Annals of Burns and Fire Disasters - vol. XI - n. 2 - June 1998

CLINICAL AND STATISTICAL DATA ON THE OCCURRENCE OF PULMONARY COMPLICATIONS IN SEVERE BURN PATIENTS TREATED IN AN INTENSIVE CARE UNIT

Belba M., Pema L., Dauti L, Mingomataj L, Isaraj S., Belba G.

Clinic of Burns and Plastic Surgery, University Centre Hospital, Tirana, Albania

SUMMARY. burns continue to be a seriously dangerous illness with a strong potentiality of a fatal outcome, despite the intensive propaganda aimed at their prevention and the great steps taken in the field of scientific treatment. One of the possible complications of the course of the illness is pulmonary disease. The problem is focused on in this paper, which provides a full epidemiological view of the complication seen in its different aspects. A detailed analysis of the results of our work in the intensive care unit over a threeyear period of time and the discussion of cases in accordance with the data in the Tables highlight the age-groups most afflicted, the time of appearance of the complication, and the interrelations between cause of burn, extent of burn, and death rate.

Introduction

The treatment of severely burned patients is complex and difficult. The medical staff has to face very severe situations before the condition gradually ameliorates. One important problem that appears during the course of the disease is that of pulmonary complications. Prevention is possible but in most cases it is the causative agent of the burn itself that conditions their development. Even when the causative agent does not act directly on the respiratory tract the pathophysiology of the burn injury presupposes the occurrence of pulmonary complications that may have dangerous consequences as regards general prognosis.
Pulmonary complications may occur in the early acute post-burn and as well as in the later period because of the prolonged profound catabolic state of the patient
A number of factors - familiarity with the burn disease, the taking of a detailed history, a careful physical examination, a careful check of laboratory data, monitoring of the patient and the follow-up - all help to estimate and predict the possible occurrence of pulmonary complications, which are justifiably considered to be one of the main causes of death in the severely burned patient.
The aim of this clinical and statistical survey was to provide data on the results of work in our intensive care unit (ICU) in a three-year period of treating burned patients with pulmonary complications.

Materials, methods and results

This paper presents an epidemiological and clinical report on 97 cases treated in the ICU at the burns and Plastic Surgery Clinic of the University Centre Hospital, Tirana, in the period January 1993-January 1996. All the patients considered developed pulmonary complications.
Patients treated in the ICU fulfilled the following criteria:

• Adults with 111-degree burns in more than 15% BSA Adults with 11-degree burns in more than 20% BSA
• Children with deep 11-degree or 111-degree burns in more than 10% BSA
• Burns of the respiratory tract, chemical and electrical burns, involvement of critical areas of the body in the elderly or in early infancy, whatever the percentage

The amount of fluids to be given in the first 48 h was determined according to the Parkland formula .4, ' The diagnosis of a pulmonary complication was made on the basis of clinical, laboratory and X-ray examination. In this paper we analyse the incidence of pulmonary complications, the age groups of the patients, the time of appearance of complications, the different kinds of pulmonary complications according to age group, the relationship with the extent of the burn and the burning agent, the death rate, the causes of death, and the mean duration of ICU hospitalization.
The results of the study are shown in the Tables.
The study reveals that the presence of a pulmonary complication in a severely burned patient had a generally constant occurrence rate, which varied from year to year but was present in approximately one in five patients. Table I shows the cases with pulmonary complications and the relevant percentages in successive years.

Table 1 - Frequency of pulmonary complications and the relevant percentages for each year Year Number of patients Pulmonary complications 1993 142 41 (29%) 1994 117 26 (22%) 1995 170 30 (18%) Total 429 97 (22%)

Regarding the age groups (Table II), children constituted 50 cases (51%), adults 38 cases (40%), and elderly patients 9 cases (9%). The prevalence of children is explained by the fact that more than half of the patients admitted to our ICU during this period were paediatric cases. Adults rather than children were prone to pulmonary complications (28% and 19%, respectively), as seen if we analyse the total number of patients according to age group.

Table II - Grouping of patients according to age (numbers in parentheses refer to pulmonary complications) Years Children (<14 yr) Adults Elderly (>60 yr) Total 1993 85 (25) 48 (11) 9 (5) 142 (41) 1994 65 (13) 43 (11) 9 (2) 147 (26) 1995 113 (12) 44 (16) 13 (2) 170 (30) Total 263 (50) 135 (38) 31 (9) 429 (27)

Table III, showing the time of development of pulmonary complications, indicates that 32, i.e. one-third of the cases, occurred within the first 48 h post-burn. Respiratory failure predominated in the early post-burn period, generally in severe flame burns. The other 65 cases (two-thirds) occurred after more than 48 h, corresponding to the septic phase of disease. The complications in this phase were mainly acute pulmonary oedema, ARDS, bronchopneumonia and pleurisy.

