LIMITACIONES DEL ESTUDIO

In the years following 1953 the techniques of intensive care, particularly respiratory support, were applied to a widening range of critical illness.

Crushed chest

Patients with crushing injuries to the thoracic cage usually have several ribs fractured both at the front and at the back of the chest so that a portion of the chest wall is rendered ineffective; when the rest of the chest wall expands during inspiration, the damaged part, instead of moving outward, is sucked in and therefore does not contribute to expanding the lung. In 1956 Avory, Mørch and Benson

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Rivera AM, Strauss KW, Van Zundert A, Mortier E. The history of peripheral

intravenous catheters: How little plastic tubes revolutionized medicine. Acta Anaesth Belg 2005;56:271-82.

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Norman J. Personal communication 2009

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Note: a Nightingale ward was a large ward with typically 32 beds and a Sister‘s Office at one end. It was named after the pioneer nurse Florence Nightingale. A primitive system of progressive patient care was maintained by putting the most seriously ill patients at the end of the ward nearest to the Sister‘s Office.

successfully treated a very severely injured patient by IPPV. As the lung is inflated by the ventilator the damaged part of the chest wall is pushed out to its normal position; in effect the chest wall is ‗pneumatically splinted‘ by the intrathoracic pressure. Two papers on the use of IPPV in crushed chest injuries were published in the British medical literature: In 1957 AK Boyle and colleagues in Glasgow described two patients with crushed chests treated with fixation of the ribs and positive pressure ventilation.304 Their lungs were ventilated with a Newcastle ventilator which had a patient triggered function. It inflated the lungs when the patient attempted to breathe. Both patients died. A patient reported in a paper from Clarkson and Robinson at Whiston Hospital near Liverpool survived being run over by the back wheels of a lorry.305 He did not have surgical fixation of his ribs. Instead he was rendered apnoeic by administration of d-tubocurarine (‗curare‘) and his lungs were deliberately inflated through a tracheostomy to a greater extent than normal (hyperventilated) . His ribs were thus pneumatically splinted as described above and the fractures were kept in their normal place while they healed.

Head injuries.

Ian MacIver (a neurosurgeon), Ivor Frew (an ear nose and throat surgeon) and John Matheson (an anaesthetist) in Newcastle General Hospital described the importance of maintaining adequate oxygenation in patients with head injuries.306 Initially the emphasis was on tracheostomy to maintain a clear airway. Later pulmonary hyperventilation and hypothermia were used to reduce cerebral oxygen demand to a level which could be supplied when cerebral blood flow might be reduced, particularly by swelling of the injured brain. The Newcastle group recommended that such patients should be treated in a special unit but they had not at this time managed to establish one.

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Avery EE, Mørch ET, Benson DW. Critically crushed chests: a new method of treatment with continuous mechanical ventilation. J thoracic surg. 1956;32:291-311.

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Boyle AK, Murray JR. Crush injury of the chest: A report of two cases. Anaesthesia. 1957;12:453-62.

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Clarkson WB, Robinson JS. Deliberate hyperventilation in the treatment of a crush injury to the chest. A case report. Br J Anaesth. 1962;34:471-5.

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MacIver IN, Frew IJC, Matheson JG. The role of respiratory insufficiency in the management of severe head injuries. Lancet. 1958;1:390-3.

Asthma

Philip Hugh-Jones delivered a paper at the Royal Society of Medicine in 1958 describing the treatment of acute asthma at Hammersmith Hospital.307 The paper contained a detailed description of the mechanism by which breathing is regulated, emphasising (with experimental evidence) that breathlessness (dyspnoea) is caused by overstimulation of nerves sensitive to stretch of the lungs rather than as is conventionally taught, by falling oxygen and rising carbon dioxide levels in the blood. Hugh-Jones described the treatment of acute shortage of breath, which he idiosyncratically called ‗oligopnœa‘, with oxygen and drugs, but stated that although this would be sufficient in the majority of cases, if it is not completely successful, he had no hesitation in performing tracheostomy and using artificial mechanical ventilation. He had an East Radcliffe ventilator, which incidentally was the same machine with which Keith Sykes instituted postoperative cardiac surgical patients at the Hammersmith Hospital. Hugh-Jones realised the importance of humidification of the inspired air to liquefy the ‗rubbery‘ secretions which were blocking the patients‘ airways.

