RESUMO

Hemostasis plays a critical role in surgical procedures and is essential for a successful outcome. Advances in hemostatic agents offer new approaches to controlling bleeding thereby making surgeries safer. The appropriate choice of these agents is crucial. Volume replacement, another integral part of Patient Blood Management (PBM), maintains adequate tissue perfusion, preventing cellular damage. Individualization in fluid administration is vital with the choice between crystalloids and colloids depending on each case. Colloids, unlike crystalloids, increase oncotic pressure, contributing to fluid retention in the intravascular space. Understanding these aspects is essential to ensure safe and effective surgery, minimizing complications related to blood loss and maintaining the patient's hemodynamic status.

RESUMO

Abstract Hemostasis plays a critical role in surgical procedures and is essential for a successful outcome. Advances in hemostatic agents offer new approaches to controlling bleeding thereby making surgeries safer. The appropriate choice of these agents is crucial. Volume replacement, another integral part of Patient Blood Management (PBM), maintains adequate tissue perfusion, preventing cellular damage. Individualization in fluid administration is vital with the choice between crystalloids and colloids depending on each case. Colloids, unlike crystalloids, increase oncotic pressure, contributing to fluid retention in the intravascular space. Understanding these aspects is essential to ensure safe and effective surgery, minimizing complications related to blood loss and maintaining the patient's hemodynamic status.

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RESUMO

Introducción: la administración de fluidos durante el transoperatorio, tiene como premisa mantener un volumen intravascular adecuado para asegurar un equilibrio hidroelectrolítico y ácido-básico, y optimizar el transporte de oxígeno y la función de los factores de la coagulación.Objetivo: evaluar la relación entre la pauta de administración de fluidos como soluciones de reemplazo en el transoperatorio y la aparición de complicaciones hemodinámicas en el posoperatorio inmediato. Método: se realizó un estudio prospectivo, descriptivo, de corte transversal con una revisión exhaustiva de las historias clínicas a los pacientes que recibieron tratamiento quirúrgico en el Hospital Clínicoquirúrgico Hermanos Ameijeiras, en el período de enero de 2009 a enero de 2011; y al día siguiente del acto quirúrgico se entrevistaron los anestesiólogos actuantes. Resultados: de una muestra de 42 pacientes, 15 presentaron comportamiento hemodinámico sugerente de demanda de volumen, en las primeras 24 horas de concluida la intervención. La demanda de volumen se relacionó con intervenciones quirúrgicas abdominales y espinales complejas, reposición del volumen con coloides en las pérdidas hemáticas y de volemia en menos del 100 por ciento, y un tiempo quirúrgico mayor de 5 horas. No influyeron los valores de hematocrito, el peso y el por ciento de pérdidas hemáticas. Conclusiones: la estabilidad hemodinámica posoperatoria, en los pacientes a quienes se les realizaron intervenciones con pérdidas hemáticas mayores de 1 000 mL, estuvo influenciada por el porcentaje de sangre perdida y su reposición. Los mejores resultados se obtuvieron cuando la expansión superó las pérdidas y la reposición se realizó con coloides. El tiempo quirúrgico influyó significativamente en la estabilidad hemodinámica(AU)

Introduction: fluid administration during the transoperative period is aimed at maintaining an adequate intravascular volume to ensure appropriate hydroelectrolytic and acid-base balance and optimize oxygen transport and the function of coagulation factors. Objective: evaluate the relationship between the fluid administration regimen based on replacement solutions in the transoperative period and the appearance of hemodynamic complications in the immediate postoperative period. Method: a prospective cross-sectional descriptive study was conducted based on an exhaustive review of the medical records of patients undergoing surgical treatment at Hermanos Ameijeiras Clinical Surgical Hospital from January 2009 to January 2011. Additionally, the anesthesiologists involved were interviewed on the day after each operation. Results: in a sample of 42 patients, 15 showed hemodynamic behavior suggesting volume demand in the 24 hours following surgery. Volume demand was associated with abdominal and complex spinal surgery, colloidal volume replacement in blood losses or volemic losses under 100 percent, and a surgical time greater than 5 hours. No influence was exerted by hematocrit values, weight or percentage of blood loss. Conclusions: the postoperative hemodynamic stability of patients undergoing surgical interventions with blood losses above 1 000 mL was influenced by the percentage of blood lost and its replacement. The best results were obtained when the expansion exceeded the losses and when the replacement was conducted with colloids. Surgical time had a significant influence on hemodynamic stability(AU)

