1 History of Intensive Care Jennifer Jones When the first World Congress of Intensive Care was held in London in June 1974, it was attended by more than 2,000 delegates from all parts of the globe and the astonished organisers had to hire extra space to accommodate them all. The success of the event illustrated the fact that, over the previous decade, the provision of care for critically ill patients in units separate from general wards had been accepted as an essential feature of hospitals throughout the world. How did this acceptance come about and what changes have taken place since? It had been recognised for many years that there were advantages in treating patients with the greatest need for care in one place. In the Crimean War, Florence Nightingale s insistence on keeping the sickest patients closest to the central nursing station may be regarded as an early example of the practice. Before the Second World War recovery rooms adjacent to operating theatres were introduced. Shock wards were established during the war to treat the most severely injured casualties, and coronary care units after the war demonstrated that mortality from acute myocardial ischemia could be reduced by treating the victims in a single area. Mechanical ventilation of the lungs was introduced to treat victims of poliomyelitis and tetanus. It was originally believed that negative pressure ventilation (NPV) was the physiological way to ventilate the lungs, and machines were designed to enclose the patient from the neck down 1
2 J. Jones in a box from which air was rhythmically pumped in and out to mimic expiration and inspiration. The first electrically driven device was the iron lung devised in the USA by Drinker and Shaw and introduced into clinical practice in 1928 [1]. In the USA, four large poliomyelitis units were set up to meet the country s needs for artificial respiration. Intermittent positive pressure ventilation (IPPV) combined with tracheostomy (which is very difficult to manage in combination with a tank respirator) was introduced during the poliomyelitis epidemic in Copenhagen in 1952. Lassen, who was in charge of the hospital for infectious diseases, which lacked enough tank respirators to deal with the influx of patients, asked an anaesthetist, Ibsen, if techniques used in the operating theatre could be applied to the management of patients with respiratory failure on the wards. To begin with, positive pressure ventilation was provided manually, using a to-and-fro breathing system, by relays of medical students [2]. Later, the students were superseded by the Engstrom ventilator. During the course of the Copenhagen epidemic, Astrup s work on blood gas analysis made it possible to assess the adequacy of alveolar ventilation and established the superiority of IPPV over NPV in this regard [3]. It also became clear that another and perhaps the greatest advantage of IPPV was the ease of access to the patient that it offered to nursing staff. Lassen s account of the epidemic stresses the need for humidification of inspired gas in preventing encrustation of respiratory secretions in a patient with a trachcostomy and physiotherapy in airway management, although both were improved in later years. The importance of the poliomyelitis epidemic in Copenhagen in the development of intensive care was, therefore, profound. It not only demonstrated the superiority of IPPV over NPV in respiratory support, but introduced the concept of a multidisciplinary approach to the management of very sick patients and involved anaesthetists in the provision of their care. Some intensive care specialists today might not consider the latter an advantage. The introduction of the Salk vaccine in 1955, which consists of injected inactivated poliomyelitis virus, and of the oral Sabin vaccine in 1957, which uses an attenuated live virus, has eradicated poliomyelitis from most countries in the world [4]. However, the demand for respiratory
