Arterial Blood pH Research Articles

T-cell immunoglobulin mucin-3 and galectin-9 levels in peripheral blood mononuclear cells predict fetal acidemia in twin pregnancies

Purposes: The pH in the umbilical artery at delivery provides information on the fetal environment and is related to postnatal outcomes. The ability to predict fetal acidemia at delivery would improve clinical management and neonatal well-being. We hypothesized that an alteration in maternal immunity would accompany placental changes that precede a decrease in pH in the fetal circulation in twin gestations. Methods: Peripheral blood mononuclear cells (PBMCs), obtained from 86 women with twin pregnancies, were lysed and assayed for concentrations of T-cell immunoglobulin mucin domain 3 (Tim-3) and galectin-9 (gal-9) by ELISA. Tim-3–gal-9 interaction is a primary mechanism promoting immune suppression. At delivery, the pH of arterial cord blood was determined. Results: In eight women (9.3%), the pH in the placental arteries from both twins was <7.15, indicating fetal acidosis. In the remaining 78 women the arterial pH was ≥7.15 in both twins. The median Tim-3 level was 361 pg/ml when arterial pH was <7.15 and 199 pg/ml when pH was ≥7.15 (p = .003). Similarly, gal-9 was 31.2 versus 12.4 ng/ml when pH was <7.15 or ≥7.15, respectively (p = .001). A Tim-3 concentration >260 pg/ml predicted arterial pH <7.15 with a sensitivity of 87.5%, specificity of 79.5% and negative predictive value of 98.4%. A gal-9 level >18.4 predicted arterial pH <7.15 with a sensitivity of 100%, specificity of 73.8% and a negative predictive value of 100%. Conclusion: We conclude that elevations in Tim-3 and gal-9 in PBMCs during gestation predict the subsequent occurrence of a pH <7.15 in the fetal arteries at delivery in twin gestations.

The patient with metabolic alkalosis

ABSTRACTMetabolic alkalosis defined by the increase of both plasma HCO3- level (>26 mmol/L) and blood arterial pH (>7.43) is quite frequent and usually accompanied by hypokalemia. Its pathogenesis requires both the generation of alkalosis and its maintenance. Generation may be due to excessive hydrogen ion loss by the gastrointestinal tract (e.g. vomiting) or by the kidney (e.g. use of loop diuretics) or may be due to exogenous base gain. Maintenance reflects the inability of the kidney to excrete the excess of bicarbonate because of hypovolemia, chloride depletion, hypokalemia, hyperaldosteronism, renal failure or a combination of these factors. The evaluation of volemic status and measurement of urinary Cl- and plasma levels of renin and aldosterone are crucial to identify the cause(s) of metabolic alkalosis. The cornerstone of treatment is the correction of existing depletions and the prevention of further losses. In vomiting-induced chloride depletion alkalosis, infusion of potassium chloride restores the excretion of bicarbonate by the kidney.

Hemoglobin oxygen saturation targets in the neonatal intensive care unit: Is there a light at the end of the tunnel? 1.

The optimal oxygenation target needed to prevent the extremes of hypoxia and oxygen toxicity in premature and sick newborns has been the subject of much research and debate. The advent of the pulse oximeter has allowed the continuous monitoring of oxyhemoglobin saturation and the delivery of oxygen with greater precision. Well-run, large clinical trials to determine the safest oxygen concentration have led to several revisions in guidelines for neonatal care. However, monitoring of oxyhemoglobin saturation has its limitations and does not provide a comprehensive assessment of tissue oxygenation. To identify optimal oxygen therapy, various other factors (partial pressure of arterial carbon dioxide, hemoglobin concentration, blood pH, and tissue metabolic demand) that influence perfusion and tissue oxygenation need to be considered.

Arterial blood gas and acid-base balance in patients with pregnancy-induced hypertension syndrome.

This study aimed to investigate the expression of arterial blood gas and acid-base balance in patients with pregnancy-induced hypertension syndrome and their influence on newborns. A total of 348 patients with pregnancy-induced hypertension syndrome (research group) admitted and treated in the First People's Hospital of Jining from March 2013 to March 2016 were retrospectively analyzed, and another 156 cases of healthy pregnant women who were physically examined were selected as the control group. Blood gas analysis was performed on pregnant women, and pH value, partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), bicarbonate radical (HCO3−) and base excess (BE) were included as test indexes. Apgar score was made for newborns for neonatal asphyxia. The evaluation was performed at 1, 5, and 10 min after birth to analyze the correlation between the maternal arterial blood pH and the neonatal Apgar score. The pH value, and PO2 and HCO3− levels in the research group were lower than those in the control group (p<0.05). PCO2 and BE levels in the research group were higher than those in the control group (p<0.05). The incidence of neonatal mild asphyxia (Apgar score, 4–6 points) and neonatal severe asphyxia (Apgar score, <4 points) in the research group were higher than that in the control group (p<0.05). The Apgar score of newborns was positively correlated with the pH value of the arterial blood of pregnant women. Blood gas analysis in patients with pregnancy-induced hypertension syndrome is useful to a certain extent to evaluate the condition of the patient. The combination of the pH value of the patient and the Apgar score of the newborns may help improve the judgement rate of neonatal asphyxia so as to improve the quality of childbirth by early monitoring and intervention of the newborns.

