undergoing a parotidectomy was nasally intubated with a TaperGuard 6.5 Nasal RAE tube using a C-MAC KARL STORZ GmbH & Co. KG Mittelstrae 8, 78532 Tuttlingen, Germany, video-laryngoscope. Part 1: anaesthesia, British Journal of Anaesthesia, vol. With air providing the seal in the cuff the mean rise in cuff pressure was 23 cmH2O . 36, no. 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. 20, no. General anesthesia was induced by intravenous bolus of induction agents, and paralysis was achieved with succinylcholine or a non-depolarizing muscle relaxant. It has been demonstrated that, beyond 50cmH2O, there is total obstruction to blood flow to the tracheal tissues. 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. An anesthesia provider inserted the endotracheal tubes, and the intubator or the circulating registered nurse inflated the cuff. T. M. Cook, N. Woodall, and C. Frerk, Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. 1984, 288: 965-968. 2017;44 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! If air was heard on the right side only, what would you do? 1). The cookie is not used by ga.js. Luna CM, Legarreta G, Esteva H, Laffaire E, Jolly EC: Effect of tracheal dilatation and rupture on mechanical ventilation using a low-pressure cuff tube. Used by Google DoubleClick and stores information about how the user uses the website and any other advertisement before visiting the website. If the patient is able to talk, the cuff is not inflated adequately (air is vibrating the vocal cords). Measured cuff pressures averaged 35.3(21.6)cmH2O; only 27% of the patients had measured pressures within the recommended range of 2030 cmH2O. 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. This is used to present users with ads that are relevant to them according to the user profile. The Data Safety Management Board (DSMB) comprised an anesthesiologist, a statistician, and a member of the SOMREC IRB who would be informed of any adverse event. This single-blinded, parallel-group, randomized control study was performed at Mulago National Referral Hospital, Uganda. Only 27% of pressures were within 2030 cmH2O; 27% exceeded 40 cmH2O. Volume+2.7, r2 = 0.39 (Fig. 795800, 2010. American Society of Anesthesiology, Committee of Origin: Committee on Quality Management and Departmental Administration (QMDA). This is an open access article distributed under the, 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. We included ASA class I to III adult patients scheduled to receive general anesthesia with endotracheal intubation for elective surgical operation. However, increased awareness of over-inflation risks may have improved recent clinical practice. In the early years of training, all trainees provide anesthesia under direct supervision. 2003, 13: 271-289. Does that cuff on the trach tube get inflated with air or water? 10911095, 1999. Retrieved from. 7, no. Gac Med Mex. We conducted a single-blinded randomized control study to evaluate the LOR syringe method in accordance with the CONSORT guideline (CONSORT checklist provided as Supplementary Materials available here). Sanada Y, Kojima Y, Fonkalsrud EW: Injury of cilia induced by tracheal tube cuffs. However, they have potential complications [13]. This result suggests that clinicians are now making reasonable efforts to avoid grossly excessive cuff inflation. B) Defective cuff with 10 ml air instilled into cuff. It is used to either assist with breathing during surgery or support breathing in people with lung disease, heart failure, chest trauma, or an airway obstruction. ETT cuff pressures would be measured with a cuff manometer following estimation by either the PBP method or the LOR method. Springer Nature. The patient was then preoxygenated with 100% oxygen and general anesthesia induced with a combination of drugs selected by the anesthesia care provider. The data collected including the number visitors, the source where they have come from, and the pages visited in an anonymous form. 87, no. Study participants were randomized to have their endotracheal cuff pressures estimated by either loss of resistance syringe or pilot balloon palpation. 1993, 42: 232-237. CRNAs (n = 72), anesthesia residents (n = 15), and anesthesia faculty (n = 6) performed the intubations. In case of a very low pressure reading (below 20cmH2O), the ETT cuff pressure would be adjusted to 24cmH2O using the manometer. Incidence of postextubation airway complaints in the study population. Adequacy of cuff inflation is conventionally determined by palpation of the external balloon. Bunegin L, Albin MS, Smith RB: Canine tracheal blood flow after endotracheal tube cuff inflation during normotension and hypotension. 