History of Intensive Care 3 support continued to increase, driven by the needs of patients with tetanus and chest injuries and, perhaps most importantly, by the proliferation of cardiac surgery. As mechanical ventilators were increasingly used to support patients with acute pulmonary disease, their design became more sophisticated and more subtle modes of IPPV were introduced (see Chapters 7 and 8). Awareness of the dangers of IPPV grew at the same time. The introduction of positive end-expiratory pressure (PEEP) to improve arterial oxygenation rapidly showed that excessive intrathoracic pressures could be associated with barotrauma in the shape of pneumothorax or mediastinal emphysema or with a reduction in cardiac output, which could be overcome by expanding the circulating volume to improve venous return [5]. Methods of assessing best PEEP for optimising oxygen delivery to the tissues were explored [6]. More recently, it has been recognised that over-distension of the alveoli during IPPV with excessive tidal volumes may result in pulmonary damage, and lower than traditional tidal volumes have gained acceptance [7]. Ventilator-associated pneumonia is a common nosocomial infection which has been shown to be associated with prolonged intensive care stay and a marked increase in mortality [8]. The intensive care units set up in the 1960s and 1970s were, for the most part, small. A report from the British Medical Association [9], which confined itself to recommendations, envisaged that only 1% of acute hospital beds would need to be set aside for intensive care, although it clearly saw that such beds would need huge amounts of space, staff and services. Most of these intensive care units were run by anaesthetists, the majority of whom regarded intensive care as a hobby in addition to their sessions in the operating theatre and almost all of whom learned on the job. There was no recognition of intensive care as a specialty, no supervised training programmes and no literature. One of the most important sequels to the first World Congress of Intensive Care is that these points have been addressed. Intensive care is now recognised internationally as a specialty, training programmes are ubiquitous and there are a huge number of journals of critical care. Standards for space and facilities exist at national and international levels. The question of whether intensive care units should be open or closed
4 J. Jones has been settled in favour of the trained specialist intensivist, who is today running a much larger unit than those of the 20th century. Intensive care is expensive. No one least of all the paymasters wants to see it profligately dispensed to patients who cannot benefit. Numerous scoring systems have been devised to assess the severity of a patient s illness (of which Knaus Acute Physiology and Chronic Health Evaluation II (APACHE II) [10], is perhaps the most widely used) but, so far, none of them can be used to predict outcome in an individual case. The incorporation of APACHE II into the Intensive Care National Audit and Research Centre (ICNARC) system of audit in the UK [11] has made it possible to assess the performance of individual intensive care units, and has provided a useful monitor of standards of care. At the turn of the 20th and 21st centuries, a new approach to the management of sick patients, which has come to be known as outreach, was taken in Australia. In certain hospitals the cardiac arrest team was replaced by a medical emergency team of intensive care doctors and nurses who could be summoned by ward staff to attend patients who showed marked physiological abnormalities which might lead to a cardiac arrest [12]. When a paper published in the UK suggested that the care provided for sick patients in general wards was often inadequate [13], a similar concept, with modified call-out criteria, was introduced with support from the Department of Health and guidance from the Intensive Care Society [14]. Outreach schemes are based on the premise that early intervention in the development of critical illness can improve outcome. By nipping such illnesses in the bud, it might also obviate the need for a number of admissions to the intensive care unit. Outreach might, it was hoped, save lives and perhaps even money. The evidence collected so far is disappointing: outreach has not as yet fulfilled its promises of improved outcome or reduced costs [15]. In terms of organisation, then, the history of intensive care may be seen as one of steady progress and growing professionalism. Clinical progress is also evident in the development of respiratory support and in the understanding and management of the acute respiratory distress syndrome (ARDS) first described in 1967 [16]. With the introduction of haemofiltration, early recourse to renal replacement therapy in acute renal failure (ARF) has supplanted the practice of squeezing a urine output from failing kidneys with diuretics and dopamine infusions.
