Association of alactic base excess with in-hospital mortality in patients with acute myocardial infarction: a retrospective cohort study.

BACKGROUND: Alactic base excess (ABE) is a novel biomarker to evaluate the renal capability of handling acid-base disturbances, which has been found to be associated with adverse prognosis of sepsis and shock patients. This study aimed to evaluate the association between ABE and the risk of in-hospital mortality in patients with acute myocardial infarction (AMI). METHODS: This retrospective cohort study collected AMI patients' clinical data from the Medical Information Mart for Intensive Care (MIMIC)-IV database. The outcome was in-hospital mortality after intensive care unit (ICU) admission. Univariate and multivariate Cox proportional hazards models were performed to assess the association of ABE with in-hospital mortality in AMI patients, with hazard ratios (HRs) and 95% confidence intervals (CI). To further explore the association, subgroup analyses were performed based on age, AKI, eGFR, sepsis, and AMI subtypes. RESULTS: Of the total 2779 AMI patients, 502 died in hospital. Negative ABE (HR = 1.26, 95%CI: 1.02-1.56) (neutral ABE as reference) was associated with a higher risk of in-hospital mortality in AMI patients, but not in positive ABE (P = 0.378). Subgroup analyses showed that negative ABE was significantly associated with a higher risk of in-hospital mortality in AMI patients aged>65 years (HR = 1.46, 95%CI: 1.13-1.89), with eGFR<60 (HR = 1.35, 95%CI: 1.05-1.74), with AKI (HR = 1.32, 95%CI: 1.06-1.64), with ST-segment elevation acute myocardial infarction (STEMI) subtype (HR = 1.79, 95%CI: 1.18-2.72), and without sepsis (HR = 1.29, 95%CI: 1.01-1.64). CONCLUSION: Negative ABE was significantly associated with in-hospital mortality in patients with AMI.

The use of venous blood gas in assessing arterial acid-base and oxygenation status - an analysis of aggregated data from multiple studies evaluating the venous to arterial conversion (v-TAC) method.

BACKGROUND: Several methods exist to reduce the number of arterial blood gases (ABGs). One method, Roche v-TAC, has been evaluated in different patient groups. This paper aggregates data from these studies, in different patient categories using common analysis criteria. RESEARCH DESIGN AND METHODS: We included studies evaluating v-TAC based on paired arterial and peripheral venous blood samples. Bland-Altman analysis compared measured and calculated arterial values of pH, PCO2, and PO2. Subgroup analyses were performed for normal, chronic hypercapnia and chronic base excess, acute hyper- and hypocapnia, and acute and chronic base deficits. RESULTS: 811 samples from 12 studies were included. Bias and limits of agreement for measured and calculated values: pH 0.001 (-0.029 to 0.031), PCO2 -0.08 (-0.65 to 0.49) kPa, and PO2 0.04 (-1.71 to 1.78) kPa, with similar values for all sub-group analyses. CONCLUSION: These data suggest that v-TAC analysis may have a role in replacing ABGs, avoiding arterial puncture. Substantial data exist in patients with chronic hypercapnia and chronic base excess, acute hyper- and hypocapnia, and in patients with relatively normal acid-base status, with similar bias and precision across groups and across study data. Limited data exist for patients with acute and chronic base deficits.

Independent variables of pH: Ten Knights of the Hydrogen Ion Kingdom-Part I. A prospective observational study.

CO2, HCO3, SID, and total weak acids have been defined as pH's independent variables. However, according to Gamble, HCO3 should be equal to the difference between the sum of cations and the sum of anions besides HCO3. Therefore, if this mathematical expression is substituted for HCO3 in the Henderson-Hasselbalch equation, all independent variables of pH can be demonstrated. Our aim is to test this theory in this study. This prospective observational study was conducted between 2019 and 2020. All admitted patients to the intensive care unit who were >18 years old were included. Demographic data, blood gas parameters, albumin, magnesium, and inorganic phosphorus levels, and outcomes were recorded twice (at admission and at the 24th hour). The multivariate linear regression model was used to determine pH's independent variables. In the multivariate linear regression model, pH was significantly increased by each unit increase in Na, K, Ca, and Mg (mmol L-1). In contrast, pH was significantly decreased by each unit increase in CO2, Cl, lactate, albumin (g dL-1), inorganic phosphorus (mg dL-1), and the strong ion gap. Ten independent variables can accurately predict the changes in pH. For this reason, all ten independent variables should be separately evaluated when interpreting the acid-base status. With this understanding, all algorithms regarding acid-base evaluation may become unnecessary.

