A novel approach to measuring circulating blood volume: the use of a hemoglobin-based oxygen carrier in a rabbit model

Hemoglobin-based oxygen carriers (HBOC) may be ideal for monitoring circulating plasma volume (CV-P) and circulating blood volume (CV-B). We used an HBOC (Hemoglobin glutamer-200 [bovine], Oxyglobin; Biopure, Cambridge, MA) as an indicator for relative CV-B in the rabbit model. Accuracy of the technique was determined by comparison with the Evans blue dye (EBD) dilution technique in 19 anesthetized female New Zealand rabbits weighing 2.0 to 10.6 kg. The measurements were performed at baseline, after hemorrhage (1/3 of CV-B), normovolemic hemodilution (replacement of 1/3 CV-B by Hextend; Abbot Laboratories, North Chicago, IL), and hypervolemic hemodilution (additional infusion of Hextend(R) in a volume equal to 1/3 of CV-B). Hemoglobin concentration was measured by using a HemoCue photometer (HemoCue AB, Angelholm, Sweden). EBD concentration was analyzed by using linear regression to estimate Time 0 concentration; Time 0 was defined as EBD injection time. The difference between CV-P values determined by EBD and HBOC dilution was independent from the magnitude of the CV-P value. The relative bias was 1.29 mL, and the precision (one SD) was 2.82 mL. The difference did not reach statistical significance. IMPLICATIONS: Circulating plasma and blood volumes can be accurately estimated by plasma hemoglobin concentration measurements by using hemoglobin-based oxygen carrier infusion.     

The effects of positive end-expiratory pressure during active compression decompression cardiopulmonary resuscitation with the inspiratory threshold valve

The use of an inspiratory impedance threshold valve (ITV) during active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) improves perfusion pressures, and vital organ blood flow. We evaluated the effects of positive end-expiratory pressure (PEEP) on gas exchange, and coronary perfusion pressure gradients during ACD + ITV CPR in a porcine cardiac arrest model. All animals received pure oxygen intermittent positive pressure ventilation (IPPV) at a 5:1 compression-ventilation ratio during ACD + ITV CPR. After 8 min, pigs were randomized to further IPPV alone (n = 8), or IPPV with increasing levels of PEEP (n = 8) of 2.5, 5.0, 7.5, and 10 cm H(2)O for 4 consecutive min each, respectively. Mean +/- SEM arterial oxygen partial pressure decreased in the IPPV group from 150 +/- 30 at baseline after 8 min of CPR to 110 +/- 25 torr at 24 min, but increased in the PEEP group from 115 +/- 15 to 170 +/- 25 torr with increasing levels of PEEP (P <0.02 for comparisons within groups). Mean +/- SEM diastolic aortic minus diastolic left ventricular pressure gradient was significantly (P < 0.001) higher after the administration of PEEP (24 +/- 0 vs 17 +/- 1 mm Hg with 5 cm H(2)O of PEEP, and 26 +/- 0 vs 17 +/- 1 mm Hg with 10 cm H(2)O of PEEP), whereas the diastolic aortic minus right atrial pressure gradient (coronary perfusion pressure) was comparable between groups. Furthermore, systolic aortic pressures were significantly (P < 0.05) higher with 10 cm H(2)O of PEEP when compared with IPPV alone (68 +/- 0 vs 59 +/- 2 mm Hg). In conclusion, when CPR was performed with devices designed to improve venous return to the chest, increasing PEEP levels improved oxygenation. Moreover, PEEP significantly increased the diastolic aortic minus left ventricular gradient and did not affect the decompression phase aortic minus right atrial pressure gradient. These data suggest that PEEP reduces alveolar collapse during ACD + ITV CPR, thus leading to an increase in indirect myocardial compression. IMPLICATIONS: Inspiratory impedance during active compression-decompression cardiopulmonary resuscitation improves perfusion pressures, and vital organ blood flow during cardiac arrest. Increasing levels of positive end-expiratory pressure during performance of active compression-decompression cardiopulmonary resuscitation with an inspiratory impedance valve improves oxygenation, and increases the diastolic aortic-left ventricular pressure gradient and systolic arterial blood pressure.     

