Arterial Blood pH Research Articles

The evaluation of early lactate clearance rate in respect of prognosis in patients with severe COPD

Objective To investigate the clinical significance of early lactate clearance rate in respect of the prognosis of patients with severe chronic obstructive pulmonary disease (COPD) . Methods A total of 108 COPD patients with respiratory failure were studied prospectively. The patients were divided into survival group ( n = 82) and the death group ( n = 26) , and the survival group further divided into the conventional treatment subgroup ( n = 55 ) and the invasive ventilation subgroup ( n = 27 ) . Arterial blood lactate, arterial gas analysis, APACHE Ⅱ score and the 6-hour clearance rate were measured before and 6 hours after treatment in 3 groups. The high lactate clearance rate group (n =71 ) was defined as a lactate clearance rate ＞ 10% , and the low lactate clearance rate group (n = 37) with a lactate clearance rate ＜ 10%. The correlation between 6-hour lactate clearance rate and prognosis in patients was analyzed. Results Compared the survival patients in invasive ventilation group with the death group, there were no statistical differences in arterial blood lactate, pH value, PaCO2, PaO2, oxygenation index and APACHE Ⅱ score before the treatment. The 6-hour lactate clearance rate in survival patients in conventional treatment group or invasive ventilation group was significantly higher than that in the death group (t =31.2, P＜0. 01; t =34.6, P＜0. 01, respectively), while there were no statistical differences in APACHE Ⅱ score and pH value between these 3 groups. Between the conventional ventilation treatment group and the invasive ventilation treatment group, there was no statistical difference in 6-hour lactate clearance rate ( P ＞ 0. 05 ) . There was no statistical difference in APACHE Ⅱ score between before treatment and after treatment in 3 groups. Mortality in high lactate clearance rate group (4. 2% ) was significantly lower than that in low lactate clearance rate group (62. 2% ) (x2 = 121.9, P ＜ 0. 01 ) .Conclusions The early (6h) lactate clearance rate could be used as a marker for evaluating the severity,therapeutic efficacy and prognosis of patients with severe COPD. Key words: Chronic obstructive pulmonary disease; Respiratory failure; Early lactate clearance rate; Prognosis

Clinical nursing of pulmonary surfactant in treatment of premature babies with respiratory distress syndrome

Objective To investigate the therapeutic effect and nursing ways of pulmonary surfactant in premature babies with respiratory distress syndrome. Methods From July 2008 to January 2011,63 cases of premature babies with respiratory distress syndrome were admitted to our department, pulmonary surfactant was dripped through trachea into these patients, the treatment effect after medication was observed. Results Among these premature babies, one case died of respiratory failure, one case died from pulmonary hemorrhage, sixty-one cases were cured, the cure rate was 96.8%. After treatment, the arterial blood pH, partial pressure of oxygen(PaO2) and oxygen saturation(SaO2) of the 61 patients was significantly higher than before treatment, the arterial blood partial pressure of carbon dioxide (PaCO2)、 total carbon dioxide (TCO2)、actual bicarbonate (AB)was significantly lower than before treatment. Conclusions Pulmonary surfactant combined with appropriate nursing ways is able to cure premature babies with respiratory distress syndrome effectively. Key words: Pulmonary surfactant; Premature baby; Respiratory distress syndrome; Blood gas analysis

