ABO and Rhesus Blood Groups in Acute Puumala Hantavirus Infection

Puumala hantavirus (PUUV) causes hemorrhagic fever with renal syndrome. We aimed to evaluate whether ABO and rhesus blood groups associate with the susceptibility or the severity of PUUV infection. We analyzed blood groups in 289 adult patients treated in Tampere University hospital due to PUUV infection during the years 1982–2017. Patients’ blood group distribution was compared to that of healthy, voluntary blood donors living in the Tampere University Hospital responsibility area (n = 21,833). The severity of PUUV infection, as judged by the severity of acute kidney injury (AKI), thrombocytopenia, inflammation, capillary leakage, and the length of hospital care, was analyzed across the groups. The ABO and rhesus blood group distributions did not differ between the patients and blood donors. Patients with non-O blood groups had lower systolic blood pressure compared to patients with blood group O, but there was no difference in other markers of capillary leakage or in the severity of AKI. Minor deviations in the number of platelets and leukocytes were detected between the O and non-O blood groups. To conclude, patients with blood group O may be less susceptible to hypotension, but otherwise blood groups have no major influences on disease susceptibility or severity during acute PUUV infection.

Pannexin 1 channels control the hemodynamic response to hypoxia by regulating O2-sensitive extracellular ATP in blood

Pannexin 1 (Panx1) channels export ATP and may contribute to increased concentration of the vasodilator ATP in plasma during hypoxia in vivo. We hypothesized that Panx1 channels and associated ATP export contribute to hypoxic vasodilation, a mechanism that facilitates the matching of oxygen delivery to metabolic demand of tissue. Male and female mice devoid of Panx1 (Panx1-/-) and wild-type controls (WT) were anesthetized, mechanically ventilated, and instrumented with a carotid artery catheter or femoral artery flow transducer for hemodynamic and plasma ATP monitoring during inhalation of 21% (normoxia) or 10% oxygen (hypoxia). ATP export from WT vs. Panx1-/-erythrocytes (RBC) was determined ex vivo via tonometer experimentation across progressive deoxygenation. Mean arterial pressure (MAP) was similar in Panx1-/- (n = 6) and WT (n = 6) mice in normoxia, but the decrease in MAP in hypoxia seen in WT was attenuated in Panx1-/- mice (-16 ± 9% vs. -2 ± 8%; P < 0.05). Hindlimb blood flow (HBF) was significantly lower in Panx1-/- (n = 6) vs. WT (n = 6) basally, and increased in WT but not Panx1-/- mice during hypoxia (8 ± 6% vs. -10 ± 13%; P < 0.05). Estimation of hindlimb vascular conductance using data from the MAP and HBF experiments showed an average response of 28% for WT vs. -9% for Panx1-/- mice. Mean venous plasma ATP during hypoxia was 57% lower in Panx1-/- (n = 6) vs. WT mice (n = 6; P < 0.05). Mean hypoxia-induced ATP export from RBCs from Panx1-/- mice (n = 8) was 82% lower than that from WT (n = 8; P < 0.05). Panx1 channels participate in hemodynamic responses consistent with hypoxic vasodilation by regulating hypoxia-sensitive extracellular ATP levels in blood.NEW & NOTEWORTHY Export of vasodilator ATP from red blood cells requires pannexin 1. Blood plasma ATP elevations in response to hypoxia in mice require pannexin 1. Hemodynamic responses to hypoxia are accompanied by increased plasma ATP in mice in vivo and require pannexin 1.

Central Administration of Angiotensin-(1-7) Improves Vasopressin Impairment and Hypotensive Response in Experimental Endotoxemia

Angiotensin-(1-7) [Ang-(1-7)]/Mas receptor is a counter-regulatory axis that counteracts detrimental renin-angiotensin system (RAS) effects, especially regarding systemic inflammation, vasopressin (AVP) release, and hypothalamic-pituitary-adrenal (HPA) activation. However, it is not completely understood whether this system may control centrally or systemically the late phase of systemic inflammation. Thus, the aim of this study was to determine whether intracerebroventricular (i.c.v.) administration of Ang-(1-7) can modulate systemic inflammation through the activation of humoral pathways in late phase of endotoxemia. Endotoxemia was induced by systemic injection of lipopolysaccharide (LPS) (1.5 mg/kg, i.v.) in Wistar rats. Ang-(1-7) (0.3 nmol in 2 µL) promoted the release of AVP and attenuated interleukin-6 (IL-6) and nitric oxide (NO) levels but increased interleukin-10 (IL-10) in the serum of the endotoxemic rats. The central administration of Mas receptor antagonist A779 (3 nmol in 2 µL, i.c.v.) abolished these anti-inflammatory effects in endotoxemic rats. Furthermore, Ang-(1-7) applied centrally restored mean arterial blood pressure (MABP) without affecting heart rate (HR) and prevented vascular hyporesponsiveness to norepinephrine (NE) and AVP in animals that received LPS. Together, our results indicate that Ang-(1-7) applied centrally promotes a systemic anti-inflammatory effect through the central Mas receptor and activation of the humoral pathway mediated by AVP.

Point-of-care blood analysis of hypotensive patients in the emergency department

OBJECTIVE

The aim of this study is to compare a point-of-care (POC) analysis, Enterprise POC (epoc), using the capillary blood obtained from skin puncture with conventional laboratory tests using arterial and venous blood in hypotensive patients.

METHODS

This study was conducted at the emergency department of a tertiary care hospital between June and November 2018. 231 hypotensive patients were enrolled. Three types of blood samples (capillary blood from skin puncture and arterial and venous blood from blood vessel puncture) were collected and analyzed. We compared a total of 13 parameters (pH, pCO2, pO2, HCO3-, Ca2+, lactate, Na+, K+, Cl-, glucose, Hb, Hct, and creatinine) between the POC analysis and reference analyzers by performing the equivalence test and Bland-Altman plot analysis.

RESULTS

In hypotensive patients, with the exception of two parameters (pCO2, pO2), the pH, HCO3-, Ca2+, lactate, Na+, K+, Cl-, glucose, Hb, Hct, and creatinine parameters measured by the POC analysis were equivalent to or correlated with the reference values. In the patients with cardiac arrest group, nine parameters (pH, HCO3-, Ca2+, Na+, K+, glucose, Hb, Hct, and creatinine) analyzed by the epoc system were equivalent to the reference values.

CONCLUSION

Most parameters, except pO2, measured by the epoc system using the capillary blood in hypotensive patients were equivalent to or correlated with those measured by the reference analyzers.

A randomized, crossover study of the acute effects of acarbose and gastric distension, alone and combined, on postprandial blood pressure in healthy older adults

BACKGROUND

Postprandial hypotension (PPH) occurs frequently in the elderly and patients with type 2 diabetes, and lacks a satisfactory treatment. Gastric distension and the α-glucosidase inhibitor, acarbose, may attenuate the postprandial fall in blood pressure (BP) by complementary mechanisms. We aimed to determine whether gastric distension and acarbose have additive effects to attenuate the fall in BP induced by oral sucrose.

METHODS

Ten healthy older adults (74.0 ± 1.4 yr) had measurements of BP and superior mesenteric artery (SMA) blood flow for 120 min after receiving either (i) the 'study drink' of 100 g sucrose in 300 mL of water (control treatment), (ii) a 300 mL water 'preload' 15 min before the 'study drink' (distension treatment), (iii) 100 mg acarbose dissolved in the 'study drink' (acarbose treatment) or (iv) a 300 ml water 'preload' 15 min before 100 mg acarbose dissolved in the 'study drink' (acarbose and distension treatment).

RESULTS

The area under the curve (AUC)_0-120min for mean arterial pressure (MAP) was greater (P = 0.005) and the maximum fall in MAP was less (P = 0.006) during treatments with acarbose. Gastric distension did not affect the MAP-AUC_0-120min response to acarbose (P = 0.44) and there was no effect of gastric distension alone (P = 0.68). Both acarbose treatments attenuated the rise in SMA blood flow (P = 0.003), whereas gastric distension had no effect.

CONCLUSIONS

In healthy older adults, acarbose (100 mg), but not gastric distension, attenuates the fall in BP and rise in SMA blood flow after oral sucrose. The observations support the use of acarbose, but not gastric distension, to attenuate a postprandial fall in BP.

TRIAL REGISTRATION

The study was retrospectively registered at ( ACTRN12618000152224 ) on February 02nd 2018.

Targeting low-normal or high-normal mean arterial pressure after cardiac arrest and resuscitation: a randomised pilot trial

PURPOSE

We aimed to determine the feasibility of targeting low-normal or high-normal mean arterial pressure (MAP) after out-of-hospital cardiac arrest (OHCA) and its effect on markers of neurological injury.

