Evaluation of laryngoscopic view, intubation difficulty and sympathetic response during direct laryngoscopy in sniffing position versus simple head extension: a clinical comparative study

The effect of patient position on mask ventilation, laryngoscopic view, intubation difficulty, and the stance adopted by the anesthesiologist during laryngoscopy and tracheal intubation was investigated in 546 anesthetized adults in this prospective, randomized study. Patients were randomly assigned to either the sniffing position group or the simple extension group. The distribution of Cormack grades was comparable between the two groups (P=0.144). The IDS score [median (IQR)] was 0 (0–2) in the sniffing group and 1 (0–2) in the simple extension group;P=0.002. There were significant differences between groups with regard to intensity of lifting force, external laryngeal manipulation, alternate techniques used, number of attempts, and the stance adopted by anesthesiologist. We conclude that the sniffing position is superior to simple head extension with regard to ease of intubation as assessed by IDS. An upright stance is adopted by more anesthesiologists performing intubation with patients in the sniffing position.

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Cricoid Pressure Does Not Increase the Rate of Failed Intubation by Direct Laryngoscopy in Adults

Anesthesiology ◽

10.1097/00000542-200502000-00012 ◽

2005 ◽

Vol 102 (2) ◽

pp. 315-319 ◽

Cited By ~ 60

Author(s):

Alexis F. Turgeon ◽

Pierre C. Nicole ◽

Claude A. Trépanier ◽

Sylvie Marcoux ◽

Martin R. Lessard

Keyword(s):

Scale Score ◽

Direct Laryngoscopy ◽

Cricoid Pressure ◽

Anesthesia Induction ◽

Intubation Time ◽

Failed Intubation ◽

Laryngoscopic View ◽

Intubation Difficulty ◽

Lehane Grade ◽

Difficulty Scale

Background Cricoid pressure (CP) is applied during induction of anesthesia to prevent regurgitation of gastric content and pulmonary aspiration. However, it has been suggested that CP makes tracheal intubation more difficult. This double-blind randomized study evaluated the effect of CP on orotracheal intubation by direct laryngoscopy in adults. Methods Seven hundred adult patients undergoing general anesthesia for elective surgery were randomly assigned to have a standardized CP (n = 344) or a sham CP (n = 356) during laryngoscopy and intubation. After anesthesia induction and complete muscle relaxation, a 30-s period was allowed to complete intubation with a Macintosh No. 3 laryngoscope blade. The primary endpoint was the rate of failed intubation at 30 s. The secondary endpoints included the intubation time, the Cormack and Lehane grade of laryngoscopic view, and the Intubation Difficulty Scale score. Results Groups were similar for demographic data and risk factors for difficult intubation. The rates of failed intubation at 30 s were comparable for the two groups: 15 of 344 (4.4%) and 13 of 356 (3.7%) in the CP and sham CP groups, respectively (P = 0.70). The grades of laryngoscopic view and the Intubation Difficulty Scale score were also comparable. Median intubation time was slightly longer in the CP group than in the sham CP group (11.3 and 10.4 s, respectively, P = 0.001). Conclusions CP applied by trained personnel does not increase the rate of failed intubation. Hence CP should not be avoided for fear of increasing the difficulty of intubation when its use is indicated.

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Comparison of sniffing position and simple head extension for visualization of glottis during direct laryngoscopy.

Kathmandu University Medical Journal ◽

10.3126/kumj.v9i1.6265 ◽

2012 ◽

Vol 9 (1) ◽

pp. 58-63 ◽

Cited By ~ 2

Author(s):

B Bhattarai ◽

S K Shrestha ◽

S Kandel

Keyword(s):

Tracheal Intubation ◽

Direct Laryngoscopy ◽

Elective Surgery ◽

Demographic Profiles ◽

Intubation Difficulty ◽

Ideal Position ◽

Head Extension ◽

Extension Group ◽

Difficulty Scale ◽

Difficulty Score

Background The ability of good glottis visualization during direct laryngoscopy is major determinant of easy tracheal intubation. Sniffing position for laryngoscopy is considered as gold standard and ideal position. Several studies have questioned the validation of sniffing potion. Objectives This study aims to compare relative efficacy of sniffing position and simple head extension for visualization of glottis during direct laryngoscopy. Methods Four hundred patients undergoing elective surgery under general anesthesia requiring endotracheal intubation were randomized into two groups and study was concluded. Glottic visualization was assessed using modified Cormack and Lehane classification. After laryngoscopy, tracheal intubation was performed and intubation difficulty scale was noted. Results Both the groups were comparable regarding glottis visualization. Both the groups were comparable in demographic profiles. All the intubation difficulty scale variables were comparable in both the groups except N3. Total Intubation Difficulty Score was better in sniffing position than in simple head extension group. Conclusion Glottic visualization and intubation difficulty score was better in sniffing position as compared to simple head extension.http://dx.doi.org/10.3126/kumj.v9i1.6265 Kathmandu Univ Med J 2011;9(1):58-63

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Randomized Study Comparing the “Sniffing Position” with Simple Head Extension for Laryngoscopic View in Elective Surgery Patients

Anesthesiology ◽

10.1097/00000542-200110000-00009 ◽

2001 ◽

Vol 95 (4) ◽

pp. 836-841 ◽

Cited By ~ 133

Author(s):

Frédéric Adnet ◽

Christophe Baillard ◽

Stephen W. Borron ◽

Christophe Denantes ◽

Laurent Lefebvre ◽

...