7 It has been shown that the best way to ensure adequate sealing and avoid underinflation (or overinflation) is to monitor the intracuff pressure periodically and maintain the intracuff pressure within Copyright 2013-2023 Oxford Medical Education Ltd. Myasthenia Gravis (MG) Neurological Examination, Questions about DVT (Deep Vein Thrombosis), Endotracheal tube (ETT) insertion (intubation), Supraglottic airway (e.g. P. Biro, B. Seifert, and T. Pasch, Complaints of sore throat after tracheal intubation: a prospective evaluation, European Journal of Anaesthesiology, vol. Previous studies suggest that this approach is unreliable [21, 22]. A systematic approach to evaluation of air leaks is recommended to ensure rapid evaluation and identification of underlying issues. This method is cheap and reproducible and is likely to estimate cuff pressures around the normal range. The cookie is used to determine new sessions/visits. 71, no. Related cuff physical characteristics. By using this website, you agree to our We evaluated three different types of anesthesia provider in three different practice settings. The PBP method, although commonly employed in operating rooms, has been repetitively shown to administer cuff pressures out of the optimal range (2030cmH2O) [2, 3, 25]. 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. A wide-bore intravenous cannula (16- or 18-G) was placed for administration of drugs and fluids. 2003, 29: 1849-1853. The pressures measured were recorded. This type of aneroid manometer is nearly as accurate as a mercury manometer, but easier to use [23]. P. Sengupta, D. I. Sessler, P. Maglinger et al., Endotracheal tube cuff pressure in three hospitals, and the volume required to produce an appropriate cuff pressure, BMC Anesthesiology, vol. CAS D) Pressure gauge attached to pilot balloon of defective cuff with reading of 30 mmHg with cuff not appropriately inflated. 2001, 137: 179-182. - in cmH2O NOT mmHg. But opting out of some of these cookies may have an effect on your browsing experience. "Aire" indicates cuff to be filled with air. 10.1055/s-2003-36557. Cuff pressure in tube sizes 7.0 to 8.5 mm was evaluated 60 min after induction of general anesthesia using a manometer connected to the cuff pilot balloon. Provided by the Springer Nature SharedIt content-sharing initiative. These cookies do not store any personal information. Cuff pressure should be measured with a manometer and, if necessary, corrected. Analytics cookies help us understand how our visitors interact with the website. Male patients were intubated with an 8 or 8.5 mm internal diameter endotracheal tube, and female patients were intubated with a 7 or 7.5 mm internal diameter endotracheal tube. 1990, 44: 149-156. 617631, 2011. Over-inflation of an endotracheal tube (ETT) cuff may lead to tracheal mucosal irritation, tracheal wall ischemia or necrosis, whereas under-inflation increases the risk of pulmonary aspiration as well as leaking anesthetic gas and polluting the environment. 2006;24(2):139143. 408413, 2000. With IRB approval, we studied 93 patients under general anesthesia with an ET tube in place in one teaching and two private hospitals. 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]. Thus, appropriate inflation of endotracheal tube cuff is obviously important. The author(s) declare that they have no competing interests. CAS However, there was considerable variability in the amount of air required. Conventional high-volume, low-pressure cuffs may not prevent micro-aspiration even at cuff pressures up to 60 cm H2O [2], although some studies suggest that only 25 cm H2O is sufficient [3]. The datasets analyzed during the current study are available from the corresponding author on reasonable request. The cookie is created when the JavaScript library executes and there are no existing __utma cookies. Patients who were intubated with sizes other than these were excluded from the study. However, post-intubation sore throat is a common side effect of general anesthetic and may partly result from ischemia of the oropharyngeal and tracheal mucosa [810], and the most common etiology of non-malignant tracheoesophageal fistula remains cuff-related tracheal injury [11, 12]. The difference in the incidence of sore throat and dysphonia was statistically significant, while that for cough and dysphagia was not. Inject 0.5 cc of air at a time until air cannot be felt or heard escaping from the nose or mouth (usually 5 to 8 cc). Underinflation increases the risk of air leakage and aspiration of gastric and oral pharyngeal secretions [4, 5]. 70, no. Measured cuff volume averaged 4.4 1.8 ml. We tested the hypothesis that the tube cuff is inadequately inflated when manometers are not used. This cookie is used to enable payment on the website without storing any payment information on a server. First, inflate the tracheal cuff and deflate the bronchial cuff. Informed consent was sought from all participants. Guidelines recommend a cuff pressure of 20 to 30 cm H2O. At this point the anesthesiology team decided to proceed with exchanging the ETT, which was successful. 