METHODS

In the Carbon dioxide, Oxygen and Mean arterial pressure After Cardiac Arrest and REsuscitation (COMACARE) trial, we used a 23 factorial design to randomly assign patients after OHCA and resuscitation to low-normal or high-normal levels of arterial carbon dioxide tension, to normoxia or moderate hyperoxia, and to low-normal or high-normal MAP. In this paper we report the results of the low-normal (65-75 mmHg) vs. high-normal (80-100 mmHg) MAP comparison. The primary outcome was the serum concentration of neuron-specific enolase (NSE) at 48 h after cardiac arrest. The feasibility outcome was the difference in MAP between the groups. Secondary outcomes included S100B protein and cardiac troponin (TnT) concentrations, electroencephalography (EEG) findings, cerebral oxygenation and neurological outcome at 6 months after cardiac arrest.

RESULTS

We recruited 123 patients and included 120 in the final analysis. We found a clear separation in MAP between the groups (p < 0.001). The median (interquartile range) NSE concentration at 48 h was 20.6 µg/L (15.2-34.9 µg/L) in the low-normal MAP group and 22.0 µg/L (13.6-30.9 µg/L) in the high-normal MAP group, p = 0.522. We found no differences in the secondary outcomes.

CONCLUSIONS

Targeting a specific range of MAP was feasible during post-resuscitation intensive care. However, the blood pressure level did not affect the NSE concentration at 48 h after cardiac arrest, nor any secondary outcomes.

Syncope and hypotension associated with carotid sinus hypersensitivity in a patient with nasopharyngeal carcinoma: A case report

RATIONALE

Carotid sinus hypersensitivity (CSH) is traditionally classified into 3 subgroups: cardioinhibitory, vasodepressor, and mixed subtypes. However, the underlying mechanism of CSH in head and neck cancer is controversial. Several pathological mechanisms of CSH have been proposed: atherosclerotic noncompliance, sternocleidomastoid proprioceptive denervation, and generalized autonomic dysfunction.

PATIENT CONCERNS

We reported a 75-year-old man who had recurrent syncope attacks secondary to hypotension and reduced plasma norepinephrine (NE) levels. CSH was suspected when carotid massage induced syncope-like symptom.

DIAGNOSES

Nasopharynx carcinoma with regional lymph node involvement and CSH.

INTERVENTIONS

On admission, dopamine was administered to maintain the blood pressure. When NE deficiency was confirmed, intravenous NE combined with oral midodrine replaced the dopamine treatment.

OUTCOMES

The syncopal episodes completely resolved with periodic occurrence of hypertension.

LESSONS

Our case suggests a potential role of carotid sinus in regulating the release of NE in adrenal gland and that the monitoring of catecholamine level is recommended in the CSH cases either from head and neck tumors or other mechanical manipulation of carotid sinus.

Cortisol evaluation during the acute phase of traumatic brain injury-A prospective study

BACKGROUND

Biochemical diagnosis of adrenal insufficiency (AI) is difficult in the context of traumatic brain injury (TBI).

AIM

To assess the frequency and predictive factors of AI in victims of TBI from Algiers.

METHODS

Between November 2009 and December 2013, TBI victims had a single 8-9 am serum cortisol measurement during the acute postinjury period (0-7 days). AI was defined according to basal cortisol levels of 83, 276 and 414 nmol/L. Variables studied were TBI severity according to Glasgow coma scale, duration of intubation and coma, pupillary status, hypotension, anaemia, brain imaging findings, diabetes insipidus and medication. Insulin tolerance test was performed during the recovery phase, defining AI as peak cortisol <500 nmol/L.

RESULTS

Cortisol samples were obtained at median 3 (1-7) days from 277 patients (257M: 20F) aged 32 (18-65) years. Acute AI frequency was 8 (2.8%), 20 (21%) and 35 (37%), respectively using the three cortisol cut-offs. Factors predicting AI were diastolic hypotension, sedative medication, diabetes insipidus, skull base fracture and intraparenchymal haematoma. Mortality was highest in patients with acute cortisol <276 nmol/L (44.6% with OR for death 1.64, 95% CI 0.92-3.0, P = .12). During the recovery phase, AI was present in 3 of 3, 12 of 24, 4 of 16 and 20 of 66 patients with week 1 cortisol <83, 83-276, 277-414 and >414 nmol/L.

CONCLUSION

Hydrocortisone replacement is advised in TBI patients with morning cortisol <276 nmol/L or those <414 nmol/L with additional risk factors for AI. As acute and subsequent AI are poorly correlated, patients with moderate/severe TBI require adrenal re-evaluation during the recovery phase.

Pneumatic Compression, But Not Exercise, Can Avoid Intradialytic Hypotension: A Randomized Trial

BACKGROUND

Conventional hemodialysis (HD) is associated with dialysis-induced hypotension (DIH) and ineffective phosphate removal. As the main source of extracellular fluid removed during HD are the legs, we sought to reduce DIH and increase phosphate removal by using cycling and pneumatic compression, which would potentially provide higher venous return, preserving central blood flow and also offering more phosphate to the dialyzer.

METHODS

We evaluated 21 patients in a randomized crossover fashion in which each patient underwent 3 different HD: control; cycling exercise during the first 60 min; and pneumatic compression during the first 60 min. Data obtained included bioelectrical impedance, hourly blood pressure measurement, biochemical parameters, and direct quantification of phosphate through the dialysate. DIH was defined as a drop in mean arterial pressure (MAP) ≥20 mm Hg.

RESULTS

There was no difference in the ultrafiltration rate (p = 0.628), delta weight (p = 0.415), delta of total, intra and extracellular body water among the control, cycling, and pneumatic compression (p = 0.209, p = 0.348, and p = 0.467 respectively). Delta MAP was less changed by pneumatic compression when compared to control, cycling, and pneumatic compression respectively (-4.7 [-17.2, 8.2], -4.7 [-20.5, -0.2], and -2.3 [-8.1, 9.0] mm Hg; p = 0.021). DIH occurred in 43, 38, and 24% of patients in control, cycling, and pneumatic compression respectively (p = 0.014). Phosphate removal did not increase in any intervention (p = 0.486). Higher phosphate removal was dependent on ultrafiltration, pre dialysis serum phosphate, and higher parathyroid hormone.

CONCLUSION

Pneumatic compression during the first hour of dialysis was associated with less DIH, albeit there was no effect on fluid parameters. Neither exercise nor pneumatic compression increased phosphate removal.

Refrigerated platelets stored in whole blood up to 5 days adhere to thrombi formed during hemorrhagic hypotension in rats

Essentials In vivo function of platelets stored at various conditions was studied in normo- and hypotension. Refrigerated platelets stored up to 5 days performed as well as those stored at room temperature. Platelet adhesion and thrombus formation were higher in ruptured vessels of hemorrhaged animals. In vivo data suggest that refrigerated platelets are hemostatically effective during hypotension.

SUMMARY

Background There is renewed interest in the therapeutic use of cold-stored platelets for bleeding patients. However, critical information is absent or partially available in vitro. Therefore, thrombus formation and platelet adhesion were studied in vivo, in situ, using bleeding and thrombosis models in instrumented rats, and confocal intravital videomicroscopy. Objectives We tested the hypothesis that refrigerated (4 °C) platelets (stored for 24 h or 5 days) participated in thrombus formation as well as platelets stored at room temperature (RT, 22 °C). This hypothesis was tested in normovolemia and hemorrhagic hypotension. Methods & Results After fluorescently-labeled platelet infusion, endothelial injury and vessel rupture were laser-induced in cremaster microvessels and platelet adhesion in > 230 developing thrombi was evaluated. Blood samples were collected for biochemistry and coagulation assays while multiple systemic physiologic parameters were recorded. Hemorrhagic hypotension study animals were subjected to 40% hemorrhage, leading to hypotension and hemodilution, during in vivo platelet adhesion assessments. The fluorescence intensity associated with labeled platelet adherence provided a quantitative index of adhesion. Cold-stored platelets performed as well as those stored at RT in normovolemic animals. During hypotension, cold-stored platelets still performed as well as RT-stored platelets, whereas platelet adhesion and thrombus formation were increased relative to normovolemic animals, in bleeding model experiments. Conclusions We found the methodology suitable for evaluating platelet function in vivo after different storage conditions in fully monitored animals. Refrigerated platelets (stored up to 5 days) participated as well as RT-stored platelets in thrombi formed after hemorrhage, suggesting that refrigerated platelets are effective during hypotensive situations.

