Annals of Burns and Fire Disasters - vol. XIII - n. 2 - June 2000

RESUSCITATION APPROACH AND CLINICAL EVALUATION IN BURNS VICTIM AFTER MASS ACCIDENTS - PART TWO. HAEMATOLOGICAL STUDY AND ANALYSES

Hadjiiski O., Rashkov V., Emanuilov J., Lubomirov M.

Centre for Burns and Plastic Surgery, Pirogov Medical Institute, Sofia, Bulgaria

SUMMARY. This study continues our exploration of the treatment of patients with burns suffered in mass accidents (Part One was published in the March 2000 issue of Annals of Burns and Fire Disasters). We observed the changes in various laboratory parameters, such as the dynamic of the haemoglobin and haematocrit levels, proteins, potassium, sodium, and the acid-base balance related to the application of Baxter's modified scheme in the treatment of burn patients in the first three days post-burn. Our results show a normalization of haematocrit and protein levels, plus a stable electrolyte balance and satisfactory normalization of the acid-base level

The management of burns after mass accidents is a frequent problem in Bulgaria, considering the limited size of our country. Mass burn accidents lead to a great number of deaths and the survivors usually present a large burn area, which creates treatment problems. Various formulas are recommended for the stabilization of vital signs after such accidents. We use the modified Baxter scheme with Ringer's lactate solution in the first 24h after the accident! We prefer this solution because it is widely known, with clear therapeutic effects, thus making it very suitable in the event of mass accidents
We include protein solutions after the first 24h, because then the increased capillary permeability begins to lessen and their deficiency becomes manifest, The studies of the Cochran Injury Group show that the use of colloids in cases of post-burn hypovolaemia leads to an the increase,in the mortality rate. Collo ids can be used only in patients with a pre-existing protein deficit, such as those with inhalation injury, as a preparation for necrectomy. As a criterion for the effectiveness of treatment we use various parameters as well as numerous laboratory findings. Some of these are monitored owing to their doubtful informative value, which on the other hand shows the effectiveness of the resuscitation efforts. Our results confirm that this scheme of treatment is very suitable not only in the management of haemodynamic instability but also in the management of the delicate electrolyte, base-acid and protein balance. Another reason for our preference for this scheme is the availability of the necessary solutions in every hospital, as patients are normally transferred early to larger centres where colloids are available. We use simple parameters for observation, and stabilization continues up to the end of the period in most patients. The mortality rate is not high. The non-use of blood transfusion with this scheme means that haemoglobin (Hb) and haematocrit (Hct) values are not altered.

Materials and methods

The results of the treatment of 43 burn victims form the object of observation and statistical analysis. We divided the patients into three groups on the basis of burn area:

• first group - 13 patients, burns up to 29% TBSA
• second group - 16 patients, burns from 30 to 59% TBSA
• third group - 14 patients, burns from 60 to 100% TBSA

The great majority of the patients (37) were male; only six were female. The commonest burn agent was flame (32 patients), while scalding accounted for 11 patients. The burn trauma was usually associated with other injuries. We diagnosed 60 combined injuries (1.40 per patient).
The patients were treated according to the scheme proposed by the team of the SIEM Pirogov Burns and Plastic Surgery Centre, which is accepted in our country as the preferred scheme for the treatment of the thermal shock phase. In this study we observed and analysed the effect of fluid resuscitation on the patients. During thermal shock our scheme of fluid resuscitation prescribes 3 ml/kg/% TBSA crystalloid (Ringer's lactate) in the first 24 h period after the accident and 03-0.5 ml/kg/% TBSA protein solutions, plus 1.0-1.5 rnl/kg/% TBSA 5% glucose solution in the second and third 24 h period after the accident. For more precise details, Part One of this article will be of assistance.
The following parameters were measured on the first three post-trauma days: Hb, Hct level at 3-h intervals, levels of base excess from blood gas analysis every 6 h, sodium and potassium (daily), and plasma proteins.