[Blood gas analysis in the intensive cardiac care unit]. / La rapida lettura dell'emogasanalisi in unità di terapia intensiva cardiologica.

Arterial blood gas (ABG) analysis is a simple and quick test that can provide multiple respiratory and metabolic parameters. The interpretation of ABG analysis and acid-base disorders represents one of the most complex chapters of clinical medicine. In this brief review, the authors propose a rational approach that sequentially analyzes the information offered by the ABG to allow a rapid classification of the respiratory, metabolic or mixed disorder. The patient's history and clinical-instrumental assessment are the framework in which to insert the information derived from the ABG analysis in order to characterize the critical heart patient.

Association between peri-transplant acid-base parameters and graft dysfunction types in kidney transplantation.

Perioperative acid-base disturbance could be informative regarding the possible slow graft function (SGF) or delayed graft function (DGF) development. There is a lack of data regarding the relationship between perioperative acid-base parameters and graft dysfunction in kidney transplant (KT) recipients. We aim to determine the incidence of graft dysfunction types and the association between them and acid-base parameters. We performed a prospective, cohort study on 54 adults, KT recipients, between 1st of January 2019 and 31st of December 2019. Graft function was defined and classified in three categories: immediate graft function (IGF) (serum creatinine < 3 mg/dL at day 5 after KT), SGF (serum creatinine ≥ 3mg/dL at day 5 or ≥ 2.5mg dL at day 7 after KT) and DGF (the need for at least one dialysis treatment in the first week after kidney transplantation). Among the 54 KT recipients, the incidence of SGF and DGF was 13% and 11.1%, respectively. SGF was significantly associated with lower intraoperative pH (7.26± 0.05 vs 7.35± 0.06, p= 0.004), preoperative and intraoperative base excess (BE) [-7.0 (-10.0 ߝ -6.0) vs -3.4 (-7.8 ߝ - 2.1) mmol/L, p= 0.04 and -10.3 (-11.0 ߝ -9.1) vs -4.0 (-6.3 ߝ - 3.0) mmol/L, p= 0.002, respectively] and serum bicarbonate (HCO3-) (16.0± 2.7 vs 19.3± 3.4 mmol/L, p= 0.01 and 14.1± 1.9 vs 18.8± 3.2 mmol/L, p= 0.002 respectively), compared to IGF. DGF was significantly associated with lower intraoperative values of pH (7.27± 0.05 vs 7.35± 0.06, p= 0.003), BE [-7.1 (-10.9 ߝ -6.1) vs -4.0 (-6.3 ߝ - 3.0) mmol/L, p= 0.02] and HCO3- (15.9± 2.4 vs 18.8± 3.2 mmol/L, p=0.02) compared to IGF. No differences were observed between SGF and DGF patients in any of the perioperative acid-base parameters. In conclusion we found that kidney graft dysfunction types are associated with perioperative acid-base parameters and perioperative metabolic acidosis could provide important information to predict SGF or DGF occurrence.

Changes in acid-base status in oxygen toxicity at 230 kPa oxygen as a function of exposure time.

Breathing less than 50 kPa of oxygen over time can lead to pulmonary oxygen toxicity (POT). Vital capacity (VC) as the sole parameter for POT has its limitations. In this study we try to find out the changes of acid-base status in a POT rat model. Fifty male rats were randomly divided into five groups, exposed to 230 kPa oxygen for three, six, nine and 12 hours, respectively. Rats exposed to air were used as controls. After exposure the mortality and behavior of rats were observed. Arterial blood samples were collected for acid-base status detection and wet-dry (W/D) ratios of lung tissues were tested. Results showed that the acid-base status in rats exposed to 230 kPa oxygen presented a dynamic change. The primary status was in the compensatory period when primary respiratory acidosis was mixed with compensated metabolic alkalosis. Then the status changed to decompensated alkalosis and developed to decompensated acidosis in the end. pH, PCO2, HCO3-, TCO2, and BE values had two phases: an increase and a later decrease with increasing oxygen exposure time, while PaO2 and lung W/D ratio showed continuously increasing trends with the extension of oxygen exposure time. Lung W/D ratio was significantly associated with PaO2 (r = 0.6385, p = 0.002), while other parameters did not show a significant correlation. It is concluded that acid-base status in POT rats presents a dynamic change: in the compensatory period first, then turns to decompensated alkalosis and ends up with decompensated acidosis status. Blood gas analysis is a useful method to monitor the development of POT.