Correlation between arterial blood PH on admition and outcome in ICU patients

Correlation between arterial blood PH on admition and outcome in ICU patients

Establishing Prolonged Hyperlactemia in Anesthetized Dogs

Previously, we have shown that lactate (La-) infusates must be at pH 3.4-4.0 to maintain normal arterial blood pH when raising La- concentration to ≈10 mM. However, the time frame was short (< 2 h) and plasma ion concentrations were not measured. PURPOSE:To evaluate the impact of hyperlactemia (≥ 8 mM) on acid-base and ionic status over a prolonged period (i.e., 10 h) in an anesthetized canine model. METHODS:Six mongrel dogs were anesthetized with pentobarbital, intubated, and ventilated by respirator. Following the placement of sampling and infusion catheters, and baseline measurements of PO2, PCO2, O2 saturation, pH, La-, potassium (K+), calcium (Ca++), and glucose (Glu), the animal was infused with an aqueous solution (650 mM) of sodium lactate/lactic acid. The infusate pH was varied in an attempt to maintain arterial pH at ≈ 7.4. Once the blood La- reached 10 mM, the rate of infusion was decreased to maintain levels at 8-10 mM. RESULTS:Prior to lactate infusion the resting arterial blood lactate concentration was 0.6 ±0.2 mM. La- was elevated and maintained at 9.0 ± 0.6 mM for 10 h. In all cases, hyperlactatemia elicited declines in K+ and Ca++, requiring infusion of KCl and CaCl2 to maintain normal physiological levels. With low infusate pH, (2.2-3.4), hemolysis occurred. Therefore, infusate pH was increased to 4.6. Hemolysis was prevented, but in order to maintain arterial pH below 7.55, ventilation was decreased so that PCO2 rose to 52-55 mmHg. CONCLUSIONS:We were able to raise and maintain blood La- concentration in the 8mM range for 10 h; however, maintaining ion balance and pH required additional infusions and permissive hypercapnia.

Experimental Model Considerations for the Study of Protein-Energy Malnutrition Co-Existing with Ischemic Brain Injury

Protein-energy malnutrition (PEM) affects ~16% of patients at admission for stroke. We previously modeled this in a gerbil global cerebral ischemia model and found that PEM impairs functional outcome and influences mechanisms of ischemic brain injury and recovery. Since this model is no longer reliable, we investigated the utility of the rat 2-vessel occlusion (2-VO) with hypotension model of global ischemia for further study of this clinical problem. Male, Sprague-Dawley rats were exposed to either control diet (18% protein) or PEM induced by feeding a low protein diet (2% protein) for 7d prior to either global ischemia or sham surgery. PEM did not significantly alter the hippocampal CA1 neuron death (p = 0.195 by 2-factor ANOVA) or the increase in dendritic injury caused by exposure to global ischemia. Unexpectedly, however, a strong trend was evident for PEM to decrease the consistency of hippocampal damage, as shown by an increased incidence of unilateral or no hippocampal damage (p=0.069 by chi-square analysis). Although PEM caused significant changes to baseline arterial blood pH, pO(2), pCO(2), and fasting glucose (p<0.05), none of these variables (nor hematocrit) correlated significantly with CA1 cell counts in the malnourished group exposed to 2-VO (p>0.269). Intra-ischemic tympanic temperature and blood pressure were strictly and equally controlled between ischemic groups. We conclude that co-existing PEM confounded the consistency of hippocampal injury in the 2-VO model. Although the mechanisms responsible were not identified, this model of brain ischemia should not be used for studying this co-morbidity factor.

Effect of positivepressure ventilation extubation on arterial blood gas indexes of patients undergoingcardiac surgery

：Objective To study theeffect of positive pressure ventilation extubation on arterial blood gas indexes ofpatients undergoing cardiac surgery. Methods 50 patients with orotracheal intubation afterintracardiac opening operation under direct vision were randomly divided into the controlgroup and the experimental group with 25 cases in each group. We used traditional methodto pull out tracheal intubation in the control group. And positive pressure ventilation at5 ～15 cm H2O during inspiration and pulling out tracheal intubationduring expiration in the experimental group. The change of arterial blood PaO2, PaCO2,SaO2, pH and respiratory rate before and 1min、5min、10min after extubation wasobserved,and also the incidence rate of air tube obstruction was recorded. Results Thechange amplitude of arterial blood gas indexes of patients in the experimental group wasobviously lower,and the length of change time reduced more than 50%. There were 4 air tubeobstructions in the control group and there was no obstruction in the experimental group.The difference was statistically significant. Conclusions Positive pressure ventilationextubation can raise lung's compliance and improve oxygenation. And arterial blood gasindexes are more stable. It can decrease the incidence rate of hypoxemia and is a muchmore safe method. Key words: Open heart surgery; Pulling out tracheal intubation; Arterial blood gas analysis; Nursing care

