Intracuff Pressure and Tracheal Morbidity: Influence of Filling Cuff with Saline during Nitrous Oxide Anesthesia

Background : Diffusion of nitrous oxide into the cuff of the endotracheal tube results in an increase in cuff pressure. Excessive endotracheal tube cuff pressure may impair tracheal mucosal perfusion and cause tracheal damage and sore throat. Filling the cuff of the endotracheal tube with saline instead of air prevents the increase in cuff pressure due to nitrous oxide diffusion. This method was used to test whether tracheal morbidity is related to excess in tracheal cuff pressure during balanced anesthesia.

Methods : Fifty patients with American Society of Anesthesiologists physical status I or II were randomly allocated to two groups with endotracheal tube cuffs initially inflated to 20-30 cm H2O with either air (group A) or saline (group S). Anesthesia was maintained with isoflurane and nitrous oxide. At the time of extubation, a fiberoptic examination of the trachea was performed by an independent observer, and abnormalities of tracheal mucosa at the level of the cuff contact area were scored. Patients assessed their symptoms (sore throat, dysphagia, and hoarseness) at the time of discharge from the postanesthesia care unit and 24 h after extubation on a 101-point numerical rating scale.

Results : Cuff pressure increased gradually during anesthesia in group A but remained stable in group S. The incidence of sore throat was greater in group A than in group S in the postanesthesia care unit (76 vs. 20%) and 24 h after extubation (42 vs. 12%;P < 0.05). Tracheal lesions at time of extubation were seen in all patients of group A and in eight patients (32%) of group S (P < 0.05).     

Lidocaine 10% in the endotracheal tube cuff: blood concentrations, haemodynamic and clinical effects

The purpose of this study was to evaluate the effects (common haemodynamic variables, peak cuff pressures, the incidence of reaction ('bucking') during extubation and the incidence of sore throat after operation) of lidocaine 10% instilled into the endotracheal tube cuff in intubated patients. Plasma concentrations of lidocaine were assayed. Seventy ASA class I-II patients scheduled for plastic surgery were studied. Patients were randomly divided in two groups: the cuff of the endotracheal tube was inflated with either lidocaine 10% (group L) or with saline (group S) immediately after endotracheal intubation. In group L patients, the haemodynamic changes were less (P < 0.05), and the peak cuff pressure was lower (P < 0.01) than for group S. At extubation, more patients reacted ('bucked') in group S (70.5% vs. 19.4%, P < 0.01). The incidence and severity of sore throat were significantly lower in group L 1 and 24-h after extubation. Plasma lidocaine concentrations did not reach toxic values. Lidocaine 10%, compared with saline, in the endotracheal tube cuff was associated with less disturbance of haemodynamic responses and less incidence of bucking during tracheal extubation. Lidocaine was also effective in reducing of incidence and severity of sore throat after operation.     

Nitrous oxide increases endotracheal cuff pressure and the incidence of tracheal lesions in anesthetized patients.

The pressure in air-filled endotracheal cuffs increases steadily throughout general anesthesia with nitrous oxide (N2O). High cuff pressures can be responsible for local ischemia, which may induce tracheal mucosal injury. In this study, cuff pressure was monitored in anesthetized patients, and postanesthesia endotracheal lesions were assessed by endoscopy. Sixty-five patients undergoing general anesthesia with tracheal intubation >1 h in duration were randomized into two groups. The endotracheal tube cuff was inflated to 30-40 cm H2O with air in Group 1 (n = 33) and with a gas mixture (N2O 50% in oxygen) in Group 2 (n = 32). At the time of tracheal extubation, a fiberoptic examination via the endotracheal tube was performed by an independent observer. Aspects of trachea at the level of cuff contact area were scored as 0 = normal, 1 = mucosal erythema or edema, 2 = mucosal erosion or hemorrhage, 3 = mucosal erosion or hemorrhage on both anterior and posterior tracheal walls. Cuff pressure increased throughout the procedure (P<0.01) in Group 1 and remained stable in Group 2. In Group 1, tracheal lesions in the area of the cuff were more frequent than they were in Group 2 (79% vs. 37%; P<0.001). Tracheal injury was correlated to cuff pressure (r = 0.62, P<0.001). No postoperative respiratory complication was observed in any patient. In patients anesthetized with N2O, the inflation of the tracheal tube cuff with a gas mixture of the same composition as the inhaled mixture can prevent excessive cuff pressure and reduce the incidence of tracheal injury. IMPLICATIONS: In patients anesthetized with nitrous oxide, the inflation of the tracheal tube cuff with a gas mixture of the same composition as the inhaled mixture can prevent excessive cuff pressure and reduce the incidence of tracheal injury.     