Base-excess chloride; the best approach to evaluate the effect of chloride on the acid-base status: A retrospective study.

To practically determine the effect of chloride (Cl) on the acid-base status, four approaches are currently used: accepted ranges of serum Cl values; Cl corrections; the serum Cl/Na ratio; and the serum Na-Cl difference. However, these approaches are governed by different concepts. Our aim is to investigate which approach to the evaluation of the effect of Cl is the best. In this retrospective cohort study, 2529 critically ill patients who were admitted to the tertiary care unit between 2011 and 2018 were retrospectively evaluated. The effects of Cl on the acid-base status according to each evaluative approach were validated by the standard base excess (SBE) and apparent strong ion difference (SIDa). To clearly demonstrate only the effects of Cl on the acid-base status, a subgroup that included patients with normal lactate, albumin and SIG values was created. To compare approaches, kappa and a linear regression model for all patients and Bland-Altman test for a subgroup were used. In both the entire cohort and the subgroup, correlations among BECl, SIDa and SBE were stronger than those for other approaches (r = 0.94 r = 0.98 and r = 0.96 respectively). Only BECl had acceptable limits of agreement with SBE in the subgroup (bias: 0.5 mmol L-1) In the linear regression model, only BECl in all the Cl evaluation approaches was significantly related to the SBE. For the evaluation of the effect of chloride on the acid-base status, BECl is a better approach than accepted ranges of serum Cl values, Cl corrections and the Cl/Na ratio.

Prognostic role of perioperative acid-base disturbances on the risk of Clostridioides difficile infection in patients undergoing cardiac surgery.

BACKGROUND: It is unclear whether acid-base balance disturbances during the perioperative period may impact Clostridium difficile infection (CDI), which is the third most common major infection following cardiac surgery. We hypothesized that perioperative acid-base abnormalities including lactate disturbances may predict the probability of incidence of CDI in patients after cardiac procedures. METHODS: Of the 12,235 analyzed patients following cardiac surgery, 143 (1.2%) developed CDI. The control group included 200 consecutive patients without diarrhea, who underwent cardiac procedure within the same period of observation. Pre-, intra and post-operative levels of blood gases, as well as lactate and glucose concentrations were determined. Postoperatively, arterial blood was drawn four times: immediately after surgery and successively; 4, 8 and 12 h following the procedure. RESULTS: Baseline pH was lower and PaO2 was higher in CDI patients (p < 0.001 and p = 0.001, respectively). Additionally, these patients had greater base deficiency at each of the analyzed time points (p < 0.001, p = 0.004, p = 0.012, p = 0.001, p = 0.016 and p = 0.001, respectively). Severe hyperlactatemia was also more common in CDI patients; during the cardiac procedure, 4 h and 12 h after surgery (p = 0.027, p = 0.004 and p = 0.001, respectively). Multivariate logistic regression analysis revealed that independent risk factors for CDI following cardiac surgery were as follows: intraoperative severe hyperlactatemia (OR 2.387, 95% CI 1.155-4.933, p = 0.019), decreased lactate clearance between values immediately and 12 h after procedure (OR 0.996, 95% CI 0.994-0.999, p = 0.013), increased age (OR 1.045, 95% CI 1.020-1.070, p < 0.001), emergent surgery (OR 2.755, 95% CI 1.565-4.848, p < 0.001) and use of antibiotics other than periprocedural prophylaxis (OR 2.778, 95% CI 1.690-4.565, p < 0.001). CONCLUSION: This study is the first to show that perioperative hyperlactatemia and decreased lactate clearance may be predictors for occurrence of CDI after cardiac surgery.

Modulation of the Association of Hypobicarbonatemia and Incident Kidney Failure With Replacement Therapy by Venous pH: A Cohort Study.

