Alkalinization of Intracuff Lidocaine: Efficacy and Safety

Nasal Intubation is not Associated with "Smoother" Emergence from General Anesthesia for Carotid Endarterectomy: A Case-Cohort Study

BACKGROUND

Postoperative hematoma after carotid endarterectomy (CEA) is a devastating complication and may be more likely in patients with uncontrolled hypertension and coughing on emergence from anesthesia. We sought to determine if intubation with a nasal endotracheal tube (ETT)-instead of an oral ETT-is associated with "smoother" (i.e., less hemodynamic instability) emergence from general anesthesia for CEA.

METHODS

Patients receiving CEA between December 2015 and September 2021 at a single tertiary academic medical center were included. We examined the electronic anesthesia records for 323 patients who underwent CEA during the 6-year study period and recorded consecutive systolic blood pressure (SBP) values during the 10 minutes before extubation as a surrogate for "smoothness" of the emergence.

RESULTS

Intubation with a nasal ETT, when compared with intubation with an oral ETT, was not associated with any difference in maximum, minimum, average, median, or standard deviation of serial SBP values in the 10 minutes before extubation. The average SBP on emergence for patients with an oral ETT was 141 mm Hg and with a nasal ETT was 144 mm Hg (P = 0.562). The maximum SBP for patients with oral and nasal ETTs were 170 mm Hg and 174 mm Hg, respectively (P = 0.491). There were also no differences in the qualitative "smoothness" of emergence or in the percentage of patients who required an intravenous dose of 1 or more antihypertensive medications. The incidence of postoperative complications was similar between the 2 groups.

CONCLUSIONS

When SBP is used as a surrogate for smoothness of emergence from general anesthesia for CEA, intubation with a nasal ETT was not associated with better hemodynamic stability compared to intubation with an oral ETT.

Effect of chewing gum of different weights before surgery on sore throat after total thyroidectomy: A randomized controlled trial

BACKGROUND

Postoperative sore throat (POST) is a common postoperative complication.

COMPLICATION

Chewing gum can inhibit the growth of oral bacteria, cleanse, and lubricate the oral cavity, which can help reduce postoperative sore throat. We hypothesize that chewing gum before surgery could relieve POST.

METHODS

Patients planned to undergo total thyroidectomy under general anesthesia with tracheal intubation were randomized to swallow saliva twice or chew 1.4 g/2.8 g of gum for 2 minutes before surgery. A standard anesthesia protocol was performed. The numerical rating scale scores of POST at 1, 24, and 48 h after surgery were collected. The primary outcome was the incidence of moderate/severe POST (numerical rating scale score >3) within 48 h.

RESULTS

Data from 148 patients (control group, n = 50; 1.4 g group, n = 48; and 2.8 g group, n = 50) were included in the analysis. Within 48 h, there was a significant difference among the three groups in the incidence of moderate/severe POST (control group: 74% vs. 1.4 g group: 65% vs. 2.8 g group: 50%. P = 0.04). The 2.8 g group had less incidence of moderate/severe POST than the control group (Odds Ratio = 0.351 95% Confidence Interval: (0.152 and 0.814) P = 0.02).

CONCLUSION

Chewing 2.8 g gum before total thyroidectomy can reduce the incidence of moderate/severe POST within 48 h after surgery.

The Effect of Endotracheal Tube Cuff Shape on Post-extubation Sore Throat in Critically Ill Patients in a Rural Tertiary Care Hospital

BACKGROUND

Patients admitted to the critical care unit often require extended periods of mechanical ventilation. After extubation, patients often report discomfort in their throats, coughing, and hoarseness of voice. These symptoms have been linked to the shape of the cuff on the endotracheal tube and are described in terms of the surface area of the cuff in contact with the trachea.

METHODS

During this pilot study, 160 adults receiving intensive primary care were randomly assigned to one of two groups (Gathering A or Gathering B; 80 patients each). Intubated patients were separated into two groups: Group C consisted of those who wore a looser, barrel-shaped sleeve, and Group T consisted of those who wore a more restrictive sleeve. The severity of post-extubation side effects was assessed, including sore throat, dry voice, and hack, and the occurrence of these symptoms was also documented.

RESULT

Neither the number of intubation attempts nor the experience level of the residents who performed them differed significantly between the two groups (p > 0.05). A smaller percentage of patients in Gathering T experienced sore throats in the first, 12th, and 24th hours after extubation compared to patients in Group C at these same time points (p = 0.05). With time passing, fewer people in Group C and Group T experienced hoarseness of voice after extubation. There is a declining trend in the incidence of cough post-extubation in Group T, as compared to an initial increase in the trend for cough post-extubation with a gradual decline as time progressed in Group C.

CONCLUSION

There is an overall decrease in the incidence of post-extubation emergence phenomena with tapered shape cuffed endotracheal tubes when compared with conventional cylindrical type cuffed endotracheal tubes.