Acute Lower Limb Ischemia as a Triggering Condition in Hypoxic Hepatitis

Acute centrilobular liver cell necrosis in hypoxic hepatitis (HH) occurs mainly in the setting of hemodynamic failure owing to cardiac failure, respiratory failure, and septic-toxic shock. Cases of HH were also reported under specific conditions such as heat stroke, grand mal seizure, obstructive sleep apnea, and complicated aortic aneurysm. In this study, we report 5 cases of HH occurring in the course of acute lower limb ischemia (ALLI). To the best of our knowledge, the association between HH and ALLI has not yet been reported. In a prospective and consecutive series of 142 cases of HH, we identified 5 cases (3.5%) in which ALLI was the triggering condition. The clinical, hemodynamic, and liver laboratory data of these 5 cases are reported. A review of the literature on liver injury observed in the case of ALLI is also made. The 5 patients were 4 males and 1 female of mean age 63 years. All 5 had typical HH after ALLI. Four of them were in shock on admission. Arterial blood pH lower than 7.15 was observed upon admission in the 3 patients who died. Other potential causes of liver hypoxia were present in all patients. Urgent and efficient revascularization of the ischemic limb was a necessary condition for survival. Acute lower limb ischemia should be added to the list of conditions able to trigger HH. In this particular setting, urgent revascularization of the ischemic limb seems to be a prerequisite for survival.

Risk factors for fatality in HIV-infected patients with dideoxynucleoside-induced severe hyperlactataemia or lactic acidosis.

Lactic acidosis (LA) and severe hyperlactataemia (HL) are infrequent but serious complications of antiretroviral therapy that have been associated with a high fatality rate. In a multinational retrospective cohort study, LA was defined as arterial blood pH<7.35, bicarbonate <20 mmol/l and lactate above normal, and HL as confirmed blood lactate >5 mmol/l. Logistic regression was used to identify factors associated with fatality. Sensitivity and specificity of different case definitions as predictors of death were compared. The overall case-fatality rate was 19/110 (17.3%), but among acidotic patients it was 33% (16/49 cases). There were 10 asymptomatic patients and none of them died as a consequence of the event. The median lactate for fatal, non-fatal and all patients was 8.3 mmol/l (IQR 7.2-13.1), 6.4 mmol/l (IQR 5.4-7.8) and 6.7 mmol/l (IQR 5.5-8.1), respectively. After adjusting for age and current CD4(+) T-cell count, lactate >7 mmol/l (OR 6.27, 95% CI 1.13-34.93), blood bicarbonate <12 mmol/l (OR 10.02 relative to >18 mmol/l, 95% CI 1.33-75.65) and concurrent opportunistic infections (OR 8.69, 95% CI 1.45-52.22) were independently associated with case fatality. Blood lactate >7 mmol/l showed a sensitivity of 84% for fatality with a specificity of 60%, whereas bicarbonate <12 mmol/l showed a better specificity (85%) but a poorer sensitivity (42%). Bicarbonate <18 mmol/l appears to be as good as lactate <7 mmol/l at predicting death (sensitivity 90% and specificity 54%). Our data suggest that blood lactate >7 mmol/l and blood bicarbonate <18 mmol/l appear to predict death and might help clinicians in selecting patients who may benefit from more intense monitoring.