Intrapartum Fetal Heart Rate: A Possible Predictor of Neonatal Acidemia and APGAR Score.

Background: Predicting perinatal outcomes based on patterns of fetal heart rate (FHR) remains a challenge. The aim of this study was to evaluate intrapartum FHR variability as predictor for neonatal acidemia and APGAR score.Methods: This was a retrospective observational study of 552 childbirths. Multivariable linear regression models were used to assess the association between FHR variability and each of the following outcomes: arterial cord blood pH and base deficit, Apgar 1, and 5 scores. Variables used for adjustment were maternal age, comorbidities (gestational diabetes, preeclampsia, maternal fever, and hypertension), parity, gravidity, uterine contractions, and newborn gestational age, and weight at birth.Results: The following factors were associated with an increased risk of metabolic acidosis and low Apgar scores at birth: increased mean and coefficient of variation (CV) of the FHR, type of delivery and decreased parity. Each 10-beat/min increase in the FHR was associated with an increase of 0.43 mEq/L in the base deficit, and a decrease of 0.01 in the pH, 0.2 in the Apgar 1, and 0.14 in the Apgar 5 scores. Each 10% increase in the CV of the FHR was associated with an increase of 4.05 mEq/L in the base deficit and a decrease of 0.13 in the pH, 1.31 in the Apgar 1, and 0.86 in the Apgar 5 scores.Conclusion: These data suggest the intrapartum FHR variability is physiologically relevant and can be used for predicting the acidemia and Apgar scores at birth of the newborn infants without severe cases of morbidity and from uncomplicated pregnancies.

The Proposal of Molecular Mechanisms of Weak Organic Acids Intake-Induced Improvement of Insulin Resistance in Diabetes Mellitus via Elevation of Interstitial Fluid pH.

Blood contains powerful pH-buffering molecules such as hemoglobin (Hb) and albumin, while interstitial fluids have little pH-buffering molecules. Thus, even under metabolic disorder conditions except severe cases, arterial blood pH is kept constant within the normal range (7.35~7.45), but the interstitial fluid pH under metabolic disorder conditions becomes lower than the normal level. Insulin resistance is one of the most important key factors in pathogenesis of diabetes mellitus, nevertheless the molecular mechanism of insulin resistance occurrence is still unclear. Our studies indicate that lowered interstitial fluid pH occurs in diabetes mellitus, causing insulin resistance via reduction of the binding affinity of insulin to its receptor. Therefore, the key point for improvement of insulin resistance occurring in diabetes mellitus is development of methods or techniques elevating the lowered interstitial fluid pH. Intake of weak organic acids is found to improve the insulin resistance by elevating the lowered interstitial fluid pH in diabetes mellitus. One of the molecular mechanisms of the pH elevation is that: (1) the carboxyl group (R-COO−) but not H+ composing weak organic acids in foods is absorbed into the body, and (2) the absorbed the carboxyl group (R-COO−) behaves as a pH buffer material, elevating the interstitial fluid pH. On the other hand, high salt intake has been suggested to cause diabetes mellitus; however, the molecular mechanism is unclear. A possible mechanism of high salt intake-caused diabetes mellitus is proposed from a viewpoint of regulation of the interstitial fluid pH: high salt intake lowers the interstitial fluid pH via high production of H+ associated with ATP synthesis required for the Na+,K+-ATPase to extrude the high leveled intracellular Na+ caused by high salt intake. This review article introduces the molecular mechanism causing the lowered interstitial fluid pH and insulin resistance in diabetes mellitus, the improvement of insulin resistance via intake of weak organic acid-containing foods, and a proposal mechanism of high salt intake-caused diabetes mellitus.

Therapeutic effect of combination of traditional Chinese medicine and western medicine on chronic obstructive pulmonary disease complicated with respiratory muscle fatigue and its effects on serum IL-6 and IL-8