Compound lidocaine/prilocaine cream combined with tetracaine prevents cough caused by extubation after general anaesthesia: a randomised controlled trial

BACKGROUND

Coughing caused by tracheal extubation is common following general anaesthesia. Heavy aerosol production by coughing during recovery from general anaesthesia in patients with respiratory infections (especially COVID-19) may be one of the highest risk factors for infection in healthcare workers. The application of local anaesthetics to the endotracheal tube is an effective method to reduce coughing. The most commonly used anaesthetics are compound lidocaine/prilocaine cream and tetracaine spray. However, coughing still occurs when the two anaesthetics are used alone. We speculated that the application of compound lidocaine/prilocaine combined with tetracaine spray would better prevent coughing caused by tracheal extubation.

METHODS

Patients scheduled for laparoscopic cholecystectomy or cholecystectomy combined with common bile duct exploration under general anaesthesia were randomly assigned to Group C (saline spray), Group L (2 g compound lidocaine/prilocaine cream contains 5 mg of lidocaine and 5 mg prilocaine)), Group T (tetracaine) and Group F (compound lidocaine/prilocaine cream combined with tetracaine). The incidence of coughing, the endotracheal tube tolerance assessment, the incidence of agitation, the active extubation rate, the incidence of postoperative pharyngeal pain and the incidence of postoperative cough were recorded and analysed. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and the plasma concentrations of epinephrine and norepinephrine were measured immediately before extubation and 1 min after extubation.

RESULTS

A total of 211 patients were randomly assigned to Group C (53 cases), Group L (52 cases), Group T (52 cases) and Group F (54 cases). The primary result is assessment of the incidence of cough. The patients emerged from general anaesthesia, 96% of Group C had cough, which was significantly reduced in Group L (61.5%, P < 0.001), Group T (75%, P < 0.05) and Group F (22.2%, P < 0.001). Group F had a significantly reduced incidence of cough compared to Group L and Group T (P < 0.05 or P < 0.01, respectively). The secondary results were assessed. The endotracheal tube tolerance score in Group C ((1, 3) 4, P < 0.001) was higher than Group L ((0, 1) 2), Group T ((0, 1.25) 3) and Group F ((0, 0) 1). Group F had a significantly lower score than Group L and Group T (P < 0.05, P < 0.01, respectively). The incidence of agitation and the active extubation rate were also higher in Group C (96.2% and 71.7%, respectively, P < 0.001) than Group L (48.1% and 15.4%, respectively), Group T (61.5% and 26.9%, respectively) and Group F (17.3% and 7.7%, respectively). Blood pressure, HR and plasma concentrations of epinephrine and norepinephrine were significantly higher in Group C than in all other groups at the time of extubation and 1 min after extubation (P < 0.001). Group F exhibited significantly reduced blood pressure, heart rate and plasma concentrations of epinephrine and norepinephrine compared to Group L and Group T (P < 0.05, P < 0.01 or P < 0.001, respectively). The incidence of postoperative pharyngeal pain and the incidence of postoperative cough were not significantly different among the groups.

CONCLUSIONS

Compound lidocaine/prilocaine cream combined with tetracaine may be a more effective approach for preventing coughing and stabilising circulation during extubation following general anaesthesia. This may play an important role in preventing medical staff from contracting respiratory infectious diseases.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2200058429 (registration date: 09-04-2022) "retrospectively registered".

BIS-guided sedation prevents the cough reaction of patients under general anaesthesia caused by extubation: a randomized controlled trial

Background

The multiple modes of SARS-CoV-2 transmission including airborne, droplet, contact and faecal–oral transmissions that cause coronavirus disease 2019 (COVID-19) contribute to a public threat to the lives of people worldwide. Heavy aerosol production by coughing and the big peak expiratory flow in patients with respiratory infections (especially SARS-CoV-2) during recovery from general anaesthesia are the highest risk factors for infection in healthcare workers. To perform sedation before extubation significantly reduced the incidence of coughing during recovery from general anaesthesia. However, there are few studies on endotracheal tube removal under BIS-guided sedation in postanaesthesia care unit (PACU). We speculated that the BIS-guided sedation with dexmedetomidine and propofol would better prevent coughing caused by tracheal extubation and reducing peak expiratory flow.

Methods

Patients with general anaesthesia were randomly assigned to Group S (dexmedetomidine was infused in the operating room for 30 min, and the bispectral index (BIS) value was maintained 60–70 by infusion propofol at 0.5~1.5 μg/ml in the PACU until the endotracheal tubes were pulled out) and Group C (no dexmedetomidine and propofol treatment, replaced with the saline treatment). The incidence of coughing, agitation and active extubation, endotracheal tube tolerance and the peak expiratory flow at spontaneous breathing and at extubation were assessed.

Results

A total of 101 patients were randomly assigned to Group S (51 cases) and Group C (50 cases). The incidence of coughing, agitation and active extubation was significantly lower (1(51), 0(51) and 0(51), respectively) in Group S than (11(50), 8(50) and 5(50), respectively) in Group C (p < 0.05 or p < 0.01, respectively); the scores of cough were significantly reduced (1(1, 1)) in Group S than (1(1, 2)) in Group C (p < 0.01); and the endotracheal tube tolerance was significantly improved (0(0, 1)) in Group S than (1(1, 3)) in Group C (p < 0.001). The peak expiratory flow at spontaneous breathing and at extubation was significantly reduced (5(5, 7) and 6.5(6, 8), respectively) in Group S than (8(5, 10) and 21(9, 32)) in Group C (p < 0.001).

