Haruki Kido

Cricoid pressure impedes tracheal intubation with the Pentax-AWS Airwayscope®: a prospective randomized trial

BACKGROUND It is unclear how cricoid pressure affects tracheal intubation with the Pentax-AWS Airwayscope(®) (AWS). We conducted a prospective randomized clinical trial in anaesthetized patients. METHODS Sixty patients were allocated to either the cricoid pressure (CP) group (n=30) or the sham group (n=30). We compared the two groups with regard to intubation time, number of attempts required for insertion of the Intlock blade (disposable blade of the AWS) and tracheal intubation, percentage of glottic opening (POGO) score, and subjective difficulty of both laryngoscopy and passage of a tube through the glottis. RESULTS Intubation time was significantly longer in the CP group (median 45[IQR40-59] s) than in the sham group (32[28-45] s) (P=0.003, 95% CI for median difference 5-24 s). The number required for insertion of the Intlock blade did not differ between the groups (P=0.08), but the number for tracheal intubation was significantly higher in the CP group (1 attempt in 14 patients, 2 in 7, 3 in 9) than in the sham group (1 attempt in 24 patients, 2 in 6; P=0.002). POGO score did not differ significantly between the groups (P=0.60), nor did the subjective difficulty of laryngoscopy (P=0.06). The visual analogue scale score for passage of a tube through the glottis was significantly higher in the CP group than in the sham group (P<0.001). CONCLUSIONS Cricoid pressure impedes tracheal intubation using the AWS, and is associated with longer intubation time, which can be attributed to increased difficulty in the passage of a tube through the glottis. CLINICAL TRIAL REGISTRY NUMBER UMIN000018209.

Comparison of McGRATH MAC and Macintosh laryngoscopes for double-lumen endotracheal tube intubation by anesthesia residents: a prospective randomized clinical trial.

STUDY OBJECTIVE This study aimed to compare the utility of McGRATH MAC (McG) and Macintosh (McL) laryngoscopes for double-lumen endotracheal tube intubation in patients undergoing elective surgery. DESIGN Randomized clinical trial. SETTING Operating room. PATIENTS Fifty adult patients scheduled for elective surgery under 1-lung ventilation with American Society of Anesthesiologists physical status 1 to 3. INTERVENTIONS Double-lumen endotracheal tube intubation was performed with the McG (McG group; 25 patients) or conventional McL (McL group; 25 patients) laryngoscope by anesthesia residents. MEASUREMENTS The number of attempts to successful intubation, intubation time, percentage of glottis opening score, and subjective difficulty of laryngoscopy and tube passage through the glottis were assessed. MAIN RESULTS The total numbers of intubation attempts were 1 (McG group, 24 patients; McL group, 16 patients), 2 (McG group, 1 patient; McL group, 8 patients), and 3 (McG group, 0 patient; McL group, 1 patient), with significant differences between the two groups (P = .018). Intubation time was significantly shorter in the McG group compared with the McL group (McG: 17.1 ± 4.6 seconds vs McL: 20.8 ± 5.9 seconds, P = .026). The percentage of glottis opening score was significantly higher in the McG group compared with the McL group (McG: 88.4% ± 13.7% vs McL: 71.4% ± 20.4%, P = .004). CONCLUSIONS The McG demonstrated a better intubation profile compared with the McL, possibly due to its ease of use for double-lumen endotracheal tube intubation. Clinical Trial registry number: UMIN000014636.