Disseminated intravascular coagulopathy in pregnancy: thorough comprehension of etiology and management reduces obstetricians’ stress

In pregnancy and puerperium disseminated intravascular coagulopathy may accompany abruptio placenta, intrauterine fetal demise with retained dead fetus, amniotic fluid embolism, endotoxin sepsis, preecalampsia with HELLP and massive transfusion. Clinical signs and symptoms of DIC can include oozing from venupuncture sites and/or mucous membranes, red cell lysis from activation of the complement system, hemorrhage from coagulopathy and possible uterine atony, hypotension from hemorrhage and/or bradykinin release, and oliguria from end-organ insult and hypovolemia/hypotension. Treatment of DIC consists of replacement of volume, blood products, and coagulation components and cardiovascular and respiratory support with elimination of underlying triggering mechanism. Received: August 1998 / Accepted: 10 May 1999     

Association of amelia and anal atresia is separate from VACTERL association

Amelia and anal atresia with kidney agenesis and/or heart defects is discussed together with the hypotheses that this may either be the severest manifestation of VACTERL association or a separate association.     

Feeding problems in young PKU children

Behavioural feeding problems were found to be more prevalent in a group of 15 PKU children aged 1-5 years when compared to non-PKU controls. The parents of PKU children identified poorer appetites ( p < 0.01), a more limited range of foods consumed ( p < 0.03) and more gastrointestinal symptoms such as vomiting and constipation ( p < 0.03) than control children. The children were slower to feed ( p < 0.03), were more likely to dislike sweet foods and some ate separately from the rest of the family at mealtime ( p < 0.03). The effects on normal feeding behaviour should be considered when advocating strict diet therapy for young PKU children.     

The premenstrual syndrome

PMS is probably a group of entities which include various symptoms that occur during the 7 to 10 days before menstruation and disappear a few hours after the onset of menstruation. The definition of PMS lacks objective criteria. The most common symptoms are irritability, bloating, aggressiveness, mastodynia, and headaches. The prevalence of PMS is estimated at 30 to 40 per cent. PMS is more prevalent among women working outside the home, alcoholics, women of high parity, and women with toxemic tendency; it probably runs in families. The etiology of PMS is no less obscure to us than when it was first described by Frank in 1931. No single theory has been established to explain the entire diversity of PMS symptomatology. The multitude of possible etiologic factors includes psychosocial bases, progesterone deficiency, prolactin excess, thyroid hypofunction, renin angiotensin alternations, antidiuretic hormone excess, decreased colloidosmotic pressure, endorphin activity alternations, serotonin metabolism alternations, prostaglandin action, vitamin deficiency, and such unconventional theories as the ovarian infection or the "yeast overgrowth" theory. A partial resolution of this divergence of hypotheses comes from the biopsychosocial model developed by Keye and Trunnel. According to this model, a biologic, perhaps genetically determined, predisposition to PMS is realized when past and present life experiences, attitudes, beliefs, coping styles, and social forces interact to stress a woman. The diagnosis of PMS is based on establishing a relationship between the luteal phase of the cycle and the symptoms. The evaluation of PMS patients includes the use of a monthly diary to scale the symptoms, a physical examination, and biochemical studies to rule out other disorders. Management includes education, reassurance, and drug therapy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Elevated carcinoembryonic antigen levels and biliary tract obstruction.

Circulating carcinoembryonic antigen (CEA) levels and their relation to liver function test values were studied in 29 jaundiced patients with benign extrahepatic biliary tract obstruction and inflammation. During the obstructive and inflammatory phase, 15 (52%) of the patients had CEA levels greater than 2.5 ng/ml. Elevated CEA levels were associated more frequently with common bile duct stones (and cholangitis) than with gallbladder stones (and cholecystitis) alone, although this difference was not statistically significant. The former often had values greater than 5.0 ng/ml. The highest values were found in two patients with liver abscesses. T'HE CEA levels returned to normal following relief of obstruction in seven of ten patients and increased in two patients who had progressive inflammation. Serum alkaline phosphatase and bilirubin levels were significantly higher in the patients with elevated CEA levels (p smaller than .05). Serum alkaline phosphatase levels showed a significant positive correlation with CEA levels (p smaller than .02). Patients with obstructive jaundice and elevated CEA levels do not necessarily have cancer.