Neonatal morbidity in term neonates is related to gestational age at birth and level of care

The objective of this study was to assess whether the incidence of neonatal morbidity of neonates born at term and admitted to a neonatal intensive care unit (NICU) differs by gestational age and level of care. This is a 5-year retrospective cohort study of singleton term births admitted to the NICU of the VU University Medical Center with a gestational age ≥37+0 weeks. In total, 497 neonates were included in the study. The incidence of neonates born with an arterial cord blood pH<7.10, neonatal asphyxia, and meconium aspiration syndrome increased with advancing gestational age. The incidence of secondary cesarean section and operative vaginal delivery also increased with advancing gestational age. Neonatal death occurred in 29 (5.84%) of the 497 cases; 27 (93%) of 29 were due to asphyxia. Seventeen (34%) of the 50 neonates born in primary care were admitted for asphyxia. Eight (47%) of these 17 neonates died. Neonatal morbidity in term neonates is related to gestational age at birth. Since asphyxia is an important cause of both morbidity and mortality in term neonates, it is important to clearly define and include asphyxia in future perinatal audits.

Respiratory symptoms in preterm infants: burden of disease in the first year of life

ObjectiveWhile respiratory symptoms in the first year of life are relatively well described for term infants, data for preterm infants are scarce. We aimed to describe the burden of respiratory disease in a group of preterm infants with and without bronchopulmonary dysplasia (BPD) and to assess the association of respiratory symptoms with perinatal, genetic and environmental risk factors.MethodsSingle centre birth cohort study: prospective recording of perinatal risk factors and retrospective assessment of respiratory symptoms during the first year of life by standardised questionnaires. Main outcome measures: Cough and wheeze (common symptoms), re-hospitalisation and need for inhalation therapy (severe outcomes). Patients: 126 preterms (median gestational age 28.7 weeks; 78 with, 48 without BPD) hospitalised at the University Children's Hospital of Bern, Switzerland 1999-2006.ResultsCough occurred in 80%, wheeze in 44%, rehospitalisation in 25% and long term inhalation therapy in wheezers in 13% of the preterm infants. Using logistic regression, the main risk factor for common symptoms was frequent contact with other children. Severe outcomes were associated with maximal peak inspiratory pressure, arterial cord blood pH, APGAR and CRIB-Score.ConclusionsCough in preterm infants is as common as in term infants, whereas wheeze, inhalation therapy and re-hospitalisations occur more often. Severe outcomes are associated with perinatal risk factors. Preterm infants who did not qualify for BPD according to latest guidelines also showed a significant burden of respiratory disease in the first year of life.

Influence of modified open lung concept ventilation on the cardiovascular and pulmonary function of horses during total intravenous anaesthesia

The influence of a modified open lung concept (mOLC) on pulmonary and cardiovascular function during total intravenous anaesthesia (TIVA) in horses was evaluated. Forty-two warmblood horses (American Society of Anesthesiologists...