Impact of pillow height on double-lumen endotracheal tube intubation with McGRATH MAC: a prospective randomized clinical trial

STUDY OBJECTIVE This study aimed to compare the impact of pillow height on double-lumen tracheal tube (DLT) intubation with McGRATH MAC (McG) in patients undergoing elective surgery. DESIGN Randomized clinical trial. SETTING Operating room. PATIENTS Fifty adult patients scheduled for elective surgery under 1-lung ventilation with an American Society of Anesthesiologists physical status of 1 to 3. INTERVENTIONS DLT intubation with McG was performed with a high pillow (HP group; 25 patients) or low pillow (LP group; 25 patients) by anesthesiologists. MEASUREMENTS Intubation time, number of laryngoscopy, number of tracheal intubation attempts to successful intubation, percentage of glottic opening score, and subjective difficulty of laryngoscopy and tube passage through the glottis were assessed. MAIN RESULTS Intubation time was significantly shorter in the HP group compared with the LP group (HP: 32.1±14.9seconds vs LP: 49.4±11.2seconds, P<.001). The number of laryngoscopy were 1 (HP group, 22 patients; LP group, 17 patients), 2 (HP group, 3 patient; LP group, 7 patients), and 3 (HP group, 0 patient; LP group, 1 patient), with no significant difference between the 2 groups (P=.197). Although the percentage of glottic opening score did not significantly differ between HP and LP groups (HP: 95.6%±6.7% vs LP: 96.0%±12.3%, P=.08), the number of tracheal intubation attempts was significantly lower in the HP group compared with the LP group (P=.009). The visual analog scale score for laryngoscopy did not significantly differ between the 2 groups (P=.54). However, the visual analog scale for tube passage through the glottis was significantly higher in the LP group than in the HP group (P<.001). CONCLUSIONS Intubation with an HP was associated with a better DLT intubation profile than with an LP with McG, possibly due to smoother tracheal tube progression through the glottis.

Muscle relaxant facilitates i-gel insertion by novice doctors: A prospective randomized controlled trial

STUDY OBJECTIVE This study aimed to determine whether muscle relaxants facilitates insertion efficacy of the i-gel supraglottic device (i-gel) by novice doctors in anesthetized patients. DESIGN Randomized clinical trial. SETTING Operating room. PATIENTS Seventy adult patients scheduled for elective surgery under general anesthesia. INTERVENTIONS Seventy adult patients were assigned to the rocuronium (MR group; 35 patients) or control group (C group; 35 patients). Anesthesia was induced with propofol and remifentanil, and 0.9mgkg(-1) rocuronium was administered in the MR group. MEASUREMENTS The number of attempts to successful insertion, sealing pressure, and subjective difficulty of insertion were compared between the groups. MAIN RESULTS The total number of insertion attempts were as follows: one (MR group, 17 cases; C group, 4 cases), two (MR group, 13 cases; C group, 14 cases), three (MR group, 4 cases; C group, 14 cases), and failure (MR group, 1 case; C group, 3 cases), which was significantly different (P<.001). Sealing pressure was significantly higher in the MR group than in the C group (MR group, 22.1±5.4 cmH2O; C group, 18.7±3.2 cmH2O, P<.001). Subjective difficulty of insertion was significantly lower in the MR group than in the C group (C group, 72.4±19.0mm; MR group, 29.4±18.3mm; P<.001). CONCLUSIONS Our randomized clinical trial suggests that muscle relaxation facilitates i-gel insertion efficacy in anesthetized patients, as assessed by successful insertion rate, sealing pressure, and subjective difficulty of insertion.

Evaluation of ultrasound-guided posterior quadratus lumborum block for postoperative analgesia after laparoscopic gynecologic surgery

STUDY OBJECTIVE This study aimed to determine the efficacy of ultrasound-guided posterior quadratus lumborum block (QLB) in treating postoperative pain following laparoscopic gynecologic surgery. DESIGN Prospective randomized controlled study. PATIENTS Seventy adult patients scheduled for elective laparoscopic gynaecological surgery under general anesthesia. INTERVENTION This randomized controlled study involved two groups of adult females who were scheduled to undergo laparoscopic gynecologic surgery under general anesthesia. Patients were randomly assigned to either the QLB group or Control group. In the QLB group, patients underwent posterior QLB with 20mL of 0.375% ropivacaine on each side. Patients were blinded to treatment. MEASUREMENTS At 0, 1, 3, and 24 hours after anesthesia recovery, evaluator recorded the severity of postoperative pain in movement and at rest using a Numeric Rating Scale (NRS). We also evaluated the severity of nausea using NRS and number of additional analgesics. MAIN RESULTS Immediately after recovery from anesthesia, the NRS score for pain in movement did not differ significantly between groups. NRS scores for pain both in movement and at rest were significantly higher in the Control group than in the QLB group at 1, 3, and 24h after recovery from anesthesia. CONCLUSION Our results suggest that posterior QLB significantly reduces postoperative pain in movement and at rest following laparoscopic gynecologic surgery.

