Elevated K/iCa ratio is an ancillary predictor for mortality in patients with severe hemorrhage: A decision tree analysis

Benefit of balance? Odds of survival by unit transfused: Retrospective analysis of the ACS-TQIP database

BACKGROUND

The critical blood shortage in January 2022 threatened the availability of blood. Utility of transfusion per unit was reported in a previous study, revealing patients receiving balanced transfusion are more likely to die after 16 units of packed red blood cells. We aimed to validate this study using a larger database.

METHODS

Retrospective analysis utilizing the American College of Surgeons Trauma Quality Improvement Program was performed. Trauma patients aged ≥16 receiving transfusion within 4 hours of arrival were included and excluded if they died in the emergency department, received <2 units of packed red blood cells, did not receive fresh frozen plasma, or were missing data. Primary outcome was mortality. Subgroups were balanced transfusion if receiving ≤2:1 ratio of packed red blood cells:fresh frozen plasma, and unbalanced transfusion if >2:1 ratio.

RESULTS

A total of 17,047 patients were evaluated with 28% mortality (4,822/17,408). Multivariable logistic regression identified advancing age (odds ratio 1.03 95% confidence interval 1.03-1.04), higher ISS (odds ratio 1.04, 95% confidence interval 1.03-1.04), and lower GCS (odds ratio 0.82, 95% confidence interval 0.82-0.83) as risk factors for mortality. Protective factors were balanced transfusion (odds ratio 0.81 95% confidence interval 0.71-0.93), male sex (odds ratio 0.90, 95% confidence interval 0.81-0.99), and blunt mechanism (odds ratio 0.74, 95% confidence interval 0.67-0.81). At 11 units of packed red blood cells, balanced transfusion patients were more likely to die (odds ratio 0.88, 95% confidence interval 0.80-0.98). Balanced transfusion patients survived at a higher rate for each unit of packed red blood cells, between 6 and 23 units of packed red blood cells.

CONCLUSION

Mortality increases with each unit of packed red blood cell transfused. At 11 units of packed red blood cells, mortality is the more likely outcome. Balanced transfusion improves the chance of survival through 23 units of packed red blood cells.

Hypocalcaemia upon arrival (HUA) in trauma patients who did and did not receive prehospital blood products: a systematic review and meta-analysis

PURPOSE

Hypocalcaemia upon arrival (HUA) to hospital is associated with morbidity and mortality in the trauma patient. It has been hypothesised that there is an increased incidence of HUA in patients receiving prehospital transfusion as a result of citrated blood products. This research aimed to determine if there was a difference in arrival ionised calcium (iCa) levels in trauma patients who did and did not receive prehospital transfusion.

METHODS

We conducted a systematic review and meta-analysis of patients with an Injury Severity Score (ISS) > / = 15 and an iCa measured on hospital arrival. We then derived mean iCa levels and attempted to compare between-group variables across multiple study cohorts.

RESULTS

Nine studies reported iCa on arrival to ED, with a mean of 1.08 mmol/L (95% CI 1.02-1.13; I2 = 99%; 2087 patients). Subgroup analysis of patients who did not receive prehospital transfusion had a mean iCa of 1.07 mmol/L (95% CI 1.01-1.14; I2 = 99%, 1661 patients). Transfused patients in the 3 comparative studies had a slightly lower iCa on arrival compared to those who did not receive transfusion (mean difference - 0.03 mmol/L, 95% CI - 0.04 to - 0.03, I2 = 0%, p = 0.001, 561 patients).

CONCLUSION

HUA is common amongst trauma patients irrespective of transfusion. Transfused patients had a slightly lower initial iCa than those without transfusion, though the clinical impact of this remains to be clarified. These findings question the paradigm of citrate-induced hypocalcaemia alone in trauma. There is a need for consensus for the definition of hypocalcaemia to provide a basis for future research into the role of calcium supplementation in trauma.

PROSPECTIVE EXAMINATION OF THE K/ICA RATIO AS A PREDICTOR FOR MORTALITY IN SEVERE HEMORRHAGE

ABSTRACT

Background: Patients receiving massive transfusion protocol (MTP) are at risk for posttransfusion hypocalcemia and hyperkalemia. Previous retrospective analysis has suggested the potassium/ionized calcium (K/iCa) ratio as a prognostic indicator of mortality. This prospective study sought to validate the value of the K/iCa ratio as a predictor for mortality in patients receiving MTP. Methods: This was a prospective analysis of adult trauma patients who underwent MTP activation from May 2019 to March 2021 at an urban level 1 trauma center. Serum potassium and iCa levels within 0 to 1 h of MTP initiation were used to obtain K/iCa. Receiver operator characteristic curve analysis assessed predictive capacity of K/iCa on mortality. Kaplan-Meier survival analysis and Cox regression examined the effect of K/iCa ratio on survival. Results: A total of 110 of 300 MTP activation patients met inclusion criteria. Overall mortality rate was 31.8%. No significant differences between the elevated K/iCa and lower K/iCa groups were found for prehospital or emergency department initial vitals, shock index, or injury severity. However, nonsurvivors had a significantly higher median K/iCa ratio compared with those who survived ( P < 0.01). Multivariable logistic regression revealed the total number of blood products to be significantly associated with elevated K/iCa (odds ratio, 1.02; 95% CI, 1.01-1.04; P = 0.01). The Kaplan Meier survival curve demonstrated a significantly increased rate of survival for those with an elevated K/iCa ratio ( P < 0.01). Multivariable Cox regression adjusted for confounders showed a significant association between K/iCa and mortality (Hazard Ratio, 4.12; 95% CI, 1.89-8.96; P < 0.001). Conclusion: This evidence further highlights the importance of the K/iCa ratio in predicting mortality among trauma patients receiving MTP. Furthermore, it demonstrates that posttransfusion K levels along with iCa levels should be carefully monitored in the MTP setting. Level of Evidence: Level II. Study Type: Prognostic/epidemiological.

