Resuscitation of the moribund asthmatic

Effective clinical policies in a district general hospital

Effective clinical practice in a hospital needs current knowledge together with the skills and right attitude; these should be applied continuously. Failure of this system can be due to ignorance or arrogance. We attempted to correct these deficiencies by formulating a set of policies which were enforced from 1962 to 1983. The policies related to the following: intensive care (including asthma, nutrition and organ donation), drug prescribing and resuscitation. We believe that these rules improved patient care and the standards of training; the prescribing policy also saved money.

The evolution and nursing history of a general intensive care unit (1962-1983)

In this paper we have reviewed the origin and evolution of Whiston Hospital's General Intensive Care Unit (ICU) from its humble beginnings as an offshoot of a general ward in the early 1960s. The length of service of the senior nursing staff over a period of 21 years was also calculated. The average duration of service was 16.5 years--a figure which significantly surpassed those quoted in the literature. In addition, we have outlined the development of nurse training in intensive care as well as the role of the nurses in research in the ICU. The question as to whether later college-based training was superior to the previous hospital-based course remained unanswered.

Cardiorespiratory effects of manually compressing the rib cage during tidal expiration in mechanically ventilated patients recovering from acute severe asthma

OBJECTIVES

To determine the cardiorespiratory effects of manual expiratory rib cage compression in mechanically ventilated patients recovering from acute severe asthma; and to extrapolate these findings to emergency asthma management where ventilation cannot be achieved by positive-pressure ventilation.

DESIGN

A prospective, clinical study.

SETTING

Intensive care unit.

PATIENTS

Four intubated, mechanically ventilated (volume-controlled), adult patients recovering from acute severe asthma.

INTERVENTIONS

Patients were studied before, during, and after a 2- to 3-min period of manual compressions applied bilaterally over the lower rib cage (ribs 8 to 10) during consecutive tidal expirations.

MEASUREMENTS AND MAIN RESULTS

Air flow (pneumotachograph), airway pressure, radial or brachial arterial pressure, and the hand pressure applied to the patient's rib cage were monitored and recorded on magnetic tape. Playback of the recorded data enabled measurement of changes in lung volume (air flow integration). Changes during rib cage compression consisted chiefly of small decreases in lung volume and peak inspiratory airway pressure that were only observed in the least obstructed patient and were fully reversed after the cessation of compressions. Air flow-time and air flow-volume plots demonstrated expiratory air flow limitation during essentially the entire tidal expiration in each patient, except the least obstructed patient.

CONCLUSION

The results suggest that manual compression of the rib cage during consecutive tidal expirations would be ineffective in reducing pulmonary hyperinflation during the emergency management of asthma when air flow obstruction is so severe that ventilation cannot be achieved by positive-pressure ventilation.

Asthma requiring mechanical ventilation. A low morbidity approach

STUDY OBJECTIVE

There is considerable uncertainty about the clinical features, respiratory physiology, and optimal management of patients with asthma requiring mechanical ventilation. Furthermore, the ventilatory and pharmacologic management of asthma requiring mechanical ventilation remain controversial. We hypothesized (1) that there are clinically identifiable and pathophysiologically different subgroups presenting with asthma requiring ventilation; (2) that lower dose steroid therapy (< 400 mg/d intravenous hydrocortisone) is adequate; (3) that permissive hypercapnia is safe; (4) that prolonged paralysis is generally unnecessary; and (5) that clinical outcome would be favorable in patients treated with this approach.

DESIGN

Review of medical records and intensive care charts and statistical analysis of findings.

SETTING

ICU of tertiary institution.

PATIENTS

Thirty-five consecutive cases of life-threatening asthma requiring mechanic ventilation.

RESULTS

Three clinical subgroups of ventilation-requiring asthmatics could be identified. Those presenting with steady deterioration (10), those with unstable asthma followed by a sudden "dip" (16), and those with a sudden unexpected dip (9). Patients in the first group had a significantly lower PaCO2 (p < 0.01) at presentation, but required ventilation for longer periods. Those in the second group had a significantly higher PaCO2 (p < 0.01) and required ventilation for a shorter period. Those in the third group had an intermediate PaCO2 level before intubation and the shortest period (p < 0.01) of mechanical ventilation. Five patients experienced their sudden dip after ingesting aspirin. Ten cases received "high" dose hydrocortisone therapy (mean: 980 mg/24 h), and 25 received lower dose hydrocortisone (mean: 341 mg/24 h). No differences in illness severity at presentation or outcome could be detected between these two groups. Mean duration of ventilatory support was 36 h and mean duration of the ICU stay 52.1 h. Muscle relaxation was used in 12 patients for a mean period of 11.1 h. One patient was brain dead on arrival. All others survived.

CONCLUSIONS

Life threatening asthma is an endpoint for several different clinical patterns of disease. No major clinical advantage could be found in our group of patients when high-dose steroids were used. Long-term use of muscle relaxants and prolonged mechanic ventilation are rarely needed in the management of patients with life-threatening asthma and excellent results can be achieved with a relatively simple management strategy.

Assisted ventilation in severe acute asthma

During the period 1973-85 assisted ventilation was used for the treatment of severe asthma on 48 occasions in 18 patients (one patient was ventilated 29 times). On each occasion arterial blood gas abnormalities were restored to normal as quickly as possible irrespective of peak inflation pressures. One patient was thought to be brain dead on transfer from another hospital but was ventilated for 48 hours while this diagnosis was confirmed. There was one episode of mediastinal emphysema. There were no other complications apart from transient hypotension (blood pressure less than 100/60 mm Hg), which occurred on 17 occasions but did not have any sequelae. There was no relationship between hypotension and inflation pressure but there was an association between hypotension and rate of fall of arterial carbon dioxide tension. It is concluded that the risks of barotrauma during the ventilation of patients with severe asthma are theoretical or extremely small. Rapid correction of respiratory acidosis abolishes hypercapnic respiratory drive, allowing ventilation without use of muscle relaxants. It may also enable a shorter duration of ventilation, thus decreasing the likelihood of complications.

A service for the adult asthmatic

A service for 300 adult asthmatics is described. Since the service was started in 1970 only one death has occurred and this patient failed to comply with treatment or advice. Two patients required intermittent positive pressure ventilation. The success of the service is founded on two facts. Firstly, the natural history of life-threatening asthma usually allowed time to change treatment at home or in a clinic and this prevented the development of the severe grades. Secondly, the great majority of asthmatics could be taught how to recognise worsening of their asthma and to communicate with a doctor who then changed the treatment. An essential feature of the service is that the patients had at all times easy access to a doctor with appropriate knowledge and attitudes.

Right heart pressures on bronchial asthma

Right heart pressures, electrocardiograms, blood gases, and peak expiratory flow rates were measured in nine patients admitted to hospital with severe bronchial asthma. Low or normal right heart pressures were found despite electrocardiographic changes in five patients consisting of right atrial P waves, abnormal right axis deviation, and in one patient T-wave changes in precordial leads. These electrocardiographic changes reverted towards normal on recovery of the patient from the asthmatic attack.