Lucia Cachafeiro

A protocol for resuscitation of severe burn patients guided by transpulmonary thermodilution and lactate levels: a 3-year prospective cohort study

IntroductionThe use of urinary output and vital signs to guide initial burn resuscitation may lead to suboptimal resuscitation. Invasive hemodynamic monitoring may result in over-resuscitation. This study aimed to evaluate the results of a goal-directed burn resuscitation protocol that used standard measures of mean arterial pressure (MAP) and urine output, plus transpulmonary thermodilution (TPTD) and lactate levels to adjust fluid therapy to achieve a minimum level of preload to allow for sufficient vital organ perfusion.MethodsWe conducted a three-year prospective cohort study of 132 consecutive critically burned patients. These patients underwent resuscitation guided by MAP (>65 mmHg), urinary output (0.5 to 1 ml/kg), TPTD and lactate levels. Fluid therapy was adjusted to achieve a cardiac index (CI) >2.5 L/minute/m2 and an intrathoracic blood volume index (ITBVI) >600 ml/m2, and to optimize lactate levels. Statistical analysis was performed using mixed models. We also used Pearson or Spearman methods and the Mann-Whitney U-test.ResultsA total of 98 men and 34 women (mean age, 48 ± 18 years) was studied. The mean total body surface area (TBSA) burned was 35% ± 22%. During the early resuscitation phase, lactate levels were elevated (2.58 ± 2.05 mmol/L) and TPTD showed initial hypovolemia by the CI (2.68 ± 1.06 L/minute/m2) and the ITBVI (709 ± 254 mL/m2). At 24 to 32 hours, the CI and lactic levels were normalized, although the ITBVI remained below the normal range (744 ± 276 ml/m2). The mean fluid rate required to achieve protocol targets in the first 8 hours was 4.05 ml/kg/TBSA burned, which slightly increased in the next 16 hours. Patients with a urine output greater than or less than 0.5 ml/kg/hour did not show differences in heart rate, mean arterial pressure, CI, ITBVI or lactate levels.ConclusionsInitial hypovolemia may be detected by TPTD monitoring during the early resuscitation phase. This hypovolemia might not be reflected by blood pressure and hourly urine output. An adequate CI and tissue perfusion can be achieved with below-normal levels of preload. Early resuscitation guided by lactate levels and below-normal preload volume targets appears safe and avoids unnecessary fluid input.

Prevalence of intra-abdominal hypertension (IAH) among patients with severe burns

o solve the problem of non-availability of conventional sites or electrocardiogram (ECG) electrode placement in patients ith burn, authors have described successful use of ‘staple Panel A) [5]. The ‘left leg’ electrode was placed over burn free superior aspect of the left iliac crest [5]. The ECG tracing obtained (Fig. 1, Panel B) without any adjustment factor and in the bandwidth of 0.05–150 Hz was satisfactory (Philips Intellivue 40 monitor, Philips Medizin Systeme, Boeblingen, Germany) [5]. On examination of the ST and QT snippet, satisfactory wave morphology was observed (Fig. 1, Panel B). We have been using this technique since then. If ECG lead configuration of more than 3 leads is desirable, the description by Farroha et al. provides advantage over the technique presented by us [2]. But as ECG tracing is influenced b u r n s 4 0 ( 2 0 1 4 ) 5 2 5 – 5 3 7 32

Are we near to the end of the standard dose of micafungin

We have carefully read the study titled “Population pharmacokinetics/pharmacodynamics of micafungin against Candida species in obese, critically ill, and morbidly obese critically ill patients” [1] and congratulate the authors for such an interesting initiative. The researchers conclude the lack of adequate micafungin exposure with a 100 mg/24 h dose regardless of the Candida species or the patient’s weight. Further, micafungin exposure was adequate to cover Candida albicans with a 150 mg/24 h dose for patients weighing up to 115 kg and with a 200 mg/24 h dose for those surpassing this weight. The 200 mg/24 h dose covered Candida glabrata for patients weighing up to 115 kg. These results could correlate with, and also support those that we previously obtained in the first study [2] published on the pharmacokinetics (PK) of micafungin in plasma and burn eschar tissue in critically ill patients with severe burn injuries, which were compared with the PK of micafungin in patients with intra-abdominal infections [3]. In our study, 15 burn patients were compared with ten patients with intra-abdominal infection; all patients were treated with 100 to 150 mg/day of micafungin. We also observed that the standard dose of micafungin, 100 mg/day, achieves optimal PK/pharmacodynamics (PD) targets in plasma for MIC values of 0.008 mg/L and 0.064 mg/L for non-parapsilosis Candida spp. and Candida parapsilosis, respectively. By increasing the dose to 200 mg/day, the optimal PK/PD targets in plasma could be achieved for MIC cutoff values that are twofold higher (0.016 mg/L and 0.125 mg/L, respectively). To these subpopulations of critically ill patients we must add patients with sepsis and mechanical ventilation [4]. The authors recommended dose of 100 mg/day of micafungin would be associated with a very low probability of reaching the AUC0-24/MIC ratio in cases of infection with C. albicans or C. glabrata with MIC ≥ 0.015 mg/L, as well as in almost all cases of infection due to C. parapsilosis. Finally, the conclusions presented above in relation to the most recent PK studies of micafungin, performed in different subpopulations of critically ill patients, would provide us with significant evidence that we should consider an increase in the standard dose (100 mg/day) for the treatment of invasive candidiasis and that it would be advisable, in our opinion, to propose PK/PD studies to patients in whom a lack of clinical or microbiological efficacy due to a suboptimal dose of treatment is suspected.