Artificial intelligence in emergency medicine. A systematic literature review

Motivation and objective: Emergency medicine is becoming a popular application area for artificial intelligence methods but remains less investigated than other healthcare branches. The need for time-sensitive decision-making on the basis of high data volumes makes the use of quantitative technologies inevitable. However, the specifics of healthcare regulations impose strict requirements for such applications. Published contributions cover separate parts of emergency medicine and use disparate data and algorithms. This study aims to systematize the relevant contributions, investigate the main obstacles to artificial intelligence applications in emergency medicine, and propose directions for further studies.

METHODS

The contributions selection process was conducted with systematic electronic databases querying and filtering with respect to established exclusion criteria. Among the 380 papers gathered from IEEE Xplore, ACM Digital Library, Springer Library, ScienceDirect, and Nature databases 116 were considered to be a part of the survey. The main features of the selected papers are the focus on emergency medicine and the use of machine learning or deep learning algorithms.

FINDINGS AND DISCUSSION

The selected papers were classified into two branches: diagnostics-specific and triage-specific. The former ones are focused on either diagnosis prediction or decision support. The latter covers such applications as mortality, outcome, admission prediction, condition severity estimation, and urgent care prediction. The observed contributions are highly specialized within a single disease or medical operation and often use privately collected retrospective data, making them incomparable. These and other issues can be addressed by creating an end-to-end solution based on human-machine interaction.

CONCLUSION

Artificial intelligence applications are finding their place in emergency medicine, while most of the corresponding studies remain isolated and lack higher generalization and more sophisticated methodology, which can be a matter of forthcoming improvements.

Biochemical disturbance in damage control resuscitation: mechanisms, management and prognostic utility

PURPOSE OF REVIEW

With advances in resuscitative techniques, trauma patients are surviving increasingly severe injuries and physiological insult. Timely recognition of futility remains important in terms of patient dignity and resource preservation yet is increasingly challenging in the face of these advances. The understanding of biochemical derangement from pathophysiological processes of trauma and iatrogenic effects of resuscitation has expanded recently.

RECENT FINDINGS

Acidosis and hypocalcaemia have been recognized as important contributors to mortality among trauma patients. Although less well recognized and studied, critical injury and high blood product volume resuscitation render patients vulnerable to life-threatening hyperkalaemia. The methods of correcting disruptions to acid-base and electrolyte homeostasis during damage control resuscitation have changed little recently and often rely on evidence from undifferentiated populations. Biochemical disturbances have value as ancillary predictors of futility in trauma resuscitation.

SUMMARY

These findings will contribute to a greater understanding among anaesthesiologists of the causative mechanisms and effects of biochemical derangement after severe injury and aid them in the delivery of well tolerated and effective damage control resuscitation. Gaps in the evidence base are highlighted to encourage future work.

Tulane STAR (Sending Texts, Advancing Results): impact of text messaging on bariatric post-operative protocol compliance

BACKGROUND

Text messaging is frequently employed in the outpatient setting to communicate with or send reminders to patients. However, there is a paucity of literature on the impact of text messaging on inpatient care. In this study, the use of text messaging in hospitalized patients is evaluated by assessing patient compliance to a post-operative bariatric protocol.

METHODS

This was a randomized controlled trial that studied compliance to a post-operative bariatric protocol in patients who underwent bariatric surgery at a tertiary, academic medical center between February and May 2021. Patients were randomized to either the control group, in which they received standard post-operative education alone or the Tulane Sending Texts, Advancing Results (STAR) intervention arm, in which participants received the same post-operative education along with two text message reminders to drink water, use their incentive spirometers, and ambulate (per post-operative instructions) on post-operative day (POD) # 0 and POD # 1. The primary outcome was compliance with the protocol, defined as the number of 1-oz cups of water consumed, incentive spirometry usage, and ambulation frequency and distance. Secondary outcomes include length of stay and complications.

RESULTS

A total of 35 patients were enrolled in the study (17 control, 18 STAR intervention). There was no significant difference in age, BMI, or type of surgery performed between the two groups. Clear liquid consumption was significantly higher in the STAR intervention group with an average of 27.7 ± 3.5 cups as compared to 18.2 ± 8.9 in the control group (p < 0.001). Similarly, statistically significant increases in incentive spirometry usage (p < 0.01) and ambulation distance and frequency (p < 0.02) were observed in the STAR intervention group.

CONCLUSIONS

While patients are in the hospital, text messaging can improve compliance to post-operative protocols. Peri-operative text messaging can enhance patient education and communication.