Objective To investigate the clinical effect of integrated traditional Chinese and western medicine in the treatment of chronic obstructive pulmonary disease (COPD) complicated with respiratory muscle fatigue, and to analyze its effects on serum levels of interleukin-6(IL-6) and interleukin-8(IL-8). Methods A total of 92 COPD patients complicated with respiratory muscle fatigue in the Traditional Chinese Medicine Hospital of Keqiao District were selected and randomly divided into observation group and control group according to the digital table, with 46 cases in each group.The control group received routine treatment, the observation group was given Liujunzi Decoction on the basis of the control group.The arterial blood pH values, blood carbon dioxide partial pressure(PaCO2), partial pressure of oxygen(PaO2) and the changes of serum IL-6 and IL-8 levels were compared between the two groups. Results Before treatment, the arterial blood pH, PaCO2, PaO2 between the two groups had no statistically significant differences(t=0.274, 0.108, 0.233, all P>0.05). After treatment, the arterial blood PaCO2 of the observation group [(37.18±3.06)mmHg] was significantly lower than that of the control group [(40.23±2.97)mmHg](t=7.004, P 0.05). Before treatment, the serum IL-6, IL-8 levels between the two groups had no statistically significant differences(t=0.506, 0.412, all P>0.05). After treatment, the levels of serum IL-6, IL-8 in the observation group were (14.27±1.05)pg/mL, (41.26±3.97)pg/mL, respectively, which were significantly lower than those in the control group [(18.38±1.76)pg/mL, (60.54±4.31)pg/mL](t=6.358, 7.138, all P<0.05). The total effective rate of the observation group was 97.8%, which was higher than 73.9% of the control group (χ2=8.617, P<0.05). Conclusion The combination of traditional Chinese medicine and western medicine in the treatment of COPD complicated with respiratory muscle fatigue has significant effect, it can effectively alleviate respiratory muscle fatigue, improve blood gas index, reduce serum IL-6 and IL-8 levels, it is worthy of application. Key words: Pulmonary disease, chronic obstructive; Respiratory muscles; Six gentlemen decoction; Interleukin-6; Interleukin-8

Double-balloon catheter versus dinoprostone insert for labour induction: a meta-analysis.

To assess the efficacy and safety of a double-balloon catheter versus dinoprostone insert for labour induction. PubMed, MEDLINE, Embase, ClinicalTrials.gov, and the Cochrane Central Register of Clinical Trials databases were searched from 1985 to April 2018. Randomized controlled trials that compared a double-balloon catheter and dinoprostone insert for cervical ripening were identified. Eligible study populations consisted of women with singleton pregnancies that had any indication for labour induction and were randomly assigned to undergo induction with a double-balloon catheter or dinoprostone insert. The main outcomes were incidence of vaginal delivery within 24h and caesarean section, and neonatal outcomes. Five randomized trials (603 women; 305 with a double-balloon catheter and 298 with a dinoprostone insert) were eligible for inclusion. No differences were observed between the two groups in terms of vaginal delivery within 24h [relative risk (RR) 1.21, 95% confidence interval (CI) 0.93-1.59] and incidence of caesarean section (RR 0.99, 95% CI 0.77-1.27). Compared with the double-balloon catheter, the dinoprostone insert was associated with a reduced need for oxytocin administration in the process of labour induction (RR 1.95, 95% CI 1.45-2.62). However, there was a higher incidence of excessive uterine activity (RR 0.17, 95% CI 0.06-0.54) and neonatal umbilical cord arterial blood pH < 7.1 (RR 0.36, 95% CI 0.15-0.84) in the dinoprostone insert group. This review showed that the efficacy of labour induction using both the double-balloon catheter and dinoprostone insert was similar. However, the double-balloon catheter seemed to be a safer method.

Artificial liver support system for acute-on-chronic liver failure combined with successful liver transplantation in stage III - IV hepatic encephalopathy: an analysis of 14 cases

Objective: To evaluate the effect of plasma exchange combined with high-dose continuous venovenous hemodiafiltration method (CVVHDF) in the treatment of patients with acute-on-chronic liver failure with stage III-IV hepatic encephalopathy and the feasibility of pre-operative preparation for liver transplantation. Methods: Clinical data of 14 cases of medical intensive care unit of our hospital with acute-on- chronic liver failure accompanied with stage III-IV hepatic encephalopathy that underwent plasma exchange combined with high-dose CVVHDF from March 2015 to September 2017 were retrospectively summarized. The indexes of liver and kidney function, blood coagulation function, arterial blood PH, lactic acid and blood ammonia were monitored before and after treatment. Heart rate, blood pressure, APACHE II score, and consciousness recovery time were observed. Student's t- test was used to compare the mean values between the two groups. Results: Serum total bilirubin (t = 9.43, P < 0.01), serum creatinine (t = 3.40, P < 0.01), serum ammonia (t = 10.64, P < 0.01), prothrombin activity (t = 9.19, P < 0.01), serum lactate (t = 9.25, P < 0.01), heart rate (t = 4.47, P < 0.01), and mean arterial pressure (t = 4.41, P < 0.05) were significantly improved in 14 patients before and after treatment. In addition, respiratory rate (t = 6.01, P < 0.01) and APACHE II score (t = 7.19, P < 0.01) were significantly improved (P < 0.05). Eight patients with stage III hepatic encephalopathy were treated with intermittent plasma exchange combined with CVVHDF for 3 to 14 days, and six patients with stage IV were transformed to stage III to II. Liver transplantation was successfully performed on 14 patients with shortest time duration of 3days, and longest time duration of 1 month. Conclusion: Plasma exchange combined with CVVHDF can significantly improve liver and kidney functions, reduce blood ammonia level and improve mental health in patients with hepatic failure accompanied with stage III-IV hepatic coma. In addition, it also effectively increases the average arterial pressure, maintain stability of vital signs, maintain fluids, electrolytes and acid-base balance, create a stable internal environment for liver transplantation before operation, and extend time for liver transplantation.

The clinical characteristics and prognosis of subgaleal hemorrhage in newborn.