RATIONALE & OBJECTIVE: Studies showing an association between lower bicarbonate levels and worse kidney disease prognosis have not accounted for the influence of pH. It remains unknown whether this association is consistent across a wide range of blood pH values. This study sought to assess how pH modifies the relationship between hypobicarbonatemia and incident kidney failure requiring kidney replacement therapy (KFRT). STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: 1,058 Japanese patients with estimated glomerular filtration rates<60mL/min/1.73m2. EXPOSURE: Baseline venous bicarbonate levels and venous pH. OUTCOME: KFRT defined as initiation of kidney replacement therapy (hemodialysis, peritoneal dialysis, and kidney transplantation). ANALYTICAL APPROACH: Cox proportional hazards model assessing the interaction between baseline bicarbonate levels and venous pH on incident KFRT. RESULTS: In the lowest bicarbonate quartile (≤21.5 mEq/L), 59% of patients had acidemia (pH<7.32), whereas 38% had venous pH within the normal range and 3% had alkalemia (pH>7.42). During a median follow-up of 3.0 years, 374 patients developed KFRT. Venous pH modified the association between bicarbonate level and rate of KFRT (P for interaction=0.04). After adjustment for potential confounders, including capacity for respiratory compensation, the lowest (vs the highest) bicarbonate quartile was associated with a 2.29-fold (95% CI, 1.10-4.77; P=0.03) higher rate of KFRT among patients with acidemia (pH<7.32). In contrast, among patients without acidemia (pH≥7.32), no significant association was found between bicarbonate level and KFRT. In an exploratory analysis, patients with higher respiratory compensation capacity had a lower rate of KFRT (HR per 0.1 increase in respiratory compensation capacity, 0.90; 95% CI, 0.87-0.94; P<0.001). LIMITATIONS: Observational study design; blood gas measurements were performed in a select patient population. CONCLUSIONS: Venous pH modified the association of hypobicarbonatemia with progression of chronic kidney disease to KFRT. Measurement of venous pH may be valuable for identifying patients with chronic kidney disease and hypobicarbonatemia and may inform treatment.

Early-Life Multiple Sevoflurane Exposures Alleviate Long-term Anxiety-Like Behaviors in Mice via the proBDNF/ERK Pathway.

Early-life multiple anesthetics exposure causes neurotoxicity and hence cognitive dysfunction on developing brain. However, the effects of early-life multiple sevoflurane exposures on emotional changes, especially upon stress, are far beyond understood. In young male C57BL6/J mice, the present study showed that 3% sevoflurane inhalation for 2 h in three consecutive days did not influence anxiety-like behaviors as measured by open field test, light dark transition, and elevated plus maze test. In addition, foot shocks stress induced both the short- and long-term anxiety-like behaviors. However, triple sevoflurane exposures ameliorated the long-term anxiety-like behaviors induced by the foot shocks. In parallel, foot shocks stress upregulated the expression of phosphorylated extracellular signal-regulated kinase (p-ERK) and brain-derived neurotrophic factor precursor (proBDNF) in the anterior cingulate cortex (ACC), which were significantly inhibited by triple sevoflurane exposures. Immunofluorescence further indicated that the increased p-ERK was mainly expressed in the proBDNF-positive staining cells. Intra-ACC injection of recombinant proBDNF protein upregulated the p-ERK expression and blocked the anxiolytic effect of sevoflurane exposure on long-term anxiety-like behaviors. Therefore, our study demonstrated that multiple sevoflurane exposures alleviate long-term anxiety-like behaviors upon acute stress in young mice by inhibiting proBDNF-ERK signaling in the ACC.

Serum Anion Gap Is Associated with All-Cause Mortality among Critically Ill Patients with Congestive Heart Failure.

BACKGROUND: Congestive heart failure (CHF) is a complex clinical syndrome, with high morbidity and mortality. Serum anion gap (SAG) is associated with the severity of various cardiovascular diseases. However, the role of SAG indicators in CHF is unclear. METHODS AND RESULTS: A retrospective analysis of data from Multiparameter Intelligent Monitoring in Intensive Care III version 1.4 was conducted in critically ill patients with CHF. The clinical information of each patient, including demographic data, comorbidities, vital signs, scores, and laboratory indicators, were successfully obtained. Cox proportional hazards models were used to determine the relationship between SAG and mortality in patients with CHF, the consistency of which was further verified by subgroup analysis. RESULTS: A total of 7426 subjects met the inclusion criteria. Multivariate analysis showed that after adjusting for age, gender, ethnicity, and other potential confounders, increased SAG was significantly related to an increase in 30- and 90-day all-cause mortalities of critically ill patients with CHF compared with decreased SAG (tertile 3 versus tertile 1: adjusted hazard ratio, 95% confidence interval: 1.74, 1.46-2.08; 1.53, 1.32-1.77). Subgroup analysis indicated that the association between SAG and all-cause mortality presented similarities in most strata. CONCLUSION: SAG at admission could be a promising predictor of all-cause mortality in critically ill patients with CHF.