139143, 2006. What is the device measurements acceptable range? The secondary objective of the study evaluated airway complaints in those who had cuff pressure in the optimal range (2030cmH2O) and those above the range (3140cmH2O). Surg Gynecol Obstet. Numbers 110 were labeled LOR, and numbers 1120 were labeled PBP. Bernhard WN, Yost L, Joynes D, Cothalis S, Turndorf H: Intracuff pressures in endotracheal and tracheostomy tubes. Volume + 2.7, r2 = 0.39. PubMedGoogle Scholar. Nor did measured cuff pressure differ as a function of endotracheal tube size. Our results are consistent in that measured cuff pressure exceeded 30 cmH2O in 50% of patients and were less than 20 cmH2O in 23% of patients. Categorical data are presented in tabular, graphical, and text forms and categorized into PBP and LOR groups. Vet Anaesth Analg. 56, no. 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. Fernandez R, Blanch L, Mancebo J, Bonsoms N, Artigas A: Endotracheal tube cuff pressure assessment: pitfalls of finger estimation and need for objective measurement. When this point was reached, the 10ml syringe was then detached from the pilot balloon, and a cuff manometer (VBM, Medicintechnik Germany. If more than 5 ml of air is necessary to inflate the cuff, this is an . LOR = loss of resistance syringe method; PBP = pilot balloon palpation method. 5, pp. 2, pp. In our study, 66.3% of ETT cuff pressures estimated by the LOR syringe method were in the optimal range. 106, no. If an air leak is present, add just enough air to seal the airway and measure cuff pressure again. - Manometer - 3- way stopcock. A limitation of this study is that cuff pressure was evaluated just once 60 minutes after induction of anesthesia. Air sampling is an insensitive means of detecting Legionella pneumophila, and is of limited practical value in environmental sampling for this pathogen. Background Cuff pressure in endotracheal (ET) tubes should be in the range of 20-30 cm H2O. H. Jin, G. Y. Tae, K. K. Won, J. There is consensus that keeping ETT cuff pressures low decreases the incidence of postextubation airway complaints [11]. However, this could be a site-specific outcome. Notes tube markers at front teeth, secures tube, and places oral airway. Misting can be clearly seen to confirm intubation. AW contributed to protocol development, patient recruitment, and manuscript preparation. 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 loss of resistance syringe method was superior to pilot balloon palpation at administering pressures in the recommended range. If the silicone cuff is overinflated air will diffuse out. This method has been achieved with a modified epidural pulsator syringe [13, 18], a 20ml disposable syringe, and more recently, a loss of resistance (LOR) syringe [21, 23, 24]. C) Pressure gauge attached to pilot balloon of normal cuff reading 30 mmHg with cuff inflated. 1990, 18: 1423-1426. if GCS <8, high aspiration risk or given muscle relaxation), Potential airway obstruction (airway burns, epiglottitis, neck haematoma), Inadequate ventilation/oxygenation (e.g. LoCicero J: Tracheo-carotid artery erosion following endotracheal intubation. We appreciate the assistance of Diane Delong, R.N., B.S.N., Ozan Aka, M.D., and Rainer Lenhardt, M.D., (University of Louisville). If the tracheal lumen is in the appropriate position (i.e., it has not been placed too deeply), bilateral breath sounds will. The air leak resolved with the new ETT in place and the cuff inflated. 30. In case of a very low pressure reading (below 20cmH, https://pdfs.semanticscholar.org/c12e/50b557dd519bbf80bd9fc60fb9fa2474ce27.pdf. . 6422, pp. This was a randomized clinical trial. Use low cuff pressures and choosing correct size tube. 513518, 2009. Terms and Conditions, 686690, 1981. Hahnel J, Treiber H, Konrad F, Eifert B, Hahn R, Maier B, Georgieff M: [A comparison of different endotracheal tubes. The mean volume of inflated air required to achieve an intracuff pressure of 25 cmH2O was 7.1 ml. studied the relationship between cuff pressure and capillary perfusion of the rabbit tracheal mucosa and recommended that cuff pressure be kept below 27 cm H2O (20 mmHg) [19]. 101, no. Measure 5 to 10 mL of air into syringe to inflate cuff. The distribution of cuff pressures (unadjusted) achieved by the different care providers is shown in Figure 2. The initial, unadjusted cuff pressures from either method were used for this outcome. Dullenkopf A, Gerber A, Weiss M: Fluid leakage past tracheal tube cuffs: evaluation of the new Microcuff endotracheal tube. A CONSORT flow diagram of study patients. 5, pp. volume4, Articlenumber:8 (2004) V. Foroughi and R. Sripada, Sensitivity of tactile examination of endotracheal tube intra-cuff pressure, Anesthesiology, vol. High-volume low-pressure cuffed endotracheal tubes (ETT) are the standard of airway protection. distance from the tip of the tube to the end of the cuff, which varies with tube size. This was statistically significant. 