Main limitations of transpulmonary thermodilution: set targets

Background We read with great interest the review by Xavier Monnet and Jean-Louis Teboul [1]. This review concluded that transpulmonary thermodilution (TPTD) provides a full haemodynamic evaluation. The authors discuss the limitations of previous studies reporting a lack of outcome improvement in patients treated using TPTD-based fluid management. They stated that the objectives of these studies were not comparable and that questionable protocols were used. Based on our previous studies of TPTD in burn patients [2], we would like to make some comments. The TPTD technique provides parameters that must be interpreted having previous knowledge about situations which may influence results. In addition, the normal values of healthy individuals may not be appropriate comparators for critically ill patients. Therefore, the successful use of this device should be based on the achievement of appropriate objectives [3]. Extravascular lung water or the pulmonary vascular permeability index can be useful parameters for reducing the fluid load if it is elevated, but not to provide more volume if it is low because the patient may not exhibit preload responsiveness or may show only ‘temporary’ responsiveness. For instance, if there is high capillary leakage, the haemodynamic benefits obtained may be lost in a short time. Furthermore, it is erroneous to equate alteration of the pulmonary vascular permeability index with the systemic vascular permeability index [4]. In any case, this technique can help determine other parameters, such as stroke volume variation, or measure the responses of these parameters to fluid challenge. In our study, we have found that critically ill patients with slightly low preload values (global end-diastolic volume < 600 ml/m) achieve adequate cardiac index (>2.5 L/min/m) and lactate values (<2 mmol/L), avoiding excessive volume contributions [2, 5]. Finally, it is important to acknowledge possible complications in certain circumstances. For example, in burn patients with severe hypovolemia we found a higher incidence of transient ischaemia in the lower limbs than the 0.4% reported in some studies.

Réplica al artículo «tratamiento de necrolisis epidérmica tóxica con ciclosporina A»

emos leído muy atentamente el artículo publicado en Mediina Intensiva publicado por Fernández Carmona et al.1, onde se exponen tres casos de necrolisis epidérmica tóxica ratados con éxito con ciclosporina A. Esta patología, como eñalan los autores, aunque es muy infrecuente, se asoia con una alta mortalidad, de ahí la importancia de una etección precoz y un adecuado tratamiento. A pesar de os numerosos estudios realizados, el tratamiento específico el síndrome de Stevens Johnson (SSJ) y de la necrolisis epiérmica tóxica (NET) continúa siendo controvertido2,3. Por sta razón, nos gustaría comentar nuestra experiencia en el ratamiento de esta patología con inmunoglobulinas como ratamiento específico, ya que ha demostrado su eficacia en umerosos estudios4. En nuestro centro, los pacientes con sospecha de NET SSJ se ingresan en la Unidad de Quemados Críticos. Por as características de las lesiones deben ser tratados como uemados críticos, y por tanto, deben ser trasladados a una nidad especializada lo antes posible, ya que esto ha demosrado disminuir la mortalidad5. Una vez ingresados se pone n marcha un protocolo de actuación en el que se trabaja onjuntamente con otras especialidades, como cirugía plásica, oftalmología, inmunología, alergología, farmacología línica y dermatología. Desde el ingreso se extraen analítias, cultivos, serología y se realizan estudios inmunológicos biopsias para obtener el diagnóstico de certeza, además de ecibir el tratamiento de soporte necesario en función de la ravedad. Como escala de gravedad utilizamos el SCORTEN como tratamiento específico las inmunoglobulinas. En los últimos dos años, hemos ingresado 14 casos de ET y SSJ confirmados mediante biopsia, con un SCORTEN edio de tres, de los cuales cinco requirieron ventilación ecánica. Todos ellos fueron tratados desde el ingreso on 0,75 g/kg/día de inmunoglobulinas durante tres días onsecutivos. La mortalidad esperada según SCORTEN era Consideramos que esta patología, por su alta mortalidad, debe ser tratada de manera integral, por un equipo multidisciplinar y en una Unidad de Quemados Críticos. Al contrario que los autores, creemos que el diagnóstico de certeza debe hacerse mediante biopsia, para poder diferenciarlo de otras patologías que cursan con clínica similar e iniciar lo antes posible el tratamiento específico. Así mismo, y a pesar de ser necesarios más estudios, creemos que el uso de las inmunoglobulinas continúa siendo a día de hoy, la mejor opción terapéutica para el tratamiento específico de esta patología.