Differential Role of Neurohypophysial Hormones in Hypotension and Nitric Oxide Production During Endotoxaemia

Besides their well-established endocrine roles, vasopressin and oxytocin are also important regulators of immune function, participating in a complex neuroendocrine-immune network. In the present study, we investigated whether and how vasopressin and oxytocin could modulate lipopolysaccharide (LPS)-induced nitric oxide (NO) production in a well-established model of experimental endotoxaemia. Male Wistar rats were previously treated i.v. with vasopressin V1 or oxytocin receptor antagonists and then received either an i.v. LPS injection to induce endotoxaemia or a saline imjection as a control. The animals were divided into two groups: in the first group, blood was collected at 2, 4 and 6 h after LPS injection; in the second group, mean arterial blood pressure (MABP) and heart rate (HR) were recorded over 6 h. Plasma vasopressin and oxytocin values were higher in LPS- compared to saline-injected animals at 2 and 4 h but returned to basal levels at 6 h. NO levels exhibited an opposite pattern, showing a progressive increase over the entire period. The previous administration of a vasopressin V1 receptor antagonist significantly reduced NO plasma concentrations at 2 and 4 h but not at 6 h. By contrast, oxytocin receptor agonist pre-treatment had no effect on the NO plasma concentration. In relation to MABP, previous treatment with vasopressin V1 receptor antagonist reversed the LPS-induced hypotension at 4 h, although this was not the case for oxytocin antagonist-treated animals. None of the antagonists affected HR. Our findings indicate that vasopressin (but not oxytocin) has effects on NO production during endotoxaemia in rats, although they do not lend support to the proposed anti-inflammatory actions of vasopressin during endotoxaemia.

Arteriovenous blood gas agreement in intensive care patients with varying levels of circulatory compromise: a pilot study

OBJECTIVE

Venous blood gas (VBG) analysis is suggested as an alternative to arterial blood gas (ABG) analysis. In haemodynamically stable patients, there is clinically acceptable arteriovenous (AV) agreement for pH and bicarbonate (HCO3-) concentration, but in haemodynamically unstable patients, evidence is conflicting. We aimed to evaluate the level of AV agreement for the values of pH, PCO2, base excess, HCO3- and lactate between ABGs and VBGs in critically ill patients with varying degrees of hypotension.

DESIGN AND SETTING

A prospective cohort study of a convenience sample of patients in an intensive care unit of a metropolitan teaching hospital.

INTERVENTION

Paired ABG and central VBG samples were drawn within 5 minutes of each other from existing arterial lines and central venous lines, and analysed for AV agreement of pH, PCO2, base excess, HCO3- and lactate. The outcome of interest was AV agreement with varying levels of blood pressure (BP). Analysis was by descriptive statistics, box whisker plot and Bland-Altman bias plot analysis.

RESULTS

We studied 50 patients with 117 paired ABG and VBG samples. The AV differences (venous-arterial) were: pH, -0.04; HCO3-, -0.37 mmmol/L; base excess, 0.08 mEq/ L; and lactate, 0.16 mmol/L. There was not a clinically relevant deterioration in agreement for these parameters with falling BP.

CONCLUSION

In critically ill patients with varying degrees of hypotension in the ICU, there is clinically acceptable AV agreement for the values of pH, HCO3-, base excess and lactate, an agreement that does not deteriorate significantly with falling blood pressure.

Association Between Serum Levels of Adipocyte Fatty Acid-binding Protein and Free Thyroxine

Adipocyte fatty acid-binding protein (AFABP) has been shown to be a biomarker of body weight change and atherosclerosis. Changes in thyroid function are associated with changes in body weight and risks of cardiovascular diseases. The association between AFABP and thyroid function status has been seldom evaluated.The aim of this study was to compare the serum AFABP concentrations in hyperthyroid patients and those in euthyroid individuals, and to evaluate the associations between serum AFABP and free thyroxine (fT4) levels.For this study, 30 hyperthyroid patients and 30 euthyroid individuals at a referral medical center were recruited. The patients with hyperthyroidism were treated with antithyroid regimens as clinically indicated. No medication was given to the euthyroid individuals. The body weight, body mass index, thyroid function, serum levels of AFABP, and biochemical data of both groups at baseline and at the 6th month were compared. Associations between AFABP and fT4 levels were also analyzed.At the baseline, the hyperthyroid patients had significantly higher serum AFABP levels than the euthyroid individuals (median [Q1, Q3]: 22.8 [19.4, 30.6] ng/mL vs 18.6 [15.3, 23.2] ng/mL; P = 0.038). With the antithyroid regimens, the AFABP serum levels of the hyperthyroid patients decreased to 16.6 (15.0, 23.9) ng/mL at the 6th month. No difference in the AFABP level was found between the hyperthyroid and the euthyroid groups at the 6th month. At baseline, sex (female vs male, ß = 7.65, P = 0.022) and fT4 level (ß = 2.51, P = 0.018) were significantly associated with AFABP levels in the univariate regression analysis. At the 6th month, sex and fT4 level (ß = 8.09, P < 0.001 and ß = 3.61, P = 0.005, respectively) were also significantly associated with AFABP levels. The associations between sex and fT4 level with AFABP levels remained significant in the stepwise multivariate regression analysis, both at baseline and at the 6th month.The patients with hyperthyroidism had higher serum AFABP levels than the individuals with euthyroidism. In the patients with hyperthyroidism, the serum AFABP concentrations decreased after the antithyroid treatment. In this study, the serum AFABP concentrations were positively associated with female sex and the serum fT4 level.

Serum cystatin C levels in preterm newborns in our setting: Correlation with serum creatinine and preterm pathologies

BACKGROUND

Cystatin C (CysC) is a renal function marker that is not as influenced as creatinine (Cr) by endogenous or exogenous agents, so it is therefore proposed as a marker in preterm infants.

OBJECTIVES

To determine serum CysC values in preterm infants during the first week of life, compared to Cr. To analyze alterations caused by prematurity diseases.

METHOD

The design involved a longitudinal, observational study of prospective cohorts. Groups were based on gestational age (GA): Group A (24-27 weeks), Group B (28-33 weeks), Group C (34-36 weeks). Blood samples were collected at birth, within 48-72hours and after 7 days of life.

STATISTICS

SPSS v.20 software was used. The statistical methods applied included chi-squared test and ANOVA.

RESULTS

A total of 109 preterm infants were included in the study. CysC levels were: 1.54mg/L (±0.28) at birth; 1.38mg/L (±0.36) within 48-72hours of life; 1.50mg/L (±0.31) after 7 days (p<0.05). Cr levels were: 0.64mg/dL (±0.17) at birth; 0.64mg/dL (±0.28) within 48-72hours; 0.56mg/dL (±0.19) after 7 days (P<.05). CysC values were lower in hypotensive patients and those with a respiratory disease (P<.05), and no alterations associated with other diseases were observed. There were no differences in Cr levels associated with any disease. Creatinine levels were higher in patients ≤1.500g (P<.05).

CONCLUSIONS

Serum CysC decreased within 48-72hours of life, and this decline showed significance (P<.05). The levels increased after 7 days in all 3 GA groups, and there was no difference in CysC levels among the groups. More studies in preterm infants with hypotension and respiratory disease are required. CysC is a better glomerular filtration (GF) marker in ≤1.500g preterm infants.

ECG of the Month. Unexpected Atrioventricular Conduction in High-Grade Atrioventricular Block. DIAGNOSIS: Sinus rhythm; high-grade second-degree atrioventricular block with a junctional escape rhythm and three capture complexes, each with right bundle branch block aberration; possible septal myocardial infarct of indeterminate age; ST-T and U wave changes suggesting hypokalemia

A 90-year-old man with a history of high blood pressure, a cerebrovascular accident without focal residua, dementia, and stage 3 chronic kidney disease went to the emergency department because of dizziness and near syncope. His medications were aspirin 81 mg qd, clopidogrel 75 mg qod, escitalopram oxalate 10 mg qd, quetiapine fumarate 25 mg qd, and memantine hydrochloride 10 mg qd. He had orthrostatic hypotension with supine blood pressure of 173/77 mmHg falling to 116/68 on standing, while pulse increased from 66 to 84 beats/min. He received IV fluid and returned home. Two days later, he saw his primary care physician because of episodes of dizziness and confusion. The Figure shows an electrocardiogram recorded during that visit.

Dialysis hypotension: a role for inadequate increase in arginine vasopressin levels? A systematic literature review and meta-analysis

BACKGROUND

Intradialytic hypotension is a common complication of hemodialysis (HD). Some studies have suggested that inadequate arginine vasopressin (AVP) increase could play a role in the pathogenesis of intradialytic hypotension. However, AVP levels during HD and its relation to hypotension has never been systematically studied.

