Robert Reynolds Macintosh

Sir Robert Reynolds Macintosh (1897 – 1989) was a New Zealand Anaesthetist.

In the 1940s he became concerned with the number of unexpected deaths seen whilst patients were under anaesthesia; along with William Mushin he developed a research project to look into unexpected deaths but this was initially met with hesitation from the association of anaesthetists until 1949 where they assigned a committee designated to investigate death associated with anaesthesia. He helped to establish academic chairs and the fostering of high standards of training and practice within anaesthesia in developing countries and the commonwealth.

Macintosh developed many useful anaesthetic devices including the gum elastic bougie (1949); the Illuminated introducer for endotracheal tubes (1957); Epstein-Macintosh-Oxford Inhaler; and the life-jacket…It has been said that his greatest contribution came from his teaching

Macintosh developed the ‘Oxford Vaporiser’ – a simple, portable machine that allowed accurate administration of ether in the war, which made anaesthesia safer.

Eponymously affiliated with the Macintosh Laryngoscope. The curved blade of the laryngoscope allows larynx exposure by directly lifting the epiglottis. This required lighter planes of anaesthesia and was useful in intubating semi-conscious patients on the battlefield.


Biography
  • Born on October 17, 1897 in Timaru, New Zealand. His father, Charles Nicholson Macintosh was mayor of Timaru (1901-2) and All Black Number 39, touring Australia in 1893
  • Macintosh was baptised with the Maori name Rewi Rawhiti Macintosh and changed his name to Robert Reynolds after WWI
  • 1915 – served as a pilot in the Royal Flying Corps in WW I. Shot down behind German lines 26 May 1917, imprisoned and made many failed attempts to escape. Repatriated 1918.
  • 1924 – Graduated Guys Hospital Medical School MRCS LRCP
  • 1927 – Fellow of the Royal College of Surgeons, Edinburgh
  • 1937 – Nuffield Professor of Anaesthetics, Oxford University. Post was first Chair in anaesthetics in Europe and second in the world (after Ralph Waters, University of Wisconsin); professorship made at the behest of Lord Nuffield’s, but against the University wishes, for at the time Anaesthetics lacked academic credentials
  • 1941 – Air Commodore in the Royal Air Force and Royal Navy in WW II. Advisor and consultant, carried out tests on life jackets with Edgar Pask (1912-1966) – life jacket is still in use today
  • 1955 – Knighted
  • 1965 – Retired; Emeritus Professor, Nuffield Department of Anaesthetics, Oxford
  • Died on August 28, 1989 in Oxford, England

Medical Eponyms
Macintosh Laryngoscope (1943)

In 1943, Macintosh discovered the principle of indirect elevation of the epiglottis and developed the laryngoscope which bears his name.

The Macintosh laryngoscope has a curved blade which allows exposure of the larynx by positioning the tip in the vallecula, anterior to the epiglottis, lifting it out of view.

Macintosh laryngoscope 1943 comparison 2

(A) Standard laryngoscope with long straight blade.
(B) Laryngoscope with short curved blade.
Macintosh RR. Lancet 1943

This laryngoscope is designed to lessen the difficulty of exposing the larynx to pass an endotracheal tube. Normally the long straight blade of the standard laryngoscope (fig. lA) is passed beyond the epiglottis in order to evert it.

The new laryngoscope is designed so that when its short curved blade is in position the tip will fit into the angle made by the epiglottis with the base of the tongue (fig. 2); and a direct view thus obtained (fig. 3). If the laryngoscope is now lifted the base of the tongue will be pushed upwards (fig. 4); the epiglottis, because of its attachment to the base of the tongue, is drawn upwards and the larynx (fig. 5).

Macintosh RR. Lancet 1943
Macintosh laryngoscope 1943 action
Fig. 2 and 3: Site of blade and view obtained before lifting laryngoscope.
Fig. 4 and 5: Site of blade and view obtained when laryngoscope is lifted in direction of arrow.
Macintosh RR. Lancet 1943

Key medical contributions
Gum elastic bougie (1949)

Macintosh first described the use of a gum elastic introducer as an aid to passing endotracheal tubes. He described the introducer as projecting some 2-3 inches beyond the distal end of the tube, and being malleable the curve could be shaped to facilitate its introduction through the cords. Once the tip of the introducer was within the trachea the endotracheal tube slides over it, easily, into position.