Hugh-Jones‘s paper ended with the statement ‗The use of mechanical ventilation in the ventilatory defects of polio, tetanus &c., is well established. We would like to see the treatment of acute oligopnœa in chronic respiratory disease become equally accepted.‘ 308

Their wish was granted. Over the next decade IPPV was used to treat more patients so that by the late 1960s several series had been published. In a retrospective description of the development of the ICU in Whiston Hospital, Merseyside, Eric Sherwood Jones and Ian Gordon were able to state ‗The results over the 10-year period from 1970-1980 showed that only one patient on our [asthma] register died from asthma. This was in contrast to 23 patients who died in our area between 1974 and 1977 but who were not on the register.309 Anthony Gilbertson opened an intensive therapy unit in 1970 at Sefton General Hospital, Liverpool and until the Hospital closed in 1979 no patient died who was alive on arrival at the unit suffering from acute asthma. It is a sad fact that there are still

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Hugh-Jones P. Oligopnœa. Proc R Soc Med. 1958;51:104-8.

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Hugh-Jones P. Oligopnœa 1958:108.

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Jones ES, Gordon IJ. The evolution and nursing history of a general intensive care unit (1962-1983). Intensive Crit Care Nurs 1998;14:252-7.

accounts in the press of patients who have died of asthma without having been referred to an ICU.

Poisoning

In 1958 R P Wise of the Department of Anaesthetics at the Westminster Hospital, London described the treatment of barbiturate poisoning.310 The treatment of respiratory depression in patients overdosed with barbiturates had since the 1930s been based on the use of respiratory stimulants. The complications included convulsions, vomiting (with an aspiration hazard) and cardiac arrhythmias. Wise described treatment by the alternative strategy of ventilation of the lungs until the patient excreted the barbiturate as described by Plum and Swanson in the USA in the previous year.311 This became the accepted method of treating barbiturate poisoning, which was a very common method of attempted suicide in the 1950s and 1960s. Wise advocated the treatment of such patients in special units but had not at that time established one.

Myasthenia Gravis

Another condition which required collaboration between specialists in medicine, surgery and anaesthesia was myasthenia gravis. This is a disease characterised by muscle weakness and muscle fatigue. The receptors which transmit the signal for a muscle to contract become blocked by antibodies, and do not respond to the transmitter acetylcholine which conveys the signal to contract from the nerve to the muscle. The medical treatment of the disease is by means of drugs such as neostigmine or its congeners which prevent the breakdown of acetylcholine (anticholinesterases), thus allowing its concentration at the nerve endings to increase and overcome the insensitivity of the receptor site on the muscle. However as the receptors become increasingly insensitive to acetylcholine this treatment becomes ineffective, weakness increases and may lead to respiratory failure. Surgical removal of the thymus gland at the base of the neck (thymectomy) may cause remission in myasthenia gravis. In severe cases with respiratory failure and failure to respond to

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Wise RP. Treatment of barbiturate poisoning. Br J Anaesth. 1958;30:533-41.

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Plum F, Swanson AG. Barbiturate poisoning treated by physiological methods; with observations of effects of beta-beta-methylethyl-glutarimide and electrical stimulation. JAMA. 1957;163:827

anticholinesterases, a period of IPPV with withdrawal of the drug may ‗rest‘ the receptors and they may again become responsive to neostigmine. In 1958 Griffin, Nattrass and Pask described a case of a complicated condition in a fifteen-year old boy in Newcastle.312 He had at first muscle weakness not helped by neostigmine, but greatly improved by ephedrine, given to him by a friend who had asthma. There is no obvious reason why ephedrine should help in such a condition but it had worked and his general practitioner therefore prescribed it for the next three years! In June 1955 the boy developed more typical myasthenic symptoms with weakness greatly improved by rest and a temporary response to neostigmine. However the weakness increased and after a week he had a respiratory arrest and IPPV was started at first through an endotracheal tube. After two days a tracheostomy was performed. On the 36th day, with great trepidation due to the boy‘s poor condition, thymectomy was done. After nine days the patient was able to breathe by himself and never needed the respirator again. At the time of writing, he had for four months been back at his work as a clerk and his only medication was ephedrine. Thymectomy and support by IPPV became accepted treatment for myasthenia gravis.