This is a retrospective study of patients whose tracheas were impossible to intubate on a previous occasion. There is a correlation between the degree of difficulty and the anatomy of the oropharynx in the same patient. The study was initially on obstetric patients but was extended to nonobstetric surgical patients in order to increase the number of cases investigated. The incidence of failed intubations in the obstetric group over a 3-year period was seven out of 1980 cases, whereas in the surgical group the results were six out of 13,380 patients. Any screening test which adds to our ability to predict difficulty in intubation must be welcomed, as failure to intubate can potentially lead to fatality.

Difficult tracheal intubation: A retrospective study

Purpose
To review the current literature and generate recommendations on the role of newer technology in the management of the unanticipated difficult airway.

/pdf/the-unanticipated-difficult-airway-with-recommendations-for-1fnpjad04s.pdf

The unanticipated difficult airway with recommendations for management

The isolation of an opioid receptor-related clone soon led to the isolation and characterization of a new neuropeptide, termed orphanin FQ or nociceptin (OFQ/N). This heptadecapeptide binds to the NOP(1) (previously termed ORL1) receptor with exceedingly high affinity, but does not interact directly with classical opioid receptors. Functionally, the actions of OFQ/N are diverse and intriguing. Most work has focused upon pain mechanisms, where OFQ/N has potent anti-analgesic actions supraspinally and analgesic actions spinally. Other OFQ/N activities are less clear. The diversity of responses might reflect NOP(1) receptor heterogeneity, but this remains to be established. The actions of this neurochemical system may also be uniquely dependent on contextual factors, both genetic and environmental. This review will address the molecular biology and behavioral pharmacology of OFQ/N and its receptor.

The Molecular and Behavioral Pharmacology of the Orphanin FQ/Nociceptin Peptide and Receptor Family

Background. The GlideScope® Video Laryngoscope is a new intubating device. It was designed to provide a view of the glottis without alignment of the oral, pharyngeal and tracheal axes. The aim of the study was to describe the use of the GlideScope® in comparison with direct laryngoscopy for elective surgical patients requiring tracheal intubation. Methods. Two hundred patients were randomly assigned to intubation by direct laryngoscopy using a Macintosh size 3 blade (DL, n=100) or intubation using the GlideScope® (GS, n=100). Prior to intubation all patients were given a Cormack and Lehane (C&L) grade by a separate anaesthetist using a Macintosh size 3 blade. The patient was then intubated, using direct laryngoscopy or the GlideScope®, by a different anaesthetist during which the larynx was inspected and given a laryngoscopy score. Time to intubate was measured. Results. In the GS group, laryngoscopy grade was improved in the majority (28/41) of patients with C&L grade >1 and in all but one of patients who were grade 3 laryngoscopy (P Conclusion. In most patients, the GlideScope® provided a laryngoscopic view equal to or better than that of direct laryngoscopy, but it took an additional 16 s (average) for tracheal intubation. It has potential advantages over standard direct laryngoscopy for difficult intubations.

The GlideScope® Video Laryngoscope: randomized clinical trial in 200 patients

Prediction of difficult laryngoscopy in obese patients is challenging. In 50 morbidly obese patients, we quantified the neck soft tissue from skin to anterior aspect of trachea at the vocal cords using ultrasound. Thyromental distance 2, abnormal upper teeth, neck circumference >45 cm, and sleep apnoea were considered predictors of difficult laryngoscopy. Of the nine (18%) difficult laryngoscopy cases, seven had obstructive sleep apnoea history; whereas, only 2 of the 41 easy laryngoscopy patients did (P<0.001). Difficult laryngoscopy patients had larger neck circumference [50 (3.8) vs. 43.5 (2.2) cm; P<0.001] and more pre-tracheal soft tissue [28 (2.7) mm vs. 17.5 (1.8) mm; P<0.001] [mean (SD)]. Soft tissue values completely separated difficult and easy laryngoscopies. None of the other predictors correlated with difficult laryngoscopy. Thus, an abundance of pretracheal soft tissue at the level of vocal cords is a good predictor of difficult laryngoscopy in obese patients.

/pdf/prediction-of-difficult-laryngoscopy-in-obese-patients-by-293ofu8w1s.pdf

Prediction of difficult laryngoscopy in obese patients by ultrasound quantification of anterior neck soft tissue

The displacement of the larynx in the three specific directions (a) posteriorly against the cervical vertebrae, (b) superiorly as possible, and (c) slightly laterally to the right have been reported and named the “BURP” maneuver. We evaluated the efficacy of the BURP maneuver in improving visualization of the larynx. Six hundred thirty patients without obvious malformation of the head and neck participated in this study. We divided the degree of visualization of the larynx using laryngoscopy into five grades and compared the visualization of the larynx using the BURP maneuver with that of laryngoscopy with and without simple laryngeal pressure (“Back”). The maneuver of Back and BURP significantly improved the laryngoscopic visualization from initial inspection. The BURP maneuver also significantly improved the visualization compared with the Back maneuver. We concluded that the BURP maneuver improved the visualization of the larynx more easily than simple back pressure on the larynx. (Anesth Analg 1997;84:419-21)

The Efficacy of the "BURP" Maneuver During a Difficult Laryngoscopy

Sevoflurane suppresses behavioral response in the rat formalin test: combination with intrathecal lidocaine produced profound suppression of the response

Naltrexone, but not atropine or yohimbine, antagonizes suppression of formalin-induced spinal sensitization by intrathecal nociceptin.

https://www.jpsmjournal.com/article/S0885-3924(97)00271-6/pdf

High-Dose Intrathecal Morphine to Control Cancer Pain .A Case Report

https://www.jstage.jst.go.jp/article/jjspc1994/1/3/1_3_404/_pdf

Hidemichi Ogawa

Papers

The Efficacy of the "BURP" Maneuver During a Difficult Laryngoscopy

Sevoflurane suppresses behavioral response in the rat formalin test: combination with intrathecal lidocaine produced profound suppression of the response

Naltrexone, but not atropine or yohimbine, antagonizes suppression of formalin-induced spinal sensitization by intrathecal nociceptin.

High-Dose Intrathecal Morphine to Control Cancer Pain .A Case Report

The effect of superior cervical ganglionectomy on rat weight development