PurposeSubgaleal hemorrhage (SGH) is a rare but potentially fatal condition in newborns; however, few studies have reported on this condition. We aimed to identify the clinical characteristics and prognostic factors of SGH.MethodsWe retrospectively reviewed the medical records of 20 neonates diagnosed with SGH between January 2000 and June 2017. Enrolled neonates were clinically diagnosed when they had tender fluctuant scalp swelling that crossed the suture lines.ResultsAmong 20 neonates with SGH, 12 were boys and 7 were girls; median hospitalization duration was 9.7±6.9 days. Fourteen neonates (70%) were born via vacuum-assisted vaginal delivery, and 4 via vacuum-assisted cesarean section. Of the neonates enrolled, half of them initially showed unstable vital signs, including apnea, desaturation, and cyanosis. Ten neonates had acidosis and 3 had asphyxia (pH<7.0). Intracranial lesions associated with SGH were observed in 15 neonates (75%), including subdural hemorrhage (50%), subarachnoid hemorrhage (15%), intraventricular hemorrhage (5%), cerebral infarct (15%), skull fracture (30%), and cephalohematoma (20%). Twelve neonates (60%) required transfusion, 5 (25%) had seizures, and 3 (15%) died. Eight neonates (40%) had hyperbilirubinemia (mean total bilirubin, 13.1±7.4). The mean follow-up period was 8.4±7.5 months. At follow-up, 10 neonates (58.8%) were healthy with normal development, whereas 7 (41.2%) had neurological deficits.ConclusionThe morbidity rate was 41.2% due to severe metabolic acidosis. Anemia, hyperbilirubinemia, low Apgar scores, and subdural hemorrhage did not affect the prognosis. The long-term outcomes of neonates with SGH are generally good. Only arterial blood pH was significantly associated with death.

Effect of different crystalloids on internal environment in patients with septic shock receiving early fluid resuscitation: a prospective randomized controlled trial

To compare the effect of 0.9% NaCl solution, Ringer solution, and acetate sodium potassium magnesium calcium glucose solution (ASPMCG solution) on internal environment in patients with septic shock receiving early fluid resuscitation. A prospective randomized controlled trial was conducted. From June 2016 to January 2018, a total of 280 patients with septic shock admitted to intensive care unit (ICU) of Northern Jiangsu People's Hospital were enrolled. All eligible patients were randomly divided into 0.9% NaCl solution group (group N), Ringer solution group (group L) and ASPMCG solution group (group P) with random number table. In all patients, catheters were placed in the right internal jugular vein or subclavian vein and were infused with 30 mL/kg of corresponding crystalloid within 3 hours after admission. According to fluid responsiveness, the rehydration rate and fluid volume were determined by the researcher within 6 hours. Other treatments were based on the 2012 Surviving Sepsis Campaign (SSC) guidelines during the study. In this study, 6-hour or 24-hour fluid volume and 7-day exogenous insulin use were recorded. The changes in arterial blood pH, base excess (BE), blood glucose (Glu), lactic acid (Lac), and serum Na+, K+, Cl-, Ca2+ were observed at 0, 3, 6, 24 hours, and 3 days and 7 days of resuscitation. In this study, a total of 1 082 patients were admitted to the ICU, and patients who did not meet the diagnostic criteria for septic shock, death or discharge within 24 hours of ICU admission were excluded. Finally, 280 patients with septic shock were enrolled in the analysis, with 94 patients in group N, 94 patients in group L and 92 patients in group P. There was no significant difference in the amount of crystalloid, colloidal fluid, total fluid within 6 hours or 24 hours or exogenous insulin dose within 7 days among the three groups. After fluid resuscitation, blood Cl- concentration in the three groups was increased in different degrees, peaked at 24 hours, but it in group N was significantly higher than that in group L and group P (mmol/L: 107.5±5.6 vs. 106.1±4.8, 105.1±4.2, both P < 0.05). Moreover, blood Ca2+ concentration also showed an increased tendency, it was significantly lower at 3 hours and 6 hours in group N than that in group L and group P (mmol/L: 1.10±0.08 vs. 1.15±0.09, 1.12±0.10 at 3 hours, 1.12±0.10 vs. 1.16±0.08, 1.15±0.09 at 6 hours, all P < 0.05). There was no significant difference in blood Cl- or Ca2+ between groups L and P (both P > 0.05). Arterial blood pH, BE, Glu, Lac, Na+, or K+ at each time point during fluid resuscitation also showed no difference among the three groups. Among patients with septic shock receiving early fluid resuscitation, compared with Ringer solution and ASPMCG solution, 0.9% NaCl solution may cause hyperchloremia and hypocalcemia, but has no significant effect on acid-base balance. Chinese Clinical Trial Registry, ChiCTR-IOR-16009176.

Analysis of risk factors for perioperative mortality in elderly patients with intertrochanteric fracture.