LMA-ProSeal insertion by novice doctors as affected by a 90° bend created by an intubating stylet: a randomized clinical trial.

STUDY OBJECTIVE This study aimed to test the hypothesis that insertion of the supraglottic device LMA-ProSeal (ProSeal) by novice doctors in anesthetized patients can be improved by using an intubating stylet to create a 90° bend and that better sealing pressure is achieved. DESIGN Randomized clinical trial. SETTING Operating room. PATIENTS Seventy adult patients scheduled for elective surgery under general anesthesia using ProSeal with American Society of Anesthesiologists physical status 1 to 3. INTERVENTIONS ProSeal were inserted with the 90° bend created by the intubating stylet (90D group, 35 patients) or not (ie, conventional insertion; C group, 35 patients). MEASUREMENTS The number of attempts to successful insertion, sealing pressure, subjective difficulty of insertion by novice doctors, and postoperative pharyngeal pain or hoarseness were compared between groups. MAIN RESULTS The total number of insertion attempts for the 90D and control groups were 1 (24 and 8, respectively), 2 (8 and 13), 3 (3 and 9), and failure (0 and 5), respectively, showing significant differences between groups (P<.001). Sealing pressure was significantly higher in the 90D group than in the C group (90D group, 23.3±3.7cm H2O; C group, 19.5±2.6cm H2O; P<.001), and the subjective difficulty of insertion was significantly lower in the 90D group (90D group, 27.3±17.6mm; C group, 55.4±22.8mm; P<.001). The incidence of postoperative pharyngeal pain and hoarseness did not differ significantly between groups. CONCLUSIONS Our results suggest that creating a 90° bend using an intubating stylet facilitates ProSeal insertion by novice doctors, as reflected by higher successful insertion rates, higher sealing pressure, and lower subjective difficulty of insertion in anesthetized patients.

Evaluation of double-lumen endotracheal tube extubation force by extraction angle: a prospective randomized clinical trial

STUDY OBJECTIVE Gentle and noninvasive double-lumen tracheal tube (DLT) extubation is important for both airway and circulatory management, especially after lung resection. We performed a prospective randomized clinical trial comparing DLT extubation force based on 2 different extraction angles. DESIGN Randomized clinical trial. SETTING Operating room. PATIENTS Sixty adult patients scheduled for elective surgery under general anesthesia using DLT with ASA physical status 1 to 3. INTERVENTIONS Sixty patients who underwent lung resection with a DLT were randomly assigned to extraction angles of 60° (30 patients) and 90° (30 patients) relative to the ground. MEASUREMENTS Extubation forces and changes in vital signs were compared between groups. Results were analysed with the Mann-Whitney U test, non-paired t test, and χ(2) test. P<.05 was considered significant. MAIN RESULTS Less extraction force was needed at 60° compared to 90° (90°, 13.9±2.3 N; 60°; 7.1±2.1 N; P<.001). The rate of increase in systolic and diastolic blood pressure (post-extubation/pre-extubation) was significantly smaller at 60° than at 90° (systolic blood pressure, P<.001; diastolic blood pressure, P=.002). CONCLUSIONS Our findings suggest that DLT extubation at 60° requires less force than at 90° and was accompanied by a smaller increase in blood pressure. Thus, extraction at 60° may be less invasive and beneficial for patients undergoing DLT extubation.