Results and discussion

Our results show that the infusions administered were sufficient for stabilization of the general status of the patients and for their circulation. The patients received a little more than the calculated quantity of infusion solutions. During the first 24-h period they received only crystalloids - the quantity received was 10.17 to 10.79% higher than that calculated. During the following two days, when consolidation of the blood vessel wall began, we compensated for protein losses - the necessary volume was obtained by means of free water solutions. The total volume was also higher than that calculated (10.32 to 11.89%), in spite of the burn area range.
During the second and third 24-h period we used as colloids 5% human serum alburnin or plasma. The quantity was 0.3 ml/kg/O/o TBSA in patients with burns in up to 29% TBSA, 0.3-0.4 ml/kg/O/o in patients with 30-50% TBSA burns, and 0.4-0.5 ml/kg/% in patients with over 60% TBSA burns. Patients in the first and second groups received this quantity with a variation of 6-11%. Patients in the third group received 42-46% less than the quantity calculated with a significant difference (p < 0.01).
Despite the individual characteristics of each single patient, the proposed quantity and type of solutions during the period were accurately calculated for all the groups. The cause of the statistically significant insufficiency of the infusion therapy in patients with burns in over 60% TBSA on days 2 and 3 can be attributed to the large quantity of protein solution that we were Lmable to provide in time.
In order to ensure the efficiency of the treatment, we not only followed up the patients' conditions but also kept a dynamic record of various vital parameters. We observed three patient groups in order to be able to compare the results in the respective groups and to provide statistical confirmation.
The dynamic of the Hb level is presented in Fig. 1. In the first group of patients, the Hb level exceeded the normal borderline (159 g/1) only on day 1, while on the following two days the values were normal. In the second group of patients, the values on the first two days were over the normal borderline range (184 gft and normalization occurred on day 3 (151 g/1). In the third group of patients, despite the dynamic decrease the values remained above the normal borderline range (193 g/l on day 1; 159 g/l at the end of the period).
The mean values in all the groups were highest on the day of the trauma, as a result of blood concentration. The results clearly indicate that there was a definite correlation between the extent of the burn and the timing of the restoration of fluid losses. The increase in the first group (burns up to 29% TBSA) was 15.2%, in the second it was 32%, and in the third (burns over 60% TBSA) the increase was 38.2% over the accepted normal value; the difference between the groups was statistically significant.
In the first group normalization occurred 24 h after initiation of treatment and in the second group half-way through day 3; in the third group it remained 14.3% above the normal range after treatment, which shows partial restoration of blood concentration in this group.
The statistically significant differences at the beginning and the end of treatment show the reliability of the results in the interpretation of the treatment and the level of restoration of haemodynamics.
The Hct dynamic is presented in Fig. 2. In the first group of patients the Hct was above normal values (0.50 ± 0.06) until the 40th hour after the accident, after which it slowly decreased; at the end day it was normal (0.43 ± 0.07). This finding indicates a moderate blood concentration on day 1 and in the first half of day 2, followed by normalization of the circulating blood volume. The statistical analysis as connected with the different hours excerpt show that the mean Hct values were from 0.53 to 0.42, standard deviation (SD) from ± 0.07 to ± 0.04, and standard error (SE) from 0.034 to 0.021, where the significant rate is p < 0.039, proving the reliability of the 250 results.
In the second group of patients, the Het was above the normal borderline (from 0.57 to 0.49 ± 0.07 g/1 at the end of day 2) until the 48th h after the accident, after which it slowly decreased to normal values on day 3 (0.40 ± 911 0.06). This finding shows a marked blood concentration on the first two days and gradual normalization of the 100 circulating blood volume on the third day post-trauma. The statistical analysis of the data shows that the mean Het values were statistically significant during the whole period in all the groups compared. The values were from 0.58 to 0.40 gfi (standard deviation from 0.078 to ± 0.049, standard error from 0.017 to 0.022), with a high significance rate of 0.01 to 0.003 (p < 0.01), confirming the reliability of the results.
In the third group of patients, the Het remained above normal borderline values (0.50 ± 0.09) up to the 48th h after the accident and then gradually decreased, until at the end of day 3 it was below the normal borderline (0.39 ± 0. 12). This finding shows blood concentration in the first two days and the development of anaemia owing to blood losses from the wound surface during dressing procedures and to the onset of infection in some patients, with correspondingly low Hb. The statistical analysis of the data shows that the mean Het values were statistically significant during the whole period in all the groups compared, while the significance rate of 0.01 to 0.003 confirms the reliability of the results.
This parameter is significant for estimating the hypovolaemic state. The mean Het values were highest on the day of the trauma. The reason for this is the same as for the Hb blood concentration. The increase in the first group was 21.4% over the normal range, but in different investigations this difference was statistically non significant (38% in the second group and 41.67% in the third group above the normal borderline); the differences between the groups were statistically significant. The Het gradually level decreased but at the end of the observation period it was near the normal range. In some studies it was below the normal range; the differences with few exceptions were statistically significant. There was a definite correlation between burn extent and the time necessary for restoration of fluid losses.
With regard to the blood acid-base balance, several parameters were observed: blood pH, oxygen saturation, quantity of carbon dioxide, etc. Fig. 3 illustrates one of these parameters - the base excess (BE). In the first group of patients BE was minus 4.94 ± 3.59 at the beginning of the period, which confirms the disturbance in the metabolism and acidosis. However, this parameter normalized at the beginning of the second day. In patients in the second group, BE was below the normal borderline range (minus 6.87 ±  6.7).

