Anaesthesia

Anaesthesia

Z. LETT
Copyright Date: 1983
Pages: 400
https://www.jstor.org/stable/j.ctt2jc7zw
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  • Book Info
    Anaesthesia
    Book Description:

    This recent publication is a unique contribution to the history of specialized medicine in Hong Kong. Written by two of Hong Kong's foremost practitioners and teachers of anaesthesiology, the work details the history of this specialty in Hong Kong, including early pioneers, the development of the Society of Anaesthetists, the teaching of anaesthesiology at undergraduate and postgraduate levels, the establishment of the Hong Kong College of Anaesthesiologists, and recent developments in clinical anaesthesiology. A wide range of appendices, including lists of successive office-holders of the specialist societies, lists of scientific meetings relating to anaesthesiology held in Hong Kong, and over 30 pages of plates featuring prominent personages in the field of anaesthesiology, ensure that this will remain a landmark volume in recording the development of anaesthesiology in Hong Kong.

    eISBN: 978-988-220-005-0
    Subjects: Health Sciences

Table of Contents

  1. Front Matter
    (pp. i-iv)
  2. Table of Contents
    (pp. v-vi)
  3. Foreword
    (pp. vii-viii)
    Tan Sri G.B. Ong

    As a leader of modern anaesthesia in Hong Kong, Dr Lett has had the opportunity of exercising his expertise on all types of patients. Further, he not only organized the anaesthetic service but has also been teaching medical students and postgraduates for more than a quarter of a century.

    This book aims to bring the subject to students of medicine, dentistry and those who are considering learning about and, perhaps specializing in anaesthesia. The book narrates the topics chosen lucidly and will help its readers to understand and appreciate the material mentioned. As a surgeon I find the author’s expression...

  4. Preface
    (pp. ix-x)
  5. I. INTRODUCTION
    • 1. Pain
      (pp. 3-13)

      It has been said that the most humane application of chemistry is for the purpose of achieving anaesthesia. Although the benefits to the patient (derived from the increasing skill, knowledge and experience of the anaesthetists) can be felt in many fields of medical practice, e.g. cardio-pulmonary resuscitation, care of the unconscious patient, Intensive Therapy Units (I.T.U.), etc., it is mainly in the operating theatres that the major part of the anaesthetists’ work and commitments are carried out. And here the main objective of anaesthesia is to render surgical interventions (operations and painful and unpleasant investigations) safe and free from pain....

    • 2. Development of Anaesthesia
      (pp. 14-22)

      The word ‘anaesthesia’ is derived from the Greek and means ‘without feeling’. Dioscorides, the Greek surgeon in the army of the Roman Emperor Nero, first used it in AD 60. It was introduced into general usuage in 1847 by the famous American thinker Oliver Wendel Holmes. It was believed that the first doctor to use diethylether was Crawford Williamson Long in 1842 in the U.S.A., but it has since been discovered that nearly 100 years before him, another surgeon by the name of M. Turner advocated the inhalation of ether to relieve pain. Dr McEwen of Glasgow is credited with...

  6. II. ANAESTHESIA MANAGEMENT
    • 3. The Pre-Operative Period
      (pp. 25-50)

      The participation of anaesthetists in the immediate pre-operative care lowers the rate of morbidity and mortality in surgical patients. It is advisable that every patient due to undergo a surgical intervention should be seen by his anaesthetist beforehand, and therefore should be admitted to hospital earlier to allow sufficient time for this.

      The anaesthetist should review all past and present hospital records of his patient, paying particular attention to previous anaesthetic experiences, physiological and pathological changes due to the current condition and all medication the patient has been receiving.

      The anaesthetists usually pay their first visit and get acquainted with...

    • 4. Preparing for Anaesthesia and Surgery
      (pp. 51-64)

      The nursing staff will usually play the most active role in the period prior to the patient’s operation. Most patients consider an operation an ordeal to go through. A cheerful, intelligent, thoughtful and understanding nurse can help considerably in the psychological preparation of the patient for operation. Patients should be reassured and, if possible, placed in beds next to other patients, preferably also intelligent, who are successfully recovering from a similar (or some other) operation.

      The patient should be advised to stop smoking at least 24 hours before surgery. This may help to prevent troublesome bronchial secretions, post-operative cough and...

    • 5. Induction of General Anaesthesia
      (pp. 65-80)

      When it has been decided to give the patient general anaesthesia, induction of anaesthesia (i.e. the process of transferring the patient from the conscious to the unconscious state) may be achieved by the following routes:

      (a) Inhalation.

