Computerized Axial Tomography in patients with severe abdominal trauma: is it a justifiable risk? / Tomografia no trauma abdominal grave: risco justificável?

OBJECTIVE: to evaluate the evolution of severe abdominal trauma patients, for whom the massive transfusion protocol was triggered, and who were submitted to Computed Axial Tomography (CAT) in the emergency room (ER), in order to verify the patient's prognosis and the diagnostic efficiency of CAT in this scenario. METHODS: retrospective, longitudinal and observational study performed at a referral center for trauma care in Curitiba, Parana, Brazil. We selected 60 severe abdominal trauma patients who had massive transfusion protocol activation and divided them into two groups: patients who underwent CAT at ER and patients who did not. We verified the diagnostic accuracy of CAT-scan examination and compared the number of deaths, hospitalization time, and transfused blood components in both groups. RESULTS: considering the 60 patients, 66.67% received red blood cells at ER; 33.3% underwent CAT on admission due to hemodynamic improvement, and 66.7% did not perform the examination at the entrance. The percentage of deaths was 35% in both groups. Considering the two groups, the difference between the mean lengths of hospital stay was not statistically significant, as well as the difference between the mean numbers of transfused red blood cells. In the group that underwent CAT, 45% did not require exploratory laparotomy. CONCLUSION: CAT could be rapidly performed in patients with hemodynamic instability on arrival at ER, sparing some patients from an unnecessary exploratory laparotomy and not significantly influencing mortality.

OBJETIVO: avaliar a evolução de pacientes vítimas de trauma abdominal grave, nos quais o protocolo de transfusão maciça foi acionado, e que foram submetidos à Tomografia Axial Computadorizada (TAC) no Pronto Socorro (PS), com o intuito de verificar o prognóstico do paciente e a eficiência diagnóstica da TAC nesse cenário. MÉTODOS: estudo retrospectivo, longitudinal e observacional, feito em centro de referência para trauma. Foram selecionados 60 pacientes vítimas de trauma abdominal grave que ativaram o protocolo de transfusão maciça, divididos em dois grupos: os submetidos à TAC no PS e os que não foram. Verificou-se a acurácia da TAC, comparou-se o número de óbitos nos dois grupos, o tempo de internamento e os hemocomponentes transfundidos. RESULTADOS: dos 60 pacientes, 66,67% receberam concentrados de hemácias ainda no PS; 33,3% foram submetidos à TAC na admissão, pela melhora hemodinâmica, e 66,7% não realizaram o exame na entrada. O percentual de óbitos foi de 35% em ambos os grupos. A diferença entre as médias do tempo de internamento entre os grupos não foi estatisticamente significativa, assim como a média da quantidade de concentrado de hemácias transfundido. No grupo que fez TAC, 45% não necessitaram de laparotomia exploratória. CONCLUSÃO: a TAC pôde ser realizada de maneira rápida em pacientes com instabilidade hemodinâmica na chegada ao PS, não influenciou significativamente a mortalidade e poupou alguns doentes de uma laparotomia exploratória desnecessária.

Tomografia no trauma abdominal grave: risco justificável? / Computerized Axial Tomography in patients with severe abdominal trauma: is it a justifiable risk?

RESUMO Objetivo: avaliar a evolução de pacientes vítimas de trauma abdominal grave, nos quais o protocolo de transfusão maciça foi acionado, e que foram submetidos à Tomografia Axial Computadorizada (TAC) no Pronto Socorro (PS), com o intuito de verificar o prognóstico do paciente e a eficiência diagnóstica da TAC nesse cenário. Métodos: estudo retrospectivo, longitudinal e observacional, feito em centro de referência para trauma. Foram selecionados 60 pacientes vítimas de trauma abdominal grave que ativaram o protocolo de transfusão maciça, divididos em dois grupos: os submetidos à TAC no PS e os que não foram. Verificou-se a acurácia da TAC, comparou-se o número de óbitos nos dois grupos, o tempo de internamento e os hemocomponentes transfundidos. Resultados: dos 60 pacientes, 66,67% receberam concentrados de hemácias ainda no PS; 33,3% foram submetidos à TAC na admissão, pela melhora hemodinâmica, e 66,7% não realizaram o exame na entrada. O percentual de óbitos foi de 35% em ambos os grupos. A diferença entre as médias do tempo de internamento entre os grupos não foi estatisticamente significativa, assim como a média da quantidade de concentrado de hemácias transfundido. No grupo que fez TAC, 45% não necessitaram de laparotomia exploratória. Conclusão: a TAC pôde ser realizada de maneira rápida em pacientes com instabilidade hemodinâmica na chegada ao PS, não influenciou significativamente a mortalidade e poupou alguns doentes de uma laparotomia exploratória desnecessária.

ABSTRACT Objective: to evaluate the evolution of severe abdominal trauma patients, for whom the massive transfusion protocol was triggered, and who were submitted to Computed Axial Tomography (CAT) in the emergency room (ER), in order to verify the patient's prognosis and the diagnostic efficiency of CAT in this scenario. Methods: retrospective, longitudinal and observational study performed at a referral center for trauma care in Curitiba, Parana, Brazil. We selected 60 severe abdominal trauma patients who had massive transfusion protocol activation and divided them into two groups: patients who underwent CAT at ER and patients who did not. We verified the diagnostic accuracy of CAT-scan examination and compared the number of deaths, hospitalization time, and transfused blood components in both groups. Results: considering the 60 patients, 66.67% received red blood cells at ER; 33.3% underwent CAT on admission due to hemodynamic improvement, and 66.7% did not perform the examination at the entrance. The percentage of deaths was 35% in both groups. Considering the two groups, the difference between the mean lengths of hospital stay was not statistically significant, as well as the difference between the mean numbers of transfused red blood cells. In the group that underwent CAT, 45% did not require exploratory laparotomy. Conclusion: CAT could be rapidly performed in patients with hemodynamic instability on arrival at ER, sparing some patients from an unnecessary exploratory laparotomy and not significantly influencing mortality.