Sore throat after endotracheal intubation.

Nitrous oxide can diffuse into the cuff of an endotracheal tube during tracheal intubation, and the cuff pressure against the tracheal wall may cause mucosal damage. An endotracheal tube has been developed (Brandt Anesthesia Tube) that effectively limits nitrous oxide-related intracuff pressure increases. We determined whether the incidence of postoperative sore throat could be reduced by using this tube. Forty-eight female patients, 18-50 yr of age, were included in the study. Endotracheal intubation was performed with either a Brandt Anesthesia Tube or a Mallinckrodt endotracheal tube. All patients were interviewed postoperatively after 20-30 h by individuals who did not know which tube was used. In the Mallinckrodt group, 12 of 20 patients had a sore throat and 10 patients had intracuff pressures greater than 25 mm Hg. Only 3 of 20 patients in the Brandt group had a sore throat. We found that the incidence of sore throats after intubation could be significantly reduced by using the Brandt Anesthesia Tube (P less than 0.005).     

Does sealing endotracheal tube cuff pressure diminish the frequency of postoperative laryngotracheal complaints after nitrous oxide anesthesia?

STUDY OBJECTIVES: To study endotracheal tube (ETT) cuff pressures during nitrous oxide (N2O) anesthesia when the cuffs are inflated with air to achieve sealing pressure, and to evaluate the frequency of postoperative laryngotracheal complaints. DESIGN: Prospective, randomized, blind study. SETTING: Metropolitan teaching hospital. PATIENTS: 50 ASA physical status I and II patients scheduled for elective abdominal surgery. INTERVENTIONS: Patients received standard general anesthesia with 66% N2O in oxygen. In 25 patients, the ETT cuff was inflated with air to achieve a sealing pressure (Pseal group). In 25 patients, the ETT cuff was inflated with air to achieve a pressure of 25 cm H2O (P25 group). MEASUREMENTS AND MAIN RESULTS: ETT intracuff pressures were recorded before (control) and at 30, 60, 90, 120, and 150 minutes during N2O administration. We investigated the frequency and intensity of sore throat, hoarseness, and dysphagia in patients in the Post-Anesthesia Care Unit (PACU) and 24 hours following tracheal extubation. The cuff pressures in the Pseal group were significantly lower than in the P25 group at all time points studied (p < 0.001), with a significant increase with time in both groups (p < 0.001). The cuff pressures exceeded the critical pressure of 30 cm H2O only after 90 minutes in the Pseal group and already by 30 minutes in the P25 group. The frequency and intensity of sore throat, hoarseness, and dysphagia were similar in both groups in the PACU and 24 hours after tracheal extubation (p > 0.05). CONCLUSIONS: Minimum ETT sealing cuff pressure during N2O anesthesia did not prevent, but instead attenuated, the increase in cuff pressure and did not decrease postoperative laryngotracheal complaints.     

