Zaidi M, Franka M.R., Abusetta k Shehata G, Shahin A.

Burn and Plastic Surgery Department, Tripoli, Libya

SUMMARY. Our study covers 224 patients with smoke inhalation admitted to our Burn Intensive Care Unit in the period 1.1.9331.12.96. The criteria for admission to our ICU are extensive burns, inhalation injury, and Burns with other systemic problems. We diagnose smoke inhalation on the basis of history, facial Burn, sooty sputum, hoarseness of the voice, laboratory investigations, ABG, carboxyhaemoglobin level in the blood, and bronchoscopy. In the four-year period 1. 1.93-31.12.96, 224 patients with smoke inhalation were admitted to our Burn ICU, divided into two groups. The 86 patients in the first group were treated with appropriate resuscitation, improvement of oxygenation by oxygen mask, nasal oxygen catheter, nasal endotracheal tube, calcium channel blocker, and cardiopulmonary support, together with PPV and PEEP in the presence of hypoxia and pulmonary insufficiency. Of these patients admitted with smoke inhalation 51 died (59%). The 138 patients in the second group admitted with smoke inhalation were managed with the same treatment and with improvement of oxygenation by PPV with PEEP soon after admission, without waiting for hypoxia or pulmonary insufficiency. Out of these patients admitted with smoke halation 57 died (41 %).

It is well known that inhalation injury is one of the main causes of mortality in Burn patients. The use of new synthetic materials in domestic furniture and in clothes has led to much more complex forms of injury due to extremely combustible products (see chart below). The tracheobronchial epithelium sloughs and combines with a proteinrich exudate, leading to obstruction of the airways. Our study covers 224 patients with smoke inhalation admitted to a Burn ICU in Tripoli. The patients were divided into two groups. The first group (86 patients) was admitted in the period 1.1.93-31.12.94 and was managed with increased Fi02, cardiopulmonary support, Ca channel blockers, bronchial toilet, antibiotics, 02, face mask, oxygen nasal catheter, and nasal endotracheal tube, together with PPV with PEEP when there was severe hypoxia and pulmonary insufficiency. Out of the 86 patients admitted, 51 died (59%), mostly with burned area 50-100% and aged over 14 yr. The second group (138 patients) was admitted in the period 1.1.95-31.12.96 and treated in the same way, however with PPV + PEEP on admission. Out of these 138 patients, 57 died (41%), mostly with high percentage Burn area and aged over 14 yr.
We diagnose smoke inhalation by history, facial Burn, sooty sputum and hoarseness of voice, ABG, carboxyhaernoglobin level in the blood, and bronchoscopy.

The aims of the treatment are to achieve better oxygenation by increasing Fio, and improving perfusion and ventilation, to increase cardiopulmonary support and at the same time to provide appropriate IVF resuscitation.
In our Burn ICU we use the Evans formula and modified Evans in children as follows:

• Ringer's lactate: 1 ml/kg/% TBSA/24 h Plasma protein: I ml/kg/% TBSA/24 h
• Dextrose/saline: according to body weight, half the amount given in the first 8 h, 1/4 in the 2nd 8 h, and 1/4 in the 3rd 8h

All vital signs are carefully monitored (heart rate, respiratory rate, blood pressure, hourly urine output and ABG, carboxyhaemoglobin level in the blood, and serum electrolyte every 12 h)

In the four-year period 1 January 1993-31 December 1996, 224 patients with smoke inhalation were admitted to our ICU, divided into two groups.
The first group was composed of 86 patients with smoke inhalation admitted in the period from 1 January 1993 to 31 December 1994. Our treatment consisted of resuscitation by IVF, the improvement of oxygenation by use of an oxygen mask, nasal oxygen catheter, nasal endotracheal tube, a channel block, cardiopulmonary support, and PPV and PEEP when there were hypoxia and pulmonary insufficiency.
Table I shows that there were 55 patients with a Burn area of 5 1 - 100%, of whom 44 were older than 14 years of age.

