Hemodilution and intravenous perflubron emulsion as an alternative to blood transfusion: effects on tissue oxygenation during profound hemodilution in anesthetized dogs

BACKGROUND: Intravenously administered perfluorocarbon (PFC) emulsions increase oxygen solubility in plasma. PFC might therefore temporarily replace red cells (RBCs) lost during intraoperative hemorrhage. In patients who have undergone hemodilution, the return of autologous blood may be delayed by the administration of PFC, and autologous RBCs may be saved for transfusion after surgical bleeding is stopped and PFC is cleared by the reticuloendothelial system. STUDY DESIGN AND METHODS: In 22 anesthetized, hemodiluted dogs (hemoglobin [Hb] 7 g/dL) breathing 100-percent O2, an intraoperative volume-compensated blood loss was simulated. The efficacy of three therapeutic regimens in maintaining tissue oxygenation was compared: 1) RBC group (n = 7): maintenance of a Hb > 7 g per dL by transfusion of autologous RBCs; 2) PFC group (n = 7): bolus application of a second-generation PFC emulsion (60% wt/vol perflubron) and further acute normovolemic hemodilution (ANH) to a Hb of 3 g per dL; and 3) control group (n = 7): further ANH alone to a Hb of 3 g per dL. Systemic and myocardial oxygenation status and tissue oxygenation were assessed. RESULTS: Autologous RBCs transfused to maintain a Hb of 7 g per dL preserved hemodynamics and tissue oxygenation during blood loss. In the PFC and control groups, heart rate and cardiac index increased significantly in response to further ANH. Tissue oxygenation was not different in the PFC and the RBC groups. Direct comparison of the PFC and control groups revealed better tissue oxygenation in the PFC group, as reflected by significantly higher mixed venous, coronary venous, and local tissue pO2 on liver and skeletal muscle. CONCLUSION: Bolus intravenous administration of 60- percent (wt/vol) perflubron emulsion and further hemodilution from a Hb of 7 g per dL to one of 3 g per dL were as effective as autologous RBC transfusion in maintaining tissue oxygenation during volume-compensated blood loss designed to mimic surgical bleeding.     

The factors controlling stem cell recirculation. i. Migration of hemopoietic stem cells in adrenalectomized mice

The influence of bilateral adrenalectomy on hemopoietic stem cell (CFU) migration in mice has been studied. Formation of endogenous spleen colonies in lethally irradiated, leg-shielded mice was sharply increased by prior adrenalectomy, and this increase was not dependent on the volume of shielded bone marrow. Adrenalectomy was shown to increase endogenous spleen colony formation in sublethally irradiated mice as well. However, it had no affect on formation of spleen colonies in lethally irradiated mice injected with syngeneic bone marrow. The CFU content of murine bone marrow decreased acutely after removal of the adrenals, and this decrease was accompanied by a concomitant increase in the peripheral blood and splenic CFU. Thus, adrenalectomy appeared to have no affect on the splenic plating efficiency or proliferative rate of hemopoietic stem cells, but it did result in increased migration of stem cells from the bone marrow to the blood, and thence to the spleen. It is concluded that the adrenal steroids may be of physiologic importance in the regulation of ehmopoietic stem cell migration.     

Implication of sympathetic innervation of the heart in antiarrhythmic action of intra-atrial laser irradiation

The role of sympathetic nervous system in the antiarrhythmic effect of intra-atrial laser irradiation (λ=632.8 nm) during myocardial ischemia was studied in acute experiments on Nembutal-anesthetized cats. Laser irradiation applied after bilateral, dextral, or sinistral transection of cardiac branches of stellate ganglia increased the number of ischemic rhythm disturbances that developed after occlusion of the circumflex branch of the left coronary artery. The maximum increase in the number of arrhythmias was observed after dextral transection, the occurrence of ventricular fibrillation being 100%. Bilateral transection provoked a larger number of ischemic rhythm disturbances than the sinistral transection. It is probable that the development of the antiarrhythmic effect of laser irradiation requires sustained sympathetic activity targeted at the nonischemic regions in the myocardium that could play a stabilizing role during local ischemic damage to the heart. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 11, pp. 522–526, November, 1998     

Sudden death in mitral valve prolapse

The authors describe a case of sudden death (SD) of a patient with unaltered coronary arteries, myxomatous degeneration and mitral valve prolapse (MVP). The case was marked by an isolated prolapse of the anterior cusp of the mitral valve because of its congenital structural abnormalities, which was not encountered previously in MVP patients who died suddenly. Microscopic examination showed large-focal cardiosclerosis at the basis of the papillary muscles determined by dysfunction of the mitral apparatus which might be related to the pathogenesis of lethal arrhythmia. It is believed that MVP patients should constitute a separate group with high risk of SD.     

Effect of Serotonin on Impulse Activity of Bulbar Cardiovascular Neurons

Alteration of impulse activity of afferent and intercalatory neurons of bulbar cardiovascular center upon serotonin microinjection was demonstrated in acute experiments in rabbit. Afferent neurons were more sensitive to serotonin than interneurons. Translated from Byulleten’ Experimental’noi Biologii i Meditsiny, Vol. 147, No. 2, pp. 124–126, February, 2009     

Intrapartum Rupture of the Uterus Diagnosed by Ultrasound

Background

Spontaneous uterine rupture is a life threatening obstetrical emergency encountered infrequently in the emergency department. Its diagnosis is often missed or delayed, leading to maternal and fetal mortality.

Method

We present a case of ruptured uterus diagnosed by ultrasound in a 33-year-old gravid female with two previous cesarean sections.

Objective

To show the role of ultrasound in uterine rupture

Result

Ultrasound demonstrates uterine laceration and intra-abdominal dislocation of placenta and foetus

Conclusion

Because of the severity of the complication and the great variation of symptoms in connection with it, the authors encourage the use of ultrasound screening in the detection of this rare, but often catastrophic complication.