SUMMARY

PubMed and Embase were searched (1970-2013, search terms 'vasopressin' and 'hemodialysis') for studies reporting on AVP levels during standard HD or other dialysis techniques. Observational studies reporting on AVP levels pre- and postdialysis were additionally included in a meta-analysis. Thirty-seven studies were included in the systematic literature review, of which 26 studies were eligible for meta-analysis. The main findings were that pretreatment AVP levels were higher in dialysis patients compared with healthy controls (6.4 ± 3.5 vs. 2.5 ± 1.3 pg/ml, p = 0.003) and that plasma AVP levels showed little or no increase during HD (from 7.0 ± 4.9 to 8.8 ± 9.3, p = 0.433). Significant heterogeneity was found between studies. Meta-regression analysis revealed no significant associations between AVP and patient or study characteristics. Studies on other dialysis techniques showed mixed results regarding the AVP course. The eight studies that addressed the relation between intradialytic hypotension and AVP also showed inconsistent results.

KEY MESSAGES

Plasma AVP levels are higher in dialysis patients compared with healthy controls, but show little or no increase during HD. The lack of a rise in AVP levels during HD may be pathophysiologically involved in the onset of intradialytic hypotension, but firm conclusions are not possible from our review of the literature.

Glyburide, a K(+)(ATP)channel blocker, improves hypotension and survival in anaphylactic shock induced in Wistar rats sensitized to ovalbumin

Allergens can induce anaphylactic shock and death due to serve hypotension. Potassium channel blockers (K(+)(ATP)) such as glyburide (GLY) induce vasoconstriction. The effect of (K(+)(ATP)) channel blockers on anaphylactic shock is poorly understood. Objective of the study was to test the hypothesis that GLY reduces hypotension induced in anaphylactic shock and increases survival. Rats were grouped into: G1-N=Naïve; G2-SC=Sensitized-Control; G3-SG=Sensitized-GLY (glyburide 40 mg/kg); G4-SE=Sensitized-EPI (epinephrine 10 mg/kg). G2 to G4 groups were sensitized with ovalbumin (OVA) and shock was induced by i.v. injection of OVA. Treatments were administered intravenously 5 min later. Mean arterial pressure (MAP), heart rate (HR), and mean survival time (MST) were measured for 60 min following OVA injection and treatments administration. At the end of the experiment, blood withdrawal was performed to measure plasma levels of histamine, leukotriene B(4) (LTB(4)), prostaglandin E(2) (PGE(2)) and prostaglandin F(2) (PGF(2)). Additionally blood gas (paO2, paCO2, SaO2) and electrolytes (Na(+), K(+) and Ca (++)) were measured. MAP was normal in G1-N; severe hypotension, negative inotropic and short MST were observed in G2-SC; normalization of MAP, with lesser negative inotropism and increased MST were observed in G3-SG; full recovery was observed in G4-SE. Histamine level was significantly higher in G2-SC; reduced in G3-SG and G4-SE. PGE(2) increased in G3-SG; PGF(2) increased in G2-SC and G3-SG. Na(+) and Ca (++) concentration decreased in sensitized rats but reversed in treated groups, without change in K(+) concentration. In conclusion, our data suggest that administration of GLY reduced hypotension and increases survival time in rat anaphylactic shock.

Increased anxiety induced by listening to unpleasant music during stress exposure is associated with reduced blood pressure and ACTH responses in healthy men

The relationship between anxiety and the neuroendocrine response to stress stimuli is still not fully understood. The aim of this study was to evaluate the contribution of an acute increase in state anxiety to neuroendocrine activation under stress conditions. To do so, it was necessary to find a stress condition of the same character and intensity with and without a rise in state anxiety. We decided to examine the effects of listening to music on anxiety and to apply a new methodological approach. A group of 14 healthy volunteers participated in a counterbalanced crossover design study. The stress procedure consisted of mental (Stroop test, mental arithmetic) and physical (handgrip exercise) tasks combined with listening to music played forward (pleasant) or backwards (unpleasant). The results confirmed our hypothesis, namely the condition with listening to unpleasant music was anxiogenic, while the other was not. In case of increased state anxiety, the rise in ACTH concentrations in response to mental challenge and the increase in systolic blood pressure induced by handgrip exercise was reduced compared to the situation with unchanged anxiety. Concentrations of testosterone, oxytocin, vasopressin and aldosterone were slightly increased in response to the stress paradigm accompanied with increased anxiety. In conclusion, the present data demonstrate that an acute increase in state anxiety contributes to neuroendocrine activation under stress conditions. Moreover, the results show that listening to music may both positively and negatively influence the perception of stress and the level of anxiety, which might have functional consequences.

Differential modulation by vascular nitric oxide synthases of the ethanol-evoked hypotension and autonomic dysfunction in female rats

We recently reported that chronic exposure to ethanol lowers blood pressure (BP) via altering cardiac contractility and autonomic control in female rats. In this investigation we conducted pharmacological and molecular studies to elucidate the role of constitutive and inducible nitric oxide synthase (NOS) in these hemodynamic effects of ethanol. Changes caused by selective inhibition of eNOS [N(5)-(1-iminoethyl)-l-ornithine; l-NIO], nNOS (N(ω)-propyl-l-arginine; NPLA), or iNOS (1400W) in BP, heart rate (HR), myocardial contractility index (dP/dt(max)), and power spectral indices of hemodynamic variability were evaluated in telemetered female rats receiving ethanol (5%, w/v) or control liquid diet for 8 weeks. Ethanol increased plasma nitrite/nitrate (NOx) and enhanced the phosphorylation of eNOS and nNOS, but not iNOS, in the tail artery. Ethanol also reduced BP, +dP/dt(max), low-frequency bands of interbeat intervals (IBI(LF), 0.25-0.75 Hz) and IBI(LF/HF) ratio while high-frequency bands (IBI(HF), 0.75-3 Hz) were increased, suggesting parasympathetic overactivity. l-NIO (20 mg/kg i.p.) caused greater increases in BP in control than in ethanol-fed rats but elicited similar reductions in IBI(LF/HF) and +dP/dt(max) both groups. NPLA (1 mg/kg i.p.) caused minimal effects in control rats but exacerbated the reductions in BP, +dP/dt(max), and IBI(LF/HF) in ethanol-fed rats. No hemodynamic modifications were caused by 1400W (5 mg/kg i.p.) in either rat group. Together, these findings suggest that nNOS acts tonically to offset the detrimental cardiovascular actions of ethanol in female rats, and the enhanced vascular NO bioavailability may explain the blunted l-NIO evoked pressor response in ethanol-fed rats.

Admission hematocrit and transfusion requirements after trauma

BACKGROUND

The decision to transfuse packed RBCs (PRBC) during initial resuscitation of trauma patients is based on physiologic state, evidence for blood loss, and potential for ongoing hemorrhage. Initial hematocrit (Hct) is not considered an accurate marker of blood loss. This study tests the hypothesis that admission Hct is associated with transfusion requirements after trauma.

METHODS

From June to December 2008, data from 1,492 consecutive admissions at a Level I trauma center were retrospectively reviewed to determine whether initial Hct was associated with PRBC transfusions. From October 2009 through October 2011, data from 463 consecutive transfused patients were retrospectively reviewed to determine whether Hct correlated with number of PRBC units received.

RESULTS

Packed RBC transfusion was not correlated with heart rate and was more highly correlated with Hct (r = -0.45) than with systolic blood pressure or base deficit (r = -0.32 or r = -0.26). Hematocrit was a better overall predictor than systolic blood pressure (sensitivity 45% vs 29%, specificity 94% vs 98%, area under receiver operator characteristic curve 0.71 vs 0.64). Lower Hct was associated with hypotension, more advanced shock, higher blood loss, and increased transfusion of PRBC, plasma, platelets, or cryoprecipitate (all, p < 0.01).

CONCLUSION

Admission Hct is more strongly associated with the PRBC transfusion than either tachycardia, hypotension, or acidosis. Admission Hct is also correlated with 24-hour blood product requirements in those receiving early transfusions. These findings challenge current thinking and suggest that fluid shifts are rapid after trauma and that Hct can be important in initial trauma assessment.

Improvement of intradialytic hypotension in diabetic hemodialysis patients using vitamin E-bonded polysulfone membrane dialyzers

Currently, there are no detailed reports on the effects of vitamin E-bonded polysulfone (PS) membrane dialyzers on intradialytic hypotension (IDH) in diabetic hemodialysis (HD) patients. This study was designed to evaluate changes in intradialytic systolic blood pressure (SBP) using "VPS-HA" vitamin E-bonded super high-flux PS membrane dialyzers. The subjects were 62 diabetic HD patients whose intradialytic SBP fell by more than 20%. Group A comprised patients who required vasopressors to be able to continue treatment or who had to discontinue therapy due to their lowest intradialytic SBP being observed at 210 min (28 patients). Group B comprised patients who showed no symptoms and required no vasopressors but showed a gradual reduction in blood pressure, with the lowest intradialytic SBP seen at the end of dialysis (34 patients). The primary outcome was defined as the lowest intradialytic SBP after 3 months using VPS-HA. Secondary outcomes included changes in the following: lowest intradialytic diastolic blood pressure, pulse pressure, pulse rate, plasma nitric oxide and peroxynitrite, serum albumin, and hemoglobin A1c. Group A's lowest intradialytic SBP had significantly improved at 3 months (128.0 ±  25.1 mm Hg vs. 117.1 ± 29.2 mm Hg; P = 0.017). Group B's lowest intradialytic SBP had significantly improved at 1 month (134.4 ± 13.2 mm Hg vs. 121.5 ± 25.8 mm Hg; P =  0.047) and 3 months (139.1 ± 20.9 mm Hg vs. 121.5 ±  25.8 mm Hg; P = 0.011). We conclude that VPS-HA may improve IDH in diabetic HD patients.