Keyword(s):

Direct Laryngoscopy ◽

Elective Surgery ◽

Randomized Study ◽

Orotracheal Intubation ◽

Simple Extension ◽

Laryngoscopic View ◽

Head Extension ◽

Group A ◽

Group B ◽

Neck Mobility

Background The "sniffing position" is recommended for optimization of glottic visualization under direct laryngoscopy. However, no study to date has confirmed its superiority over simple head extension. In a prospective, randomized study, the authors compared the sniffing position with simple head extension in orotracheal intubation. Methods The study included 456 consecutive patients. The sniffing position was obtained by placement of a 7-cm cushion under the head of the patient. The extension position was obtained by simple head extension. The anesthetic procedure included two Laryngoscopies without paralysis: the first was used for topical glottic anesthesia. During the second direct laryngoscopy, intubation of the trachea was performed. The head position was randomized as follows: group A was in the sniffing position during the first Laryngoscopy and the extension position during the second, group B was in the extension position during the first laryngoscopy and the sniffing position during the second. Glottic exposure was assessed by the Cormack scale. Results The sniffing position improved glottic exposure (decreased the Cormack grade) in 18% of patients and worsened it (increased the Cormack grade) in 11% of patients, in comparison with simple extension. The Cormack grade distribution was not significantly modified between the two groups. Multivariate analysis showed that reduced neck mobility and obesity were independently related to improvement in laryngoscopic view with application of the sniffing position. Conclusions Routine use of the sniffing position appears to provide no significant advantage over simple head extension for tracheal intubation in this setting. The sniffing position appears to be advantageous in obese and head extension-limited patients.

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Characteristics of Sympathetic Response in the Patients with Chronic Low Back Pain : A Comparative Study

Jouranl of Korean Association of EMG Electrodiagnostic Medicine ◽

10.18214/jkaem.2011.13.2.91 ◽

2011 ◽

Vol 13 (2) ◽

pp. 91-96

Author(s):

김성훈 ◽

박정미 ◽

허동민 ◽

김정문 ◽

Seong Hoon Kim ◽

...

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Comparative Study ◽

Chronic Low Back Pain ◽

Low Back ◽

Sympathetic Response

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Comparison of Laryngoscopic Views between C-MAC™ and Conventional Laryngoscopy in Patients with Multiple Preoperative Prognostic Criteria of Difficult Intubation. An Observational Cross-Sectional Study

Medicina ◽

10.3390/medicina55120760 ◽

2019 ◽

Vol 55 (12) ◽

pp. 760

Author(s):

Aikaterini Amaniti ◽

Panagiota Papakonstantinou ◽

Dimitrios Gkinas ◽

Ioannis Dalakakis ◽

Evangelia Papapostolou ◽

...

Keyword(s):

Prognostic Factors ◽

Difficult Intubation ◽

Elective Surgery ◽

Significant Risk ◽

Significant Risk Factor ◽

Cross Sectional Study ◽

Laryngoscopic View ◽

Cross Sectional ◽

Intubation Difficulty ◽

Difficulty Scale

Background and Objectives: Video laryngoscopy has been proven useful under difficult airway scenarios, but it is unclear whether anticipated improvement of visualization is related to specific difficult intubation prognostic factors. The present study evaluated the change in laryngoscopic view between conventional and C-MAC® laryngoscopy and the presence of multiple difficult intubation risk factors. Materials and Methods: Patients scheduled for elective surgery with >2 difficult intubation factors, (Mallampati, thyromental distance (TMD), interinscisor gap, buck teeth, upper lip bite test, cervical motility, body mass index (BMI)) were eligible. Patients underwent direct laryngoscopy (DL) followed by C-MAC™ laryngoscopy (VL) and intubation. Change of view between DL and VL, time for best view, intubation difficulty scale (IDS) and correlation between prognostic factors, laryngoscopic view improvement, and IDS were measured. Results: One-hundred and seventy-six patients completed the study. VL lead to fewer Cormarck–Lehane (C/L) III-IV, compared to DL (13.6% versus 54.6%, p < 0.001). The time to best view was also shorter (VL: 10.82 s, DL: 12.08 s, p = 0.19). Mallampati III-IV and TMD ≤ 6 cm were related to improvement of C/L between DL and VL. Logistic regression showed these two factors to be a significant risk factor of the glottis view change (p = 0.006, AUC-ROC = 0.57, 95% CI: 0.47–0.66). 175/176 patients were intubated with VL. 108/176 were graded as 0 < IDS ≤ 5 and 12/176 as IDS > 5. IDS was only correlated to the VL view (p < 0.0001). Conclusion: VL improved laryngoscopic view in patients with multiple factors of difficult intubation. Mallampati and TMD were related to the improved view. However, intubation difficulty was only related to the VL view and not to prognostic factors.

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