As can be seen in Table II, the number of mortalities in relation to age and total body surface area burned was 51, of whom 43 patients had a Burn area ranging from 51 to 100% and 35 were aged over 14 years. It can be seen that the mortality rate was still high (59%), increasing with age and high percentage Burn.

The second group (138 patients) was admitted to our Burn ICU in the period from 1 January 1995 to 31 December 1996. We managed this group with the same treatment, improving Fi02 by PPV with PEEP early after admission, without waiting for hypoxia or pulmonary insufficiency. We intubated the patients after admission and connected them to mechanical ventilation - 100% 02 for 2 h to displace CO from haemoglobin, then 80% 02 for 2 h, 60% 02 for 2 h, followed by 40% 02. We extubated the patients after the first operation in our ICU. Wound management was performed by early excision 12-24 h post-Burn.
Table III shows the total number of patients with smoke inhalation in relation to age and percentage Burns. Out of a total number of 138 patients, 66 presented Burns in an area between 51 and 100%, and 60 patients were over 14 years of age.

Table IV indicates the mortality rate in relation to age and percentage Burns. Out of a total number of 57 patients, 48 had a Burn area ranging from 51 to 100% and 44 were over 14 years of age.

Tables III and IV show that overall mortality was 57 patients (41 %). Mortality remained high with elevated Burn percentage and advanced age.

From Tables VIII and IX we can see that the total number of mortalities due directly to smoke inhalation was 108 (19%) among all the patients admitted to our Burn ICU in the period in question.

Results

We studied 224 patients with smoke inhalation complications, representing 40% of the total number of patients admitted to our the ICU in the period between 1 January 1993 and 31 December 1996. The majority of the patients were over 14 years of age (74% of admissions). Most patients (67%) presented a burned TBSA area between 51 and 100%. The mortality rate increased in patients with more than 50% TBSA Burns.
Early intubation and assisted ventilation helped to ecreased the mortality rate from 59% in the first two years of the study to 41% in the last 2 years, when early intubation and ventilation were frequently performed.

Conclusions

Smoke inhalation is still a major complication of Burns that requires special attention. We believe that the outcome depends on correct early resuscitation, early intubation, assisted ventilation with PEEP, early wound management by surgical excision, and support of the patient by early enteral and parenteral nutrition. Physiotherapy and early mobilization are essential in these patients in order to induce early recovery from the complications resulting from the Burn trauma.

Fig. 1 - female patient, 60% TBSA burns with inhalation injuty Fig. 2 - male patient, 61% TBSA burns with inhalation injury

RESUME. Notre étude concerne 224 patients atteints d'inhalation de fumée hospitalisés dans notre Centre des Soins Intensifs dans la période 1. 1.93-31.12.96. Les critères pour l'hospitalisation dans ce centre sont les brûlures étendues, les lésions dues à l'inhalation et d'autres problèmes systémiques. Nous diagnostiquons l'inhalation de fumée sur la base de l'histoire du cas, les brûlures faciales, l'expectoration fuligineuse et l'enrouement de la voix, les investigations de laboratoire, le niveau de FABG et de la carboxybémoglobine dans le sang, et la bronchoscopie. Les patients ont été divisés en deux groupes. Le premier groupe était composé de 86 patients traités avec la réanimation appropriée, l'amélioration de l'oxygénation moyennant le masque à oxygène, le cathéter d'oxygène nasal, le tube endotrachéal nasal, le bloquant des canaux calciques, le support cardiopulmonaire, la ventilation à pression positive (VPR) et la pression positive résiduelle expiratoire (PPRE) dans les cas d'hypoxie et d'insuffisance pulmonaire. Des 86 patients hospitalisés atteints d'inhalation de fumée 51 (59%) sont morts. Le deuxième groupe était composé de 138 patients atteints d'inhalation de fumée traités avec la même thérapie mais aussi avec l'amélioration de l'oxygénation moyennant la VPR et la PPRE immédiatement après l'hospitalisation, sans attendre la manifestation de l'hypoxie ou de l'insuffisance pulmonaire. Dans ce groupe, des 138 patients atteints d'insuffisance pulmonaire 57 (41%) sont morts.