Altered thyroid function in severely injured patients

BACKGROUND

Hemorrhagic shock profoundly affects the neuroendocrine profile of trauma patients, and we hypothesized that massive resuscitation would negatively impact thyroid function.

METHODS

A prospective, observational study investigating thyroid function in hypotensive trauma patients (systolic blood pressure <90 mm Hg × 2) who survived >48 h was conducted at a Level I center over a 6-mo period. Blood samples for thyroid function were collected at time of presentation to the trauma bay and serially for 48 h. Collected data included demographics, injury data, vital signs, transfusion needs, crystalloid use, and vasopressor requirements. Patients receiving >5 units packed red blood cells (PRBC) within 12 h were compared with those receiving ≤5 units.

RESULTS

Patients who required >5 units of PRBC/12 h had significantly lower total and free T4 levels on initial presentation, and levels remained significantly depressed over the next 48 h when compared with patients who required a less aggressive resuscitative effort. T3 values were markedly suppressed during the initial 48 h post trauma in all patients, but were significantly lower in patients requiring >5 units PRBC. TSH levels remained within the normal range for all time points. Lower trauma admission T4 levels were associated with the need for greater crystalloid resuscitation within the first 24 h.

CONCLUSION

Measurements of thyroid function are significantly altered in severely injured patients on initial presentation, and low T4 levels predict the need for large resuscitation. Further research investigating the profile and impact of thyroid function in trauma patients during resuscitation and recovery is warranted.

The use of laboratory and physiological parameters in predicting mortality in sepsis induced hypotension and septic shock patients attending the emergency department

INTRODUCTION

In this study, we sought to determine whether laboratory and physiological parameters can be useful in predicting mortality in patients with sepsis-induced hypotension and septic shock.

METHODOLOGY

This prospective cohort study was carried out in the emergency department at an academic medical center. A total of 51 patients met enrollment criteria during the study period and 41 of them were included in the study. Inclusion criteria were patients 18 years old or older, diagnosed to have either sepsis-induced hypotension or septic shock and investigated sepsis marker (blood lactate and leukocytes) measured. Other physiological variables were also measured in this study. The main outcome measure was 30-day mortality. Kaplan-Meier, Log-rank and Cox's methods were used for statistical analysis using SPSS version 12.0.1.

RESULTS

61% were diagnosed to have sepsis-induced hypotension and 39% were diagnosed with septic shock. Twenty two (54%) deaths occurred within the 30 day follow up. The overall mean blood lactate level and leukocyte counts were 3.52 mmol/L (5D = 2.29) and 11.37 x 109 (SD = 6.38) respectively. A Cox Proportional Hazard Analysis revealed an increase in blood lactate levels in the ED was associated with an increased risk of death (B = 0.35, HR = 1.45, 95% CI 1.22, 1.73, p < 0.001). However no significant correlation between the physiological parameters and the 30-day mortality. Patients with septic shock state prior to initial presentation has a lower 30 day survival compared to any other septic conditions.

CONCLUSION

Our results support blood lactate level as a promising risk stratification tool when compared with leukocytes counts and other physiological parameters. The multivariate analysis showed that for every increment of lactate value of 1 mmol/L, the hazards of dying are expected to increase by 1.5 times (p < 0.001).

Glucocorticoid exposure of sheep at 0.7 to 0.75 gestation augments late-gestation fetal stress responses

OBJECTIVES

Exposure to glucocorticoid levels inappropriately high for current maturation alters fetal hypothalamo-pituitary-adrenal axis (HPAA) development. In an established fetal sheep model, we determined whether clinical betamethasone doses used to accelerate fetal lung maturation have persistent effects on fetal HPAA hypotensive-stress responses.

STUDY DESIGN

Pregnant ewes received saline (n = 6) or betamethasone (n = 6); 2 × 110 μg/kg body weight doses injected 24 hours apart (106/107 and 112/113 days' gestational age, term 150 days). Basal adrenocorticotropin (ACTH) and cortisol and responses to fetal hypotension were measured before and 5 days after the first course and 14 days after the second course.

RESULTS

Basal ACTH and cortisol were similar with treatment. HPAA responses to hypotension increased after the second but not first course and ACTH/cortisol ratio increased indicating central HPAA effects.

CONCLUSIONS

Results demonstrate latency in the emergence of fetal HPAA hyperresponsiveness following betamethasone exposure that may explain hyperresponsiveness in full-term but not preterm neonates.

Influence of plaque volume on hemodynamic response and stress hormone release in patients undergoing carotid artery stenting

AIM

Carotid artery stenting (CAS) may cause bradycardia and hypotension due to barostimulation. The impact of periprocedural hypotension on CAS outcome remains controversial. The role of carotid plaque volume and catecholamine hormone release during CAS on hemodynamic changes has not been investigated so far. The aim of this prospective study was to evaluate if carotid artery plaque characteristics are predictive for stress hormone release or for postprocedural hemodynamic instability.

METHODS

In 26 patients undergoing CAS, carotid plaque volume and morphology were assessed by two- and three-dimensional (3D)-Duplex sonography prior to the procedure. Arterial plasma adrenaline, noradrenaline and renin concentrations were measured at the time of sheath insertion and 5 minutes after stent placement. ECG, heart rate, and invasive blood pressure were monitored throughout the procedure.

RESULTS

CAS caused no significant changes in hormone release, but increasing plaque volume was related to the degree of bradycardia following stent deployment (r=0.57; P=0.01). Plaque size was not associated with postprocedural hypotension. Plaque echogenicity (echolucent, heterogeneous or echogenic) did not correlate with changes in systolic blood pressure, heart rate or catecholamine hormone release.

CONCLUSION

CAS caused bradycardia in relation to plaque size, but did not cause catecholamine release which may indicate that the endovascular procedure is not associated with a relevant stress reaction.

[Optimizing blood pressure in patients with sellar region tumors during complicated postoperative period]

Mechanism of arterial hypotension (AH) in patients with sellar region tumors (SRT) and complicated postoperative period consists in decrease of systemic vascular resistance and relative hypovolemia. Therapeutic directions for blood pressure (BP) stabilization are clear. However criteria of optimal BP in these patients are absent. Object of the study was defining such criteria. Prospective study was conducted from January, 2011 to January, 2012. Inclusion criteria were: adults; SRT; early postoperative period. Thirty patients were included into the study. Patients were divided into three groups. Group I (n=11) consisted of patients with uncomplicated postoperative period; group II (n=12) - patients with complicated postoperative and with stable hemodynamics; group III (n=7) - patients with complicated postoperative period and AH. Median of central venous saturation (ScvO2) was normal in all groups. ScvO2 was significantly higher than jugular vein saturation (SjvO2) in all measurement. In group I SjvO2 was normal, and it was higher, than in group II. In group SjvO2 did not achieve normal level during three days of the study. Mean BP did not change during these days. In group III SjvO2 was decreased if mean BP was between 70 and 90 mmHg. This level of SjvO2 did not differ from SjvO2 in group II. When mean BP increased up to 100-110 mmHg SjvO2 significantly increased too in the group III and achieved level of the group I (normal level). Outcomes were favorable in all patients of the group I (GOS=4, 5). Median of length of stay (LOS) in the ICU was 1 day. In group II outcomes were favorable in 10 (83.3%) patients, 2 (16.7%) patients died. Median LOS in ICU was 7 days. In group III outcomes were favorable in 6 (85.7%) patients, unfavorable outcome (GOS=3) was in 1 (24.3%) patient. Median LOS in ICU was 12 days. There were no significant differences in all groups in the lactate levels both in central vein and in jugular vein. ScvO2 can not be a criterion for BP optimization in patients with SRT. In patients with uncomplicated postoperative period SjvO2 is normal. In patients with complicated postoperative period and normal BP SjvO2 remains decreased. In patients with complicated postoperative period and arterial hypotension normal level of SjvO2 can be achieved if mean BP is increased up to 100-110 mmHg. SjvO2 normalization can improve outcomes in patients with SRT and complicated postoperative period.