Conclusions

BIS-guided sedation with dexmedetomidine and propofol significantly prevented coughing and reduced peak expiratory flow during recovery from general anaesthesia, which may play an important role in preventing medical staff from contracting COVID-19.

Trial registration

Chinese Clinical Trial Registry: ChiCTR2200058429 (registration date: 09-04-2022) “retrospectively registered”.

Comparison of Normal Saline and Alkalinized 2% Lignocaine to Reduce Emergence Phenomenon and Post-Intubation Morbidities: A Prospective, Double-Blind, Randomized Study

BACKGROUND

 Endotracheal intubation for airway management in general anesthesia is associated with post-intubation morbidities due to tracheal mucosa injury caused by endotracheal tube (ETT) cuff. Nitrous oxide (N₂O) diffuses into tracheal tube cuffs filled with air. The rate of diffusion of N₂O through the membrane is proportional to its concentration gradient. High-volume low-pressure cuffs expand with only a slight increase in pressure until fully inflated. At this point, owing to the inelasticity of the material, the cuff pressure rises rapidly. This increased pressure can damage the tracheal mucosa. This phenomenon can be avoided, if we inflate the cuff with either a liquid or a gas mixture identical to the inspired gas and monitor the cuff pressure and volume at regular intervals. When lignocaine is used to inflate the ETT cuff, it diffuses to the underlying tracheal mucosa. Thus reducing local irritation and inflammation of the airway through its local anesthetic action. Alkalinization of lignocaine increases its rate of diffusion across the ETT cuff. It also reduces the dose of local anesthetic required to achieve the desired result.

AIMS AND OBJECTIVES

 We sought to determine the benefits of filling the ETT cuff with alkalinized lignocaine 2% over normal saline, to prevent ETT-induced emergence phenomenon and reduce the incidence of post-intubation morbidities like sore throat, hoarseness, and nausea.

MATERIAL AND METHODS

This prospective, randomized, double-blind, and comparative study was done at a multispecialty hospital. A total of 120 individuals of American Society of Anesthesiologists (ASA) physical status 1 and 2, posted for surgery under general anesthesia, were randomly selected and divided into two groups: alkalinized 2% lignocaine group (group L) and normal saline group (group S). After induction of general anesthesia, the airway was secured with appropriate-sized ETT. The ETT cuff was inflated with either of the study media. Continuous cuff pressure monitoring was done to keep cuff pressure below 30 centimeters of water (cm of H₂O), at all times. At extubation, the response was evaluated in terms of percentage change in heart rate (HR) and blood pressure from baseline, coughing, bucking, and restlessness. All the surgeries lasted more than two hours. Post-operatively, the patients were evaluated for sore throat and hoarseness, at regular intervals of up to 24 hours.

OBSERVATIONS AND RESULTS

ETT cuff pressure was initially less in group S, which rose to a significantly higher level at extubation, compared to group L (p <0.001). At extubation, there was a significant increase in HR and systolic blood pressure (SBP) from baseline, in group S than in group L (p <0.001 and p=0.001, respectively). The incidence of cough and restlessness was less in group L, compared to group S (p<0.001 and p=0.002, respectively). Mean extubation time and emergence time was more in group S than in group L (p<0.001). Post-operatively, the incidence and severity of sore throat were significantly higher in group S than in group L (p<0.001). Meanwhile, the incidence of hoarseness and nausea was comparable in the two groups.

CONCLUSION

 Continuous ETT cuff pressure monitoring helps to keep cuff pressure below tracheal mucosa capillary occlusion pressure. Filling the ETT cuff with alkalinized lignocaine further reduces extubation response and post-intubation morbidities.

Comparison of dexmedetomidine and remifentanil on reducing coughing during emergence from anesthesia with tracheal intubation: A meta-analysis

Background: Dexmedetomidine and remifentanil are well known to suppress airway reflex during emergence from anesthesia, but which one is more effective is unclear. We conducted a meta-analysis to compare the effect of dexmedetomidine and remifentanil on reducing the occurrence of coughing.

Methods: We systematically searched PubMed, Embase, and Cochrane Library for randomized controlled trials (published between 1 January 1950, and 30 December 2021; no language restrictions) comparing dexmedetomidine infusion with remifentanil infusion. The primary endpoint was the incidence of moderate to severe coughing during the recovery period. The secondary endpoints were the time of recovery and extubation, and residual sedation. We assessed pooled data by using a random-effects model.

Results: Eight studies with 502 participants were included. The meta-analysis showed no statistically difference between dexmedetomidine and remifentanil in the occurrence of moderate to severe coughing during emergence from anesthesia (OR 1.45,95%CI 0.62–3.38), the extubation time (MD 0.93 min, 95%CI -0.28–2.14), and the residual sedation (OR 2.52, 95%CI 0.92–6.91). Compared with dexmedetomidine, the average recovery time of remifentanil was shorter (MD 3.88 min, 95%CI 1.01–6.75).

Conclusion: Dexmedetomidine and remifentanil infusion had no difference in the occurrence of moderate to severe coughing during emergence from anesthesia.

Clinical Trial Registration:https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021239710

A randomised controlled trial of intracuff lidocaine and alkalised lidocaine for sedation and analgesia requirements in mechanically ventilated patients

Background

Airway irritation caused by prolonged inflation of endotracheal tube (ETT) cuff results in post-intubation morbidities.