Table III - Presentation of pulmonary complications according to time of appearance Years Children (< 14 yr) Adults Elderly (>60 yr) Total Early complications <48h 12 16 4 32 Late complications >48 h 38 22 5 65 Total 50 38 9 97

Table IV shows the pulmonary complications in relation to age and overall mortality. Diffuse bronchitis had the highest incidence in children (19 cases, 5 deaths). Unilateral bronchopneumonia occurred in 13 cases (2 deaths), and respiratory failure developed in 12 adults (11 deaths). Other types of pulmonary complications had an insignificant occurrence rate but they must be taken into consideration in specific cases during treatment.

Referring to Table V, we notice that pulmonary complications generally developed in burns involving 2040% BSA and nearly always in flame burns in more than 50% BSA.

The overall death rate (Table VI) for the three-year period of study was 26.3%. This rate reached 44.3% (43 deaths in 97 cases) in patients developing a pulmonary complication.

Year Number of patients Deaths Pulmonary complications Deaths 1993 142 39 41 14 1994 117 43 26 19 1995 170 30 30 10 Total 429 112 97 43 Table VI - General mortality and mortality in cases with pulmonary complications

The causes of death (Table VII) were respiratory failure (16 cases, out of 26 patients with airway burns), septic shock and congestive heart failure (15 cases), acute pulmonary oedema (7 cases), and others.

The mean hospital stay of a patients admitted to the ICU who developed a pulmonary complication was 11-20 days (Table VIII). The short hospital stay corresponds to thecourse and prognosis of the patients, and falls into two categories. The first category represents patients who successfully faced complications and quickly recovered, while the second category corresponds to patients with sepsis or airway burns, who died within an even shorter time.

Table VIII - Mean hospital stay in insensitive care unit Year Mean hospital stay (days) 1993 20 1994 11.3 1995 15

Discussion

Our statistical data confirm the possibility of the occurrence of pulmonary complications in a severely burned patient, and their increasing incidence. This is related not only to the increasing number of patients who on admission present damage to the airways but also to the onset of a pulmonary complication during the prolonged course of the disease in a septic patient.
In our data, the death rate of patients who developed a pulmonary complication was 1.6 times that of other burned patients. Of the 112 patients who had a fatal outcome in the three-year study period, 43 (38.4%) died because of the severity of irreversibility of a pulmonary complication.
Although most of our patients with pulmonary complications were children, adults were also liable. The reason is that burns of the airways or extensive burns are more common in adults than in children. The onset of respiratory failure during the period of burn shock was the main cause of death in this category of patients.
Diffuse bronchitis and bronchopneumonia must be considered contributory complications of burn sepsis in children.' Mortality due to these complications requires the utmost attention, because the application of an appropriate resuscitation regimen, including vigorous antimicrobial therapy, cart considerably reduce the danger they pose to the life of a burned child. Cases with a fatal outcome generally correspond to patients who arrived late at the burn centre or were not properly treated in the initial phases, and who in addition to the complexity of their condition also suffered from a pulmonary problem.
Other pulmonary complications such as pneumonia, pleurisy and pleuropneumonia are uncommon but cannot be disregarded, as they may be fatal. Pulmonary complications were present in almost half of our elderly patients, uniformly distributed and without any special features. In an elderly patient, clearly, careful account must be taken of the circumstances of the burn accident, the history of any past or present disease, the present general condition, the immunological state, age, etc.The triad composed of cause of burn, extent of burn, and mortality is certainly the one that best explains their interrelationships which may eventually may lead to pulmonary involvement.
The death rate was clearly higher in flame burns, in burns covering more than 50% BSA, and above all in burns of the airways. When the burn agent did not directly damage the airways, and also in scald burns, pulmonary complications appeared during the septic phase, were less common, and had a better prognosis. Table V shows zero mortality in electrical burns. The explanation of this finding is meaningful and is related to early surgical treatment in these cases. Radical excisions and amputation of the limb involved prevent the development of sepsis and consequently reduce the possibility of pulmonary complications. In the absence of direct damage to the respiratory tract, the prevention of pulmonary complications can be achieved only after early excision of the burn eschar, which immediately eliminates dead tissue, thus obviating burn sepsis and its undesirable consequences. Although without statistical substantiation, this is in fact our main conclusion. In the presence of respiratory damage,  strong automatic respiratory support, in addition to supplementary therapy, is the only irreplaceable way to help face the situation.

RESUME. Les brûlures continuent à être une maladie grave et dangereuse qui peut facilement porter à la mort, malgré les campagnes de propagande pour leur prévention et les progrès réalisés dans le secteur de leur traitement scientifique. Une possible complication des brûlures consiste en la maladie pulmonaire. Ce problème est considéré par les Auteurs, qui présentent une vision épidémiologique complète de cette complication. Une analyse détaillée des résultats de leur travail dans un centre de soins intensifs pendant une période de trois ans et une discussion des cas sur la base des données présentées dans les Tableaux soulignent les groupes d'âge les plus atteints, le temps du commencement de la complication, et les rapports entre la cause de la brûlure, son extension, et le taux de mortalité.

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