      (b) Intravenous.

      (c) Intramuscular.

      (d) Others (rectal, enteral).

      It should be realized that the induction of general anaesthesia and rendering the patient unconscious will immediately necessitate the institution of all those procedures that are essential for the care of the unconscious patient. The basis of all these are still (1) the institution and maintenance of a free airway, (2) continued respiration (either spontaneous...

    • 6. Respiration and Anaesthesia
      (pp. 81-112)

      The tongue is a striated muscular organ attached to the hyoid bone, floor of the mouth and symphysis of the mandible. In a conscious person, under normal circumstances, there is a gap between the tongue and the posterior pharyngeal wall. Regardless of the person’s position, this gap will always be present due to the tongue maintaining sufficient tone (Fig. 6.1).

      When a person becomes unconscious (including under general anaesthesia), the lower jaw and the tongue tend to fall back. Consequently, the gap between the tongue and the posterior pharyngeal wall (through which, under normal circumstances, the air passes unhindered) becomes...

    • 7. Maintenance of General Anaesthesia
      (pp. 113-137)

      General anaesthesia can be maintained by the patient either (1) breathing spontaneously (if no profound muscular relaxations are required) or (2) being ventilated artificially (by means of intermittent positive pressure ventilation) with muscular relaxants administered intravenously (on top of the usually light general anaesthesia). Artificial ventilation is used when profound degrees of muscular relaxation are required or the patients (due to any cause) are unable to breathe adequately by themselves.

      Commonly used agents are of 3 types: gases, volatile agents and intravenous adjuvants.

      (1) Nitrous oxide (Chemical name: Nitrogen monoxide. Official preparation: Nitrous oxide (B.P. and U.S.P.))

      It is a...

    • 8. Muscular Relaxation and Recovery
      (pp. 138-156)

      Guedel’s ‘Table of Signs of Anaesthesia’ (1920) divides anaesthesia into stages and planes and applies to patients without any pre-operative medication and anaesthetized with ‘open’ ether (Fig. 8.1). It shows the disappearance of various reflexes as well as muscular tone with deepening anaesthesia.

      During the four stages, the respiration, ocular movements, eye reflexes, secretion of tears, laryngeal and pharyngeal reflexes, respiratory response to skin incision and muscular tone all progressively diminish until they all disappear at the bottom of stage 4. On the other hand, the pupil keeps enlarging at the beginning and then again from stage 3, plane 2....

    • 9. Local and Regional Analgesia
      (pp. 157-188)

      A local analgesic drug is one that temporarily blocks nerve conduction when applied locally to nerve tissue in appropriate concentration.

      Local analgesic drugs may be classified into three broad groups:

      1. Hydroxy compounds. These are a small group of drugs used mainly for topical analgesia. Because of their toxicity, they are not used any more for injection.

      2. Esters of aromatic acids. These may be called the ‘procaine-cocaine group’, comprising a fairly large number of drugs. The acid is typically an aromatic acid and the alcohol is of the aliphatic or alicyclic type, while the resulting ester also contains nitrogen,...

    • 10. Circulation and Anaesthesia
      (pp. 189-207)

      Although the systemic circulation is responsible for tissue perfusion, the anaesthetist has to consider also the blood supply to all the organs, particularly the vital ones and bear in mind the effects, deleterious or otherwise, of the drugs, techniques and procedures employed during surgery and anaesthesia on this perfusion.

      Blood pressure (B.P) is the product of cardiac output (C.O.) and peripheral resistance (P.R.) and can be expressed in the simplified formula: B.P. = C.O. x P.R. This in turn depends on such factors as (a) the state of the cardiac muscle, (b) the heart rate, and (c) the venous return...

    • 11. Intravenous Supportive Therapy
      (pp. 208-224)

      The intravenous administration of drugs, electrolyte solutions, plasma expanders and blood are an integral part of anaesthetic management. The total body water amounts to about 48.5% of the female and up to 56.8% of the male body weight and can be classified as extracellular and intracellular. The extracellular fluid volume is approximately 20% of the ideal body weight. It has two components: intravascular fluid or plasma and interstitial fluid. The osmotically active protein present in blood largely determines the proportion of the intravascular part of the extracellular fluid and is usually of the order of 1/5, the other 4/5 being...

