Effect Of Cricoid Pressure Research Articles

The Effect of Cricoid Pressure on Tracheal Intubation in Adult Patients: A Systematic Review and Meta-Analysis

(Can J Anesth/J Can Anesth. 2021;68:137–147) Cricoid pressure (CP) is used during induction of anesthesia to minimize the risk of pulmonary aspiration in high-risk patients. CP compresses the cricoid cartilage and occludes the esophagus, and prevents gastric insufflation during mask ventilation. There is not clear agreement on the effectiveness or risks of CP. This systematic review and meta-analysis aimed to evaluate the association between CP and intubation outcomes.

The effect of cricoid pressure on tracheal intubation in adult patients: a systematic review and meta-analysis.

This meta-analysis aimed to assess the impact of cricoid pressure (CP) application on intubation outcomes. Electronic databases (i.e., MEDLINE, PubMed, Embase, and Cochrane review) were searched from inception to 2 June 2020 for randomized-controlled trials that assessed the intubation outcomes in adult patients using laryngoscopic approaches with and without the application of CP (i.e., CP vs non-CP group). The primary outcome was the successful first-attempt intubation rate (SFAIR), and the secondary outcomes were intubation time, incidences of poor laryngoscopic views (i.e., Cormack and Lehane grade 3-4), airway complications, and pulmonary aspiration. A total of five trials (published from 2005 to 2018) were included, and all tracheal intubations were performed by anesthesiologists or nurse anesthetists with a video (n = 3) or Macintosh laryngoscope (n = 2) in the operating room. We found no significant difference in SFAIR (risk ratio [RR], 0.98; P = 0.37), incidence of poor laryngoscopic views (RR, 1.49; P = 0.21), and risk of sore throat (RR, 1.17; P = 0.73) between the two groups. Nevertheless, the intubation time on the first successful attempt was slightly longer (weighted mean difference = 4.40 sec, P = 0.002) and risk of hoarseness was higher (RR, 1.70; P = 0.03) in the CP group compared with in the non-CP group. The secondary outcome "pulmonary aspiration" was not analyzed because only one trial was available. The application of CP did not have a negative impact on the SFAIR or laryngoscopic view. Nevertheless, this maneuver may slightly prolong intubation time and increase the risk of postoperative hoarseness.

Effect of Cricoid Pressure on the Glottic View and Intubation with King Vision® Video Laryngoscope.

Context:To establish the usefulness of King Vision® video laryngoscope (KVL) in patients with rapid sequence anesthesia.Aims:This study aims to compare the role of KVL on glottic visualization, intubation time and associated sympathetic response in routine intubations to those intubations done with cricoid pressure (CP).Settings and Design:Randomized controlled study in a tertiary care hospital.Methodology:Seventy-six patients intubated with KVL were randomized to two groups – Group C (who did not receive any CP) and Group CP – who received CP. The percentage of glottic opening (POGO), intubation time, subjective assessment, and number of attempts taken to introduce KVL and endotracheal tube (ETT) were noted. The saturation, end-tidal carbon dioxide concentration and hemodynamic response (heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and rate pressure product) in the peri-intubation period were also recorded.Results:The demographics, airway, and technical characteristics of insertion of KVL and ETT were comparable between the groups (P > 0.05). POGO score was 100% in both groups. The significant time in insertion of KVL (Group C 29.87 ± 11.64 s and Group CP 40.68 ± 18.93 s, P = 0.004) and ETT (Group C 17.53 ± 8.71 s and Group CP 22.42 ± 10.77 s, P = 0.033) contributed to prolonged overall intubation time in CP (Group C 41.11 ± 11.65 s and Group CP 51.05 ± 17.31 s, P = 0.005). The intergroup and intragroup hemodynamic variables did not show any statistical significance (P > 0.05) over time.Conclusion:Although overall intubation time with KVL is prolonged in patients with CP, it provides excellent glottic view, eases intubation, and causes insignificant hemodynamic variation.