Admission base deficit is superior to lactate in identifying shock and resuscitative needs in trauma patients.

BACKGROUND: Base Deficit (BD) and lactate have been used as indicators of shock and resuscitation. This study was done to evaluate the utility of BD and lactate in identifying shock and resuscitative needs in trauma patients. METHODS: A prospective observational study was performed from 3/2014-12/2018. Data included demographics, admission systolic BP, ISS, BD, lactate, blood transfusion, and outcomes. BD and lactate were modeled continuously and categorically and compared. RESULTS: 2271 patients were included. BD and lactate were moderately correlated (r2 = 0.63 p < 0.001). On univariate regression, BD and lactate were associated with transfusion requirement and mortality (p < 0.001), but on multivariate regression, only BD was associated with transfusion requirement and mortality (OR = 1.2, p < 0.001; OR = 1.1, p < 0.001, respectively). BD discriminated better than lactate for hypotension, higher ISS, increased transfusion requirements and mortality. CONCLUSIONS: Admission BD and lactate levels are correlated following injury, but BD is superior to lactate in identifying shock, resuscitative needs and mortality in severely injured trauma patients.

Relationship Between Partial Carbon Dioxide Pressure and Strong Ions in Humans: A Retrospective Study.

Little is known about the role of a strong ions in humans with respiratory abnormalities. In this study, we investigated the associations between partial carbon dioxide pressure (pCO2) and each of sodium ion (Na+) concentrations, chloride ion (Cl-) concentrations and their difference (SIDNa-Cl). Blood gas data were obtained from patients in a teaching hospital intensive care unit between August 2013 and January 2017. The association between pCO2 and SIDNa-Cl was defined as the primary outcome. The associations between pCO2 and [Cl-], [Na+] and other strong ions were secondary outcomes. pCO2 was stratified into 10 mmHg-wide bands and treated as a categorical variable for comparison. As a result, we reviewed 115,936 blood gas data points from 3,840 different ICU stays. There were significant differences in SIDNa-Cl, [Cl-], and [Na+] among all categorized pCO2 bands. The respective pCO2 SIDNa-Cl, [Cl-], and [Na+] correlation coefficients were 0.48, -0.31, and 0.08. SIDNa-Cl increased and [Cl-] decreased with pCO2, with little relationship between pCO2 and [Na+] across subsets. In conclusion, we found relatively strong correlations between pCO2 and SIDNa-Cl in the multiple blood gas datasets examined. Correlations between pCO2 and chloride concentrations, but not sodium concentrations, were further found to be moderate in these ICU data.

Serum anion gap at admission as a predictor of the survival of patients with paraquat poisoning: A retrospective analysis.

Paraquat (PQ) poisoning is associated with high mortality rate. Therefore, an accurate method for predicting the survival of patients with PQ poisoning is required. This study evaluated the value of serum anion gap (AG) at admission in predicting the survival of such patients.Cases of patients with PQ poisoning admitted to Cangzhou Central Hospital between May 2012 and March 2019 were retrospectively analyzed. The patients were classified into survival and nonsurvival groups on the basis of their 90-day prognosis. Correlation analysis, Cox regression analysis, and receiver operating characteristic and Kaplan-Meier curve analyses were performed to assess the value of AG in predicting the 90-day survival of patients with PQ poisoning.Only 44 of the 108 patients with PQ poisoning survived; thus, the 90-day survival was 40.74%. AG levels at admission were significantly higher in nonsurvivors (26.53 ±â€Š4.93 mmol/L) than in survivors (20.88 ±â€Š2.74 mmol/L) (P < .001) and negatively correlated with 90-day survival (r = -0.557; P < .001). Cox regression analysis revealed that AG at admission is an independent prognostic marker of the 90-day survival of patients with PQ poisoning. AG level at admission had an area under the receiver operating characteristic curve of 0.836 (95% confidence interval: 0.763-0.909) and an optimal cut-off value of 25.5 mmol/L (59.4% sensitivity and 95.5% specificity).AG level at admission may serve as a candidate marker for predicting the survival of patients with PQ poisoning.