Objectives

We aimed to study intracuff lidocaine and alkalised lidocaine on sedation or analgesia requirements of patients undergoing mechanical ventilation in the intensive care unit (ICU). The primary outcome was to calculate the total dose of propofol and fentanyl required to obtund the unwanted airway and circulatory reflexes. Secondary outcomes were to determine the frequency and severity of cough and haemodynamic parameters.

Methods

It was a double-blinded, randomised controlled study in the ICU after emergency laparotomy, in patients aged 20 - 55 years, and classified as American Society of Anesthesiologists (ASA) classes 1E and 2E with tube in situ. Exclusion criteria were patients with body mass index >30 kg/m² , haemodynamic instability, requiring positive end-expiratory pressure ≥7 cm H2O, and a history of chronic obstructive pulmonary disease. After ethics clearance and written consent, patients were randomly assigned into two groups (36 in each), Group L (ETT cuff inflated with lidocaine 2%) and Group AL (cuff inflated with a mixture of lidocaine 2% and sodium bicarbonate 1:1).

Results

Mean dose of propofol consumed in Group AL was significantly less than that in Group L (p<0.001). The mean standard deviation (SD) fentanyl utilisation in Group AL was 1 323.61 (187.27) µg, and that in Group L was 1433.09 (42.58) µg (p=0.040). Group L patients had a significantly higher incidence of cough than those in Group AL (p=0.01). There was no significant difference in the mean arterial pressure (p=0.22), although heart rate was significantly higher in Group L (p<0.001).

Conclusion

Alkalised lidocaine reduces the requirement of sedation, analgesia, and the incidence of cough in intubated patients maintaining haemodynamic stability when compared with lidocaine.

Contributions of the study

Alkalised lidocaine when used in endotracheal tube cuff inflation reduces the need for sedation and analgesia in mechanically-ventilated patients, and improves haemodynamic stability.

Intracuff alkalinized lidocaine to prevent postoperative airway complications: A meta-analysis

BACKGROUND

Post-extubation cough is a common phenomenon in surgical patients undergoing general anesthesia, which can lead to potentially dangerous complications. In this meta-analysis, we evaluated the efficacy and safety of intracuff alkalinized lidocaine in patients with tracheal intubation to prevent cough and other airway complications during the perioperative period.

AIM

To perform a systematic review and meta-analysis of intracuff alkalinized lidocaine for the prevention of postoperative airway complications.

METHODS

PubMed, Embase, Cochrane, and Web of Science were searched for randomized controlled trials (RCTs) that compared intracuff alkalinized lidocaine to placebo. We used risk-of-bias assessment to assess the RCTs, and the quality of evidence was assessed using the grading of recommendations, assessment, development, and evaluations.

RESULTS

Twelve randomized trials (1175 patients) were analyzed. Meta-analysis showed that intracuff alkalinized lidocaine was associated with less cough compared to that produced by placebo [risk ratio (RR): 0.38; 95% confidence interval (CI): 0.23-0.63]. Similarly, intracuff alkalinized lidocaine was more effective than the control in reducing postoperative sore throat at 24 h (RR: 0.19; 95%CI: 0.09-0.41) and postoperative hoarseness (RR: 0.38; 95%CI: 0.21-0.69).

CONCLUSION

Intracuff alkalinized lidocaine is an effective adjuvant that can decrease airway complications, such as coughing, hoarseness, and sore throat.

Efficacy of intracuff lidocaine in reducing coughing on tube: a systematic review and meta-analysis

Objective

Method

Results

Conclusion

-Effects of Local Anesthetics on Smooth Muscle Tissue in Rat Trachea: An In Vitro Study

OBJECTIVES

We evaluated the muscle responses of rat trachea to LA drugs, such as lidocaine and prilocaine, in terms of airway spasms.

MATERIALS AND METHODS

A total of 16 male rats were used. After ketamine anesthesia, the tracheal ring of each rat was removed and placed in the organ bath in the Krebs solution. The rat tracheal veins were randomly divided into two groups based on the LA applied at the basal tonus level: group 1 (n=8), lidocaine; group 2 (n=8), prilocaine. Second, the baths were washed. Supramaximal contraction was obtained by applying acetylcholine to the tracheal rings (n=16) at a basal tonus level. The rat tracheas with supramaximal contraction were randomly divided into two groups: group 3 (n=8), lidocaine; group 4 (n=8), prilocaine. The contraction responses of each group were recorded and statistically compared.

RESULTS

Lidocaine constituted a significant relaxation response in the tracheal tissue in both basal tonus and supramaximal tonus levels. Moreover, it was observed that the relaxation of lidocaine was higher in the supramaximal contraction than in the basal tonus tension level. However, for prilocaine, no significant change was observed in both tonus levels.

CONCLUSION

This study suggests that lidocaine as a LA drug should be preferred as the first choice in patients with respiratory risk, and that its use over prilocaine should be preferred, if supported by advanced clinical studies.