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RESUMO

Introducción: la administración de fluidos durante el transoperatorio, tiene como premisa mantener un volumen intravascular adecuado para asegurar un equilibrio hidroelectrolítico y ácido-básico, y optimizar el transporte de oxígeno y la función de los factores de la coagulación. Objetivo: evaluar la relación entre la pauta de administración de fluidos como soluciones de reemplazo en el transoperatorio y la aparición de complicaciones hemodinámicas en el posoperatorio inmediato. Método: se realizó un estudio prospectivo, descriptivo, de corte transversal con una revisión exhaustiva de las historias clínicas a los pacientes que recibieron tratamiento quirúrgico en el Hospital Clínicoquirúrgico "Hermanos Ameijeiras", en el período de enero de 2009 a enero de 2011; y al día siguiente del acto quirúrgico se entrevistaron los anestesiólogos actuantes. Resultados: de una muestra de 42 pacientes, 15 presentaron comportamiento hemodinámico sugerente de demanda de volumen, en las primeras 24 horas de concluida la intervención. La demanda de volumen se relacionó con intervenciones quirúrgicas abdominales y espinales complejas, reposición del volumen con coloides en las pérdidas hemáticas y de volemia en menos del 100 %, y un tiempo quirúrgico mayor de 5 horas. No influyeron los valores de hematocrito, el peso y el por ciento de pérdidas hemáticas. Conclusiones: la estabilidad hemodinámica posoperatoria, en los pacientes a quienes se les realizaron intervenciones con pérdidas hemáticas mayores de 1 000 mL, estuvo influenciada por el porcentaje de sangre perdida y su reposición. Los mejores resultados se obtuvieron cuando la expansión superó las pérdidas y la reposición se realizó con coloides. El tiempo quirúrgico influyó significativamente en la estabilidad hemodinámica.

Introduction: fluid administration during the transoperative period is aimed at maintaining an adequate intravascular volume to ensure appropriate hydroelectrolytic and acid-base balance and optimize oxygen transport and the function of coagulation factors. Objective: evaluate the relationship between the fluid administration regimen based on replacement solutions in the transoperative period and the appearance of hemodynamic complications in the immediate postoperative period. Method: a prospective cross-sectional descriptive study was conducted based on an exhaustive review of the medical records of patients undergoing surgical treatment at Hermanos Ameijeiras Clinical Surgical Hospital from January 2009 to January 2011. Additionally, the anesthesiologists involved were interviewed on the day after each operation. Results: in a sample of 42 patients, 15 showed hemodynamic behavior suggesting volume demand in the 24 hours following surgery. Volume demand was associated with abdominal and complex spinal surgery, colloidal volume replacement in blood losses or volemic losses under 100 %, and a surgical time greater than 5 hours. No influence was exerted by hematocrit values, weight or percentage of blood loss. Conclusions: the postoperative hemodynamic stability of patients undergoing surgical interventions with blood losses above 1 000 mL was influenced by the percentage of blood lost and its replacement. The best results were obtained when the expansion exceeded the losses and when the replacement was conducted with colloids. Surgical time had a significant influence on hemodynamic stability.

RESUMO

OBJECTIVE: To test the hypothesis that pulse pressure respiratory variation (PPV) amplification, observed in hypovolemia, can also be observed during sodium nitroprusside (SNP)-induced vasodilation. INTRODUCTION: PPV is largely used for early identification of cardiac responsiveness, especially when hypovolemia is suspected. PPV results from respiratory variation in transpulmonary blood flow and reflects the left ventricular preload variations during respiratory cycles. Any factor that decreases left ventricular preload can be associated with PPV amplification, as seen in hypovolemia. METHODS: Ten anesthetized and mechanically ventilated rabbits underwent progressive hypotension by either controlled hemorrhage (Group 1) or intravenous SNP infusion (Group 2). Animals in Group 1 (n = 5) had graded hemorrhage induced at 10% steps until 50% of the total volume was bled. Mean arterial pressure (MAP) steps were registered and assumed as pressure targets to be reached in Group 2. Group 2 (n = 5) was subjected to a progressive SNP infusion to reach similar pressure targets as those defined in Group 1. Heart rate (HR), systolic pressure variation (SPV) and PPV were measured at each MAP step, and the values were compared between the groups. RESULTS: SPV and PPV were similar between the experimental models in all steps (p > 0.16). SPV increased earlier in Group 2. CONCLUSION: Both pharmacologic vasodilation and graded hemorrhage induced PPV amplification similar to that observed in hypovolemia, reinforcing the idea that amplified arterial pressure variation does not necessarily represent hypovolemic status but rather potential cardiovascular responsiveness to fluid infusion.

