Cricoid Pressure Controversies: Narrative Review.

Since cricoid pressure was introduced into clinical practice, controversial issues have arisen, including necessity, effectiveness in preventing aspiration, quantifying the cricoid force, and its reliability in certain clinical entities and in the presence of gastric tubes. Cricoid pressure-associated complications have also been alleged, such as airway obstruction leading to interference with manual ventilation, laryngeal visualization, tracheal intubation, placement of supraglottic devices, and relaxation of the lower esophageal sphincter. This review synthesizes available information to identify, address, and attempt to resolve the controversies related to cricoid pressure. The effective use of cricoid pressure requires that the applied force is sufficient to occlude the esophageal entrance while avoiding airway-related complications. Most of these complications are caused by excessive or inadequate force or by misapplication of cricoid pressure. Because a simple-to-use and reliable cricoid pressure device is not commercially available, regular training of personnel, using technology-enhanced cricoid pressure simulation, is required. The current status of cricoid pressure and objectives for future cricoid pressure-related research are also discussed.

The Cricoid Force Necessary to Occlude the Esophageal Entrance: Is There a Gender Difference?

BACKGROUND: We tested the hypothesis whether gender differences exist in the applied cricoid force necessary to prevent regurgitation. Real-time visual and dynamic means were used to assess the effectiveness of different applied cricoid forces in occluding the esophageal entrance in men (group 1) and in women (group 2). METHODS: In anesthetized and paralyzed patients, the glottis and esophageal entrance were visualized with a Glidescope video laryngoscope. Trained operators performed cricoid pressure (CP) and gastric tube insertion trials. Successful gastric tube insertion in the presence of CP was considered ineffective CP, whereas unsuccessful insertion was considered effective CP. The applied cricoid forces were measured with a novel instrument, the cricometer. The first patient in each group received 20 N. The applied cricoid force in successive patients was determined by the response of the previous patient within the same group, using the up-and-down sequential allocation technique. RESULTS: In the 30 men and 30 women who qualified for the study, the median cricoid force (cricoid force = 50) that occluded the esophageal entrance was 30.8 N (95% confidence interval = 28.15-33.5) in men, and 18.7 N in women (95% confidence interval = 17.1-20.3; P < .0001). Patency of the esophageal entrance was observed when CP was not applied and when inadequate forces that allowed successful esophageal cannulation were used. CONCLUSIONS: The current study provides evidence that the median force necessary to occlude the esophageal entrance to prevent regurgitation is less in women compared with men. Applying the appropriate cricoid force in women should also decrease airway-related problems that tend to occur with the use of excessive forces. The findings of the current study may only be applicable to patients with normal body habitus.

The effectiveness of cricoid pressure for occluding the esophageal entrance in anesthetized and paralyzed patients: an experimental and observational glidescope study.

BACKGROUND: In the last 2 decades, the effectiveness of cricoid pressure (CP) in occluding the esophageal entrance has been questioned. Recent magnetic resonance imaging studies yielded conflicting conclusions. We used real-time visual and mechanical means to assess the patency of the esophageal entrance with and without CP in anesthetized and paralyzed adult patients. METHODS: One hundred seven, nonobese ASA physical status I and II patients were recruited for the study. A cricoid force of 30 N was used. This force was standardized by using a weighing scale before application of CP in each patient. After oxygen administration, anesthetic induction, neuromuscular blockade, and establishment of manual ventilation with FIO2 = 1.0, the view of the glottis and esophageal entrance was visualized, and video recordings were obtained by using a Glidescope video laryngoscope. Attempts to insert 2 gastric tubes (GTs), size 12 and 20 F, into the esophagus were made by a "blinded" operator without and with CP, the timing of which was randomized. A successful insertion of a GT in the presence of CP was considered evidence of a patent esophageal entrance (ineffective CP), whereas an unsuccessful insertion of a GT was considered evidence of an occluded esophageal entrance (effective CP). After the attempts to insert the GTs were completed, tracheal intubation was performed while CP was applied. The position of the esophageal entrance in relation to the glottis (midline versus lateral) was assessed from the video recordings, with and without CP. RESULTS: We stopped the study when 79 patients (41 men and 38 women) qualified for and completed the study (2-sided Clopper-Pearson confidence interval (CI) 95% to 100%, n = 72). Advancement of either size GT into the esophagus could not be accomplished during CP in any patient but was easily done in all subjects when CP was not applied. This occurred whether the esophageal entrance was in a midline position or in a left or right lateral position relative to the glottis. Esophageal patency was visually observed in the absence of CP, whereas occlusion of the esophageal entrance was observed during CP in all patients. Without CP, the esophageal entrance was in a left lateral position in relation to the glottis in 57% ([95 % CI, 45%-68%)] of patients, at midline in 32% (CI, 22%-43%), and in a right lateral position in 11% (CI, 5%-21%). The position did not change with CP. CONCLUSIONS: The current study provides additional visual and mechanical evidence supporting a success rate of at least 95% by using a cricoid force of 30 N to occlude the esophageal entrance in anesthetized and paralyzed normal adult patients. The efficacy of the maneuver was independent of the position of the esophageal entrance relative to the glottis, whether midline or lateral.