Hyperkalaemia associated with hydroxyurea in a patient with polycythaemia vera

Hydroxyurea has been used for decades for the treatment of some types of malignancies [1]. It has been demonstrated to be very effective in preventing thrombosis and thus should be considered as first-line therapy in high-risk patients with myeloproliferative disorders [2]. An 81-year-old woman was admitted to hospital in December 2009 because of hyperkalaemia. Her medical history included essential hypertension for the last 15 years. She had been diagnosed with polycythaemia vera in April 2007 and an initial treatment consisted of phlebotomy and low-dose acetylsalicylic acid. In May 2009 the patient had developed iliofemoral vein thrombosis as a consequence of polycythaemia vera. To prevent further thromboembolic complications, therapy with hydroxyurea had been introduced. At the time of admission, the patient's therapy included ramipril (2.5 mg), acetylsalicylic acid (100 mg) and hydroxyurea (1,000 mg) daily. Serum potassium level was 6.7 mmol/L (normal range 3.9–5.1 mmol/L). Levels of sodium, chloride, calcium, lactate dehydrogenase and creatine kinase were all within normal values. Haemoglobin concentration, haematocrit, white and red blood cells and platelet count were normal as were values for plasma aldosterone, plasma renin activity and 24-h urinary free cortisol. Arterial blood pH and bicarbonates were mildly decreased (pH 7.318, bicarbonates 18.9 mmol/L). Patient's renal function was decreased with serum creatinine of 116 μmol/L and 24-h creatinine clearance of 41.7 ml/min. Electrocardiogram (ECG) showed no abnormality. Since there was no significant difference between the serum and plasma potassium levels, pseudohyperkalaemia could be excluded [3]. Because of the possibility that hyperkalaemia was caused by ramipril or acetylsalicylic acid, therapy with these drugs was discontinued. Repetitive administration of bicarbonate and insulin/glucose did not decrease the potassium level and after 7 days it remained high (5.8–6.4 mmol/L). The degree of hyperkalaemia could not have been explained by moderate renal insufficiency and the clinical investigation did not find any other possible cause. Thus, we suspected that it could have been caused by an adverse reaction to hydroxyurea. Therapy with hydroxyurea was discontinued and 2 days later the potassium level decreased to 5.0 mmol/L. Since hyperkalaemia was not listed as an adverse reaction in the Summary of Product Characteristics and no similar cases have been reported in the literature, we were not convinced that it was really caused by hydroxyurea. Hyperkalaemia was asymptomatic and caused no ECG changes in the presented case; thus, we believed that rechallenge would not endanger the patient. After Ethics Review Board approval she was re-administered 500 mg of hydroxyurea daily. After the second dose, the serum potassiS. Marusic (*) :N. Gojo-Tomic Department of Clinical Pharmacology, University Hospital Dubrava, Av. Gojka Suska 6, 10000 Zagreb, Croatia e-mail: srmarusic@inet.hr

Renal growth retardation following angiotensin II type 1 (AT1) receptor antagonism is associated with increased AT2 receptor protein in fetal sheep

The actions of angiotensin II on type 1 (AT₁) and type 2 (AT₂) receptor subtypes are important for normal kidney development before birth. This study investigated the effect of AT₁ receptor antagonism on renal growth and growth regulators in fetal sheep during late gestation. From 125 days of gestation (term 145±2 days), chronically catheterised sheep fetuses were infused intravenously for 5 days with either an AT₁-specific receptor antagonist (GR138950, 2-4 mg/kg per day, n=5) or saline (0.9% NaCl, n=5). Blockade of the AT₁ receptor decreased arterial blood oxygenation and pH and increased blood pCO₂, haemoglobin and lactate, and plasma cortisol and IGF-II. Blood glucose and plasma thyroid hormones and IGF-I were unchanged between the treatment groups. On the 5th day of infusion, the kidneys of the GR-treated fetuses were lighter than those of the control fetuses, both in absolute and relative terms, and were smaller in transverse cross-sectional width and cortical thickness. In the GR-infused fetuses, renal AT₂ receptor protein concentration and glomerular density were significantly greater than in the saline-infused fetuses. Blockade of the AT₁ receptor had no effect on relative cortical thickness, fractional or mean glomerular volumes, or renal protein levels of the AT₁ receptor, IGF type 1 receptor, insulin receptor or protein kinase C ζ. Therefore, in the ovine fetus, AT₁ receptor antagonism causes increased renal protein expression of the AT₂ receptor subtype, which, combined with inhibition of AT₁ receptor activity, may be partly responsible for growth retardation of the developing kidney.

P158 The strength of association between the risk of endotracheal intubation and initial arterial blood (ABG) pH in patients presenting with acute hypercapnic respiratory failure (AHRF) treated with non-invasive ventilation (NIV)

IntroductionThe risk of failure of non-invasive ventilation (NIV) in AHRF patients is greater with higher degrees of acidosis. The BTS guidelines suggest that patients with pH <7.26 have a higher...