Better cognitive and physical performance is associated with higher blood pressure in centenarians

OBJECTIVES

Knowledge of rational, evidence based health care in the hundred-year-old is still poor. The aim of the study was to evaluate health and functional state in hundred-year-old inhabitants of Upper Silesia, Poland, with a focus on the heart and vascular function.

PARTICIPANTS

Medical and nursing assessment at places of residence was performed in thirty five 100.7±1.4 (mean±SD) year-old subjects, 28 women, and 7 men.

MEASUREMENTS

The protocol included Mini-Mental State Examination (MMSE), Barthel Index (BI) and laboratory tests. A telephone follow-up was performed 180 days after the initial examination.

RESULTS

Most subjects had increased systolic blood pressure (BP), diminished albumin and folate serum levels as well as decreased Glomerular Filtration Rate. According to the quadratic polynomial regression model MMSE and BI were dependent on BP. Higher BP was associated with better performance and survival. Those who survived more than 180 days had lower levels of CRP and VCAM-1 and higher level of sCD40L.

CONCLUSION

The relationships between functional scales, survival and blood pressure suggest a beneficial effect of elevated BP on both mental and physical performance in centenarians. Further studies should determine an optimal balance between risk and benefits of elevated blood pressure in the oldest old people.

Values of using QTc and N-terminal fragment of B-type natriuretic peptide as markers for early detection of acute antipsychotic drugs-induced cardiotoxicity

We aimed at studying the acute cardiotoxicity of the most commonly used antipsychotics in Egypt using QTc interval and NT-proBNP as markers for the early detection of such cases. Eighty-two admitted patients, at El-Minia PCC (period from 1-7-2005 to 30-6-2010), were classified into 3 groups: I: acute thioridazine overdose (n = 28), II: acute pimozide overdose (n = 23), and III: acute clozapine overdose (n = 31). Patients were investigated for NT-proBNP level and QTc on admission (day 0) and after 24 h (day 1). All the studied drugs had the ability to induce cardiotoxicity in the form of hypotension and dysrhythmias. Thioridazine and pimozide had potentially serious cardiotoxic effects than clozapine. NT-proBNP levels were elevated significantly in all groups on days 0 and 1 when compared with the reference value and a significant decrease in the same parameter on day 1 when compared with that of day 0 within the same group. QTc showed a significant prolongation in all studied groups on days 0 and 1, and there was a significant shortening of QTc on day 1 when compared with that of day 0 within the same group. A significant positive correlation of NT-proBNP level elevation with QTc prolongation was reported in all groups on days 0 and 1. Serious dysrhythmias were associated with QTc prolongation greater than 500 ms. And it was concluded that NT-proBNP, in adjunction with QTc measurement, may be a valuable and sensitive laboratory biomarker to predict cardiotoxicity of antipsychotic overdose. Larger multicenter studies are still needed to verify this possible relationship.

Effects of high-flux hemodialysis on plasma adrenomedullin and sustained hypotension in elderly hemodialysis patients

BACKGROUND

Sustained hypotension during hemodialysis (HD) is an important clinical issue. Plasma adrenomedullin (AM) is increased in HD patients with sustained hypotension, but little is known about whether removing AM can improve hypotension. The objective of this study was to investigate the beneficial effects of hemodialysis using a high-flux dialyzer on removal of increased plasma AM levels and improving low blood pressure in elderly HD patients with sustained hypotension.

METHODS

Forty-eight elderly patients (age 65 or older) who had undergone maintenance HD for more than one year were recruited and studied. We evaluated plasma levels of AM in sustained hypotension (SH; n = 28) and normotensive (NT; n = 20) patients. The patients with hypotension were further divided into two subgroups and treated with either high-flux dialyzer or low-flux dialyzer for 3 months. Plasma adrenomedullin levels and blood pressure were analyzed at days 0 and 181.

RESULTS

Plasma levels of AM were significantly higher in SH than in NT patients ((24.92 ± 3.7) ng/L vs. (15.52 ± 6.01) ng/L, P < 0.05), and were inversely correlated with mean arterial blood pressure (MAP) at pre-HD. After 3 months, the level of plasma AM in high-flux group was decreased ((24.58 ± 4.36) ng/L vs. (16.18 ± 5.08) ng/L, P < 0.05), but MAP was increased ((67.37 ± 4.31) mmHg vs. (74.79 ± 3.59) mmHg, P < 0.05). There was no obvious change in low-flux group.

CONCLUSIONS

Plasma AM levels were significantly elevated in elderly HD patients with SH. High-flux dialyzer therapy can decrease plasma AM level and improve hypotension.

Changes in red blood cell size and red cell fragmentation during hemodialysis

INTRODUCTION

Intradialytic hypotension remains the commonest complication for outpatient hemodialysis. The majority of relative blood volume (RBV) monitoring techniques monitor changes in hematocrit. As hematocrit can potentially be affected by changes in red cell size and hemolysis we studied the change in red blood cell size (MCV) during dialysis and hemolysis.

METHODS

MCV was prospectively measured in 176 stable regular adult hemodialysis outpatients (56% male, 27.8% diabetic, mean age 59.5 ±16.2 years) dialyzing against a range of dialysate sodiums (136-145 mmol/L), with cooled dialysate (35-36°C), containing 1 g/L glucose, with constant ultrafiltration profiles. Red cell fragmentation was studied in 41 of the cohort.

RESULTS

Logistical regression analysis showed that the absolute change in MCV was related to the change in hematocrit (F=4.92, β=0.111, p=0.031), and inversely with red cell shrinkage associated with predialysis osmolality (F=5.06, β=0.83, p=0.029), and dialysate sodium (F=4.7, β=0.34, p=0.035). There was no significant increase in red cell fragments during the dialysis sessions.

CONCLUSIONS

Indirect assessment of RBV based upon the relative change in hematocrit, depends not only upon the change in plasma water and red blood cell numbers, but also upon MCV. Changes in MCV may theoretically lead to potential effects on RBV measurements.

Negative dialysate to sodium gradient does not lead to intracellular volume expansion post hemodialysis

INTRODUCTION

Intradialytic hypotension remains the most common complication of routine outpatient hemodialysis treatments. There is debate as to the optimum dialysate sodium concentration, with hypotonic dialysates potentially causing intracellular swelling and hypertonic ones intracellular dehydration.

METHODS

Multi-frequency bioimpedance was used to assess extracellular and intracellular fluid volumes in 53 adult hemodialysis patients. Dialysate sodium was checked by ion electrophoresis.

RESULTS

The mean decrease in extracellular volume and intracellular volumes were 1.01 ±0.09 and 0.88 ±0.18 kg, respectively. The median dialysate to sodium gradient was -3 mmol/L (-1 to -6), with a median dialysate sodium of 136 mmol/L (136-138). There was no association between changes in body fluid composition and sodium concentrations, or gradients. The mean difference between dialysate sodium prescribed and delivered was 2.4 ±0.8 mmol/L.

CONCLUSIONS

In this study we were unable to demonstrate a relationship between predialysis serum sodium and the dialysate sodium prescribed and changes in extracellular or intracellular fluid volumes. However this study showed that using a negative sodium gradient, patients can be successfully ultrafiltrated without setting up intracompartmental fluid gradients. The caveat is that the prescribed dialysate to serum sodium gradient may differ from the actual gradient.

Relation of serum albumin and C-reactive protein to hypotensive episodes during hemodialysis sessions

To evaluate the effect of albumin serum levels and C-reactive protein (CRP) on the course of dialysis induced hypotension (DIH) in chronic hemodialysis (HD) patients, we studied 58 chronic hemodialysis patients in our center during 2007. We investigated the correlation between serum albumin, highly sensitive CRP (hs-CRP) and DIH. The mean of the serum albumin levels was 4.2 +/- 0.5 g/dL, and 32.8% of the patients revealed hypoalbuminemia. Occurrence of DIH among HD patients was 27.6%. The mean of serum albumin levels in the DIH group was significantly lower compared with the normotensive group (3.9 +/- 0.4 vs 4.3 +/- 0.5 g/dL, respectively, P= 0.008). The mean of the hs-CRP levels was significantly higher in the DIH group compared with the normotensive group (12.9 +/- 12 vs. 7.2 +/- 5.2 mg/dL, respectively, P= 0.01). We conclude that high level of CRP and hypoalbuminemia may be predictors of DIH.