Medications to reduce emergence coughing after general anaesthesia with tracheal intubation: a systematic review and network meta-analysis

BACKGROUND

Emergence coughing can harm the patient following completion of surgery, but it is unclear which medication is most effective at reducing this event. We conducted a systematic review and network meta-analysis of RCTs to determine the medications' relative efficacies on decreasing moderate to severe emergence coughing after general anaesthesia. Medications studied were lidocaine (i.v., intracuff, topical, or tracheal application), dexmedetomidine, remifentanil, and fentanyl.

METHODS

We searched eight different medical literature databases, conference abstracts, and article references. After screening, included citations were evaluated for bias and had their data extracted. Pooled odds ratios and 95% confidence intervals for each treatment comparison were calculated. A surface under the cumulative ranking curve analysis (SUCRA) determined the relative rank of each intervention to decrease moderate to severe emergence coughing. Subgroup analyses included severe coughing only, extubation times, type of maintenance anaesthetic, and dosages.

RESULTS

The network meta-analysis included 70 studies and 5286 patients. All study medications had favourable odds in reducing moderate and severe peri-extubation coughing compared with either no medication or placebo. No single medication was favoured over another. Dexmedetomidine had the highest SUCRA rank, followed in order by remifentanil, fentanyl, and lidocaine via intracuff, tracheal/topical, and i.v. routes. Remifentanil was ranked highest for decreasing severe coughing only. Intracuff lidocaine had higher odds of prolonging extubation times compared with placebo, dexmedetomidine, fentanyl, and remifentanil.

CONCLUSION

All study medications were better than placebo or no medication in reducing moderate to severe emergence cough, with dexmedetomidine ranked the most effective.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42018102870.

Pharmacological methods for reducing coughing on emergence from elective surgery after general anesthesia with endotracheal intubation: protocol for a systematic review of common medications and network meta-analysis

BACKGROUND

Emergence coughing and bucking, secondary to endotracheal tube stimulation of the tracheal mucosa, frequently occurs after the general anesthetic recedes. Besides general unpleasantness, coughing has important physiological sequelae that may be detrimental to the postoperative patient. Multiple pharmacological strategies have been published, but prior systematic reviews on this topic have neither been comprehensive enough in their literature or medication search, nor provided us the answer regarding what the best pharmacological method is to prevent or minimize peri-extubation coughing. Our systematic review and network meta-analysis' primary objective is to determine the relative efficacies of different pharmacological methods on decreasing coughing (none to mild compared to moderate to severe, as defined by the modified Minogue scale) during emergence after a general anesthetic with endotracheal intubation in adult elective surgeries. Medications of interest are lidocaine or lignocaine (intravenous (IV), intracuff alkalinized, intracuff non-alkalinized, topical, endotracheal application), dexmedetomidine IV, remifentanil IV, and fentanyl IV. These medications were selected based on a preliminary review of the literature.

METHODS

Using a predefined search strategy, we will search MEDLINE, Cochrane Central Register of Controlled Trials, Embase, Cochrane Database of Systematic Reviews, ACP Journal Club, Database of Abstracts of Reviews of Effects, and the Cochrane Methodology Register, with no date or language restrictions. Gray literature search will encompass conference abstracts, Web of Science, and references from publications selected for full-text review. Two reviewers will independently screen the retrieved literature using predetermined inclusion criteria, process publications selected for full-text review, extract data from publications chosen for study inclusion, and evaluate for bias using the Cochrane risk of bias assessment. Risk ratios and 95% confidence intervals will be calculated for each study, and a surface under the cumulative ranking curve will determine the relative rank of each intervention in its ability to prevent coughing on emergence.

DISCUSSION

The proposed systematic review and network meta-analysis will not only provide a more thorough review of common medications used to decrease emergence coughing, but also inform clinicians which of these pharmacological strategies is the best approach.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018102870.

Alkalinized Lidocaine Preloaded Endotracheal Tube Cuffs Reduce Emergence Cough After Brief Surgery: A Prospective Randomized Trial

BACKGROUND

Alkalinized lidocaine in the endotracheal tube (ETT) cuff decreases the incidence of cough and throat pain on emergence after surgery lasting more than 2 hours. However, alkalinized lidocaine needs 60-120 minutes to cross the ETT cuff membrane; therefore, its usefulness in shorter duration surgery is unknown. This prospective double-blind randomized controlled trial tested the hypothesis that alkalinized lidocaine would reduce the incidence of emergence cough after surgeries lasting <120 minutes.

METHODS

After local ethics board approval, American Society of Anesthesiologists I-III patients consented to be randomized into 1 of 2 groups receiving either alkalinized lidocaine (group AL) or saline (group S) to inflate the ETT cuff. Cuffs were prefilled >90 minutes before intubation with either 2 mL of 2% lidocaine and 8 mL of 8.4% bicarbonate (group AL) or 10 mL of normal saline (group S). Cuffs were emptied immediately before intubation. After intubation, either 2 mL of 2% lidocaine (AL) or 2 mL of saline (S) were injected into the cuff. Additional 8.4% bicarbonate (AL) or saline (S) was injected into the cuff until there was no air leak. Anesthesia was maintained using desflurane, rocuronium, and either fentanyl or sufentanil to maintain vital signs within 20% of baseline values. Opioids administered in prophylaxis of extubation cough were proscribed. A standardized "no touch" emergence technique was used. A blinded assessor noted any cough above 0.2 minimum alveolar concentration (MAC) of expired desflurane. At 0.2 MAC, once every 30 seconds, the patient was instructed to open his eyes and extubation occurred once a directed response was noted.