Interpreting Anion Gap Values in Adult and Pediatric Patients: Examining the Reference Interval.

BACKGROUND: The anion gap is primarily used in the diagnosis of acid-base disorders. We conducted a study to determine the anion gap reference interval in our patient population, investigated the workup of abnormal vs normal anion gaps, and examined the anion gap variation upon repeated testing. METHODS: A retrospective review was performed on 17137 adult and pediatric patients who presented to Yale-New Haven Hospital outpatient clinics, emergency department, or intensive care units between 2012 and 2017. RESULTS: We derived a new reference interval of 7 to 18 mmol/L with a median of 13 mmol/L in healthy adults with no significant differences owing to partitioning by sex or age. Based on the new reference interval, 5%, 23%, and 18% of healthy, emergency department, and intensive care unit adult patients, respectively, were misclassified as having high values with the previous interval of 6 to 16 mmol/L. However, there were no significant differences in the number of tests ordered in patients with anion gaps above and below the upper limit of the previous reference interval. The majority of increased anion gaps that were repeated normalized by 12 h. In a subgroup of healthy adult patients with annual testing, the median percent change in each patient's anion gap from 2015 to 2016 was approximately 13%. CONCLUSIONS: The anion gap should be used with an appropriate reference interval to avoid misclassification. There may be a moderate degree of individuality that argues for comparing the anion gap with its baseline value in the same patient pending further studies that formally derive its biological variation.

Electrolyte and acid-base disorders in cancer patients and its impact on clinical outcomes: evidence from a real-world study in China.

Background: This study aims to delineate the incidence of electrolyte and acid-base disorders (EAD) in cancer patients, to figure out the risk factors of EAD, then to assess the impact of EAD on patients' in-hospital clinical outcomes.Methods: Patients with the diagnosis of malignancies hospitalized during 1 October 2014 and 30 September 2015 were recruited in Zhongshan Hospital, Fudan University in Shanghai of China. Demographic characteristics, comorbidities, and clinical data, including survival, length of stay and hospital cost, were extracted from the electronic medical record system. Electrolyte and acid-base data were acquired from the hospital laboratory database.Results: Of 25,881 cancer patients with electrolyte data, 15,000 (58.0%) cases had at least one electrolyte and acid-base abnormity. Hypocalcemia (27.8%) was the most common electrolyte disorder, followed by hypophosphatemia (26.7%), hypochloremia (24.5%) and hyponatremia (22.5%). The incidence of simple metabolic acidosis (MAC) and metabolic alkalosis (MAL) was 12.8% and 22.1% respectively. Patients with mixed metabolic acid-base disorders (MAC + MAL) accounted for 30.2%. Lower BMI score, preexisting hypertension and diabetes, renal dysfunction, receiving surgery/chemotherapy, anemia and hypoalbuminemia were screened out as the major risk factors of EAD. In-hospital mortality in patients with EAD was 2.1% as compared to those with normal electrolytes (0.3%). The risk of death significantly increased among patients with severe EAD. Similarly, the length of stay and hospital cost also tripled as the number and grade of EAD increased.Conclusion: EAD is commonly encountered in cancer patients and associated with an ominous prognosis. Patients with comorbidities, renal/liver dysfunction, and anti-tumor therapy have a higher risk of EAD. Regular monitoring of electrolytes, optimum regimen for intravenous infusion, timely correction of modifiable factors and appropriate management of EAD should not be neglected during anti-tumor treatment.

The effects of severe hemoconcentration on acid-base equilibrium in critically ill patients: the forgotten role of buffers in whole blood.