Postoperative brain stroke after shoulder arthroscopy in the lateral decubitus position.

The beach chair position is used frequently for shoulder arthroscopy surgery. However, the beach chair position has been reported to be linked to postoperative cerebral stroke. The lateral decubitus position has been used as an alternative position to avoid such neurologic complications. We report a case of postoperative brain stroke in a 52-year-old man who underwent shoulder arthroscopy surgery in the lateral decubitus position. The patient experienced a brief period of intraoperative hypotension. Physicians should be aware of this potential complication that could be irrelevant to the position used.

Bilateral guided cervical block for Zenker diverticulum excision in a patient with ankylosing spondylitis.

Patients with severe ankylosing spondylitis (AS) have difficulties in tracheal intubation. An 87-year-old man with severe AS was scheduled for Zenker diverticulum (ZD) excision. It was decided to proceed with combined bilateral cervical plexus blockade using a nerve stimulator. The surgery lasted about 3 h, with stable hemodynamics, ECG, and oxygen saturation. The use of a nerve stimulator-guided cervical block minimizes the risk of severe respiratory and/or airway compromise secondary to phrenic nerve or recurrent laryngeal nerve palsy, because it can elicit diaphragmatic muscle response, which helps to avoid the administration of local anesthetic directly to the area of the phrenic nerve, and guides correct needle placement. In conclusion, the nerve stimulatorguided bilateral cervical block in our ZD patient with AS was shown to be a safe and successful alternative anesthetic option.

Intraarticular tramadol-bupivacaine combination prolongs the duration of postoperative analgesia after outpatient arthroscopic knee surgery.

BACKGROUND: Intraarticular (IA) local anesthetics are often used for the management and prevention of pain after arthroscopic knee surgery. Recently, IA tramadol was also used for the management of these patients. However, the IA combination of local anesthetic and tramadol has not been evaluated in arthroscopic outpatients. Our primary aim in this study was to evaluate the analgesic effect of an IA combination of bupivacaine and tramadol when compared with each drug alone using visual analog scale (VAS) pain scores in patients undergoing day-care arthroscopic knee surgery. Additionally, we assessed analgesic demand. METHODS: Ninety ASA I/II patients undergoing arthroscopic partial meniscectomy, performed by a single surgeon under general anesthesia, were assigned in a randomized, double-blind manner into three groups: group B (n = 30) received 0.25% bupivacaine, group T (n = 30) received 100 mg tramadol, and group BT (n = 30) received 0.25% bupivacaine and 100 mg tramadol to a total volume of 20 mL by the IA route after surgery. Postoperative pain scores were measured on a VAS, at rest and on mobilization at 0.5, 1, 2, 4, 6, 8, 12, and 24 h. Duration of analgesia, the subsequent 24 h consumption of rescue analgesia, time to ambulation, and time to discharge were evaluated. In addition, the systemic side effects of the IA injected drugs were also assessed. RESULTS: The results showed significantly lower VAS pain scores in group BT (P << 0.1) when compared with groups T and B. Group BT had a later onset of postsurgical pain and longer time to first rescue analgesic than groups B and T. The 24 h consumption of analgesic was significantly less in group BT when compared with the other two groups (26.7% of the patients required rescue analgesia in group BT, whereas this number was 90% in group B and 86.7% in group T). In addition, time in hours to discharge and time to unassisted ambulation were significantly shorter in group BT when compared with groups T and B, and this was not associated with any detectable systemic effects. CONCLUSION: The IA admixture of tramadol 100 mg with bupivacaine 0.25% provides a pronounced prolongation of analgesia compared with either drug alone in patients undergoing day care arthroscopic knee surgery.

Pharyngeal pack placement in minor oral surgery: A prospective, randomized, controlled study.

We conducted a prospective, randomized, controlled study to investigate the influence of pharyngeal pack placement on postoperative nausea, vomiting, and throat pain after minor oral surgery. Our study group was made up of 80 patients-45 men and 35 women, aged 19 to 52 years (mean: 27.3)-who underwent a minor oral surgical procedure under general anesthesia. Patients were randomly assigned to one of three groups: 20 patients who received a pharyngeal pack under videolaryngoscopic guidance (video guidance group), 20 who had a pack placed blindly (blind insertion group), and 40 patients who received no pack at all (control group). Postoperative nausea occurred in only 4 patients (20%) in the blind insertion group (p < 0.007). No patient experienced postoperative vomiting. Postoperative throat pain occurred in all 20 video guidance patients (100%), in 17 of the blind insertion patients (85%), and in 20 of the controls (50%). The difference between the controls and each of the two pack groups was statistically significant (p < 0.006); the difference between the two pack groups was not significant.