RESULTS

A total of 213 patients were randomized and 100 patients in each group completed the experimental protocol. The incidence of extubation cough in group AL was 12%, significantly lower (1-sided P = .045) than the 22% incidence in group S. The 1-tailed risk ratio for cough in group AL was 0.55 (0-0.94, P = .045). Total amount of opioids administered (P = .194), ETT cuff preloading times (P = .259), and extubation times (P = .331) were not significantly different between groups. The average duration of surgery was 59 ± 28 minutes in group AL and 52 ± 29 minutes in group S (P = .057).

CONCLUSIONS

Alkalinized lidocaine in the ETT cuff significantly decreased general anesthesia emergence cough after surgeries with an average duration of slightly <1 hour.

Efficacy of 8 mg lidocaine and 2 mg cetylpyridinium chloride (CPC) fixed-combination lozenges on sore throat pain intensity compared with 1 mg lidocaine and 2 mg CPC fixed-combination lozenges in subjects with sore throat due to upper respiratory tract infection: a randomized double-blind parallel-group single-dose study

Background

Lozenges containing lidocaine and cetylpyridinium chloride (CPC) are commonly used for the treatment of sore throat. The lidocaine acts locally to provide pain relief and the CPC has an antiseptic effect. Mebucaine CL, a well-established fixed-combination sore throat lozenge, contains 1 mg lidocaine and 2 mg CPC. Single-agent lozenges containing 8 mg lidocaine have also been demonstrated to be significantly superior to placebo in confirmatory pain intensity assessments. This study compared a new lozenge formulation, containing 8 mg lidocaine and 2 mg CPC, with the currently marketed lozenge for the treatment and relief of sore throat symptoms in subjects diagnosed with a sore throat due to an upper respiratory tract infection (URTI).

Methods

In this double-blind parallel-group study, 250 adults with a sore throat due to an URTI were randomized to receive a single lozenge containing either 8 mg lidocaine + 2 mg CPC (n = 125) or 1 mg lidocaine + 2 mg CPC (n = 125). The primary efficacy endpoint of the study was the change in sore throat pain intensity (STPI) between baseline (immediately pre-treatment) and the 2-h post-dose assessment, measured on a 100 mm visual analog scale. STPI was measured at baseline and regular intervals up to 240 min after the lozenge was administered (evaluated in clinic). Any difficulty in swallowing and time to onset and duration of the analgesic effect were also assessed.

Results

No increase in efficacy was demonstrated with the higher dose of lidocaine. The difference in the 2-h post-dose change in STPI was not statistically significant between the treatments. There was only one statistically significant difference between the treatments in all of the efficacy outcomes assessed: pain relief scores at 4 h post-dose were higher with 1 mg lidocaine + 2 mg CPC than with 8 mg lidocaine + 2 mg CPC (P = 0.0461). The most commonly reported adverse event (AE) was a headache; the only other AE experienced by more than one subject was throat irritation. No severe adverse events were reported during the assessment period.

Conclusions

The modest difference in the pattern of effectiveness between the two treatments observed in this study does not support use of the 8 mg lidocaine + 2 mg CPC lozenge.

Trial registration

ClinicalTrials.gov, NCT01265446. Registered on 20 December 2010.

Efficacy and Safety of Using Air Versus Alkalinized 2% Lignocaine for Inflating Endotracheal Tube Cuff and Its Pressure Effects on Incidence of Postoperative Coughing and Sore Throat

Background and Objective:

We wished to compare the endotracheal tube (ETT) cuff pressure inflated with air or alkalinized lignocaine during anesthesia and evaluate clinical symptoms such as coughing and sore throat (postoperative sore throat [POST]) following tracheal extubation.

Materials and Methods:

This was a prospective randomized controlled study conducted in a tertiary care set up over a period of 1 year. We included 100 patients in age group of 18–65 years posted for elective surgeries of duration more than 90 min under general anesthesia with N₂O-O₂ mixture. Patients were randomized using computer-generated randomization table into air and lignocaine group. The ETT cuff was inflated with air or alkalinized lignocaine (2% lignocaine with 7.5% sodium bicarbonate, in the proportions of 19.0:1.0 ml) to the volume that prevented air leak using cuff pressure manometer. After extubation, an independent observer blinded to study group recorded the presence or absence of coughing and POST at immediately, 1 h and 24 h postoperatively.

Results:

Demographic data, baseline characteristics (American Society of Anesthesiologists grade, intracuff volume/cuff pressure at start of surgery), and duration of anesthesia were comparable among study groups (P > 0.05). Cuff pressure and volume achieved in the end of surgery were much higher in air group as compared to lignocaine group (P < 0.05). Incidence of coughing and POST at immediately, 1 h and 24 h postoperatively was significantly higher in air group compared to lignocaine group. Impact of duration of anesthesia on rise in cuff pressure was significantly higher in air group and its effect on cuff-induced laryngotracheal morbidity was significant in both air and lignocaine group.

Conclusion:

This study showed the significance of use of alkalinized 2% lignocaine in prevention of rise of cuff pressure and incidence of coughing and POST. Duration of anesthesia has also a significant effect on incidence of postoperative trachea-laryngeal morbidity.