Changes in intracuff pressure of endotracheal tubes permeable or resistant to nitrous oxide and incidence of postoperative sore throat

BACKGROUND: We assessed the nitrous oxide (N2O) gas-barrier properties of a new endotracheal tube cuff, the Profile Soft-Seal Cuff (Resistant: R) (Sims Portex, Kent, UK). METHODS: The tracheas of randomly selected patients were intubated with the Profile Cuff (Permeable: P) (Sims Portex) tuble or with Portex Soft-Seal Cuff (R) (n=20 each) endotracheal tube. Cuffs were inflated with air, and intracuff pressure was measured during anesthesia using 67% N2O. Postoperative sore throat was assessed. In addition, the volume-pressure relationship of the cuff was determined in vitro. RESULTS: Cuff pressure increased gradually during anesthesia in both groups. The mean cuff pressure of the group R was significantly lower than that of the group P from 10 minutes to 230 minutes. The inflated gas and the deflated gas were not significantly different in both groups. The incidence of postoperative sore throat was not significantly different between the two groups. In vitro, the mean cuff pressure of the group R was significantly lower than that of the group P. CONCLUSIONS: The difference of cuff pressure is considered due to the difference in cuff compliance.     

Postoperative sore throat and hoarseness following tracheal intubation using air or saline to inflate the cuff--a randomized controlled trial

Sore throat and hoarseness following tracheal intubation is common. The aetiology may include high tracheal cuff pressures. We performed a double-blind, randomized controlled trial in 126 intubated patients to compare the incidence and severity of sore throat and hoarseness following inflation of the cuff using air or saline. Intra-cuff pressures were compared to assess any change due to inward diffusion of nitrous oxide. The incidence of significant sore throat and/or hoarseness overall was 15.0%. There was no statistically significant difference between the groups (air 15.9%, saline 14.5%). In the air group mean intra-cuff pressure increased significantly (start 14.0 mmHg, end 40.9 mmHg), while in the saline group there was no significant increase (start 12.7 mmHg, end 14.6 mmHg). The substitution of saline reliably results in sustained low intra-cuff pressures but high tracheal cuff pressure is not an important factor in the development of sore throat or hoarseness postoperatively within the pressure range and duration of operation studied.     

控制气管导管套囊压力对全麻手术患者气管插管相关性并发症的影响:前瞻性、多中心、随机、双盲研究

目的 探讨控制气管导管套囊压力对全麻手术患者气管插管相关性并发症的影响.方法 本研究为前瞻性、多中心、随机、双盲研究.择期拟行全麻手术患者509例,ASA分级Ⅰ或Ⅱ级,年龄11～89岁,体重35～92kg,性别不限,随机分为2组:对照组(C组)和套囊压力测定组(CPM组),记录手术时间和带管时间.各组随机选取20例带管时间120～180 min的患者,于拔除气管导管时行纤维支气管镜检查.拔除气管导管后24 h内随访咳嗽及痰中带血等气管插管相关性并发症的发生情况.结果 两组患者年龄、性别构成比、手术时间及带管时间差异无统计学意义(P＞0.05).与C组比较,CPM组患者咽喉痛及痰中带血的发生率降低(P＜0.05);随带管时间延长,C组咽喉痛及痰中带血的发生率均升高,CPM组仅咽喉痛的发生率升高(P＜0.01).纤维支气管镜检查可见气管粘膜不同程度损伤,C组较CPM组严重.结论 控制气管导管套囊压力有助于减少全麻手术患者术后气管插管相关性并发症的发生.     

Postoperative hoarseness and sore throat after tracheal intubation: effect of a low intracuff pressure of endotracheal tube and the usefulness of cuff pressure indicator]

Many clinical reports have described postoperative hoarseness and sore throat after general anesthesia. In most cases, these symptoms were attributed to high pressure of the endotracheal tube cuff. The recommended cuff pressure is less than 25 mmHg, as excessive pressure produces ischemia of the tracheal mucosa. However, within the safe pressure range, postoperative hoarseness and sore throat are still often observed. In this study, one hundred and ninety patients of ASA classes I or II were allocated randomly to two groups, low cuff pressure group (< 15 mmHg) or high cuff pressure group (15-25 mmHg), using continuous monitoring with a cuff pressure gauge. We investigated the incidence of postoperative hoarseness and sore throat at 24 hours after intubation and on the seventh postoperative day. The incidence of postoperative hoarseness and sore throat was significantly decreased in the low pressure group at 24 hours after intubation as compared with the high pressure group, but there was no significant difference between the two groups on the seventh postoperative day. These results suggest that keeping the cuff pressure under 15 mmHg can prevent postoperative hoarseness or sore throat at 24 hours after intubation, and that a cuff pressure gauge is thought to be one of the indispensable monitors during anesthesia.     