Fig. 1 - Dynamic of the haemoglobin level. Fig. 2 - Dynamic of the haernatowit level.   Fig. 3 - Dynamic of the basic excess level.

This was a result of dehydration, disturbed tissue metabolism, and the presence of acidosis. Acidosis decreased on day 2 and around the 60th h BE was positive.
Also in the third group of patients BE was below the normal borderline range (minus 11.85 ± 4.52), showing a disturbed tissue metabolism and severe acidosis. The acidosis decreased on the second day and at the end of the period it was around normal values (1.40). In the first group of patients treatment of this disturbance was achieved by correct fluid resuscitation, while in the other two groups buffer correction was needed in more than half of the patients.
The results show that the metabolism was restored on day 2 in patients in the first two groups and on day 3 in the third group. The statistically significant difference at the beginning and end of the period confirms the reliability of the results and the effectiveness of the treatment.
The patients plasma protein dynamic,is presented in Table I. In the first group of patients the protein value was normal on day 1, and a moderate decrease was noted at the end of treatment (56.16 g/1). In the other two groups the values were below the normal borderline range on day 1 and progressively decreased on day 2; at the end of the period it rose slowly but remained lower than the first value measured. Our observations show that the changes in plasma proteins were related to the area of the burn and that proteins reduced as the burn area increased. In the first group of patients the values were near normal, while in the other two groups the mean values were markedly reduced. In 38% of the patients in the second group these values were below the normal range. In the third group the plasma protein loss was especially great, and in 80% of patients it was below the normal range. The differences in the plasma protein values between the different groups were statistically significant and were correlated with the burn area and the treatment effected (insufficient protein replacement in patients in the third group).

The sodium dynamic is presented in Table II. In the first group of patients the sodium value was in the low normal borderline range; the differences in values at the beginning and end of the period were not significant and did not have a common dynamic. The same holds for the second group, except that the sodium values were near the upper borderline normal range. In the third group, where the quantity of the infused solutions was high, the sodium level dynamic changed. The values were at the upper border of the normal range and in 25% of group 2 patients and in 31.23% of patients on day 3 the values were above the normal range. Our results show that in spite of the massive infusion of enriched sodium solutions, if the quality and quantity of the fluids is correctly calculated there is no risk of hypernatraernia. The statistical significance of the comparative results in every group at the beginning and end of the period  confirms their reliability and the correct choice of treatment. The potassium dynamic can be seen in Table III.

The potassium values show that the mean values remained within the normal range. In the first and the second groups of patients, these values were lower on the first day and rose progressively on the other two days, remaining however in the normal range. The differences between the two groups were not statistically significant. In the third group the mean plasma potassium values on day 1 were higher than those of the first two groups and remained the same on the following days. The differences compared with the other groups were statistically significant. The reason for the higher potassium levels on the first days was the destruction of cells due to the thermal trauma.

Conclusions

The results of this study, which is based on findings in 43 victims of mass burn accidents over a 5-yr period, enable us to recommend the proposed scheme of treatment as a method of choice in the management of the burn shock phase. The scheme is especially suitable for practical use in mass burn accidents because of the simplicity and ease of its application, the ready availability in every hospital of infusion solutions, and the satisfactory nature of the results. Monitoring includes non-specific laboratory parameters that can be obtained in any hospital. Normalization of the indices for most patients continues until the end of the shock phase period.

RESUME. Les Auteurs confinuent leur étude du traitement des patients brûlés victimes de grands désastres (la premiére partie a été publiée dans Annals of Burns and Fire Disasters dans le numéro de mars 2000). Ils observent les modifications des paramétres de laboratoire, comme la dynamique du niveau de l'hémoglobine et de l'hématocrite, des protéines, du potassium, du sodium, comme aussi de 1'équilibre acide-base lié à l'application du méthode modifié de Baxter dans le traitement des brûlés pendant les premiers trois jours aprés l'accident. Les résultats obtenus indiquent une normalisation des niveaux de l'hématocrite et des niveaux protéiques, comme aussi un équilibre stable des électrolytes et une normalisation satisfaisante du niveau acide-base.

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