Effect of Intracuff Lidocaine on Postoperative Sore Throat and the Emergence Phenomenon: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Postoperative sore throat and other airway morbidities are common and troublesome after endotracheal tube intubation general anesthesia (ETGA). We propose lidocaine as endotracheal tube (ETT) cuff inflation media to reduce the postintubation-related emergence phenomenon.

METHODS

We searched PubMed, EMBASE, and Cochrane databases systematically for randomized controlled trials (RCTs) that have investigated the outcome of intracuff lidocaine versus air or saline in patients receiving ETGA. Using a random-effects model, we conducted a meta-analysis to assess the relative risks (RRs) and mean difference (MD) of the incidence and intensity of relevant adverse outcomes.

RESULTS

We reviewed nineteen trials, which comprised 1566 patients. The incidence of early- and late-phase postoperative sore throat (POST), coughing, agitation, hoarseness, and dysphonia decreased significantly in lidocaine groups, with RRs of 0.46 (95% confidence interval [CI]: 0.31 to 0.68), 0.41 (95% CI: 0.25 to 0.66), 0.43 (95% CI: 0.31 to 0.62), 0.37 (95% CI: 0.25 to 0.55), 0.43 (95% CI: 0.29 to 0.63), and 0.19 (95% CI: 0.08 to 0.5), respectively, when compared with the control groups. The severity of POST also reduced significantly (mean difference [MD] -16.43 mm, 95% CI: -21.48 to -11.38) at 1 h and (MD -10.22 mm, 95% CI: -13.5 to -6.94) at 24 h. Both alkalinized and non-alkalinized lidocaine in the subgroup analyses showed significant benefits in emergence phenomena prevention compared with the control.

CONCLUSION

Our results indicate that both alkalinized and non-alkalinized intracuff lidocaine may prevent and alleviate POST and postintubation-related emergence phenomena.

Lidocaine for preventing postoperative sore throat

BACKGROUND

Sore throat is a common side-effect of general anaesthesia and is reported by between 30% and 70% of patients after tracheal intubation. The likelihood of a sore throat varies with the type, diameter, and cuff pressure of the endotracheal tube used. If intubation is essential, it may be helpful to give drugs prophylactically to alleviate postoperative sore throat. Local anaesthetics and steroids have been used for this purpose. This review was originally published in 2009 and was updated in 2015.

OBJECTIVES

The objective of this review was to evaluate the efficacy and any harm caused by topical and systemic lidocaine used prophylactically to prevent postoperative sore throat in adults undergoing general anaesthesia with endotracheal intubation.

SEARCH METHODS

We searched CENTRAL (The Cochrane Library 2013, Issue 9), MEDLINE (January 1966 to October 2013), and EMBASE (1980 to October 2013). We also contacted manufacturers and researchers in the field. The original search was undertaken in June 2007. We reran the search in February 2015 and found four studies of interest. We will deal with those studies when we next update the review.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of topical and systemic prophylactic lidocaine therapy versus control (using air or saline) that reported on the risk and severity of postoperative sore throat as an outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information, such as the risk of any adverse effects.

MAIN RESULTS

We included 19 studies involving 1940 participants in this updated review. Of those 1940 participants, 952 received topical or systemic lidocaine therapy and 795 were allocated to the control groups. Topical and systemic lidocaine therapy appeared to reduce the risk of postoperative sore throat (16 studies, 1774 participants, risk ratio (RR) was 0.64 (95% confidence interval (CI) 0.48 to 0.85), the quality of the evidence was low), although when only high-quality trials were included (eight studies, 814 participants) the effect was no longer significant (RR 0.71, 95% CI 0.47 to 1.09). Lidocaine given systemically in two studies (320 participants) did not reveal evidence of an effect (RR 0.44, 95% CI 0.19 to 1.05 ). The severity of sore throat as measured on a visual-analogue scale (VAS) was reduced by lidocaine therapy (six trials, 611 participants, (mean difference (MD) -10.80, 95% CI -14.63 to -6.98). The adverse effects of lidocaine were not reported in these studies, though toxicity is generally rare.

AUTHORS' CONCLUSIONS

In our revised systematic review, although the results of included studies show generally positive results, they should be interpreted carefully. The effect size of lidocaine appeared to be affected by study quality; drug concentration; route of administration; management of cuff pressure during anaesthesia; the included population; and the type of outcome measured.

Local airway anesthesia attenuates hemodynamic responses to intubation and extubation in hypertensive surgical patients

BACKGROUND

The aim of this study was to evaluate the effects of topical ropivacaine anesthesia on hemodynamic responses during intubation and extubation of hypertensive patients.

MATERIAL AND METHODS

One hundred fifty patients with hypertension ASA II-III were scheduled for noncardiac operations. Patients were divided into 3 groups: a control group receiving 5 ml saline, and 2 groups receiving topical anesthesia with 100 mg lidocaine or 37.5 mg ropivacaine. Hemodynamic responses, including blood pressure and heart rate (HR), were recorded at baseline (T0), before intubation (T1), during tracheal intubation (T2), 2 min after intubation (T3), upon eye opening on verbal commands (T4), during tracheal extubation (T5), and 2 min after extubation (T6). Patients were injected with urapidil 5 mg during intubation and extubation if their systolic blood pressure (SBP) was ≥160 mmHg or diastolic blood pressure (DBP) was ³90 mmHg, and esmolol 10 mg when HR was ≥90 bpm.