    • 12. The Post-Operative Period
      (pp. 225-237)

      Patients who have been subjected to surgery and anaesthesia need continuous surveillance which cannot normally be adequately provided by the sporadic nursing care in a general ward. Special recovery units are set up to provide the necessary care, and usually they are of 2 types:

      (a) Recovery rooms are small rooms, usually alongside the anaesthetic room, and form an integral part of the operating suite. Patients enter the operating room via the anaesthetic room and leave via the recovery room. The main advantage of these recovery rooms is their closeness to the operating theatre. Both the surgeon and the anaesthetist...

    • 13. Environmental Hazards in Operating Rooms
      (pp. 238-255)

      There are a number of ways that people in the operating theatres (both patients and working personnel) may be adversely affected. Amongst these are pollution of the operating theatre’s atmosphere by gases and vapours used in anaesthesia, hazards due to malfunctioning of electrical and other equipment and the risk of explosions and fires.

      (i) Toxicity. Although inhalational anaesthetics have been in use since the 1840s or even earlier, it was not until the report by Vaisman (1967) that attention was focused on this problem. This report noted an unusually high incidence of fatigue, headache and irritability in all those investigated...

    • 14. Anaesthesia as a Diagnostic or Therapeutic Aid
      (pp. 256-270)

      Anaesthetic techniques may help in establishing a diagnosis in patients and form the basis of suitable treatment.

      (1) Somatic nerve block (such as paravertebral) may be employed for the localization of prolapsed intervertebral discs, confirmation of a diagnosis of neuralgia, or differential diagnosis of somatic (such as intercostal neuralgia) and sympathetic pain (such as in angina plectoris or coronary insufficiency).

      (2) Sympathetic nerve blocks may be used as an aid in distinguishing between vasospasm and arterial occlusion in peripheral vascular disease.

      (3) Extradural (or subarachnoid) block or light general anaesthesia helps to differentiate between fixed and labile hypertension.

      (4) Regional...

  7. III. ANAESTHESIA AND OTHER SPECIALITIES
    • 15. Anaesthesia and Obstetrics
      (pp. 273-284)

      During the anaesthetic management of obstetrical patients, one must be mindful of the fact that two lives are involved, the mother and the baby. There are basically two periods when anaesthesia (or analgesia) are required. The first one is when dealing with ordinary labour and delivery pains, the second one is during operative delivery, such as forceps, versions and caesarean sections, and possibly repair of episiotomy wounds or perineal tears.

      Pain relief, while as effective as possible, must not interfere with the well-being and safety of the mother and the child. Uterine activity should not be impaired, so as not...

    • 16. Paediatric Anaesthesia
      (pp. 285-294)

      In paediatric anaesthesia, two main points should be remembered: (a) the difference between the young developing child and the mature adult in relationship to the structure and function of some of the important systems, (b) the differences in the respective responses to the administered drugs and their significance (Chan and Lett, 1974).

      A normal neonate has a weight of approximately 5%, a body area of approximately 11% and a length of approximately 33% of that of an adult. The neonate’s head is large in relationship to the body. Also, because of the relatively large liver and small pelvis, the abdomen...

    • 17. Anaesthesia for Neurosurgery
      (pp. 295-305)

      As in most other branches, but perhaps even more so, general anaesthesia for neurosurgical procedures must be carried out in such a meticulous manner that the whole procedure will be smooth. A smooth induction leading to a trouble-free maintenance, a scrupulous avoidance of hypoxia or hypercarbia and an uncompromising maintenance of a free airway at all times are the cornerstones on which the successful outcome of the whole anaesthetic and often even the surgical management is totally dependent. There are basically 2 areas of vital importance, cerebral blood flow (CBF) and intracranial pressure (ICP), that have to be understood and...

    • 18. Anaesthesia for Ear, Nose, Throat and Eye Operations
      (pp. 306-312)

      Operations around the ears do not pose any particular problems, provided the patient’s airway is carefully maintained and respiration is not depressed during adequate anaesthesia, so that coughing and straining are avoided. However, operations for nose and throat surgery present an additional problem (similar to dental surgery) that both the surgeon and the anaesthetist have to compete for the confined space of the patient’s mouth, throat and, sometimes, even the airway. Operations of this nature have a tendency to haemorrhage and also nausea and vomiting. Thus an early return of the protective cough reflex is particularly important.

      Mastoidectomy patients may...

    • 19. Anaesthesia for Cardiac Surgery
      (pp. 313-325)

      The anaesthetic management will largely depend on the nature of the procedure, the state of the patient and his age. It can safely be said that amongst the most spectacular advances in recent years are those pertaining to cardiac surgery and extracorporeal circulation, but in this section only the outlines can be given.