To investigate risk factors for perioperative death in elderly patients with intertrochanteric fracture. Clinical data from 1051 cases with intertrochanteric fracture from March 2005 to March 2015 were reviewed and analyzed, and causes of death during the perioperative period were statistically analyzed. Various indicators were compared byttest and χ2 test. Multivariateanalysiswas performed usingnon-conditionallogistic regression analysis. Chronic diseases of major organs (heart, brain, and lung), postoperative complications, and various indicators within 24h after admission (albumin, hemoglobin, brain natriuretic peptide [BNP], glucose, creatinine, arterial blood pH, PaO2, and APACHE II) were statistically significantly different between patients who survived and those who died. Logistic regression analysis indicated that postoperative complications, APACHE II score, BNP, and chronic diseases of major organs were the risk factors for perioperative mortality in elderly patients with intertrochanteric fracture. BNP and APACHE II score could be used as important reference indexes for predicting possible perioperative mortality in elderly patients with intertrochanteric fracture and chronic diseases of major organs. Complications after fracture may be also risk factors.

Prophylactic infusion of phenylephrine increases the median effective dose of intrathecal hyperbaric bupivacaine in cesarean section: A prospective randomized study.

Background:Phenylephrine infusion to prevent spinal-induced hypotension can attenuate cephalic spread of intrathecal bupivacaine. Therefore, we suspected the intrathecal dose requirement for bupivacaine may differ when using phenylephrine infusion to prevent spinal-induced hypotension in cesarean section. We designed a prospective, randomized study to determine the ED50 of hyperbaric bupivacaine for cesarean section under combined spinal-epidural anesthesia in healthy parturients with and without prophylactic phenylephrine infusion to prevent spinal-induced hypotension.Methods:Sixty healthy parturients rated American Society for Anesthesiology status I/II undergoing elective cesarean section were enrolled in this study, which was conducted July 2016 to February 2017 in the labor and delivery department of Jiaxing University Affiliated Women and Children Hospital. After enrollment, patients were randomized into 2 groups of 30 by blinded opaque envelopes sorted by computer-generated random allocation. Solutions were prepared by an anesthesiologist not involved in outcome measurement. Patients and anesthesiologists collecting data were blinded to group allocation. Group P (phenylephrine group) parturients received prophylactic infusion of phenylephrine at the time of intrathecal injection. Group S (saline group) parturients receive the same volume of saline. Doses of intrathecal bupivacaine for each patient were determined using an up-down allocation method; initial dose was 7 mg. Effective dose was defined as bilateral T6 or above sensory block level achieved within 10 minutes of intrathecal drug administration and no additional epidural lidocaine required for intraoperative pain. The Dixon and Massey formula was used to calculate ED50 values.Results:The ED50 values for hyperbaric bupivacaine were 7.0 mg (95% confidence interval [CI]: 6.6–7.4 mg) and 4.9 mg (95% CI: 4.4–5.4 mg) for groups P and S, respectively (P < .001). There were significant differences in incidence of hypotension and pH of umbilical arterial blood between groups S and P (60% vs 10%, P = .04 and 7.31 ± 0.04 vs 7.28 ± 0.06, P = .003, respectively).Conclusion:The ED50 of intrathecal hyperbaric bupivacaine is higher when phenylephrine infusion is used to prevent spinal-induced hypotension than when it is not used.

The Effect of Prophylactic Phenylephrine and Ephedrine Infusions on Umbilical Artery Blood pH in Women With Preeclampsia Undergoing Cesarean Delivery With Spinal Anesthesia: A Randomized, Double-Blind Trial.

Spinal anesthesia for cesarean delivery is associated with a high incidence of hypotension. Phenylephrine results in higher umbilical artery pH than ephedrine when used to prevent or treat hypotension in healthy women. We hypothesized that phenylephrine compared to ephedrine would result in higher umbilical artery pH in women with preeclampsia undergoing cesarean delivery with spinal anesthesia. This study was a randomized double-blind clinical trial. Nonlaboring women with preeclampsia scheduled for cesarean delivery with spinal anesthesia at Prentice Women's Hospital of Northwestern Medicine were randomized to receive prophylactic infusions of phenylephrine or ephedrine titrated to maintain systolic blood pressure >80% of baseline. Spinal anesthesia consisted of hyperbaric 0.75% bupivacaine 12 mg, fentanyl 15 µg, and morphine 150 µg. The primary outcome was umbilical arterial blood pH and the secondary outcome was umbilical artery base excess. One hundred ten women were enrolled in the study and 54 per group were included in the analysis. There were 74 and 72 infants delivered in the ephedrine and phenylephrine groups, respectively. The phenylephrine:ephedrine ratio for umbilical artery pH was 1.002 (95% confidence interval [CI], 0.997-1.007). Mean [standard deviation] umbilical artery pH was not different between the ephedrine 7.20 [0.10] and phenylephrine 7.22 [0.07] groups (mean difference -0.02, 95% CI of the difference -0.06 to 0.07; P = .38). Median (first, third quartiles) umbilical artery base excess was -3.4 mEq/L (-5.7 to -2.0 mEq/L) in the ephedrine group and -2.8 mEq/L (-4.6 to -2.2mEq/L) in the phenylephrine group (difference -0.6 mEq/L, 95% CI of the difference -1.6 to 0.3 mEq/L; P = .10). When adjusted for gestational age and infant gender, umbilical artery pH did not differ between groups. There were also no differences in the umbilical artery pH stratified by magnesium therapy or by the severity of preeclampsia. We were unable to demonstrate a beneficial effect of phenylephrine on umbilical artery pH compared with ephedrine. Our findings suggest that phenylephrine may not have a clinically important advantage compared with ephedrine with regard to improved neonatal acid-base status when used to prevent spinal anesthesia-induced hypotension in women with preeclampsia undergoing cesarean delivery.