Effect of Cricoid Pressure on the Insertion Efficacy of Six Supraglottic Devices: A Crossover Randomized Simulation Trial

BackgroundNo study has ever compared the efficacy of various types of supraglottic devices (SGDs) for securing the airway under cricoid pressure. ObjectiveThis study aimed to evaluate the efficacy of six SGDs, LMA-ProSeal (ProSeal), LMA-Classic (Classic), Laryngeal Tube (LT), LMA-Supreme (Supreme), air-Q (air-Q), and i-gel (i-gel), in airway management under cricoid pressure using a manikin. MethodsFifteen novice doctors and 16 experienced doctors used the six SGDs under cricoid or sham pressure on an adult manikin. Insertion time, successful ventilation rate, and subjective insertion difficulty on a visual analogue scale (VAS) were measured. ResultsBoth novice and experienced doctors had a significantly lower ventilation success rate under cricoid pressure than under sham pressure when using the ProSeal, Classic, and LT, but not when using the other three SGDs. Novice doctors required a significantly longer insertion time under cricoid pressure than under sham pressure with all SGDs. Experienced doctors required a significantly longer insertion time under cricoid pressure than with sham pressure when using the ProSeal, Classic, and LT, but not when using the other three SGDs. Subjective insertion difficulty on VAS was significantly higher under cricoid pressure than under sham pressure with all six SGDs. ConclusionVentilation success rate under cricoid pressure was significantly lower than under sham pressure when using the ProSeal, Classic, and LT, but not when using the other three SGDs in both novice and experienced doctors.

Effect of cricoid pressure on laryngoscopic view and ease of intubation with Airtraq® laryngoscope

Background: Improved laryngeal view has made Airtraq® optical laryngoscope suitable for rapid sequence induction and intubation, provided this important advantage is not lost with application of cricoid pressure (CP). This study was designed to investigate the effect of CP on laryngoscopic view and to ascertain the ease of orotracheal intubation using Airtraq® laryngoscope. Material and Methods: In this prospective randomized study, fifty patients of either gender aged 18-60yrs were randomly allocated into two groups. In Group CP, orotracheal intubation was performed using Airtraq® laryngoscope and application of CP. In Group NCP intubation was performed without application of CP. Laryngoscopic view, success, ease, duration and number of attempts at intubation were recorded. Results: In 49 out of 50 patients included in the study, CP lead to insignificant or no change in POGO score. In Group CP, 21 out of 25 patients had easy intubation, whereas in Group NCP, 23 out of 25 patients had easy intubation. Two patients in both groups had a slightly difficult intubation. Two patients had difficulty in intubation in Group CP, whereas none of the patients in Group NCP had difficulty in intubation. Conclusion: During Airtraq® assisted intubation in patients with normal airways, application of CP does not produce any clinically significant change in the laryngoscopic view and time required for intubation. However, in cases where application of CP causes hindrance in intubation despite adequate laryngeal view, we recommend release of CP to facilitate intubation.

Effect of cricoid pressure on laryngeal view during prehospital tracheal intubation: a propensity-based analysis

BackgroundThe benefit of cricoid pressure during tracheal intubation is still debated and, due to its potential negative impact on laryngeal views, its routine use is questioned. The goal of this...

The Effect of Cricoid Pressure on the Unstable Cervical Spine

BackgroundIt has been proposed that cricoid pressure can exacerbate an unstable cervical injury and lead to neurologic deterioration. ObjectiveWe sought to examine the amount of motion cricoid pressure could cause at an unstable subaxial cervical spine injury, and whether posterior manual support is of any benefit. MethodsFive fresh, whole cadavers had complete segmental instability at C5–C6 surgically created by a fellowship-trained spine surgeon. Cricoid pressure was applied to the anterior cricoid by an attending anesthesiologist. In addition, the effect of posterior cervical support was tested during the trials. The amount of angular and linear motion between C5 and C6 was measured using a Fastrak, three-dimensional, electromagnetic motion analysis device (Polhemus Inc., Colchester, VT). ResultsWhen cricoid pressure is applied, the largest angular motion was 3 degrees and occurred in flexion-extension at C5–C6. The largest linear displacement was 1.36 mm and was in anterior-posterior displacement of C5–C6. When manual posterior cervical support was applied, the flexion-extension was improved to less than half this value (1.43 degrees), and this reached statistical significance (p = 0.001). No other differences were observed to be significant in the other planes of motion with the applications of support. ConclusionsBased on the evidence presented, we believe that the application of cricoid pressure to a patient with a globally unstable subaxial cervical spine injury causes small displacements. There may be some benefit to the use of manual posterior cervical spine support for reducing motion at such an injured segment.