A rare case of accidental arterial local anesthetic injection under ultrasound-guided stellate ganglion block

A 43-year-old woman (60 kg, 158 cm) routinely visited our department for SGB to treat intractable left-side facial nerve paralysis. She had undergone USG SGB more than 10 times. Ultrasound also revealed enlarged thyroid but showed no associated symptoms. Most recently, although we confirmed major vessels by USG, arterial puncture by the block needle occurred when USG SGB was performed. After 5 minutes of astriction, we performed USG SGB again with maximum attention to avoid repuncture. Under USG SGB, the needle could be easily visualized, and no arterial leak was observed. We administered 2 mL of 1% mepivacaine, but the patient experienced convulsions and respiratory arrest immediately after injection; right carotid artery pulse was sufficient. Bag-valve-mask ventilation was initiated, and spontaneous breathing recovered within 5 minutes. After recovery of spontaneous breathing, 3 mg of midazolam was administered to control the convulsions, followed by intravenous fat emulsion (20%, 100 mL). Consciousness recovered after 20 minutes. After 5 hours, the patient recovered completely without any neurological complications and was discharged home.

Cricoid pressure force retention analysis using a simulator

Editor—We thank Dr Bennett and colleagues for their comments on our trial. Their finding of 44% of patients desaturating during the procedure (despite a higher threshold) is in line with our measurements. In our patient group, the correlation between the intraoperative haemoglobin concentration (measured after balloon valvuloplasty) revealed a high negative two-sided correlation (Spearman) to the area under the curve for desaturation (R=−0.812, P<0.001). Taking a closer look at the two described anaesthesia techniques [general anaesthesia (TAVI-GA) or sedation (TAVI-S)] revealed the following negative correlations: TAVI-GA; R=−0.902, P<0.001; and TAVI-S, R=−0.638, P=0.035. Referring to the increase of cerebral oxygenation during the recovery period, some additional factors have to be taken into account. Firstly, there are two recovery phases, one after the balloon valvuloplasty and one after the valve implantation. Secondly, each transcatheter valve has an individual haemodynamic profile during implantation. Self-expanding valves may lead to a longer hypotension based on the longer implantation period, whereas in balloon-expanding valves a short-term cardiac arrest is demanded. Third, the concurrent use of inotropes may also influence the increase of cerebral saturation. Nevertheless, we think that your results point in the same direction as ours and that all efforts to improve anaesthesia in this group of high-risk patients are welcome.

Possibility of lip pulling method not only for prevention of soft tissue injury but also for improved laryngoscopy and tracheal intubation.

Lip injuries are well-recognized complications of laryngoscopy and tracheal intubation [1]. Previous reports suggest that a nonnegligible number of lower lip (22.3%) and upper lip (7.1%) injuries occur during these procedures even in well-equipped operation room [2]. The inherent mechanism of lip injury is caused by the laryngoscopy. When performing laryngoscopy with the Macintosh laryngoscope, physicians are mainly focused onmoving the tongue with the blade and achieving a good view of the glottis. During this process, the upper and lower lips can become squeezed by the lips and teeth, which can lead to injury. This phenomenon may occur more frequently with novice physicians or in emergency situations. Empirically, lip pulling method is applied to minimize soft tissue injury. Typically, assistants or a second anesthesiologist is present during induction of anesthesia for elective surgery. Having these medical staff pull the upper and lower lips outward (upward and downward, respectively) contributes to a substantial reduction in lip injuries (Figure). The clearer view afforded by this additional step could also help minimize tooth and gum injuries as well. We noticed that this lip pullingmethod can give physicians good laryngoscopy view. In emergency situations, sufficient oral and pharyngeal observation is essential for rapid and definite tracheal intubation [4,5]. Here, we propose a modification (addition of a “lip pulling” step) to conventional tracheal intubation that minimizes the incidence of lip injury. In view of the foregoing,we propose the following steps for tracheal intubation during emergency situation: (1) physicians perform head tilting to achieve the sniffing position, (2) physicians open the patients