History of Intensive Care 5 It is also possible to trace fashions in the waxing and waning popularity of various treatment methods. To give an example, in the 1970s many intensivists believed that human albumin was the solution of choice in fluid resuscitation, and that furthermore, it was important to maintain a patient s serum albumin within the normal range as far as possible. A number of small comparative studies in North America, however, suggested that albumin conferred no advantage over (the much cheaper) Hartman s solution [17]. It was further demonstrated in a randomised prospective study of patients in an intensive care unit that outcomes were similar whether gelatine or albumin solution were employed. A meta-analysis of the small North American studies was interpreted as showing that patients were more likely to die if they received albumin during resuscitation, which discouraged many intensivists from using it at all [18]. The controversy seems to have been settled by a large randomised trial of albumin and balanced salt solution, which found that, for most patients, the use of albumin offers neither benefit nor harm [19]. Red blood cell transfusion has become less fashionable. Since the demonstration that oxygen delivery to the tissues in acute normovolaemic anaemia was optimal at haemoglobin (Hb) concentrations of 10 g/dl [20], most intensive care patients were transferred to maintain their Hb concentrations at this level. Since a large randomised Canadian study demonstrated that intensive care patients transfused to a Hb level of 8 g/dl enjoyed an outcome at least as good as those transfused to a level of 10 g/dl [21], most intensive care specialists have pursued a more conservative transfusion policy. The pulmonary artery catheter has also been a bone of contention. Introduced in 1970 by Swan and Ganz [22], its use became widespread after Shoemaker advocated the goal of supra-normal oxygen delivery in intensive care patients as a means of improving their chances of survival [23]. Enthusiasm for such goal-directed therapy was tempered after studies showed that in the acutely critically ill, seeking to raise oxygen delivery beyond normal limits was not helpful [24]. Optimisation of oxygen delivery, however, does seem to be of benefit in patients undergoing high-risk elective surgery [25]. The use of pulmonary artery catheters was further discouraged when a non-randomised cohort study suggested that their use was associated with increased patient mortality and length (and cost) of hospital
6 J. Jones stay [26]. An editorial published in the same journal demanded a moratorium on the use of pulmonary artery catheters and a prospective multicentre trial [27]. Further studies have yielded conflicting results [28] and, whilst pulmonary artery catheters continue to be employed in intensive care units, less invasive methods of assessing cardiac output have become more popular. Intravenous feeding is another example of a treatment that has been over-enthusiastically pursued, then denounced and finally reinstated with caution. There is good reason to believe that patients in intensive care units should be fed within 24 hours of admission (see Chapter 9), but enteral feeding is simpler and cheaper than intravenous, and may be associated with fewer infective complications. Parenteral feeding is now something to fall back on if attempts to establish enteral feeding fail. Clinical practice in intensive care has, then, not been without controversy. It is encouraging that, as large randomised trials have been published, intensive care has gradually become based more upon evidence than conjecture. The history of intensive care may be regarded as a story of the successful developments of a new and challenging medical specialty. In a recent critical review [29] Soni complained that its raison d être of providing support for failing organs has led the specialty to focus on syndromes such as ARDS and ARF and give them real disease status, regardless of the disparity of their causes. He argues that more attention should be paid to the causes of organ failure and suggests that it might be beneficial if the abbreviations and acronyms of intensive care ARDS, sepsis, systemic inflammatory response syndrome (SIRS), amongst others were relegated to history. Whatever happens, the future of intensive care will bring change. References [1] Drinker, P. and Shaw, L.A. (1929). An apparatus for the prolonged administration of artificial respiration I. A design for adults and children, J Clin Invest, 7, 229 247. [2] Lassen, H.C.A. (1953). A preliminary report on the 1952 epidemic of poliomyelitis in Copenhagen, with special reference to the treatment of acute respiratory insufficiency, Lancet, 1, 37 40.