Col4a1 mutation in mice causes defects in vascular function and low blood pressure associated with reduced red blood cell volume

Collagen type IV is the major structural component of the basement membrane and COL4A1 mutations cause adult small vessel disease, familial porencephaly and hereditary angiopathy with nephropathy aneurysm and cramps (HANAC) syndrome. Here, we show that animals with a Col4a1 missense mutation (Col4a1(+/Raw)) display focal detachment of the endothelium from the media and age-dependent defects in vascular function including a reduced response to nor-epinephrine. Age-dependent hypersensitivity to acetylcholine is abolished by inhibition of nitric oxide synthase (NOS) activity, indicating that Col4a1 mutations affect vasorelaxation mediated by endothelium-derived nitric oxide (NO). These defects are associated with a reduction in basal NOS activity and the development of heightened NO sensitivity of the smooth muscle. The vascular function defects are physiologically relevant as they maintain in part the hypotension in mutant animals, which is primarily associated with a reduced red blood cell volume due to a reduction in red blood cell number, rather than defects in kidney function. To understand the molecular mechanism underlying these vascular defects, we examined the deposition of collagen type IV in the basement membrane, and found it to be defective. Interestingly, this mutation also leads to activation of the unfolded protein response. In summary, our results indicate that mutations in COL4A1 result in a complex vascular phenotype encompassing defects in maintenance of vascular tone, endothelial cell function and blood pressure regulation.

Hemodynamics, diuretics, and nesiritide: a retrospective VMAC analysis

HYPOTHESIS

Hypotension has been proposed as the cause of nesiritide-associated increases in serum creatinine (SCr); however, this hypothesis has not been tested.

METHODS

This retrospective evaluation of patients who had a pulmonary artery catheter and received nesiritide in the Vasodilation in the Management of Acute Congestive Heart Failure (VMAC) trial assessed hypotension, SCr elevation, concomitant therapy, and mortality. Patients were categorized by baseline pulmonary capillary wedge pressure (PCWP) and analyzed both for overall population and by diuretic dose.

RESULTS

Compared with patients with PCWP > 23 mm Hg (n = 105), patients with PCWP < or = 23 mm Hg (n = 49) had more hypotension within 24 hours of initiating nesiritide (16% vs 7%), but neither more SCr elevation by nominal day 30 (29% vs 28%) nor higher mortality (30 days: 8.2% vs 7.7%; 6 months: 29.0% vs 29.3%). The risk of hypotension was directly related to high dose diuretics (25% vs 6%; relative risk [RR]: 4.2; 95% confidence interval [CI]: 1.10-15.82) and was not significantly increased in patients without this concomitant treatment (10% vs 7%; RR: 1.4; 95% CI: 0.34-5.93). Additionally, high dose diuretics significantly increased the risk of SCr elevation (RR: 2.6; 95% CI: 1.03-6.64) and 6 month mortality (hazard ratio: 3.6; 95% CI: 1.19-10.63) in patients with PCWP < or = 23 mm Hg.

CONCLUSIONS

Hypotension is not the primary etiology for nesiritide-associated increases in SCr. High dose diuretics increase the risk of adverse outcomes in patients with PCWP < or = 23 mm Hg and should be reserved for patients in whom PCWPs are known to be markedly elevated.

[Efficacy of enalapril combined with folic acid in lowering blood pressure and plasma homocysteine level]

OBJECTIVE

To investigate the efficacy of enalapril combined with folic acid in lowering both blood pressure and plasma total homocysteine (Hcy) in essential hypertensive patients.

METHODS

A randomized, community-based clinical trial was conducted. Subjects with hypertension were randomly assigned to one of three treatment groups:enalapril 10 mg/d alone (control), enalapril 10 mg plus folic acid 0.4 mg daily (low-dose group) and enalapril 10 mg combined with folic acid 0.8 mg daily (high-dose group) for a total of 8 weeks. Resting blood pressures of all subjects was measured at baseline, 2nd, 4th, 6th and 8th week of therapy. Plasma Hcy levels were measured at baseline, 4 week and the end of study.

RESULTS

A total of 273 hypertensive patients were enrolled. All analyses were performed according to the intention to treat. Compared with control group, both low- and high-dose group had significantly a greater efficacy in lowering both blood pressure and plasma Hcy level, or in lowering either blood pressure or plasma Hcy level, or in lowering Hcy level. The proportion of subjects showing a marked reduction in both blood pressure and plasma homocysteine in control group, low-dose group and high-dose group were 3.8%, 15.2% and 17.1% respectively; the proportion of subjects showing a marked reduction in either blood pressure or plasma homocysteine in control group, low-dose group and high-dose group were 43.8%, 70.9% and 58.5% respectively. Effect upon blood pressure lowering was not significantly different among these three regimens.

CONCLUSION

As compared to enalapril alone, enalapril combined with folic acid showed a better efficacy in reducing both blood pressure and plasma Hcy level in hypertensive subjects.

Persistent Hypotension Associated with Hypermedullipinemia: A New Syndrome

A new syndrome is described in a patient with advanced renal insufficiency. This consists of severe and persistent hypotension causing weakness but associated with a clear mental status. Also present is evidence for decreased vascular reactivity. The hypotension was not orthostatic. The hypotension was associated with a circulating vasodepressor substance having the characteristics of medullipin 1. The medullipin appears to have been derived from the remaining right kidney. Hypotension existed despite the presence of major prohypertensive mechanisms, including an endstage kidney, hyperreninemia and hyperaldosteronemia. It is likely that hypotension due to hypermedullipinemia is an entity occurring in the human being.

[Intoxication with lithium]

We report a case of a 75-year-old male patient who presented to the emergency room with arterial hypotension and impaired vigilance. The patient was on lithium therapy due to mood disorder. One month earlier medication with a betablocker, a loop-diuretic and an ACE-inhibitor had been started due to heart failure. Findings at admission included renal insufficiency, pneumonia and a slightly increased serum level of lithium. Three days later his Glasgow Coma Scale Score was 7, he showed gaze deviation, increased muscle tonus and cloni. The patient fully recovered after volume substitution and normalization of his renal function. Diagnosis of chronic intoxication with lithium was made due to the clinical picture and after exclusion of neurological pathologies. The pharmacokinetic characteristics of lithium is described and the risk factors leading to lithium intoxication and treatment of intoxication are discussed.

[Effect of a complex treatment, including glutargin and erbisol on the blood plasma content of protein P53, apoptotic markers of type II, activity of caspases and the level of sCD 117 in patients with autonomic-vascular dystonia]

It has been established that the blood content of protein P53 diminishes by 27%, the blood level of sTRAIL increases by 22%, sCD 117 increases by 44% in patients with vegeto-vascular dystonia of the hypertonic type that is accompanied by an increase of the activity of caspases-1 however the activity of caspases-3 and - 8 as well as the blood content of TNF-alpha do not change. Multimodality therapy using glutargin does not influence on the level of the blood plasma TNF-alpha and the activity of caspases-1,-3,-8, normalizes the blood content of sTRAIL and sCD 117, however does not change the plasma concentration of protein P53 which remains lower by 35% than the control indices. In patients with vegeto-vascular dystonia of the hypotonic type the concentration of blood plasma protein P53, TNF-alpha and sTRAIL and the activity of caspases-1,-3,-8 correspond to the control values against a background of an almost twofold increase of the plasma sCD 117 level. The use of erbisol in a complex of therapeutic agents does not change the activity of caspases-l,-3,-8 and does not influence on the blood content of protein p53, TNF-alpha and sTRAIL and diminishes the plasma level of sCD 117 up to control values. A considerable elevation of the blood content of type II apoptotic factors is characteristic of the mixed type of vegeto-vascular dystonia: the level of protein p53 increases 2,4 times, TNF-alpha - 1,9 times, sTRAIL - 2,3 times that is accompanied by an increased activity of caspase-1 - 4,1 times, caspase-3 - 3,3 times, caspase-8 - 3,8 times and an increase of the plasma concentration of sCD 117 - 3,5 times. The use of erbisol and glutargin in multimodality therapy normalizes the plasma concentration of TNF-alpha and diminishes the blood content of protein P53 by 33% and sTRAIL - by 42% which, nevertheless remains higher than the control value by 58% and 36% respectively. The combined effects of glutargin and erbisol in patients of this group are characterized by a decrease (but not normalization) of the blood content of sCD 117 by 47% and more than twofold decrease of the activity of caspases-1,-3 and -8.

Cortisol and 17-alpha-hydroxy-progesterone levels in infants with refractory hypotension born at 30 weeks of gestation or less

Refractory hypotension is frequent in very low-birth weight infants, whose hypothalamic-pituitary-adrenal axis has been suggested to be immature. The objective of the present study was to evaluate basal cortisol and 17-alpha-OH-progesterone in the first 36 h of life in preterm infants with and without refractory hypotension (mean arterial blood pressure below the lower limit for gestational age throughout the study despite aggressive volume expansion and use of vasopressors). Thirty-five infants with <or=30 weeks of gestation and a birth weight <or=1250 g, with no postnatal use of corticosteroid or death in the first 48 h were studied. Mean arterial pressure was measured every 4 h during the first 48 h. Cortisol and 17-alpha-OH-progesterone were determined at 12 and 36 h and patients were divided into refractory hypotensive (N = 15) and control (N = 20) groups. The groups were not different regarding type of delivery, use of prenatal corticosteroid, requirement of mechanical ventilation, use of vasopressor drugs, morphine, fentanyl, prophylactic indomethacin, and mean sample timing. Although refractory hypotensive newborns were more immature, were smaller, suffered more deaths after 48 h of life and had a higher SNAPPE-2 score, their cortisol and 17-alpha-OH-progesterone levels were not different from controls at 12 h and at 36 h. The increase of cortisol in newborns with refractory hypotension 36 h after birth was significantly higher than in controls. Despite the fact that refractory hypotensive very low-birth weight neonates were submitted to a very stressful condition, their cortisol and 17-alpha-OH-progesterone levels were similar to controls.

