Utilization and Efficacy of Resuscitation Endpoints in Trauma and Burn Patients: A Review Article

Shock is a sequelae in trauma and burn patients that substantially increases the risk for morbidity and mortality. The use of resuscitation endpoints allows for improved management of these patients, with the potential to prevent further morbidity/mortality. We conducted a review of the current literature on the efficacy of hemodynamic, metabolic, and regional resuscitation endpoints for use in trauma and burn patients. Hemodynamic endpoints included mean arterial pressure (MAP), heart rate (HR), urinary output (UO), compensatory reserve index (CRI), intrathoracic blood volume, and stroke volume variation (SVV). Metabolic endpoints measure cellular responses to decreased oxygen delivery and include serum lactic acid (LA), base deficit (BD), bicarbonate, anion gap, apparent strong ion difference, and serum pH. Mean arterial pressure, HR, UO, and LA are the most established markers of trauma and burn resuscitation. The evidence suggests LA is a superior metabolic endpoint marker. Newer resuscitation endpoint technologies such as point-of-care ultrasound (PoCUS), thromboelastography (TEG), and rotational thromboelastometry (ROTEM) may improve patient outcomes; however, additional research is needed to establish the efficacy in trauma and burn patients. The endpoints discussed have situational strengths and weaknesses and no single universal resuscitation endpoint has yet emerged. This review may increase knowledge and aid in guideline development. We recommend clinicians continue to integrate multiple endpoints with emphasis on MAP, HR, UO, LA, and BD. Future investigation should aim to standardize endpoints for each clinical presentation. The search for universal and novel resuscitation parameters in trauma and burns should also continue.

Electrolyte Concentrations and Blood Gas Values in Neonatal Calves With Diarrhea

Portable blood analyzers, which recently have been introduced to veterinary medicine, can facilitate immediate identification of sick calves in livestock farms. However, no appropriate standard values exist for neonatal calves; therefore, reference values for adult cattle guide diagnosis and treatment of newborn calves. Our goal was to determine electrolyte, blood chemistry, and blood gas values from healthy calves and compare them to those for diarrheic calves, thus providing useful information for diagnosis and prognosis. We evaluated 193 calves (£1 month old), including those with (n = 88) and without diarrhea (n = 105), using two-tailed, independent t tests after determining normality (Shapiro−Wilk test). Electrolyte measurements in the diarrheic calves included significant decreases in sodium and significant increases in potassium, chloride, and blood urea nitrogen. Strong ion difference (SID), pH, bicarbonate, partial pressure of carbon dioxide, and base excess (BE) were significantly lower in the diarrheic calves (p < 0.001); the anion gap (AG) was significantly higher among diarrheic calves aged 1-10 days (p < 0.001) compared to healthy calves. Our results demonstrate that SID, pH, bicarbonate, and BE correlated strongly with metabolic acidosis, suggesting that these indicators, including AG, can be important tools for evaluating calves’ health status and for providing useful information to diagnose diarrhea.

The time to peak blood bicarbonate (HCO3–), pH, and the strong ion difference (SID) following sodium bicarbonate (NaHCO3) ingestion in highly trained adolescent swimmers

The timing of sodium bicarbonate (NaHCO3) supplementation has been suggested to be most optimal when coincided with a personal time that bicarbonate (HCO3–) or pH peaks in the blood following ingestion. However, the ergogenic mechanisms supporting this ingestion strategy are strongly contested. It is therefore plausible that NaHCO3 may be ergogenic by causing beneficial shifts in the strong ion difference (SID), though the time course of this blood acid base balance variable is yet to be investigated. Twelve highly trained, adolescent swimmers (age: 15.9 ± 1.0 years, body mass: 65.3 ± 9.6 kg) consumed their typical pre-competition nutrition 1–3 hours before ingesting 0.3 g∙kg BM-1 NaHCO3 in gelatine capsules. Capillary blood samples were then taken during seated rest on nine occasions (0, 60, 75, 90, 105, 120, 135, 150, 165 min post-ingestion) to identify the time course changes in HCO3–, pH, and the SID. No significant differences were found in the time to peak of each blood measure (HCO3–: 130 ± 35 min, pH: 120 ± 38 min, SID: 98 ± 37 min; p = 0.08); however, a large effect size was calculated between time to peak HCO3– and the SID (g = 0.88). Considering that a difference between time to peak blood HCO3– and the SID was identified in adolescents, future research should compare the ergogenic effects of these two individualized NaHCO3 ingestion strategies compared to a traditional, standardized approach.