Profile soft-seal cuff, a new endotracheal tube, effectively inhibits an increase in the cuff pressure through high compliance rather than low diffusion of nitrous oxide

We assessed the nitrous oxide (N(2)O) gas-barrier properties of a new endotracheal tube cuff, the Profile Soft-Seal Cuff (PSSC) (Sims Portex, Kent, UK). The tracheas of randomly selected patients were intubated with the Trachelon (Terumo, Tokyo, Japan), Profile Cuff (PC) (Sims Portex), or PSSC (n = 15 for each) endotracheal tube. Cuffs were inflated with air, and intracuff pressure was measured during anesthesia with 67% N(2)O. The concentration of N(2)O in cuffs was measured at the end of anesthesia. Postoperative sore throat was assessed. The volume-pressure relationship and thickness of the cuff were also measured. Cuff pressure, which increased gradually during anesthesia, was significantly less in the PSSC and PC groups than in the Trachelon group. The PSSC had smaller pressure than the PC 120 min after the start of anesthesia (P < 0.05). There were no significant differences in the N(2)O concentration in cuffs among the groups, although the PSSC had the thinnest cuff with the highest compliance. The incidence of postoperative sore throat in the Trachelon group was significantly higher than in the other two groups. In summary, the PSSC effectively inhibits an increase in cuff pressure during anesthesia with N(2)O. The underlying mechanism is probably the higher compliance of the thinner cuff, rather than a reduction in N(2)O diffusion into the cuff.     

The effect of saline versus air for cuff inflation on the incidence of high intra-cuff pressure in paediatric MicroCuff® tracheal tubes: a randomised controlled trial

The use of cuffed tracheal tubes in paediatric anaesthesia is now common. The use of nitrous oxide in anaesthesia risks excessive tracheal tube cuff pressures, as nitrous oxide can diffuse into the cuff during the course of surgery. The aim of this single-centre, prospective, randomised controlled trial was to compare the effect of saline versus air for the inflation of tracheal tube cuffs on the incidence of excessive intra-operative cuff pressure in children undergoing balanced anaesthesia with nitrous oxide. Children (age ≤ 16 y) were randomly allocated to receive either saline (saline group) or air (air group) to inflate the cuff of their tracheal tube. The pressure in the tracheal tube cuff was measured during surgery and brought down to the initial inflation level if it breached a safe limit (25 cmH₂O). Post-extubation adverse respiratory events were noted. Data from 48 patients (24 in each group), aged 4 months to 16 y, were analysed. The requirement for reduction in intra-cuff pressure occurred in 1/24 patients in the saline group, compared with 16/24 patients in the air group (p < 0.001). The incidence of extubation-related adverse events was similar in the saline and air groups (15/24 vs. 13/24, respectively; p = 0.770). The use of saline to inflate the cuff of paediatric cuffed tubes reduces the incidence of high intra-cuff pressures during anaesthesia. This may provide a pragmatic extra safety barrier to help reduce the incidence of excessive tracheal cuff pressure when nitrous oxide is used during paediatric anaesthesia.     

Alkalinization of intracuff lidocaine improves endotracheal tube-induced emergence phenomena.