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OBJECTIVE: To test the hypothesis that pulse pressure respiratory variation (PPV) amplification, observed in hypovolemia, can also be observed during sodium nitroprusside (SNP)-induced vasodilation. INTRODUCTION: PPV is largely used for early identification of cardiac responsiveness, especially when hypovolemia is suspected. PPV results from respiratory variation in transpulmonary blood flow and reflects the left ventricular preload variations during respiratory cycles. Any factor that decreases left ventricular preload can be associated with PPV amplification, as seen in hypovolemia. METHODS: Ten anesthetized and mechanically ventilated rabbits underwent progressive hypotension by either controlled hemorrhage (Group 1) or intravenous SNP infusion (Group 2). Animals in Group 1 (n = 5) had graded hemorrhage induced at 10 percent steps until 50 percent of the total volume was bled. Mean arterial pressure (MAP) steps were registered and assumed as pressure targets to be reached in Group 2. Group 2 (n = 5) was subjected to a progressive SNP infusion to reach similar pressure targets as those defined in Group 1. Heart rate (HR), systolic pressure variation (SPV) and PPV were measured at each MAP step, and the values were compared between the groups. RESULTS: SPV and PPV were similar between the experimental models in all steps (p > 0.16). SPV increased earlier in Group 2. CONCLUSION: Both pharmacologic vasodilation and graded hemorrhage induced PPV amplification similar to that observed in hypovolemia, reinforcing the idea that amplified arterial pressure variation does not necessarily represent hypovolemic status but rather potential cardiovascular responsiveness to fluid infusion.

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OBJECTIVE: To compare variations of plethysmographic wave amplitude (ÃPpleth) and to determine the percent difference between inspiratory and expiratory pulse pressure (ÃPp) cutoff values for volume responsiveness in a homogenous population of postoperative cardiac surgery patients. INTRODUCTION: Intra-thoracic pressure variations interfere with stroke volume variation. Pulse pressure variations through arterial lines during mechanical ventilation have been recommended for the estimation of fluid responsiveness. Pulse oximetry may offer a non-invasive plethysmographic method to evaluate pulse pressure; this may be useful for guiding fluid replacement. METHODS: Controlled, prospective study in cardiac surgery patients under controlled ventilation. Simultaneous digital recordings of arterial pressure and plethysmographic waves were performed. ÃPp, systolic pressure (ÃPs), DPpleth, and systolic component (ÃSpleth) were calculated. A DPp > 13 percent identified fluid-responsive patients. Volume expansion was performed in responsive subjects. Systolic and amplitude components of pressure and plethysmographic waves were compared. RESULTS: In 50 measurements from 43 patients, ÃPp was correlated with (Ppleth (r=0.90, p<0.001), (Ps (r=0.90, p<0.001), and (Spleth (r=0.73, p<0.001). An aArea under ROC curve (AUC) identified the fluid responsiveness thresholds: (Ppleth of 11 percent (AUC = 0.95±0.04), (Ps of 8 percent (AUC=0.93±0.05), and (Spleth of 32 percent (AUC=0.82±0.07). A (Ppleth value > 11 percent predicted (Pp > 13 percent with 100 percent specificity and 91 percent sensitivity. Volume expansion, performed in 20 patients, changed (Pp, (Ppleth, (Ps and (Spleth significantly (p<0.008). CONCLUSIONS: ÃPpleth is well correlated with DPp and constitutes a simple and non-invasive method for assessing fluid responsiveness in patients following cardiac surgery.

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Guidelines for volume replacement for acutely hemorrhaged and hemodiluted trauma patients have not been well established. Purpose: To evaluate the effects of acute hemodilution on mean arterial pressure (MAP), and responsiveness of acutely hemodiluted and subsequently hemorrhaged rats to different volume therapies. Methods: 180 rats were hemodiluted to simulate hemorrhaged trauma patients with persistent bleeding after high volume replacement with isotonic solutions. Thirty hemodiluted [Anemia (ANE) group] animals received no further treatment. The remaining 150 animals were subjected to hypovolemic shock and randomized into five groups, according to the treatment option employed: Control (CTL) animals did not receive subsequent treatment after hemorrhagic hypovolemia, SAL4 animals received isotonic saline 4 mL/kg, SAL32 animals received isotonic saline 32 mL/kg, HS animals received hypertonic saline 4 mL/kg and BLD animals received re-infusion of drawn blood. Results: Highest mean arterial pressure (MAP) was achieved by BLD, followed by SAL32 and HS. MAP after treatment of BLD, HS, SAL32 and ANE were higher than CTL (p=0.036). At 85 and 95 minutes of experiment, SAL4, SAL32 and HS presented the lowest hematocrit levels (p<0.01). At day 3, ANE, CTL and HS had the highest hematocrit. SAL4 and CTL groups presented the highest mortality rates. Conclusion: Hypertonic saline is an effective and safe initial therapy for hemodiluted rats undergoing hemorrhagic shock, with an overall outcome comparable to blood replacement or high volume isotonic saline administration.(AU)

