Dehydration, hemodynamics and fluid volume optimization after induction of general anesthesia

OBJECTIVES: Fluid volume optimization guided by stroke volume measurements reduces complications of colorectal and high-risk surgeries. We studied whether dehydration or a strong hemodynamic response to general anesthesia increases the probability of fluid responsiveness before surgery begins. METHODS: Cardiac output, stroke volume, central venous pressure and arterial pressures were measured in 111 patients before general anesthesia (baseline), after induction and stepwise after three bolus infusions of 3 ml/kg of 6% hydroxyethyl starch 130/0.4 (n = 86) or Ringer's lactate (n = 25). A subgroup of 30 patients who received starch were preloaded with 500 ml of Ringer's lactate. Blood volume changes were estimated from the hemoglobin concentration and dehydration was estimated from evidence of renal water conservation in urine samples. RESULTS: Induction of anesthesia decreased the stroke volume to 62% of baseline (mean); administration of fluids restored this value to 84% (starch) and 68% (Ringer's). The optimized stroke volume index was clustered around 35-40 ml/m2/beat. Additional fluid boluses increased the stroke volume by ≥10% (a sign of fluid responsiveness) in patients with dehydration, as suggested by a low cardiac index and central venous pressure at baseline and by high urinary osmolality, creatinine concentration and ...

Alta utilidad de monitorización hemodinámica con ecocardiografía transesofágica intraoperatoria en cirugía ortopédica / Intraoperative hemodynamic monitoring using transesophageal echocardiography in orthopedic surgery

Background: Orthopedic surgery is commonly performed in elderly patients with higher cardiovascular surgical risk. Hemodynamic monitoring in these patients may prevent perioperative complications. Aim: To assess the usefulness of transesophageal echocargiography (TEE) for intraoperative cardiovascular monitoring during orthopedic surgery. Material and methods: Patients older than 65 years subjected to orthopedic surgery using general anesthesia and with a high cardiovascular risk were studied. Intraoperative TEE was performed to assess intravascular volume, myocardial contractility and the presence of myocardial ischemia. Results: Fifty three patients aged 72±5 years were studied. Hemodynamic stability was detected in 68 percent of patients, mainly reflected as episodes of hypovolemia. Myocardial ischemia was detected in two patients and embolic episodes in six (11 percent). Conclusions: Intraoperative TEE was useful for the hemodynamic evaluation of patients with high cardiovascular risk.

La mujer embarazada agredida por trauma y su atención prehospitalaria / La pregnant woman who undergoes trauma: pre-hospital care and medical attention

El trauma en el embarazo se ha incrementado en los últimos años llegando hasta un 7 por ciento. Se le ha asociado con un alto riesgo de pérdida del feto. La causa principal son los accidentes automovilísticos y el tipo más frecuente es el trauma cerrado. Para una adecuada atención prehospitalaria es necesario considerar sus cambios fisiológicos tales como la presión arterial, el pulso, el volumen sanguíneo, los cambios de posición del útero, vejiga, corazón, etc. Los efectos del trauma se pueden presentar entre otros como shock, abruptio placenta, ruptura uterina, lesiones fetales directas y hemorragia maternofetal. El abordaje debe ser conducido con la misma agresividad que para una paciente no embarazada, tomando en cuenta sus cambios fisiológicos y como primera prioridad la reanimación materna. Toda vez que los signos aparentemente estables de la madre pueden no ser indicativo real, el transporte rápido al centro de trauma es esencial