History of Intensive Care 7 [3] Astrup, P., Gotzche, H. and Neulukirch, F. (1954). Laboratory investigations during treatment of patients with poliomyelitis and respiratory paralysis, BMJ, 4865, 780 785. [4] Aylward, R.B. (2006). Eradicating polio; today s challenges and tomorrow s legacy, Ann Trop Med Parasitol, 100, 401 413. [5] Sykes, M.K., Adams, A.P., Finley, W.E.I. et al. (1970). The effects of variations in end-expiratory inflation pressure on cardiorespiratory function in normo-, hypo- and hypervolemic dogs, Brit J Anaesth, 42, 669 677. [6] Suter, P.M., Fairley, H.B. and Isenbery, M.D. (1975). Optimum end-expiratory airways pressure in patients with acute pulmonary failure, N Engl J Med, 292, 284 289 [7] The Acute Respiratory Distress Syndrome Network (2000). Ventilation with lower tidal volumes as compared with traditional volumes for acute lung injury and the acute respiratory distress syndrome, N Engl J Med, 342, 1301 1308 [8] Safdav, N., Desfulian, C., Collard, H.R. et al. (2005). Clinical and economic consequences of ventilator associated pneumonia, a systematic review, Crit Care Med, 33, 2184 2193. [9] British Medical Association (1967). Intensive care, BMA Planning UNIT Report No1, British Medical Association, London. [10] Knaus, W.A., Draper, E.A., Wagner, D.P. et al. (1985). APACHE II; a severity of disease classifications system, Crit Care Med, 13, 818 829. [11] Rowan, K.M., Kerr, J.H., Major, E. et al. (1993). Intensive Care Society s APACHE II study in Britain and Ireland II: Outcome comparisons of intensive care units after adjustments for case mix by the American APACHE II method, BMJ, 307, 977 981. [12] Lee, A., Bishop, G., Hillman, K.M. et al. (1995). The medical emergency team, Anaesth Intens Care, 23, 183 186. [13] McQuillan, P., Pilkington, S., Allan, A. et al. (1998). Confidential inquiry into quality of care before admission to intensive care, BMJ, 316, 1853 1858. [14] The Intensive Care Society (2002). Guidelines for the Introduction of Outreach Services, The Intensive Care Society, London. [15] Fletcher, S.J. and Cuthbertsen, B.H. (2010). Outreach, epistemology and the evolution of critical care, Anaesthesia, 65, 115 118. [16] Ashbaugh, D.G., Bigelow, D.B., Petty, T.L. et al. (1967). Acute respiratory distress in adults, Lancet, 2, 319 323. [17] Cochrane Injuries Group Albumin Reviewers (1998). Human albumin administration in critically ill patients; systematic review of randomised clinical trials, BMJ, 317, 235 240.
8 J. Jones [18] Stockwell, M., Soni, N. and Riley, B. (1992). Colloid solutions in the critically ill. A randomized comparison of albumin and polygeline 1. Outcome and duration of stay in the intensive care unit, Anaesthesia, 47, 3 6. [19] The SAFE Study Investigators (2004). A comparison of albumin and saline for fluid resuscitation in the intensive care unit, N Engl J Med, 350, 2247 2256. [20] Mesmer, K., Lewis, D.H., Sunder-Plassman, L. et al. (1972). Acute normovolemic hemodilution, Europ Surg Res, 4, 55 70. [21] Hébert, P.C., Wells, G., Blajchman, M.A. et al. (1999). A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care, N Engl J Med, 340, 409 417. [22] Swan, H.J., Ganz, W., Forrester, J. et al. (1970). Catheterization of the heart in man with use of a flow-directed balloon-tipped catheter, N Engl J Med, 283, 447 451. [23] Shoemaker, W.C., Appel, P.L., Kram, H.B. et al. (1988). Prospective trial of supranormal values of survivors as therapeutic goals in high-risk surgical patients, Chest, 94, 1176 1186. [24] Hayes, M.A., Tinemins, A.C., Yau, E.H. et al. (1994). Elevation of systemic oxygen delivery in the treatment of critically ill patients, N Engl J Med, 330, 1717 1722. [25] Boyd, O., Grounds, R.M. and Bennett, E.D. (1993). A randomized clinical trial of the effect of deliberate peri operative increase of oxygen delivery on mortality in high risk surgical patients, JAMA, 270, 2699 2707. [26] Connors Jr, A.F., Speroff, D., Dawson, N.V. et al. (1996). The effectiveness of right heart catheterization in the initial care of critically ill patients, JAMA, 276, 889 897. [27] Dalen, J.F. and Bobe, R.C. (1996). Is it time to pull the pulmonary artery catheter? JAMA, 276, 916 918. [28] Harvey, S., Young, D., Brampton, W. et al. (2006). Pulmonary artery catheters for adult patients in intensive care, Cochrane Database Syst Rev, C0003408. [29] Soni, N. (2010). ARDS, acronyms and the Pinocchio effect, Anaesthesia, 65, 976 979.