A conduta para reposição volêmica em pacientes traumatizados, hemodiluídos não está bem estabelecida. Objetivo: Avaliar o efeito da hemodiluição sobre a pressão arterial média (PAM), bem como a resposta de ratos agudamente hemodiluídos e submetidos a choque hemorrágico, à reanimação com diferentes soluções. Métodos: 180 ratos foram hemodiluídos, simulando pacientes traumatizados com sangramento persistente após reposição com soluções isotônicas. Trinta ratos hemodiluídos (grupo ANE) foram observados, sem tratamento. Os demais 150 foram submetidos a choque hipovolêmico e randomizados em 5 grupos segundo a opção terapêutica: CTL (controle), sem tratamento subseqüente após hipovolemia hemorrágica; SAL4 que recebeu 4 mL/kg de salina isotônica; SAL32 que recebeu 32 mL/kg de salina isotônica ; SH que recebeu 4mL/kg de salina hipertônica; e BLD que recebeu reinfusão do sangue removido. Resultados: A pressão arterial média (PAM) mais alta ocorreu no grupo BLD, seguida pelo SAL32, e SH. A PAM após tratamento nos grupos BLD, SH, SAL32 e ANE foram maiores que no CTL (-=0.036). Aos 85 e 95 minutos do experimento, SAL4, SAL32, e SH apresentaram os menores hematócritos (p<0.01). No 3º dia, ANE, CTL e SH apresentaram os maiores hematócritos. SAL4 e CTL apresentaram as maiores taxas de mortalidade. Em conclusão, nossos resultados indicam que a SH é uma terapia inicial efetiva e segura em ratos hemodiluídos, submetidos a hemorrágico choque, com prognóstico comparável à reposição com sangue ou administração de grande volume de solução isotônica.(AU)

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RESUMO

Guidelines for volume replacement for acutely hemorrhaged and hemodiluted trauma patients have not been well established. Purpose: To evaluate the effects of acute hemodilution on mean arterial pressure (MAP), and responsiveness of acutely hemodiluted and subsequently hemorrhaged rats to different volume therapies. Methods: 180 rats were hemodiluted to simulate hemorrhaged trauma patients with persistent bleeding after high volume replacement with isotonic solutions. Thirty hemodiluted [Anemia (ANE) group] animals received no further treatment. The remaining 150 animals were subjected to hypovolemic shock and randomized into five groups, according to the treatment option employed: Control (CTL) animals did not receive subsequent treatment after hemorrhagic hypovolemia, SAL4 animals received isotonic saline 4 mL/kg, SAL32 animals received isotonic saline 32 mL/kg, HS animals received hypertonic saline 4 mL/kg and BLD animals received re-infusion of drawn blood. Results: Highest mean arterial pressure (MAP) was achieved by BLD, followed by SAL32 and HS. MAP after treatment of BLD, HS, SAL32 and ANE were higher than CTL (p=0.036). At 85 and 95 minutes of experiment, SAL4, SAL32 and HS presented the lowest hematocrit levels (p<0.01). At day 3, ANE, CTL and HS had the highest hematocrit. SAL4 and CTL groups presented the highest mortality rates. Conclusion: Hypertonic saline is an effective and safe initial therapy for hemodiluted rats undergoing hemorrhagic shock, with an overall outcome comparable to blood replacement or high volume isotonic saline administration.

A conduta para reposição volêmica em pacientes traumatizados, hemodiluídos não está bem estabelecida. Objetivo: Avaliar o efeito da hemodiluição sobre a pressão arterial média (PAM), bem como a resposta de ratos agudamente hemodiluídos e submetidos a choque hemorrágico, à reanimação com diferentes soluções. Métodos: 180 ratos foram hemodiluídos, simulando pacientes traumatizados com sangramento persistente após reposição com soluções isotônicas. Trinta ratos hemodiluídos (grupo ANE) foram observados, sem tratamento. Os demais 150 foram submetidos a choque hipovolêmico e randomizados em 5 grupos segundo a opção terapêutica: CTL (controle), sem tratamento subseqüente após hipovolemia hemorrágica; SAL4 que recebeu 4 mL/kg de salina isotônica; SAL32 que recebeu 32 mL/kg de salina isotônica ; SH que recebeu 4mL/kg de salina hipertônica; e BLD que recebeu reinfusão do sangue removido. Resultados: A pressão arterial média (PAM) mais alta ocorreu no grupo BLD, seguida pelo SAL32, e SH. A PAM após tratamento nos grupos BLD, SH, SAL32 e ANE foram maiores que no CTL (-=0.036). Aos 85 e 95 minutos do experimento, SAL4, SAL32, e SH apresentaram os menores hematócritos (p<0.01). No 3° dia, ANE, CTL e SH apresentaram os maiores hematócritos. SAL4 e CTL apresentaram as maiores taxas de mortalidade. Em conclusão, nossos resultados indicam que a SH é uma terapia inicial efetiva e segura em ratos hemodiluídos, submetidos a hemorrágico choque, com prognóstico comparável à reposição com sangue ou administração de grande volume de solução isotônica.

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