Estimation of Stroke Volume and Stroke Volume Changes by Electrical Impedance Tomography.

BACKGROUND: Electrical impedance tomography (EIT) is a noninvasive imaging method that identifies changes in air and blood volume based on thoracic impedance changes. Recently, there has been growing interest in EIT to measure stroke volume (SV). The objectives of this study are as follows: (1) to evaluate the ability of systolic impedance variations (ΔZsys) to track changes in SV in relation to a baseline condition; (2) to assess the relationship of ΔZsys and SV in experimental subjects; and (3) to identify the influence of body dimensions on the relationship between ΔZsys and SV. METHODS: Twelve Agroceres pigs were instrumented with transpulmonary thermodilution catheter and EIT and were mechanically ventilated in a random order using different settings of tidal volume (VT) and positive end-expiratory pressure (PEEP): VT 10 mL·kg and PEEP 10 cm H2O, VT 10 mL·kg and PEEP 5 cm H2O, VT 6 mL·kg and PEEP 10 cm H2O, and VT 6 mL·kg and PEEP 5 cm H2O. After baseline data collection, subjects were submitted to hemorrhagic shock and successive fluid challenges. RESULTS: A total of 204 paired measurements of SV and ΔZsys were obtained. The 4-quadrant plot showed acceptable trending ability with a concordance rate of 91.2%. Changes in ΔZsys after fluid challenges presented an area under the curve of 0.83 (95% confidence interval, 0.74-0.92) to evaluate SV changes. Conversely, the linear association between ΔZsys and SV was poor, with R from linear mixed model of 0.35. Adding information on body dimensions improved the linear association between ΔZsys and SV up to R from linear mixed model of 0.85. CONCLUSIONS: EIT showed good trending ability and is a promising hemodynamic monitoring tool. Measurements of absolute SV require that body dimensions be taken into account.

Effects of fluid resuscitation on cardiovascular performance after posttraumatic pneumonectomy.

BACKGROUND: : Several factors have been implicated in the high-mortality rate of posttraumatic pneumonectomy. In this study, we evaluated the hemodynamic and echocardiographic changes induced by pneumonectomy and fluid resuscitation after hemorrhagic shock. METHODS: : Fourteen dogs were bled to a target mean arterial pressure of 40 mmHg. The animals were assigned to two groups: control (no fluid resuscitation) and lactated Ringer's (3 x shed blood volume). The left pulmonary hilum was cross clamped, and the animals were observed for 60 minutes. Systemic hemodynamics was evaluated using Swan-Ganz, arterial catheter, and ultrasonic flow probe. Systemic O2-derived variables were calculated. Ejection fraction was determined by two-dimensional echocardiography. RESULTS: : Fluid resuscitation improved the mean arterial pressure and systemic oxygen delivery. After pneumonectomy, no significant increase in right ventricular pressure was observed in the LR group. No signs of major ventricular dilation or changes in arterial oxygenation were observed. CONCLUSION: : Our data suggest that pneumonectomy is not associated with early pulmonary hypertension; gentle fluid resuscitation improves cardiovascular performance and is not associated with an increase in right ventricular pressure.

Cardiac output determination during experimental hemorrhage and resuscitation using a transesophageal Doppler monitor.

Transesophageal Doppler (TED) monitoring has been considered a noninvasive and accurate alternative to pulmonary artery catheterization for volume replacement and cardiac output measurement in patients undergoing major surgery. This study tested the hypothesis that TED can accurately predict cardiac output during hemorrhage, shock, and resuscitation, by comparing it to total pulmonary artery blood flow (PABF) and to standard intermittent bolus cardiac output (ICO). In eight anesthetized dogs (18 +/- 1.0 kg), PABF was measured with an ultrasonic flowprobe while ICO and mixed venous O2 saturation (SvO2) were measured through a Swan-Ganz catheter. A TED probe (CardioQ, Deltex Medical Inc., Irving, TX, U.S.A.), designed for adult use (minimum 30 kg, 16 years), was placed in midesophageous to evaluate stroke volume. A graded hemorrhage (20 mL/min) was produced (H5-H35) to a mean arterial pressure (MAP) of 40 mm Hg and maintained by additional blood removal for 30 min (S1-S30). Total shed blood volume was retransfused (541 +/- 54.2 mL) over 30 min (T5-T30), after which a massive hemorrhage, 100 mL/min rate, was produced over 10 min (MH5-MH10). In general, TED overestimated PABF (r2 = 0.3472), but changes in TED paralleled PABF throughout the experimental protocol, particularly during massive hemorrhage (r2 = 0.9001). We concluded that TED accurately reflected the direction and magnitude of the changes of cardiac output over time during abrupt hemodynamic changes. Probes designed for lower weights and smaller aortas may improve its accuracy in medium size animal models under less dramatic alterations induced by hemorrhage, shock, and resuscitation.