Low non-carbonic buffer power amplifies acute respiratory acid-base disorders in septic patients: an in-vitro study

Rationale: Septic patients have typically reduced concentrations of hemoglobin and albumin, the major components of non-carbonic buffer power(β). This could expose patients to high pH variations during acid-base disorders. Objectives: To compare, in-vitro, non-carbonic β of septic patients with that of healthy volunteers, and evaluate its distinct components. Methods: Whole blood and isolated plasma of 18 septic patients and 18 controls were equilibrated with different CO2 mixtures. Blood gases, pH and electrolytes were measured. Non-carbonic β and non-carbonic β due to variations in Strong Ion Difference (βSID) were calculated for whole blood. Non-carbonic β and non-carbonic β normalized for albumin concentrations (βNORM) were calculated for isolated plasma. Representative values at pH=7.40 were compared. Albumin proteoforms were evaluated via two-dimensional electrophoresis. Measurements and Main Results: Hemoglobin and albumin concentrations were significantly lower in septic patients. Septic patients had lower non-carbonic β both of whole blood (22.0±1.9 vs. 31.6±2.1 mmol/L, p<0.01) and plasma (0.5±1.0 vs. 3.7±0.8 mmol/L, p<0.01). Non-carbonic βSID was lower in patients (16.8±1.9 vs. 24.4±1.9 mmol/L, p<0.01) and strongly correlated with hemoglobin concentration (r=0.94, p<0.01). Non-carbonic βNORM was lower in patients (0.01 [-0.01 - 0.04] vs. 0.08 [0.06 - 0.09] mmol/g, p<0.01). Septic patients and controls showed different amounts of albumin proteoforms. Conclusions: Septic patients are exposed to higher pH variations for any given change in CO2 due to lower concentrations of non-carbonic buffers and, possibly, an altered buffering function of albumin. In both septic patients and healthy controls, electrolyte shifts are the major buffering mechanism during respiratory acid-base disorders.

Does varying the ingestion period of sodium citrate influence blood alkalosis and gastrointestinal symptoms?

Objectives To compare blood alkalosis, gastrointestinal symptoms and indicators of strong ion difference after ingestion of 500 mg.kg-1 BM sodium citrate over four different periods. Methods Sixteen healthy and active participants ingested 500 mg.kg-1 BM sodium citrate in gelatine capsules over a 15, 30, 45 or 60 min period using a randomized cross-over experimental design. Gastrointestinal symptoms questionnaires and venous blood samples were collected before ingestion, immediately post-ingestion, and every 30 min for 480 min post-ingestion. Blood samples were analysed for blood pH, [HCO3-], [Na+], [Cl-] and plasma [citrate]. Linear mixed models were used to estimate the effect of the ingestion protocols. Results For all treatments, blood [HCO3-] was significantly elevated above baseline for the entire 480 min post-ingestion period, and peak occurred 180 min post-ingestion. Blood [HCO3-] and pH were significantly elevated above baseline and not significantly below the peak between 150–270 min post-ingestion. Furthermore, blood pH and [HCO3-] were significantly lower for the 60 min ingestion period when compared to the other treatments. Gastrointestinal symptoms were minor for all treatments; the mean total session symptoms ratings (all times summed together) were between 9.8 and 11.6 from a maximum possible rating of 720. Conclusion Based on the findings of this investigation, sodium citrate should be ingested over a period of less than 60 min (15, 30 or 45 min), and completed 150–270 min before exercise.

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.

The time to peak blood bicarbonate (HCO3–), pH, and strong ion difference (SID) following sodium bicarbonate (NaHCO3) ingestion in highly trained adolescent swimmers

Background: Contemporary research suggests that the optimal timing of sodium bicarbonate (NaHCO 3 ) should be based upon an individual time in which bicarbonate (HCO 3 – ) or pH peaks within the blood. However, the mechanisms surrounding acidosis on exercise performance are contested, therefore it is plausible that the ergogenic effects of NaHCO 3 are instead a result of an increased strong ion difference (SID) following ingestion. Since the post-ingestion time course of the SID is currently unknown, the purpose of this study was to investigate the pharmacokinetics of the SID in direct comparison to HCO 3 – and pH. Methods: Twelve highly trained, adolescent swimmers (age: 15.9 ± 1.0 yrs, body mass: 65.3 ± 9.6 kg) consumed their typical pre-competition nutrition before ingesting 0.3 g?kg BM -1 NaHCO 3 in gelatine capsules. Capillary blood samples were then taken during quiet, seated rest on nine occasions (0, 60, 75, 90, 105, 120, 135, 150, and 165 min post-ingestion) for the assessment of time course changes in HCO 3 – , pH, and the SID. Results: On a group mean level, no differences were found in the time in which each variable peaked within the blood (HCO 3 – = 130 ± 35 min, pH = 120 ± 38 min, SID = 96 ± 35 min; p = 0.06). A large effect size was calculated between the timing of peak HCO 3 – and the SID ( g = 0.91), however, suggesting that a difference may occur between these two measures in practice. Conclusions: A time difference between peak HCO 3 – and the SID presents an interesting avenue for further research since an approach based upon individual increases in extracellular SID has yet to be investigated. Future studies should therefore compare these dosing strategies directly to elucidate whether either one is more ergogenic for exercise performance.