We sought to evaluate the effect of filling an endotracheal tube cuff with 40 mg lidocaine alone (Group L) or alkalinized lidocaine (Group LB) in comparison to an Air Control group (Group C) on adverse emergence phenomena in a randomized controlled study (n = 25 in each group). The incidence of sore throat was decreased for Group LB in comparison to Group L during the 24 postextubation hours. The difference between Group L and Group C remained significant in the two postextubation hours only. Plasma lidocaine levels increased when lidocaine was alkalinized (C(max) were 62.5 +/- 34.0 ng/mL and 3.2 +/- 1.0 ng/mL for Groups LB and L, respectively). Cough and restlessness before tracheal extubation were decreased in Group LB compared with Group L and in Group L compared with Group C. Nausea, postoperative vomiting, dysphonia, and hoarseness were increased after extubation in Group C compared with the liquid groups, and a better tolerance was recorded with Group LB compared with Group L. The increase of arterial blood pressure and cardiac frequencies during the extubation period was less in the liquid groups than in the control group and less in Group LB compared with Group L. We concluded that use of intracuff alkalinized lidocaine is an effective adjunct to endotracheal intubation. IMPLICATIONS: Use of 40 mg of alkalinized lidocaine, rather than lidocaine or air, to fill the endotracheal tube cuff reduces the incidence of sore throat in the postoperative period. This approach also decreases hemodynamic effects, restlessness, dysphonia, and hoarseness.     

快通道胃肠手术后咽部并发症处理方法的比较

目的探讨一种有效防治快通道胃肠道手术后咽部并发症的处理方法,以更好满足临床和患者的要求。 方法采用前瞻性、随机、双盲的研究方法,选择本院拟在全麻下行开腹胃肠道手术者280例,随机分为4组,各70例,A组（对照组）,气管导管用医用石蜡油润滑;B组,气管导管用丁卡因胶浆润滑;C组,气管导管用丁卡因胶浆润滑+插管后静注地塞米松10 mg;D组,C组基础上加静注帕瑞昔布钠40 mg。记录并比较各组麻醉拔管后10 min、30 min、1 h、6 h、12 h、24 h时的术后咽喉痛（POST）发生率及严重程度,观察在PACU期间1 h内的吸痰例数。 结果拔管后10 min观察点同期比较,B、C、D组POST发生率低于A组（P<0.05）;30 min观察点同期比较,B、C、D组POST发生率低于A组（P<0.05）,D组分别低于B、C组（P<0.05）;1 h观察点同期比较,B、C、D组POST发生率低于A组（P<0.05）,D组分别低于B、C组（P<0.05）;6 h观察点同期比较,D组POST发生率低于A组（P<0.05）;12 h、24 h观察点组间POST发生率差异无统计学意义。在PACU观察期间的吸痰人数,C、D组发生率低于A、B组（P<0.05）;A、B组之间,C、D组间发生率差异无统计学意义。 结论气管导管润滑复合静脉用药的多模式处理可有效防止POST,复合静注激素可有效减少拔管后气道分泌物。     

Postoperative sore throat: a systematic review

Postoperative sore throat has a reported incidence of up to 62% following general anaesthesia. In adults undergoing tracheal intubation, female sex, younger age, pre‐existing lung disease, prolonged duration of anaesthesia and the presence of a blood‐stained tracheal tube on extubation are associated with the greatest risk. Tracheal intubation without neuromuscular blockade, use of double‐lumen tubes, as well as high tracheal tube cuff pressures may also increase the risk of postoperative sore throat. The expertise of the anaesthetist performing tracheal intubation appears to have no influence on the incidence in adults, although it may in children. In adults, the i‐gel^™ supraglottic airway device results in a lower incidence of postoperative sore throat. Cuffed supraglottic airway devices should be inflated sufficiently to obtain an adequate seal and intracuff pressure should be monitored. Children with respiratory tract disease are at increased risk. The use of supraglottic airway devices, oral, rather than nasal, tracheal intubation and cuffed, rather than uncuffed, tracheal tubes have benefit in reducing the incidence of postoperative sore throat in children. Limiting both tracheal tube and supraglottic airway device cuff pressure may also reduce the incidence.     