The effect of cricoid pressure on glottic view improvement at laryngoscopy

Tehran University/Tebi Center Hospital, Department of Anaesthesiology, Tehran, Iran, Islamic Republic of

Part 8: Advanced life support: 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations

Part 8: Advanced life support: 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations

Effect of cricoid pressure on the laryngoscopic view by Airtraq in elective caesarean section: a pilot study

Effect of cricoid pressure on the laryngoscopic view by Airtraq in elective caesarean section: a pilot study

The Effect of Cricoid Pressure on Intubation Facilitated by the Gum Elastic Bougie

The Effect of Cricoid Pressure on Intubation Facilitated by the Gum Elastic Bougie

The effect of cricoid pressure on intubation facilitated by the gum elastic bougie

The effect of cricoid pressure on intubation facilitated by the gum elastic bougie

Cricoid pressure prevents placement of the laryngeal tube and laryngeal tube-suction II

The laryngeal tube has a potential role in patients with a difficult airway, but cricoid pressure is required if the patient is at risk of aspiration. The effect of cricoid pressure on insertion of these devices is unknown. In a randomized cross-over study, the laryngeal tube (25 patients) or the laryngeal tube-suction II (15 patients) was inserted with cricoid pressure applied on one occasion and with sham pressure on the other occasion. Adequacy of ventilation, time to achieve adequate ventilation, and the leak pressure were assessed. Ventilation was adequate in all patients when sham pressure was applied. Cricoid pressure significantly reduced the rate of adequate ventilation to 6 of 25 patients for the laryngeal tube [P < 0.001; 95% confidence interval (CI) for difference: 59-93%] and to 5 of 15 patients for the laryngeal tube-suction II (P < 0.05; 95% CI for difference: 43-91%). The median time taken to achieve adequate ventilation for the laryngeal tube was 10 s [inter-quartile range (IQR): 8-15] (range 5-26) for sham pressure and 25 s (15-32) (15-33) for cricoid pressure; the median leak pressure was 30 (IQR: 30-30) (range 20-30) cm H2O for sham pressure and 15.5 (14.3-20.5) (12-22) cm H2O for cricoid pressure. Continuous cricoid pressure prevents correct placement of the laryngeal tube and the laryngeal tube-suction II such that placement and ventilation via these devices are ineffective. The effect of cricoid pressure on ventilation via these devices, after correct placement, remains unknown.

Effect of Cricoid Pressure on the View at Laryngoscopy

Effect of Cricoid Pressure on the View at Laryngoscopy

The Effects of Cricoid Pressure, Remifentanil, and Propofol on Esophageal Motility and the Lower Esophageal Sphincter

Cricoid pressure is the gold standard during the induction of anesthesia when there is a risk of aspiration of gastric contents. However, the effect of cricoid pressure during the different steps of complete anesthesia induction has not been studied. The purpose of this study was to investigate the effects of cricoid pressure, remifentanil, and propofol on lower esophageal sphincter (LES) and esophageal motility. We recorded LES pressure (LESP) and calculated barrier pressure ([BrP] = LESP - gastric pressure) in 10 healthy volunteers using a Dent sleeve device. There was a significant decrease in LESP and BrP when a cricoid pressure of 30 N was performed in the awake volunteers (P < 0.05). However, this effect was not seen during the infusion of remifentanil 0.2 microg . kg(-1) . min(-1). Remifentanil per se or together with a bolus dose of propofol 1 mg/kg IV did not induce any statistical change in LESP or BrP. Remifentanil abolished spontaneous esophageal motility and completely eliminated the experience of discomfort induced by cricoid pressure. In conclusion, cricoid pressure of 30 N induced a decrease of LESP and BrP in awake volunteers. These effects were not seen during the remifentanil infusion. This shows the importance of when to apply cricoid pressure during rapid-sequence induction.