Peripartum and postpartum outcomes in uncomplicated term pregnancy following ART: a retrospective cohort study from two Italian obstetric units.

STUDY QUESTIONDo singleton uncomplicated term pregnancies conceived by assisted reproductive technology (ART) have adverse peripartum and postpartum outcomes?SUMMARY ANSWERTerm pregnancies following ART, even if uncomplicated until birth, have a higher risk of retained placenta and postpartum hemorrhage (PPH).WHAT IS KNOWN ALREADYThere is consistent evidence that pregnancies following ART have higher incidence of complications during pregnancy. However, few studies specifically investigated birth outcomes in ART term pregnancies.STUDY DESIGN, SIZE, DURATIONA retrospective cohort study was conducted on 14 415 deliveries at two university tertiary care obstetric units. Clinical data were extracted by reviewing obstetric records of all deliveries from 1 January 2010 to 31 December 2014, in a standardized electronic database regarding the mother’s health before and during pregnancy, complications during pregnancy and at birth, and neonatal outcome.PARTICIPANTS/MATERIALS, SETTING, METHODSFollowing an accurate evaluation of exclusion criteria (multiparity, maternal pre-pregnancy diseases, prior uterine surgery, fetal malformations, intrauterine deaths, elective cesarean section and pregnancy complications), the group of uncomplicated singleton term pregnancies from autologous ART conception by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) (n = 188) was compared with a maternal age and body mass index (BMI) matched group of spontaneous pregnancies (n = 1168). Cases of intrauterine insemination (IUI) (n = 14) and ovulation induction with timed intercourse (n = 18) were not included. Labor, delivery and postpartum outcomes were evaluated. Odds ratios (OR) were adjusted with multivariable logistic regression to maternal age, BMI, nationality and gestational age at birth.MAIN RESULTS AND THE ROLE OF CHANCEThe age of women in the final analysis ranged from 25 to 45 years, while BMI ranged from 17 to 34 kg/m2. Uncomplicated term pregnancies with ART conception had a higher risk of operative delivery (adjusted OR 1.40, 95% confidence interval (CI) 1.01–1.95), retained placenta (adjusted OR 2.63, 95% CI 1.31–5.26) and PPH (adjusted OR 2.86 95% CI 1.37–5.99). Conversely, ART conception did not increase the risk of induced labor (adjusted OR 1.18, 95% CI 0.85–1.65). However, patients that conceived by ART and underwent labor induction had a higher risk of failed induction compared with the control group (adjusted OR 2.53, 95% CI 1.23–5.21). Infants born after ART had a similar birthweight, Apgar score and arterial blood pH compared with spontaneously-conceived ones.LIMITATIONS, REASONS FOR CAUTIONThe database lacked specific information about causes of infertility, smoking habit, family income and details on ART (fresh versus frozen cycle, IVF versus ICSI), limiting, in part, our analysis of the results. However, only autologous IVF/ICSI pregnancies were included in order to prevent bias related to conception by oocyte/embryo donation. In vivo conception ART cases were excluded because they were too few to allow comparison with IVF/ICSI. Nevertheless, the inclusion of only uncomplicated pregnancies provides a highly homogeneous and still representative population sample. Study sample is representative of a well-resourced obstetric facility in a high-income country, limiting to some extent the generalizability of study results.WIDER IMPLICATIONS OF THE FINDINGSPregnancies conceived by autologous ART that proceed uncomplicated until term may require counseling about the risk of placental retention with PPH.STUDY FUNDING/COMPETING INTERESTSThe authors have no conflict of interest and funding to declare.

Progressive Chronic Retinal Axonal Loss Following Acute Methanol-induced Optic Neuropathy: Four-Year Prospective Cohort Study