PURPOSE: Idiopathic Systemic Capillary Leak Syndrome (ISCLS) is a paroxysmal permeability disorder characterized by abrupt onset of shock and hemoconcentration due to massive shift of fluids and proteins from the intravascular to the interstitial compartment. We hypothesize that increased hemoglobin concentration has a pivotal role in the acid-base imbalance during life-threatening crises. MATERIALS AND METHODS: Analysis of the acid-base balance fluctuations during six severe ISCLS flares admitted to ICU of a referral center for ISCLS. RESULTS: Acid-base equilibrium was assessed for plasma and the whole blood by single and multicompartmental models. The acute phase of ISCLS was characterized by shock, hypoalbuminemia, severe hemoconcentration, and acidosis. The physical-chemical approach for plasma found a remarkable component of unmeasured anions (SIG) during the acute phase. After correction of the physical-chemical model for the whole blood, the SIG variations disappeared because the buffer role of hemoglobin was relevant. CONCLUSION: Hemoglobin has a remarkable role in buffering metabolic acidosis during the shock phase of ISCLS. In these circumstances, the assessment of acid-base equilibrium in plasma alone may overestimate unmeasured anions. On the contrary, the physical-chemical model corrected for whole blood better explains the metabolic component of acid-base imbalance when marked shift of hemoglobin concentration occurs.

A Delphi Analysis to Reach Consensus on Preoperative Care in Infants with Hypertrophic Pyloric Stenosis.

INTRODUCTION: Infantile hypertrophic pyloric stenosis (IHPS) is a common gastrointestinal condition that can lead to metabolic alkalosis and, if uncorrected, to respiratory complications. A standardized approach to correct metabolic derangements and dehydration may reduce time until pyloromyotomy while preventing potential respiratory complications. Such an evidence-based policy regarding preoperative care is absent. We aim to formulate a recommendation about preoperative care for infants with IHPS using the Delphi technique. MATERIALS AND METHODS: The RAND/UCLA appropriateness method was used to reach international consensus in a panel of pediatric surgeons, pediatric anesthetists, and pediatricians. Statements on type and frequency of blood sampling, required serum concentrations before pyloromyotomy and intravenous fluid therapy, were rated online using a 9-point Likert scale. Consensus was present if the panel rated the statement appropriate/obligatory (panel median: 7-9) or inappropriate/unnecessary (panel median: 1-3) without disagreement according to the interpercentile range adjusted for symmetry formula. RESULTS: Thirty-three and twenty-nine panel members completed the first and second round, respectively. Consensus was reached in 54/74 statements (73%). The panel recommended the following laboratory tests and corresponding cutoff values prior to pyloromyotomy: pH ≤7.45, base excess ≤3.5, bicarbonate <26 mmol/L, sodium ≥132 mmol/L, potassium ≥3.5 mmol/L, chloride ≥100 mmol/L, and glucose ≥4.0 mmol/L. Isotonic crystalloid with 5% dextrose and 10 to 20 mEq/L potassium should be used for fluid resuscitation. CONCLUSION: Consensus is reached in an expert panel about assessment of metabolic derangements at admission, cutoff serum concentrations to be achieved prior to pyloromyotomy, and appropriate intravenous fluid regime for the correction of dehydration and metabolic derangements in infants with IHPS.

Association of serum chloride level alterations with in-hospital mortality.

BACKGROUND: We aimed to assess the association between alterations in serum chloride levels during hospitalisation and mortality. METHODS: We reviewed all adult patients admitted to our hospital from the year 2009 to 2013, who had at least two serum chloride measurements during hospitalisation. The serum chloride change during hospitalisation, defined as the absolute difference between the highest and lowest serum chloride levels, was categorised into seven groups; 0-2, 3-4, 5-6, 7-8, 9-10, 11-12 and ≥13 mEq/L. Multivariable logistic regression was performed to assess the independent association between serum chloride change and in-hospital mortality, using the serum chloride change of 0-2 mEq/L as the reference group. RESULTS: A total of 57 880 patients, with median serum chloride change of 5 (IQR 3-9) mEq/L, were studied. The in-hospital mortality was progressively increased with larger chloride change, from 0.6% in group of 0-2 mEq/L to 5.9% in group of ≥13 mEq/L (p<0.001). In adjusted analysis, serum chloride change of ≥7 mEq/L was significantly associated with increased in-hospital mortality. For upward trend, serum chloride change of ≥3 mEq/L was significantly associated with increased in-hospital mortality, whereas, for downward trend, serum chloride change was not consistently associated with in-hospital mortality. CONCLUSION: Alterations in serum chloride during hospitalisation were associated with increased hospital mortality. The association was more prominent with upward than downward trend of serum chloride.