Effect of cricoid pressure on the view at laryngoscopy*

The impact of cricoid pressure on laryngoscopy is unknown. We have developed a quantitative method of recording the laryngoscopic view using a rigid, zero-degree endoscope. We found that an image matching the laryngoscopist's view could be obtained by positioning the endoscope along the laryngoscopist's 'line of sight'. Photographing this image allowed us to measure laryngeal exposure. We set out to define the effect of cricoid pressure on laryngoscopy using this method. In 40 patients undergoing elective surgery, laryngoscopy was performed with cricoid pressures of 0-60 N, increasing by increments of 10 N. We photographed the laryngoscopic view at each force and recorded dynamic images as cricoid pressure was released. The change in laryngoscopic view with increasing cricoid pressure fell into one of four broad patterns: little change (11 subjects); gradual deterioration (10 subjects); improvement at low force (< 20 N) followed by deterioration (9 subjects); improvement at high force (> 30 N) (10 subjects). We identified five subjects with a good initial view (anteroposterior length of the rima glottidis > 5 mm) who showed a marked deterioration in laryngoscopic view as cricoid pressure increased; in three of these subjects this progressed to obscure the larynx completely at a force of 30 N, 40 N and 60 N, respectively. We conclude that the effect of cricoid pressure on laryngoscopy is complex. However, in some individuals, a force close to that currently recommended (30 N) may cause a complete loss of the glottic view.

Effect of Cricoid Pressure on the Success of Endotracheal Intubation with a Lightwand

Effect of Cricoid Pressure on the Success of Endotracheal Intubation with a Lightwand

Effect of cricoid pressure on gastro-oesophageal reflux in awake subjects.

This study aimed to evaluate whether cricoid pressure is associated with a high risk of gastro-oesophageal reflux. Fifteen awake, fasted volunteers were studied. A cricoid pressure of 44 N was applied for 60 s by resting a padded yoke over the cricoid cartilage. Using continuous oesophageal pH monitoring, no volunteer had gastro-oesophageal reflux during cricoid pressure, although one subject had a reflux spike soon after relieving cricoid pressure. We conclude with 95% confidence that the incidence of gastro-oesophageal reflux during cricoid pressure is not more than 20%.

Cricoid pressure applied after placement of the laryngeal mask prevents gastric insufflation but inhibits ventilation

We studied 50 patients, in a blind, crossover study, to assess if cricoid pressure applied after placement of the laryngeal mask prevented gastric insufflation without affecting ventilation. After induction of anaesthesia and neuromuscular block, a laryngeal mask was inserted and confirmed to be placed correctly. The lungs were ventilated with a maximum inflation pressure of 15 cm H2O. In the first 25 patients, expiratory volumes were measured with and without cricoid pressure (30 N). On both occasions, a free hand was placed under the patient's neck. In the next 25 patients, the effect of cricoid pressure on ventilation without support of the neck was also studied. The effect of cricoid pressure with support of the neck on gastric insufflation was then assessed using a stethoscope in all 50 patients, while the lungs were ventilated with a maximum inflation pressure of 30 cm H2O. At the end of the study, the position of the mask was re-assessed. Cricoid pressure significantly decreased mean expiratory volume (P << 0.001). This inhibitory effect was significantly greater when the pressure was applied without support of the neck (P << 0.001). Cricoid pressure significantly reduced the incidence of gastric insufflation (12 patients vs one patient; P << 0.001; 95% CI for difference 10.5-33.5%). In no patient was the mask dislodged after these procedures. Thus, although cricoid pressure applied after insertion of the laryngeal mask prevented gastric insufflation, it also decreased ventilation. The inhibitory effect of cricoid pressure on ventilation without support of the neck was greater than cricoid pressure with support of the neck.

Cricoid pressure impedes placement of the laryngeal mask airway

We have studied 22 patients to examine whether or not cricoid pressure affects ventilation of the lungs via the laryngeal mask and its correct positioning. In a randomized, crossover design, the laryngeal mask was inserted with or without cricoid pressure applied with a standardized force of 30 N using a cricoid yoke. A standardized pillow (6 cm in height) was placed under the patient's occiput, but the neck was not supported. Ventilation of the lungs via the laryngeal mask was adequate in all patients when no cricoid pressure was applied, but in only three of 22 patients when cricoid pressure was applied (P << 0.001; 95% confidence interval (CI) 0.72-1.0). The mask was positioned correctly in 18 patients when no pressure was applied, and in none after application of cricoid pressure (P << 0.001; 95% CI 0.66-0.98). We had planned to study, in an additional 20 patients, the effect of cricoid pressure without a pillow under the occiput; placement of the mask, however, was difficult even when cricoid pressure was not applied and there was a high incidence of bleeding from the oropharynx. We thus abandoned that part of the study after eight patients. In those eight patients, the success rate of ventilation via the laryngeal mask was lower when cricoid pressure was applied. We conclude that when sufficient force was applied, cricoid pressure, regardless of the method of application, did impede placement of the laryngeal mask.