175183, 2010. One such approach entails beginning at the patient and following the circuit to the machine. 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. The cookie is set by Google Analytics. Anesthesia continued without further adjustment of ETT cuff pressure until the end of the case. 1993, 104: 639-640. Summary Aeromedical transport of mechanically ventilated critically ill patients is now a frequent occurrence. 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. Circulation 122,210 Volume 31, No. If pressure remains > 30 cm H2O, Evaluate . JD conceived of the study and participated in its design. However, the performance of the air filled tracheal tube cuff at altitude has not been studied in vivo. Comparison of normal and defective endotracheal tubes. adequately inflate cuff . Tracheal Tube Cuff. 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. S. Stewart, J. Students were under the supervision of a senior anesthetic officer or an anesthesiologist. Thus, 23% of the measured cuff pressures were less than 20 mmHg. Google Scholar. The rate of optimum endotracheal tube cuff pressure was 90.5% in the group guided by manometer and 31.8% in the conventional procedure group (p < 0.001 . 1992, 49: 348-353. Cuff pressures less than 20 cmH2O 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. It was nonetheless encouraging that we observed relatively few extremely high values, at least many fewer than reported in previous studies [22]. 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. Accuracy 2cmH. Remove the laryngoscope while holding the tube in place and remove the stylet from the tube. 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 . 1984, 24: 907-909. Necessary cookies are absolutely essential for the website to function properly. This study set out to determine the efficacy of the loss of resistance syringe method at estimating endotracheal cuff pressures. A) Dye instilled into the normal endotracheal tube travels all the way to the cuff. Our results thus fail to support the theory that increased training improves cuff management. Advance the endotracheal tube through the vocal cords and into the trachea within 15 seconds. In this cohort, aspiration had the second highest incidence of primary airway-related serious events [6]. This cookie is set by Youtube. Anasthesiol Intensivmed Notfallmed Schmerzther. Christina M. Brown, MD, Resident, Department of Anesthesiology, Washington University in St. Louis, MO. 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. Using a laryngoscope, tracheal intubation was performed, ETT position confirmed, and secured with tape within 2min. Inflate the cuff with 5-10 mL of air. . 6, pp. But interestingly, the volume required to inflate the cuff to a particular pressure was much smaller when the cuff was inflated inside an artificial trachea; furthermore, the difference among tube sizes was minimal under those conditions. Comparison of distance traveled by dye instilled into cuff. The cuff was considered empty when no more air could be removed on aspiration with a syringe. Secondly, this method is still provider-dependent as they decide when plunger drawback has ceased. Anesth Analg. The relationship between measured cuff pressure and volume of air in the cuff. To obtain an adequate seal, it is recommended to inflate the cuff initially to a no-audible leak point at applied airway pressures of 20 cm H 2 O. The patient was the only person blinded to the intervention group. In our case, had the endotracheal tube been checked prior to the start of the case, the defect could have been easily identified which would have obviated the need for tube exchange. A syringe is inserted into the valve and depressed until a suitable intracuff pressure is reached. S1S71, 1977. 1995, 44: 186-188. Nitrous oxide was disallowed. 6, pp. Supported by NIH Grant GM 61655 (Bethesda, MD), the Gheens Foundation (Louisville, KY), the Joseph Drown Foundation (Los Angeles, CA), and the Commonwealth of Kentucky Research Challenge Trust Fund (Louisville, KY). CAS A) Normal endotracheal tube with 10 ml of air instilled into cuff. All tubes had high-volume, low-pressure cuffs. How much air is injected into the cuff is not a major concern for almost all anaesthetists and they usually depend on palpating the external cuff tense to judge is it too much, accurate or not enough? trachea, bronchial tree and lung, from aspiration. 2, pp. 3 Chest. All data were double entered into EpiData version 3.1 software (The EpiData Association, Odense, Denmark), with range, consistency, and validation checks embedded to aid data cleaning. BMC Anesthesiol 4, 8 (2004). N. Lomholt, A device for measuring the lateral wall cuff pressure of endotracheal tubes, Acta Anaesthesiologica Scandinavica, vol. The amount of air necessary will vary depending on the diameter of the tracheostomy tube and the patient's trachea.