RESUMEN
BACKGROUND: Recent studies have demonstrated that cerebral desaturation during rewarming period of CPB was associated with postoperative neurologic dysfunction. The prevention of cerebral desaturation during CPB may reduce the incidences of neurologic and neuropsychological complications. The present study was prospectively undertaken to compare the clinical effects between two strategies (hypercapnic CPB and high flow CPB) to prevent cerebral desaturation for establishing a proper CPB technique. MATERIAL AND METHOD: Thirty-six adult patients scheduled for elective cardiac surgery were randomized into either hypercapnic (PaCO2 45~50 mmHg, n=18) or high flow group (flow rate 2.75 L/m2/min and PaCO2 35~40 mmHg, n=18) during rewarming period of CPB. In each patient, middle cerebral artery blood flow velocity (VMCA), cerebral arteriovenous oxygen content difference (C(a-v)O2), modified cerebral metabolic rate for oxygen (MCMRO2), cerebral oxygen transport rate (TEO2), incidence of cerebral desaturation (internal jugular bulb blood oxygen saturation < or =50%), increased rate of S-100 beta concentration, and arterial and internal jugular bulb blood gas were measured during the five phases of the operation; Pre-CPB, CPB-10 min (steady-state CPB, nasopharyngeal temperature 29~30 degrees C), Rewarm-1 (rewarming phase, nasopharyngeal temperature 33 degrees C), Rewarm-2 (nasopharyngeal temperature 37 degrees C), and CPB-off. Incidence of postoperative delirium and duration were assessed in all patients. All variables were compared between the two groups. RESULT: VMCA (157.88+/-10.87 vs 120.00+/-6.18%, p=0.006), internal jugular bulb O2 saturation (68.01+/-2.75 vs 61.28+/-2.87%, p=0.03) and O2 tension (41.01+/-2.25 vs 32.02+/-1.67 mmHg, p=0.03), and TEO2 (110.84+/-7.41 vs 81.15+/-8.11%, p=0.003) at rewarming periods were higher in the hypercapnic group than in the high flow group. C(a-v)O2 (4.0+/-0.30 vs 4.84+/-0.38 mg/dL, p=0.04), COE (0.36+/-0.03 vs 0.42+/-0.03, p=0.04), increased rate of S-100 beta(391.67+/-23.40 vs 940.0+/-17.02%, p=0.003), and incidence of cerebral desaturation (2 vs 4 patients, p= 0.04) at rewarming periods, and duration of postoperative delirium (18 vs 34 hr, p=0.02) were low in the hypercapnic group compared to the high flow group. CONCLUSION: These results indicate that hypercapnic CPB may provide relatively diminished cerebral injury and beneficial effects for cerebral metabolism relatively compared to high flow CPB.
Asunto(s)
Adulto , Humanos , Velocidad del Flujo Sanguíneo , Puente Cardiopulmonar , Delirio , Hipercapnia , Incidencia , Metabolismo , Arteria Cerebral Media , Manifestaciones Neurológicas , Oxígeno , Estudios Prospectivos , Recalentamiento , Cirugía TorácicaRESUMEN
BACKGROUND: It has been recognized that systemic inflammatory reaction and oxygen free radical formed by activated leukocyte in the procedure of cardiopulmonary bypass(CPB) frequently produce postoperative cardiac and pulmonary dysfunction. The purpose of this study was to evaluate the efficacy of leukocyte-depleting filters in the cardiopulmonary bypass circuit for patients undergoing open heart surgery(OHS). MATERIAL AND METHOD: The study involved 15 patients who underwent OHS with a Leukoguard-6 leukocyte filter placed in the arterial limbs of the bypass circuit(filter group, n=15) and 15 patients who did not have the filter(control group, n=15). We analyzed the differences between the groups in intraoperative changes of peripheral blood leukocyte and platelet counts, pre- and postbypass changes of malondialdehyde(MDA), troponin-T(TnT), 5'-nucleotidase(5'-NT) in coronary sinus blood, spontaneous recovery rate of heart beat after CPB, pre-and postoperative cardiac index(CI) and pulmonary vascular resistance(PVR), and the amounts of postoperative bleeding and sternal wound complication. RESULT: During CPB, total leukocyte count of the filter group(9,567 +/- 842/mm3) was significantly less than that of the control group(13,573 +/- 1,167/mm3) (p<0.01), but there was no significant difference in platelet count between the groups. Postoperative levels of MDA(3.78 +/- 0.32 micromole/L vs 5.86 +/- 0.65 micromole/L, p<0.01), TnT(0.40 +/- 0.04 ng/mL vs 0.59 +/- 0.08 ng/mL, p<0.05) and 5'-NT(3.88 +/- 0.61 U/L vs 5.80 +/- 0.90 U/L, p<0.05) were all significantly lower in the filter group than the control group. Postoperative CI was higher in the filter group than the control group(3.26 +/- 0.18 L/m2/min vs 2.75 +/- 0.17 L/m2/min, p=0.05). PVR of the filter group was lower than that of the control group(65.87 +/- 7.59 dyne/sec/cm5 vs 110.80 +/- 12.22 dyne/sec/cm5, p<0.01). Spontaneous recovery rate of heart beat in the filter group was higher than that in the control group(12 patients vs 8 patients, p<0.05). Postoperative wound infection occurred in one case in the filter group and 4 case in the control group(p<0.05). Postoperative 24 hour blood loss of the filter group was more than that of the control group (614 +/- 107 mL vs 380 +/- 71 mL, p=0.05). CONCLUSION: These data suggest that the leukocyte-depleting filter has beneficial effects on postoperative cardiac and pulmonary functions with diminution of reperfusion injury. However, bleeding tendency at early postoperative period is higher in the filter group than the control group and thus the further studies seem to be necessary at this point.