To study the dynamics and clinical determinants of chronic retinal nerve fiber layer thickness (RNFL) loss after methanol-induced optic neuropathy. Prospective cohort study. All patients underwent complete ophthalmic evaluation including spectral-domain optical coherence tomography 3 times during 4 years of observation: 4.9 (±0.6), 25.0 (±0.6), and 49.9 (±0.5) months after discharge. Eighty-four eyes of 42 survivors of methanol poisoning, mean age (standard deviation) of 45.7 (±4.4) years; and 82 eyes of 41 controls, mean age 44.0 (±4.2) years. Global and temporal RNFL loss. Abnormal RNFL thickness was registered in 13 of 42 (31%) survivors of methanol poisoning and chronic axonal loss in 10 of 42 (24%) patients. Significant decrease of global/temporal RNFL thickness during the observation period was found in the study population compared to the controls (P < .001). The risk estimate of chronic global RNFL loss for arterial blood pH < 7.3 at admission was 11.65 (95% confidence interval 1.91-71.12) after adjusting for age and sex. The patients with chronic axonal degeneration demonstrated progressive visual loss in 7 of 10 cases. The patients with abnormal RNFL thickness had magnetic resonance signs of brain damage in 10 of 13 vs 8 of 29 cases with normal RNFL thickness (P= .003). Signs of brain hemorrhages were present in 7 of 13 patients with abnormal RNFL thickness vs 5 of 29 cases with normal RNFL thickness (P= .015). Methanol-induced optic neuropathy may lead to chronic retinal axonal loss during the following years. Arterial blood pH on admission is the strongest predictor of chronic RNFL thickness decrease. Chronic retinal neurodegeneration is associated with the progressive loss of visual functions and necrotic brain lesions.

Ultrasound-assessed diaphragmatic impairment is a predictor of outcomes in patients with acute exacerbation of chronic obstructive pulmonary disease undergoing noninvasive ventilation

BackgroundUltrasound (US) evaluation of diaphragmatic dysfunction (DD) has proved to be a reliable technique in critical care. In this single-center prospective study, we investigated the impact of US-assessed DD on noninvasive ventilation (NIV) failure in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and its correlation with the transdiaphragmatic pressure assessed using the invasive sniff maneuver (Pdi sniff).MethodsA population of 75 consecutive patients with AECOPD with hypercapnic acidosis admitted to our respiratory intensive care unit (RICU) were enrolled. Change in diaphragm thickness (ΔTdi) < 20% during tidal volume was the predefined cutoff for identifying DD+/− status. Correlations between ΔTdi < 20% NIV failure and other clinical outcomes were investigated. Correlation between ΔTdi and Pdi sniff values was analyzed in a subset of ten patients.ResultsDD+ patients had a higher risk for NIV failure than DD− patients (risk ratio, 4.4; p < 0.001), and this finding was significantly associated with higher RICU, in-hospital, and 90-day mortality rates; longer mechanical ventilation duration; higher tracheostomy rate; and longer RICU stay. Huge increases in NIV failure (HR, 6.2; p < 0.0001) and 90-day mortality (HR, 4.7; p = 0.008) in DD+ patients were found by Kaplan-Meier analysis. ΔTdi highly correlated with Pdi sniff (Pearson’s r = 0.81; p = 0.004). ΔTdi < 20% showed better accuracy in predicting NIV failure than baseline pH value and early change in both arterial blood pH and partial pressure of carbon dioxide following NIV start (AUCs 0.84 to DTdi < 20%, 0.51 to pH value at baseline, 0.56 to early change in arterial blood pH following NIV start, and 0.54 to early change in partical pressure of carbon dioxide following NIV start, respectively; p < 0.0001).ConclusionsEarly and noninvasive US assessment of DD during severe AECOPD is reliable and accurate in identifying patients at major risk for NIV failure and worse prognosis.

Arterial pH selectively predicts critical care needs in emergency department obese patients with acute dyspnea: A prospective comparative study

IntroductionObese patients with acute dyspnea may be prone to misorientation from the emergency department (ED), due to impaired gas exchange evaluation and altered basal respiratory profiles. This study aims to evaluate the prognostic value of arterial blood pH in obese ED patients with acute dyspnea in comparison to non-obese counterparts. MethodsSingle-center observational study of a cohort of 400 consecutive ED patients with acute dyspnea. The primary endpoint was a composite of Intensive Care Unit admission (with critical care needs) or in ED mortality. Predictors of the primary endpoint were assessed using multivariable logistic regression and ROC curve analysis, in obese (BMI ≥ 30 kg·m−2) and non-obese patients. Results252 patients who had arterial blood gas testing were analyzed including 76 (30%) obese comparable to non-obese in terms of clinical history. 51 patients were admitted to ICU and 2 deceased before admission (20 obese (26%) vs 33 non-obese (19%); p = 0.17). Factors associated with ICU admission were arterial blood pH (pH < 7.36 vs pH ≥ 7.36) and gender. In multivariate models adjusted for risk factors, pH remained the sole independent predictor in obese patients, with no predictive value in non-obese patients (ROC AUC: 0.74, 95% CI [0.60; 0.87], optimal threshold for pH: 7.36, odds ratio: 10.5 [95% CI 3.18; 34.68]). ConclusionArterial blood pH may selectively predict critical care needs in ED obese patients with acute dyspnea, in comparison to non-obese. A falsely reassuring pH < 7.36 should be regarded as a marker of severity when assessing acute dyspnea in obese ED patients.