Delayed toxic effects of sulfur mustard on respiratory tract of Iranian veterans

To investigate late toxic effects of sulfur mustard (SM) on the upper and lower respiratory tracts of Iranian veterans, 43 male veterans with more than 25% disability due to SM poisoning in 20-25 years after exposure, were studied. Direct laryngoscopy, pulmonary function tests, arterial blood gasses and pH, computed tomography of sinuses and lungs were investigated. The patients were aged 50.6 (8.9 SD) years with body mass index (BMI) of 26.6 (4.0) and disability of 53.2 (17.0%). The common findings of the upper respiratory tract were dysphonia (79.1%), post-nasal discharge (PND; 41.9%), lower larynx position (30.2%), limitation of vocal cords (25.6%) and mucosal inflammation of larynx (14.8%). The common lower respiratory diseases were diagnosed as chronic obstructive respiratory disease (84%), bronchiectasis (44.1%) and lung fibrosis (7.7%). Severity of disability was negatively correlated with BMI (p = 0.032), spirometric parameters (p < 0.001) and oxygen saturation (p < 0.001), but positively correlated with low-density lipoproteins (LDL <0.010), blood pressure (p = 0.008), diabetes mellitus (p < 0.001), wheezing (p = 0.0043) and bronchiectasis (p < 0.001). Delayed toxic effects of SM in upper and lower respiratory tracts were mostly inflammatory and infectious complications, SM-induced disabilities were significantly correlated with risk factors such as diabetes mellitus, hypertension, LDL and lower-respiratory complications.

960 Complications in the Near Term and Term Infants with Severe Umbilical Artery Acidemia

Background and aims: Umbilical artery acidbase status is a useful marker of the fetal condition just before birth. The objective of our study was to determine the newborn complications in near term and term infants associated with umbilical artery acidemia of pH ≤ 7.10. Study design: We retrospectively reviewed the maternal and neonatal records of infant's ≥ 35 weeks, born between March 2007 and February 2010, with umbilical artery blood pH ≤ 7.10. Umbilical artery acidemia was classified as metabolic, respiratory and mixed. Results: 179 babies had an umbilical artery pH of ≤ 7.10, of which 59 had an umbilical artery pH < 7.00 and 120 had pH between 7.00 - 7.10. Overall 129 (72%) babies showed evidence of fetal distress; 82(45%) underwent emergency caesarean section, 41(22%) underwent instrumental vaginal delivery. Table below describes the neonatal complications in the two groups. Table Conclusion: The risk of moderate or severe hypoxic ischemic encephalopathy and neonatal seizures is high if umbilical artery pH is < 7.00 along with presence of mixed or metabolic acidosis. Hence these babies should have cerebral function monitoring at least for the first 24 hours.

PP-99. Relationship between oxygen saturation and umbilical cord pH immediately after birth

Background: The aim of this study is to determine the relationship between oxygen saturation (SpO2) by pulse oximetry levels and umbilical cord arterial pH values in healthy newborns during the first 15 minutes of life. Methods: The study was performed with healthy term, appropriate-for-gestational-age newborn infants. The infants were divided in two groups: umbilical cord arterial blood pH value �7.19 (group 1)and>7.19(group2);SpO2levelsduringthefirst15minutesoflifewerecomparedbetweengroups.

Relation between umbilical cord blood pH, base deficit, lactate, 5‐minute Apgar score and development of hypoxic ischemic encephalopathy

Umbilical cord acid-base analysis is fundamental for assessing intrapartum hypoxia. The accuracy of arterial umbilical cord blood lactate, pH and base deficit to reflect a low 5-minute Apgar score and hypoxic ischemic encephalopathy (HIE) stage 2-3 was assessed, and new gestational age-adjusted reference standards were compared with traditional stationary reference values. A total of 13,735 pH-validated routine cord acid-base values from singleton deliveries were tested with stationary and gestational age-adjusted reference values using receiver operating characteristic curves and calculation of area under curve. University hospital. Accuracy of low pH, high base deficit and high lactate, alone or in combination, to imply 5-minute Apgar score < 7 or < 4 or HIE. Gestational age-adjusted values were for all parameters significantly better than crude values to indicate Apgar score < 7. For Apgar score < 4, the differences were not significant. The frequency of HIE was 0.046%, making statistical analyses pointless. Gestational age-adjusted lactate had the overall best accuracy and among combinations; a low age-adjusted pH plus high age-adjusted lactate was slightly better than a low age-adjusted pH plus high age-adjusted base deficit. The sensitivity and positive predictive value were low for all parameters. Lactate in cord arterial blood at birth is at least as good as base deficit to reflect an impaired condition at birth, and best when gestational age-adjusted values are used. Due to methodological confounding involved in calculation of base deficit, lactate may replace base deficit as an acid-base outcome parameter at birth.

