Early pH change predicts intensive care unit mortality

Abstract

Aim of the Study:Metabolic acidosis is associated with increased mortality in critically ill patients. We hypothesized that early correction of acidosis of presumed metabolic origin results in improved outcomes.Patients and Methods:We conducted a prospective, observational study from February 2015 to June 2016 in a 12 bed mixed intensive care unit (ICU) of a 1000 bed tertiary care hospital in the north of India. ICU patients aged above 18 years with an admission pH ≥7.0 to <7.35 of presumed metabolic origin were included. Arterial blood gas parameters including pH, PaO2, PaCO2, HCO3−, Na+, K+, Cl−, anion gap (AG), base excess, and lactate at 0, 6, and 24 h along with other standard laboratory investigations were recorded. The primary outcome was to assess the impact of early pH changes on mortality at day 28 of ICU.Results:A total of 104 patients with 60.6% males and 91.3% medical patients were included in the study. Sepsis of lung origin (60.6%) was the predominant etiology. By day 28, 68 (65.4%) patients had died. Median age was 49.5 years, weight 61.7 kg, Sequential Organ Failure Assessment, and Acute Physiologic and Chronic Health Evaluation II scores were 16 and 12, respectively. Nonsurvivors had a higher vasopressor index (P < 0.01), lactate and central venous oxygen saturation (P < 0.05), and lower pH (P < 0.05). A pH correction/change of ≥1.16% during the first 24 h had the best receiver operating characteristic for predicting survival at day 28, with area under the curve (95% confidence interval, 0.72 [0.62–0.82], P < 0.05) compared to HCO3-, BE, lactate, and AG.Conclusions:Metabolic acidosis is associated with higher mortality in ICU. The rate of change in pH may better predict ICU mortality than other metabolic indices.

A voltammetric pH sensor for food and biological matrices

“…The value of pH has a diagnostic value and is useful for the management of a number pathologies [9][10][11]. In particular, blood pH may be used as a marker of organs failure [12], to understand the evolution of chronic wounds [13][14][15], and as an outcome predictor of Intensive Care Unit patients suffering from acid-base disorders [16]. The value of pH is also measured in saliva and urine, since it has been found to be associated to dental plaque and oral cavity health [17,18], ongoing infections [19], renal fatigue [20] and metabolic syndrome [20].…”

Long-Term Outcome of Severe Metabolic Acidemia in ICU Patients, a BICAR-ICU Trial Post Hoc Analysis

“…Acidemia is a well-known predictor for ICU mortality (5, 30, 31), yet it remains unclear whether increased mortality in patients with severe acidemia reflects the severity of the pathology causing acidemia or whether acidemia per se contributes to mortality (32, 33).…”

PATNet: Propensity-Adjusted Temporal Network for Joint Imputation and Prediction Using Binary EHRs With Observation Bias

“…The most heavily missing features include abnormal laboratory test results of blood pH (100% missing), blood glucose (86% missing), blood RDW (79% missing), blood hemoglobin (69% missing), blood pO2 (74% missing) and blood pCO2 (88% missing). All of them have been shown closely related to mortality in ICU [51], [52], [53]. With these important predictors heavily missing, the patient is predicted to have a mortality probability of 0.05.…”