Ventilatory, Arterial Blood Gas, pH, and Electrolyte Adaptations to Chronic Hypercapnia in Healthy Goats

Respiratory diseases, such as chronic obstructive pulmonary disease (COPD), affect ~24 million U.S adults and cost $49B annually. Many of these patients hypoventilate, leading to chronic hypercapnia, cognitive dysfunction, and high mortality rates. To gain insight into hypercapnia induced changes in neural and physiological function, we studied the breathing, arterial blood gases, pH, electrolytes, and cognitive function in goats during 30 days of chronic hypercapnia (inspired CO2 (InCO2) of 6%) or normocapnia. PaCO2 increased 10 mmHg during the first day of hypercapnia, continued to rise to a maximum of 16 mmHg above control between days 11–12, and remained near this level thereafter. PaO2 remained ~20 mmHg above control throughout the exposure to hypercapnia. Minute ventilation increased by 319% above control on day 1 of hypercapnia (n=7), but declined to 249% above control by day 2 of hypercapnia (n=7). Thereafter, ventilation progressively decreased to a nadir around day 12 at 211% above control (n=6) and remained near this level for the remainder of CO2 exposure. The initial hyperpnea during hypercapnic exposure was due to increases in both tidal volume and breathing frequency. However, breathing frequency returned to near control levels during the first week of hypercapnia, while tidal volume remained elevated. Arterial blood was acidic (−0.05) during day 1 of hypercapnia, followed by a partial compensation by day 8 due to increased arterial [HCO3+] (+7.4 mEq/L). VI/PaCO2 and VI/H+ at 6% InCO2 initially increased ~250% above control and remained elevated for the duration of hypercapnic exposure. Arterial [Cl−] decreased ~4 mmol/L during the first day of CO2 exposure and remained below control (−4–5 mmol/L) for the remainder of the 30 days. Arterial [K+] increased ~0.5 mmol/L during the first week of hypercapnia, and remained above control. No changes were found in arterial [Na+] or [Ca2+]. Accuracy of shape selection (index of cognitive function) decreased nearly 50% during hypercapnia. There were no apparent changes in any physiologic measurement for up to 30 days in goats maintained in room air conditions. In conclusion, we have established a model for future study of neuroadaptive responses, that potentially underlie compromised phenotypic/cognitive function, in COPD patients.Support or Funding InformationDepartment of Veterans Affairs; NIH HL007852This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The Neurovascular Coupling Response Remains Intact During Incremental Ascent to High Altitude (4370m) in Acclimatized Healthy Volunteers

Neurovascular coupling (NVC) is the link between neuronal metabolic activity and regional cerebral blood flow. NVC is responsible for ensuring adequate delivery of nutrients (O2 and glucose) during periods of increased neuronal metabolic demand. Exposure to high‐altitude (HA) elicits ventilatory and acid‐base adjustments for maintaining blood pH. Acute exposure to HA causes hypoxic vasodilation. Hypoxia also drives a ventilatory response, inducing hypocapnia, a potent vasoconstrictor. Whether these dynamic and conflicting responses affect NVC during incremental ascent to HA is unclear.The aim of this project was to assess whether changes in arterial blood gases (ABGs) associated with ascent to HA influences the NVC response. Given that CBF is particularly sensitive to changes in PaCO2, we hypothesized that hypocapnic vasoconstriction during ascent would decrease the NVC response with ascent.10 healthy study participants (21.7±1.3 yrs, 70.46±13.65kg, mean±SD) were recruited as part of a research expedition to Everest base camp, Nepal. Resting posterior cerebral artery velocity (PCAv), ABGs (PaO2, PaCO2), SaO2, arterial blood pH and bicarbonate [HCO3−] were measured at four locations: Calgary (1045m; baseline; BL), Namche (3440m), Deboche (3820m) and Pheriche (4370m). Resting PCAv was measured using transcranial Doppler ultrasound. Arterial blood draws were taken from the radial artery and analysed using a portable blood gas/electrolyte analyser used to monitor changes in ABGs (PaCO2, PaO2, SaO2), pH and [HCO3−] during ascent. NVC was tested via visual stimulation (VS; Strobe light; 6Hz; 30sec on/off ×3). The NVC response was averaged across three VS trials at each location. NVC was quantified as the change (delta) in mean and peak PCAv from baseline, during VS.A one‐factor‐repeated measures analysis of variance (ANOVA) was used to assess for differences in baseline PCAv, NVC, ABGs, blood pH and [HCO3−] between locations. PaO2, PaCO2 and SaO2 were significantly decreased from BL at each altitude (P&lt;0.001, P&lt;0.016 and P&lt;0.013, respectively). No significant differences were found for pH at any location compared to BL (P&gt;0.05) due to reductions in arterial [HCO3−] (P&lt;0.043). No significant differences were found in baseline PCAv between locations (P&gt;0.05) or for mean or peak NVC responses (P&gt;0.085 and P&gt;0.08 respectively).As expected, incremental ascent to HA induced a state of hypoxic hypocapnia, as demonstrated by significant reductions in PaO2, SaO2 and PaCO2, whereas arterial pH was maintained via reductions in [HCO3−]. Our data suggests that NVC remains remarkably intact during incremental ascent to HA in healthy acclimatized individuals. Despite the array of superimposed stressors associated with ascent to HA, CBF and NVC regulation may be a unique function of arterial pH maintenance.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.