1949 Macintosh elastic bougie 2
Macintosh RR. An aid to oral intubation. BMJ 1949

During the past two years I have been experimenting with large-bore oral endotracheal tubes of different shapes. One of the difficulties in passing tubes beyond a certain size is that the body of the tube obscures the view of the cords through which the tip must be directed. In order to overcome this I thread the tube over a long gum-elastic catheter, the tip of which is then passed through the cords under direct vision (Figs. 1 and 2). Using the catheter as a guide the tube is gently pushed down into position (Fig. 3) and the guide is then withdrawn.

Macintosh 1949

Light wand (1957)

Macintosh and Harry Richards are frequently credited with being the first to use a lighted stylet for orotracheal intubation. In 1957, they reported the use of a lighted introducer to assist the placement of an ETT in the trachea under direct vision using a laryngoscope.

The other author [Richards] described a rigid metallic support to assist in the introduction of a flexo-metallic tube through the cords. This bougie, the end of which carries a lamp, has a curve similar to that of the well known Magill tube. It was designed not to project beyond the tip of the tube but to stop at it. It combined the function of splinting the flexo-metallic tube during its introduction, and illuminating the target, i.e. the cords.

The little device which is the subject of this short communication combines the better features of both its antecedents. The malleable introducer is 18 inches long so that it can be made to project well beyond the end of the tube. The outer casing is portex tubing which can be sealed off leaving a smooth translucent end. Tubing carries within it electrical wires to the illuminated tip, also a copper wire within a flexible casing so that the shape of the easily malleable introducer can be altered to suit any particular situation. At the proximal end of the introducer is a standard connection, obtainable at any electrician’s shop, and the counterpart of this leads to any pocket battery.

Macintosh RR, Richards H. 1957

Life Jackets and their efficiency

The Royal Navy Talbot Report of 1946 concluded that 30-40,000 officers and men had died at sea during the Second World War. One third had been killed in action and two thirds had drowned in the survival phase, principally as a result of poor survival equipment.

Macintosh and Edgar A. Pask researched the behaviour of an unconscious human in the water with and without a life jacket. In 1940/41, Pask was anaesthetized, intubated and lowered into the deep end of the Farnborough swimming pool, and much to everyone’s surprise – he sank…

Over many weeks, Macintosh anaesthetised Pask and observed if he sank or floated wearing various prototype jackets.

The experiments demonstrated that the design of the German life jacket was far superior to anything worn by the Allies. As a result, the Royal Navy Personnel Research Committee undertook an extensive research programme and created the new RFD Admiralty pattern 5580 inflatable life jacket; a marvel in design simplicity, performance and durability.

Pask and Macintosh testing life jackets anaesthetized 1941
A. Edgar Pask being anaesthetised by Robert Macintosh (barefoot at the side of the pool).
B. Buoyant overall, stable when prone.
C. Buoyant overall in rough water.
D. No life-jacket!
Macintosh, Pask 1941-1957.

Major Publications

Controversies

His research included dangerous experiments, including the immersion of an anaesthetised Edgar Pask in a wave tank to assess the effectiveness of a life jacket. He also emulated a parachute descent from high altitude by exposing several young men to hypoxic gas mixtures in a decompression chamber.


References

Biography

Eponymous terms


Cite this article as: Alex Johnson and Mike Cadogan, "Robert Reynolds Macintosh," In: LITFL - Life in the FastLane, Accessed on December 1, 2021, https://litfl.com/robert-reynolds-macintosh/.
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eponym

the person behind the name

Doctor currently working in South Wales, training in anaesthetics. Graduated Leeds University with MB ChB with BSc in microbiology in relation to medicine. Special interests in emergency medicine, critical care and anaesthetics

Emergency physician MA (Oxon) MBChB (Edin) FACEM FFSEM with a passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

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