RESULTS

During extubation, the total dosages of urapidil and esmolol were significantly higher in the saline than in the lidocaine or ropivacaine groups, and were significantly lower in the ropivacaine than in the lidocaine group. At T2, SBP, SBP, MAP, and HR were lower in the lidocaine and ropivacaine groups than in the saline group, but the differences were not significant. From T4 to T6, SBP, DBP, MAP, and HR were significantly lower in the ropivacaine group than in the other 2 groups (P<0.05 each).

CONCLUSIONS

Topical lidocaine and ropivacaine anesthesia can effectively reduce hemodynamic responses during intubation, with ropivacaine better at inhibiting hemodynamic changes at emergence in hypertensive patients.

The efficacy of lidocaine to prevent laryngospasm in children: a systematic review and meta-analysis

The purpose of this meta-analysis was to determine the efficacy of lidocaine in preventing laryngospasm during general anaesthesia in children. An electronic search of six databases was conducted. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were adhered to. We included randomised controlled trials reporting the effects of intravenous and/or topical lidocaine on the incidence of laryngospasm during general anaesthesia. Nine studies including 787 patients were analysed. The combined results demonstrated that lidocaine is effective in preventing laryngospasm (risk ratio (RR) 0.39, 95% CI 0.24-0.66; I(2)  = 0). Subgroup analysis revealed that both intravenous lidocaine (RR 0.34, 95% CI 0.14-0.82) and topical lidocaine (RR 0.42, 95% CI 0.22-0.80) lidocaine are effective in preventing laryngospasm. The results were not affected by studies with a high risk of bias. We conclude that, both topical and intravenous lidocaine are effective for preventing laryngospasm in children.

In vitro evaluation of diffusion of lidocaine and alkalinized lidocaine through the polyurethane membrane of the endotracheal tube

OBJECTIVES

Endotracheal tube (ETT) and its inflated cuff are likely to induce specific reactivity at the emergence time. In ICU, the tolerance of the ETT cuff could be a part of patient agitation and increased of sedation.

MATERIALS AND METHODS

Using specific ICU ETT cuff (thin polyurethane cuff), we perform an in vitro evaluation of diffusion of lidocaine and alkalinized lidocaine (L-B) across the PU cuff for a long duration. We evaluate the safety of this procedure by a daily injection into the cuff.

RESULTS

With lidocaine alone, we observed a low rate of diffusion through the cuff (<8% over 24h), whereas the L-B solution had a high diffusion (>90% over 24h). The released profiles were similar from day 0 to day 8, and no cuff rupture was reported over the 8-day study.

CONCLUSION

The safety, controlled release, and lack of deleterious effects on cuff membrane were confirmed. In case of unexpected cuff rupture, an adequate determination of the mixture allows to obtain a safe solution with the achievement of a physiological pH (7.4) and the small dose of lidocaine (40 mg).

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.

Lidocaine for preventing postoperative sore throat

BACKGROUND

Sore throat is a common side effect of general anaesthesia and is reported by between 30% and 70% of patients after tracheal intubation. The likelihood of a sore throat varies with the type, diameter, and cuff pressure of the endotracheal tube used. If intubation is essential, it may be helpful to give drugs prophylactically to alleviate postoperative sore throat. Local anaesthetics and steroids have been used for this purpose.

OBJECTIVES

The objective of this review was to evaluate the effectiveness and any harms of topical and systematic lidocaine for the prevention of postoperative sore throat in adults undergoing endotracheal intubation as part of general anaesthesia.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2007, Issue 3), MEDLINE (January 1966 to June 2007), and EMBASE (1980 to June 2007). We also contacted manufacturers and researchers in the field.

SELECTION CRITERIA

We included randomized controlled trials of topical and systemic prophylactic lidocaine therapy versus control (using air or saline) that reported on the risk and severity of postoperative sore throat as an outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information, such as the risk of adverse effects.

MAIN RESULTS

We included 1232 patients from 15 studies; 672 patients received topical or systemic lidocaine therapy and 560 patients were allocated to the control group. Both the topical and systemic lidocaine therapy significantly reduced the risk of postoperative sore throat (risk ratio (RR) 0.58; 95% confidence interval (CI) 0.41 to 0.82). To evaluate the severity of sore throat on a visual analogue scale (VAS), 219 patients received topical or systemic lidocaine therapy and 152 patients were allocated to the control groups. The severity of sore throat was reduced (mean difference (MD) -11.9; 95% CI -16.44 to -7.32), an effect that neared statistical significance. The adverse effects of lidocaine were not reported in these studies.

AUTHORS' CONCLUSIONS

Our systematic review establishes the effectiveness of topical and systemic lidocaine for the prevention of postoperative sore throat resulting from intubation. The risk and severity of postoperative sore throat tended to be reduced. The effect size of lidocaine appeared to be affected by drug concentration and route of administration; management of cuff pressure during anaesthesia; the included population; and the type of outcome measured.