EVIDENCE FOR INTESTINAL AND LIVER EPITHELIAL CELL INJURY IN THE EARLY PHASE OF SEPSIS

The development of sepsis and multiple organ failure are important determinants of the outcome in critically ill patients. Hepatosplanchnic hypoperfusion and resulting intestinal and hepatic cell damage have been implicated as central events in the development of sepsis and multiple organ failure. Our aim was to study (1) the relation between intramucosal perfusion and intestinal and hepatic cell damage in an early phase of sepsis and (2) the correlation of these parameters with mortality. Two groups of patients were consecutively selected after intensive care unit admission: patients with postoperative abdominal sepsis (n = 19) and patients with pneumonia-induced sepsis (n = 9). Intramucosal perfusion was assessed by gastric tonometry (Pr-aCO2 gap, Pico2). Circulating levels of intestinal fatty acid binding protein (I-FABP) and liver (L)-FABP were used as markers for intestinal and hepatic cellular damage, respectively. Outcome was determined on day 28. Pr-aCO2 gap correlated with I-FABP (Pearson r = 0.56; P < 0.001) in all patients, and gastric mucosal Pico2 correlated significantly with I-FABP (r = 0.57; P = 0.001) in patients with abdominal sepsis. At intensive care unit admission, nonsurvivors had significantly higher I-FABP and L-FABP values than survivors (I-FABP: 325 vs. 76 pg/mL, P < 0.04; L-FABP: 104 vs. 31 ng/mL, P < 0.04). Patients with abdominal sepsis was especially responsible for high-admission I-FABP and L-FABP levels in nonsurvivors (I-FABP: 405 vs. 85 pg/mL, P < 0.04; L-FABP: 121 vs. 59 ng/mL, P < 0.04). This study shows that splanchnic hypoperfusion correlates with intestinal mucosal damage, and that elevated plasma levels of I-FABP and L-FABP are associated with a poor outcome in critically ill patients with abdominal sepsis.

Postprandial hypotension due to a lack of sympathetic compensation in patients with diabetes mellitus

Postprandial hypotension is an important hemodynamic abnormality in diabetes mellitus, but few reports are available on the relationship between autonomic dysfunction and postprandial hypotension. Ten diabetic patients and 10 healthy volunteers were recruited for this study. Postural blood pressure and heart rate changes were measured before lunch, and then the hemodynamic responses to a standardized meal were investigated. Holter electrocardiogram (ECG) monitoring was conducted for assessing spectral powers and time-domain parameters of RR variations. Postural changes from the supine to the upright position decreased the systolic blood pressure of the diabetics from 133(+/-)16 to 107(+/-)20 mmHg (p<0.01), but did not decrease the systolic blood pressure of the controls. The heart rate remained constant in the diabetics but was increased in the controls. Food ingestion decreased systolic blood pressure in the diabetics, with a maximum reduction of 25(+/-)5 mmHg. This decrease was not associated with any changes in the ratio of low frequency to high frequency, and yet the heart rate remained almost constant. Indexes involving parasympathetic tone were not affected. Food ingestion did not affect blood pressure in the control group. These findings suggest that lack of compensatory sympathetic activation is a factor contributing to postprandial hypotension in diabetics, and that parasympathetic drive does not make a significant contribution to this condition.

Brain natriuretic peptide in hemodialysis patients: predictive value for hemodynamic change during hemodialysis and cardiac function

BACKGROUND

Though brain natriuretic peptide (BNP) is widely used as a clinical marker of cardiac function, there is considerable confusion in the interpretation of its value in hemodialysis (HD) patients whose BNPs are often elevated without cardiac diseases. The aim of the present study is to examine the predictive value of BNP for blood pressure (BP) fall during HD and cardiac function.

METHODS

Subjects consisted of 205 (160 males, 45 females; age 66.5 +/- 10.5 years) consecutive uremic patients requiring maintenance HD who were admitted to our hospital during 2001-2004. One hundred and eleven cases had a history of ischemic heart disease. We measured BNP in all cases and collected clinical data including age, sex, duration of HD, blood examination and echocardiography.

RESULTS

BNP of all 205 cases ranged from 6 to 16,097 pg/ml (median 831). During HD, the average BP change was -24.5 +/- 20.5 mm Hg, and 111 cases showed a systolic BP reduction >20 mm Hg. BNP did not predict the degree of BP fall. After adjusting confounding factors, the presence of ischemic heart disease, ultrafiltration rate, systolic BP before HD and serum sodium concentration showed a significant correlation with BP change (t = -2.84, -2.76, -4.68 and 2.90; p = 0.005, <0.01, <0.0001 and <0.005, respectively). In relation to echocardiographic indices, BNP >785 pg/ml could predict left ventricular dysfunction (fractional shortening of the left ventricle <30%, sensitivity 73%, specificity 65%).

CONCLUSION

The level of BNP could not predict BP fall during HD. However, BNP is a good indicator of cardiac function even in uremic patients.

Selection of Anticoagulants for Leukocytapheresis Therapy in Cases of Active Ulcerative Colitis

BACKGROUND AND AIM

Leukocytapheresis (LCAP) is an extracorporeal leukocyte removal therapy that removes immunocompetent leukocytes from the peripheral blood. Nafamostat mesilate (NM) is the most commonly used anticoagulant for LCAP due to various benefits associated with its use, such as a reduced likelihood of bleeding and minimization of adverse reactions caused by contact between blood and the LCAP device. However, adverse reactions have also been reported with NM administration. We reviewed the safety of anticoagulants other than NM, from the perspective of bradykinin production and the consequent drop in blood pressure during treatment.

METHODS

For each of 10 patients with ulcerative colitis, we used four types of anticoagulants sequentially [NM (30-50 mg), heparin, low-molecular-weight heparin (LMWH) and NM (1 mg), and LMWH] for LCAP. We then examined the changes in the blood bradykinin concentrations from the perspective of adverse reactions during LCAP.

RESULTS

The bradykinin production levels from Cellsorba EX varied, depending on the type of anticoagulant used. NM alone (30-50 mg) or LMWH + NM (1 mg) inhibited bradykinin production, whereas heparin alone or LMWH alone significantly accelerated it. However, an excessive fall of blood pressure was not noted in any of the cases. Use of LMWH alone was frequently associated with pressure elevations in the column.

CONCLUSIONS

Given the significant benefits of minimized adverse reactions of LCAP and of continuation of LCAP, we suggest that an appropriate selection of the anticoagulant(s) may allow safer execution of LCAP.

Hypoalbuminemia is an important risk factor of hypotension during hemodialysis

Hypotension during hemodialysis (HD) is an important problem in patients on HD. To investigate the risk factors that contribute to the hypotension during HD, we compared background factors of hypotensive (HP) patients during HD. Among 58 patients undergoing HD in Tamura Memorial Hospital, 12 patients could not continue full HD because of hypotension. We compared the data of ultrafiltration volume, cardiothoracic ratio (CTR), total protein (TP), serum albumin, blood urea nitrogen (BUN), serum creatinine, total cholesterol (TC), hemoglobin (Hb), blood glucose (BS), brain natriuretic peptide (BNP), and cardiac function between HP patients (HP group; n=12) and sex- and age-matched control patients (NP group; n=12). There were no significant differences of age, sex, and duration of HD between the 2 groups. Cardiothoracic ratio is bigger and BNP is higher in the HP group compared with the NP group (CTR: HP 55.8+/-2.9% vs. NP 47.7+/-1.1%, p=0.0165; BNP: HP 602+/-171 vs. NP 147+/-38, p=0.0167). Serum albumin in the HP group is significantly lower compared with the NP group (HP 3.2+/-0.1 g/dL vs. NP 3.5+/-0.1 g/dL, p=0.0130). However, there were no significant differences of ultrafiltration rate (UFR), BS, TC, Hb, and cardiac function between the 2 groups. There is a significant negative correlation between changes of systolic blood pressure (delta systolic blood pressure) and serum albumin in these patients (r=-0.598, p=0.0016). From these data, we conclude that hypoalbuminemia is a major risk factor of hypotension during HD.