Many anaesthetists are familiar with the historic 1862 photograph of Dr Joseph Clover administering chloroform by mask to a seated gentleman, while feeling the pulse at the patient's wrist. The photograph, in fact, does not illustrate the usual anaesthesia practice of the time and it took almost another century before pulse monitoring became routine.
While some anaesthetists, including Dr John Snow, advocated careful administration and observation of both pulse and respiration, it was advocated by many that assessment of the pulse provided little or no useful information on the progress or safety of anaesthesia. Even Snow agreed that ether was relatively safe: "I believe that ether is altogether incapable of causing the sudden death by paralysis of the heart ... " (1).
With chloroform the story was different, and some, including Snow, advised careful observation of the pulse. "Although the pulse of itself gives no indication as to how far a patient is under the influence of chloroform, it is proper to pay attention to it, not only during the first administration of the chloroform, but also throughout the operation ... " (1).
Lord Lister, who became Professor of Surgery in Glasgow in 1860 and subsequently Professor in Edinburgh and finally in London, was an influential force in medical opinion and one who was in favour of entrusting the administration of chloroform to medical students or junior house doctors. In 1861 he wrote, "The very prevalent opinion that the pulse is the most important symptom in the administration of chloroform is certainly a serious mistake. As a general rule, the safety of the patient will be most promoted by disregarding it altogether, so that attention may be devoted exclusively to the breathing" (2). In 1882, he reiterated his view following some research suggesting that chloroform was toxic to the heart, "These researches, by placing before the profession in an exaggerated form the effects of chloroform as a cardiac sedative, have tended to foster the idea that if chloroform kills, it always does so from the heart, and that the pulse is the main thing to be attended to in its administration. Against this pernicious error I have endeavoured ... to raise an emphatic protest".
Despite Cushing and others advocating the use of cardiac auscultation during anaesthesia in the early 20th century, peripheral pulse monitoring continued to be rarely employed until the 1950s (3,4). Partly, this was due to the fact that anaesthetists were usually working on their own and their hands were fully occupied with holding a mask and applying ether. It was also due to the persistent belief that the pulse provided little information. In the first major Australian anaesthesia textbook Anaesthetic Methods, published in 1946, the following comments appear: "Ether rarely causes any gross irregularity in the normal heart", "Of the gaseous anaesthetics, nitrous oxide and ethylene appear to be inert in respect to the heart. Untoward effects seem to be due wholly to anoxia ... ", however "Ethyl chloride ... in its myocardial effects, more nearly resembles chloroform; it must be therefore regarded as a potent anaesthetic and be used with due discretion" (5). In Essentials of General Anaesthesia, published in 1952, Macintosh and Bannister state "The pulse is of little value as a guide to nitrous oxide anaesthesia" (6).
Thus, the idea persisted, that it was more important to monitor respiration than the pulse during anaesthesia.
With the appreciation of the value of measuring blood pressure came the need to develop instruments that would monitor the pulse without the need to place a finger on the radial or other artery.
The first electronic pulse meters appeared in the 1950s. They employed carbon microphones that were placed over the radial artery, and suffered from easy dislodgement (7,8). The first pulse meter to apply the microphone directly to the thumb or toe was introduced by Simpson, and later refined by Bishop (9). The devices could easily be manufactured by a handyman anaesthetist from readily available components. The pulse was indicated by the oscillation of an ammeter needle. Further development produced devices that included a flashing light or a speaker to provide a visual or audible signal of each pulsation (10). Some included a counter (11). The carbon microphone was eventually replaced by a pressure sensor.
Beginning in 1958, Geoffrey Kaye devised several pulsemeters, examples of which are held in the collection of the Geoffrey Kaye Museum of Anaesthetic History, Australian and New Zealand College of Anaesthetists. One of his designs, using simple everyday components, combined a pulse meter with a respiratory monitor in what he described as his "Poor Man's Respulsicator".
The pulse meter became the first widely used electronic patient monitor in anaesthesia.
(1.) Snow J. On Chloroform and Other Anaesthetics: Their Action and Administration. John Churchill, London, 1858.
(2.) Lister J. The Collected Papers of Joseph, Baron Lister. Oxford. Clarendon Press 1907.
(3.) Cushing HW. Technical methods of performing certain cranial operations. Surg Gynecol Obstet 1908; 6:227.
(4.) Kane EO. Wearing of branching stethoscope by surgeons and anaesthetist during operation. Surg Gynecol Obstet 1924; 39:508-509.
(5.) Kaye G, Orton RH, Renton DG. Anaesthetic Methods. Ramsay Surgical Pty Ltd, Melbourne, 1946.
(6.) Macintosh RR, Bannister FB. Essentials of General Anaesthesia (Fifth Edition). Blackwell Scientific Publications, Oxford, 1952.
(7.) Keating VJ. Simple Pulse Indicator. Brit Med J 1952; 1:1188.
(8.) Downing DM. Continuous Blood Pressure Indication Anaesthesia. 1954; 9:35-37.
(9.) Bishop C. A Combined Pulse Indicator and Sphygmomanometer. Anaesthesia 1958; 13:328-336.
(10.) Molyneux L, Pask EA. A Transistor Pulse Counter. Br J Anaesth 1955; 5:261-263.
(11.) Lawton W, Wulfsohn NL. Pulse Frequency Meter. Anaesthesia 1958; 13:352-355.
R. N. WESTHORPE, C. BALL
Geoffrey Kaye Museum of Anaesthetic History
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|Title Annotation:||COVER NOTE|
|Author:||Westhorpe, R.N.; Ball, C.|
|Publication:||Anaesthesia and Intensive Care|
|Date:||Sep 1, 2008|
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