Time required to achieve a stable cuff pressure by repeated aspiration of the cuff during anaesthesia with nitrous oxide

BACKGROUND AND OBJECTIVE: When the endotracheal tube cuff is repeatedly aspirated to avoid excessive cuff pressure during nitrous oxide anaesthesia, a stable cuff pressure is eventually achieved. We assessed the time required to achieve a stable cuff pressure after repeated cuff deflation. METHODS: During 67% nitrous oxide and oxygen anaesthesia, air-filled cuffs of a standard tracheal tube (Mallinckrodt Hi-Contour) were repeatedly deflated every 30 min for the first 3 or 4 h to inhibit excessive pressure (Groups Def-3 or Def-4, respectively, n = 10 for each); the cuff pressure was monitored for an additional 3 h. In some patients, the study was terminated at 1, 2, 3 and 4 h (n = 6 for each). RESULTS: Cuff pressure in Group Def-3, but not in Group Def-4, > 22 mmHg after stopping cuff aspiration. Intracuff nitrous oxide concentrations increased during repeated cuff deflation and increased further in Group Def-3 during an additional 3 h (from 39.8 +/- 4.7% to 44.3 +/- 3.8%; P < 0.05), whereas intracuff nitrous oxide concentrations at 4 h were not different from those in Group Def-4 at the end of the study (43.7 +/- 4.5% versus 42.3 +/- 4.8%; P = 0.579). CONCLUSIONS: When the air-filled cuff of the standard endotracheal tube is repeatedly deflated every 30 min for 4 h, but not for only 3 h, during nitrous oxide anaesthesia, a stable cuff pressure can be achieved without further deflation of the cuff. Our data also suggest that achieving an equilibrating nitrous oxide concentration in the cuff provides a subsequent stable cuff pressure.     

Rapid deflation of the bronchial cuff of the double-lumen tube after decreasing the concentration of inspired nitrous oxide

Deflationary phenomena of the endotracheal tube cuff may occur after inspired nitrous oxide (N(2)O) concentrations are reduced, but deflationary phenomena of the double-lumen tube (DLT) cuff have not been investigated. In this study, tracheal and bronchial cuffs of left-sided Mallinckrodt (Athlone, Ireland) DLTs were inflated with air, 40% N(2)O, or 67% N(2)O (Air, N40, or N67 groups, respectively) in 24 patients undergoing thoracic surgery; 40 min later, O(2) was substituted for N(2)O in some of the patients in the N40 group (N40-c group). Intracuff gas volumes, N(2)O concentrations, and cuff compliance were also measured. Both tracheal and bronchial cuff pressures significantly increased in the Air group but decreased in the N67 group. Neither pressure significantly changed in the N40 group, but both decreased in the N40-c group after terminating N(2)O anesthesia; the time required for bronchial cuff pressures to decrease by half (12.0 +/- 5.5 min) was less than that for tracheal cuff pressures (31.2 +/- 11.0 min, P < 0.01). The volume change in the N40-c group was not significantly different between the tracheal and bronchial cuffs, but tracheal cuff compliance was significantly higher than bronchial compliance. Therefore, filling DLT cuffs with 40% N(2)O stabilizes cuff pressure during anesthesia with 67% N(2)O, but bronchial cuffs deflate more quickly than tracheal cuffs after cessation of N(2)O administration through smaller compliance. IMPLICATIONS: We demonstrated that after cessation of nitrous oxide (N(2)O) administration, bronchial N(2)O-filled cuffs of the double-lumen tube deflate more rapidly than tracheal cuffs. To avoid insufficient separation of the lungs by the bronchial cuff, a frequent check of the cuff pressure is recommended after the inspired N(2)O concentration is decreased.     

Comparação de alterações na pressão do balonete do tubo endotraqueal usando ar versus óxido nitroso nos gases anestésicos durante cirurgias abdominais laparoscópicas

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.

The effects of lidocaine spray and intracuff alkalinized lidocaine on the occurrence of cough at extubation: a double-blind randomized controlled trial

Purpose

Our study aimed to evaluate the effects of lidocaine sprayed onto the larynx and/or injected into the tracheal tube cuff to decrease the incidence of cough at extubation and postoperative sore throat.