      The occasions when anaesthesia would be required can conveniently be divided into 3 stages:

      (a) Investigations

      (b) ‘Closed’ cardiac surgery

      (c) ‘Open’ cardiac surgery

      It is of paramount importance to obtain as far as possible an answer to the following questions:

      (i) What is the cardiac lesion...

    • 20. One Lung Anaesthesia
      (pp. 326-333)

      In thoracic operations it is necessary not only to isolate the alimentary from the respiratory systems, but very often, one side of the lung from the other. The main reason in the past was the need to protect the ‘healthy lung’ from being flooded by secretions, blood or other debris from the operated side. There are nowadays fewer patients with pulmonary TB, bronchiectasis, etc. and this therefore is no longer the main reason. The emphasis is to provide a reasonably satisfactory and quiet operating field for surgery.

      In addition, in patients with broncho-pleural fistulae, the employment of one lung anaesthesia...

    • 21. Anaesthesia for Laryngectomy
      (pp. 334-335)

      Certain lesions occuring in the larynx or its vicinity are amenable to surgical treatment. The operative procedure are frequently laryngectomy with or without the block resection of glands of neck, or (as in carcinoma of the epiglottis, pharynx or upper esophagus) a pharyngo-laryngo-oesophagectomy (P.L.O.).

      If the lesion have caused respiratory difficulties before the operation, a preliminary tracheostomy will most likely, have already been performed. Anaesthesia and ventilation can then be given through this.

      However, some surgeons still prefer performing that part of the operation, which requires a thorough exposure and exploration of the neck, without having the tracheostomy tube (and...

    • 22. Anaesthesia and Corrective Spinal Surgery
      (pp. 336-339)

      The commonest diseases requiring surgical interventions on the spine, especially in children (in Hong Kong), are:

      (1) Polyomyelitis, causing scoliosis in varying degrees.

      (2) Tuberculosis of the spine, leading to kyphosis. Both (1) and (2) can become quite severe.

      (3) Congenital abnormalities of the spine.

      (4) Idiopathic Scoliosis.

      Corrective surgery (in children) often involves repeated operations that may be quite extensive in scope. For example, a tuberculous patient with kyphosis may have to undergo as many as six different operations before a permanent cure is effected:

      (a) Application of the ‘halo-pelvic’ traction apparatus (Fig. 22.1). This has enabled the ambulation...

    • 23. Anaesthetic Problems in Liver Disease
      (pp. 340-346)

      Accurate diagnosis is most important in the treatment of patients with liver disease. A wide range of new laboratory tests and diagnostic techniques have been introduced, but a careful taking of the history and thorough physical examination are still of paramount importance. Unless these are carried out, patients with drug induced jaundice, alcoholism or physical signs of chronic liver disease (spider naevi, palmar erythema) may undergo unnecessary laparotomy.

      Those currently available include the liver function tests (serum bilirubin, aspartate and alanine amino-transferases and alkaline phosphatase). These may indicate viral hepatitis (high transaminases of 100 iu/1 or higher and a small...

    • 24. Induced Hypotension
      (pp. 347-352)

      Most authorities agree that profound hypotension for surgical interventions should be employed mainly to ‘make the impossible become possible’ rather than to make the ‘difficult become easy’. Deliberate reduction of the blood pressure may be achieved by interfering either with the peripheral resistance or at other sites.

      The conventional formula is: B.P. = C.O. × P.R.

      The cardiac output (C.O.) is the sum of (a) the state of the cardiac muscle, (b) the rate and (c) the venous return. All these contribute to the stroke volume. The peripheral resistance (P.R.) depends on the tone of the arterial tree. The blocking...

    • 25. Malignant Hyperpyrexia Syndrome
      (pp. 353-360)

      Denborough and Lovell (1960) described an Australian family, whose several members had died of hyperpyrexia of sudden onset during, or shortly after, general anaesthesia. Such complications were then referred to as ‘ether convulsion’, ‘postoperative heat stroke’ or other similar terms. The present term ‘malignant hyperpyrexia’ was introduced by Gordon (1966). Since then this syndrome (with a potentially fatal outcome) of abnormal reactions to anaesthesia has been increasingly recognized. Britt and Kalow (1970) reported on 115 cases and a fair number of cases have been described from many countries. Malignant hyperpyrexia nowadays has to be on the lookout for, guarded against,...

  8. Table of Some Normal Values
    (pp. 361-366)
  9. Bibliography
    (pp. 367-370)
  10. Author Index
    (pp. 371-376)
  11. Subject Index
    (pp. 377-390)