Access to computerised analysis of intrapartum cardiotocographs improves clinicians’ prediction of newborn umbilical artery blood pH

To evaluate the impact of access to computerised cardiotocograph (CTG) analysis on reproducibility and accuracy of clinicians' predictions of umbilical artery blood pH (UAB pH) and 5-minute Apgar score. Prospective evaluation of pre-recorded cases. A tertiary-care university hospital. From databases of intrapartum CTGs acquired in singleton term pregnancies, 204 tracings with low signal loss and short time interval to delivery were consecutively selected. Tracings were randomly assigned to computer analysis by the Omniview-SisPorto 3.5 system (study group n = 104) or to no analysis (control group n = 100). Three experienced clinicians evaluated all tracing printouts independently and were asked to predict the newborns' UAB pH and 5-minute Apgar scores from them. Interobserver agreement (measured by the intraclass correlation coefficient [ICC]) and accuracy in prediction of neonatal outcomes with 95% CI. Agreement on prediction of UAB pH was significantly higher in the study group (ICC = 0.70; 95% CI 0.61-0.77) than in the control group (ICC = 0.43; 95% CI 0.21-0.60), and a trend towards better agreement was also seen in estimation of 5-minute Apgar scores (ICC = 0.55; 95% CI 0.38-0.68 versus ICC = 0.43; 95% CI 0.25-0.57). Observers predicted UAB pH values correctly within a 0.10 margin in 70% of cases in the study group (95% CI 0.61-0.79) versus 46% in the control group (95% CI 0.35-0.56). They predicted 5-minute Apgar scores within a margin of one in 81% of cases in the study group (95% CI 0.73-0.88) and in 70% of cases in the control group (95% CI 0.61-0.79). Prediction of UAB pH is more reproducible and accurate when clinicians have access to computerised analysis of CTGs.

Extracellular-derived calcium does not initiate in vivo neurotransmission involving docosahexaenoic acid

In vitro studies show that docosahexaenoic acid (DHA) can be released from membrane phospholipid by Ca(2+)-independent phospholipase A(2) (iPLA(2)), Ca(2+)-independent plasmalogen PLA(2) or secretory PLA(2 (sPLA2)), but not by Ca(2+)-dependent cytosolic PLA(2) (cPLA2), which selectively releases arachidonic acid (AA). Since glutamatergic NMDA (N-methyl-D-aspartate) receptor activation allows extracellular Ca(2+) into cells, we hypothesized that brain DHA signaling would not be altered in rats given NMDA, to the extent that in vivo signaling was mediated by Ca(2+)-independent mechanisms. Isotonic saline, a subconvulsive dose of NMDA (25 mg/kg), MK-801, or MK-801 followed by NMDA was administered i.p. to unanesthetized rats. Radiolabeled DHA or AA was infused intravenously and their brain incorporation coefficients k*, measures of signaling, were imaged with quantitative autoradiography. NMDA or MK-801 compared with saline did not alter k* for DHA in any of 81 brain regions examined, whereas NMDA produced widespread and significant increments in k* for AA. In conclusion, in vivo brain DHA but not AA signaling via NMDA receptors is independent of extracellular Ca(2+) and of cPLA(2). DHA signaling may be mediated by iPLA(2), plasmalogen PLA(2), or other enzymes insensitive to low concentrations of Ca(2+). Greater AA than DHA release during glutamate-induced excitotoxicity could cause brain cell damage.