Methods

One hundred twenty women scheduled for gynecological surgery < 120 min in duration were enrolled in this randomized double-blind prospective study. Prior to tracheal intubation, 4% lidocaine or 0.9% saline was sprayed onto the patients’ supra- and subglottic areas. After tracheal intubation, the tracheal tube cuff was filled with either an alkalinized 2% lidocaine solution or 0.9% saline. This resulted in four groups: spray-cuff, spray-saline, saline-cuff, and saline-saline. A logistic regression comprising the two factors was used for analysis. The primary outcome was the incidence of cough at extubation. The secondary outcome was the incidence and severity of sore throat reported by patients at 15 min, 60 min, and 24 hr after tracheal extubation.

Results

Cough occurred in 42%, 24%, 63%, and 69% of patients in the spray-cuff, spray-saline, saline-cuff, and saline-saline groups, respectively. The use of lidocaine spray decreased the incidence of cough at extubation (odds ratio = 0.256; 95% confidence interval 0.118 to 0.554; P < 0.001); however, the use of intracuff alkalinized lidocaine had no impact on the occurrence of cough (P = 0.471). Severity of sore throat was clinically low (visual analog scale [VAS] ≤ 3) in all groups. No significant difference was observed in hoarseness, dysphagia, nausea, or vomiting.

Conclusion

Sprayed lidocaine decreases the incidence of cough at tracheal extubation in surgeries of less than two hours. The use of alkalinized lidocaine into high-volume/low-pressure endotracheal cuffs had no impact on decreasing the incidence of cough or pain.     

The effects of tracheal tube cuffs filled with air,saline or alkalinised lidocaine on haemodynamic changes and laryngotracheal morbidity in children: a randomised,controlled trial

We studied the effects of tracheal tube cuffs filled with air, saline or alkalinised lidocaine on haemodynamic changes during tracheal extubation and postoperative laryngotracheal morbidity in children. We randomly allocated 164 children aged 3–13 years undergoing general anaesthesia to one of four groups; tracheal tube cuffs filled with air (n = 41); saline (n = 41); alkalinised lidocaine 0.5% (n = 41); or alkalinised lidocaine 1% (n = 41). Intracuff pressure was monitored and maintained below 20 cmH₂O. The mean (SD ) increases in systolic blood pressure after tracheal extubation compared with before extubation were 10.9 (10.8) mmHg, 7.3 (17.7) mmHg, 4.1 (10.5) mmHg and 1.9 (9.5) mmHg in the air, saline, 0.5% and 1% alkalinised lidocaine groups, respectively (p = 0.021). The mean (SD ) increases in diastolic blood pressure after tracheal extubation compared with before extubation were 3.9 (9.7) mmHg, 7.9 (14.6) mmHg, 0.7 (10.4) mmHg and 3.6 (6.9) mmHg in the air, saline, 0.5% and 1% alkalinised lidocaine groups, respectively (p = 0.019). The mean (SD ) increases in heart rate after tracheal extubation compared with before extubation were 14.2 (7.6) beats.min^?1, 15.5 (13.1) beats.min^?1, 5.2 (9.6) beats.min^?1 and 4.1 (6.6) beats.min^?1 in the air, saline, 0.5% and 1% alkalinised lidocaine groups, respectively (p < 0.001). The incidence of sore throat 8 h after tracheal extubation was 22.0% in the air‐filled group, 9.8% in the saline group, 4.9% in the 0.5% alkalinised lidocaine group and 2.4% in the 1% alkalinised lidocaine group, p = 0.015. We conclude that filling the tracheal tube cuff with alkalinised lidocaine‐filled reduces the haemodynamic response to tracheal extubation and postoperative laryngotracheal morbidity in children.     

Pressure and volume changes of tracheal tube cuff following inflation with various inflating agents during nitrous oxide anesthesia

The study was designed to investigate the changes in pressure and volume of a tracheal tube-cuff inflated with air, mixture of N2O + O2, saline and 4% lidocaine during nitrous oxide anesthesia. This study was conducted in 80 patients (33 male & 47 female). The pressure and volume of a tracheal tube cuff increased with air, decreased with mixture of N2O + O2 and almost remained the same with saline and 4% lidocaine. The complications were more in the air group.