View of the larynx obtained using the Miller blade and paraglossal approach, compared to that with the Macintosh blade

Anaesthesia and Intensive Care, Sept, 2008 by B. Achen, O. C. Terblanche, B.T. Finucane

(10.) Arino JJ, Velasco JM, Gasco C, Lopez-Timoneda F. Straight blades improve visualization of the larynx while curved blades increase ease of intubation: a comparison of the Macintosh, Miller, McCoy, Belscope and Lee-Fiberview blades. Can J Anesth 2003; 50:501-506.

(11.) Racz GB. Improved vision modification of the Macintosh laryngoscope. Anaesthesia 1984; 39:1249-1250.

(12.) Horton WA, Fahy L, Charters P. Factor analysis in difficult tracheal intubation: laryngoscopy-induced airway obstruction. Br J Anaesth 1990; 65:801-805.

(13.) Henderson JJ. Questions about the Macintosh Laryngoscope and the technique of laryngoscopy. Eur J Anaesthesiol 2000; 17:2-5.

(14.) Henderson JJ. Laryngeal view and ease of endotracheal intubation achieved with a new straight laryngoscope (Henderson Laryngoscope). Anesthesiology 1999; 91:563.

B. ACHEN *, O. C. TERBLANCHE [dagger], B. T. FINUCANE [double dagger]

* M.D., F.R.C.P.C., Assistant Clinical Professor.

[dagger] M.D., F.R.C.P.C., Staff Anesthesiologist.

[double dagger] M.B., B.Ch., F.R.C.P.C., Professor.

Address for reprints: Dr B. Achen, Department of Anesthesiology and Pain Medicine, University of Alberta, Clinical Sciences Building, Room 8-120, Edmonton, Alberta T6G 2G3, Canada. Accepted for publication on June 5, 2008.

Department of Anesthesiology and Pain Medicine, University of Alberta Hospital, Edmonton, Alberta, Canada

TABLE 1
Demographics

                   Mean age     % Male     % Female    Mean weight

Miller           (s) 55.7 y     48.90%       51.10%      (a) 84 kg

Macintosh        (d) 55.4 y     51.50%       48.50%      (b) 79 kg

                     *MP #1     *MP #2       *MP #3

Miller                  54%        31%          15%

Macintosh               53%        38%           9%

* MP refers to Mallampati classification, (a) = standard deviation
of 18. 17.9 kg, (s) =standard deviation of 17.0 y, (d) = standard
deviation of 17.7 y.

FIGURE 1: Comparison of the number of cases in the Miller group
with a 100% view of the vocal cords compared with the number in
the Macintosh group with a 100% view of the vocal cords.

Miller vs. Macintosh
Glottis View Observed

              100%      <100%

Miller        78.0%     22.0%
Mac           53.0%     47.0%

Note: Table made from bar graph.

FIGURE 2: Comparison of the number of cases in the Miller group
with 25% or more of the vocal cords visible compared with the
number in the Macintosh group with 25% of the vocal cords
visible.

Miller vs. Macintosh
Vocal cords visualised

              Miller       Mac

>/= 25%       95.0%        80.0%
<25%           5.0%        20.0%

Note: Table made from bar graph.

FIGURE 3: Comparison of the Cormack and Lehane grades
obtained in the two groups shown in percentages.

Miller vs. Macintosh
Laryngeal Grade

               Miller      Mac

Grade 1        96.5%       85.0%
Grade 2 to 4    3.5%       15.0%

Note: Table made from bar graph.