Resuscitative hyperkalemia in noncrush trauma: a prospective, observational study

Hyperkalaemia in bleeding trauma patients: A potential marker of disease severity - A retrospective cohort study

Background

Hyperkalaemia is a common electrolyte abnormality seen in critically ill patients. In haemorrhagic shock, it may contribute to cardiac arrest and has been identified as a potential marker for tissue hypoxia. However, the significance of its role in haemorrhagic shock and its contribution to mortality remains unclear. This study aimed to examine the potential underlying pathophysiology and evaluate the incidence and characteristics of patients with hyperkalaemia on hospital arrival in bleeding trauma patients before transfusions and its mortality.

Methods

A retrospective cohort study was conducted on adult patients with traumatic bleeding admitted to a European Major Trauma Centre between January 2016 and December 2021. Patients were classified according to their serum potassium levels on arrival, and relevant clinical parameters between non-hyperkalaemic and hyperkalaemic patients were compared.

Results

Among the 83 patients in this study, 8 (9.6 %) presented with hyperkalaemia on arrival. The median shock index showed a higher tendency in the hyperkalaemic group. Hyperkalaemia was found to be more common among younger patients who sustained penetrating trauma. Mortality rates were higher in the hyperkalaemic group, but the difference was not statistically significant.

Conclusion

Our results suggest that hyperkalaemia occurs frequently in bleeding trauma patients on hospital arrival pre-transfusions, indicating a more severe illness. Our findings provide insights into the pathophysiology and characteristics of hyperkalaemia in bleeding trauma patients. Further studies are required to investigate the mechanisms by which hyperkalaemia contributes to mortality in haemorrhagic shock patients.

K+ontrol rapidly and efficiently reduces potassium in donor blood during ex vivo circulation

BACKGROUND

Patients with kidney failure are at risk for lethal complications from hyperkalemia. Resuscitation, medications, and hemodialysis are used to mitigate increased potassium (K+) levels in circulating blood; however, these approaches may not always be readily available or effective, especially in a resource limited environment. We tested a sorbent cartridge (KC, K+ontrol CytoSorbents Medical Inc., Monmouth Junction, New Jersey) which contains a resin adsorber for K+. The objective of this study was to test the utility of KC in an ex vivo circulation system. We hypothesized that KC reduces K+ levels in extracorporeal circulation of donor swine whole blood infused with KCl.

METHODS

A six-hour circulation study was carried out using KC, a NxStage (NxStage Medical, Inc., Lawrence, MA) membrane, blood bag containing heparinized whole blood with KCl infusion, 3/16-inch ID tubing, a peristaltic pump, and flow sensors. The NxStage permeate line was connected back to the main circuit in the Control group (n = 6), creating a recirculation loop. For KC group (n = 6), KC was added to the recirculation loop, and a continuous infusion of KCl at 10 mEq/hour was administered for two hours. Blood samples were acquired at baseline and every hour for 6 h.

RESULTS

In the control group, K+ levels remained at ∼9 mmol/L; 9.1 ± 0.4 mmol/L at 6 h. In the KC group, significant decreases in K+ at hour 1 (4.3 ± 0.3 mmol/L) and were sustained for the experiment duration equilibrating at 4.6 ± 0.4 mmol/L after 6 h (p = 0.042). Main loop blood flow was maintained under 400 mL/min; recirculation loop flow varied between 60 and 70 mL/min in the control group and 45-55 mL/min in the KC group. Decreases in recirculation loop flow in KC group required 7% increase of pump RPM.

CONCLUSIONS

During ex-vivo extracorporeal circulation using donor swine blood, KC removed approximately 50% of K+, normalizing circulating levels.

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.

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.

Routine laboratory parameters predict intensive care unit admission and hospitalization in patients suffering stab injuries

Background

Knife crime has increased considerably in recent years in Northern Europe. Affected patients often require immediate surgical care due to traumatic organ injury. Yet, little is known about clinically relevant routine laboratory parameters in stab injury patients and how these are associated with intensive care unit (ICU) admission, hospitalization and number of surgeries.

Methods

We retrospectively analyzed 258 stab injury cases between July 2015 and December 2021 at an urban Level I Trauma Center. Annual and seasonal incidences, injury site, injury mechanism, Injury Severity Score (ISS), and surgical management were evaluated. First, correlations between routine laboratory parameters for hematology, coagulation, and serum biochemistry (peak, and Δ (change from admission to peak within 3 days following admission)) and length of hospital stay, ICU stay, and number of surgeries were assessed using Spearman's rank correlation coefficients. Second, multivariable Least Absolute Shrinkage and Selection Operator (LASSO) regression analyses were conducted to identify parameters predictive of clinical outcomes. Third, longitudinal developments of routine laboratory parameters were assessed during hospital admission.

Results

In 2021, significantly more stab injuries were recorded compared with previous years and occurred less during winter compared with other seasons. Mean ISS was 8.3 ± 7.3, and ISS was positively correlated with length of hospital and ICU stay (r = 0.5-0.8, p < 0.001). Aspartate transaminase (AST) (Δ) (r = 0.690), peak C-reactive protein (CrP) (r = 0.573), and erythrocyte count (Δ) (r = 0.526) showed the strongest positive correlations for length of ICU stay for penetrating, thoracoabdominal, and organ injuries, respectively. No correlations were observed between routine laboratory parameters and number of surgeries. For patients with penetrating injuries, LASSO-selected predictors of ICU admission included ISS, pH and lactate at admission, and Δ values for activated partial thromboplastin time (aPTT), K+, and erythrocyte count. CrP levels on day 3 were significantly higher in patients with penetrating (p = 0.005), thoracoabdominal (p = 0.041), and organ injuries (p < 0.001) compared with those without.

Conclusion

Our data demonstrate an increase in stab injury cases in 2021 and an important link between changes in routine laboratory parameters and ICU admission and hospitalization. Monitoring ISS and changes in AST, CrP, erythrocyte count, pH, lactate, aPTT, and K+ may be useful to identify patients at risk and adjust surgical and ICU algorithms early on.

Trauma-related electrolyte disturbances: From resuscitation to rhabdomyolysis

Traumatic injury results in drastic changes to a patient's normal physiology. The hormonal stress response, as well as some treatment strategies, lead to significant disruptions in electrolyte homeostasis that are important for clinicians to understand. In addition, advances in fluid resuscitation and modern transfusion practices have led to their own unique set of consequences, which we are just beginning to appreciate. Special attention is placed on rhabdomyolysis, as this distinct entity represents an extreme example of injury induced electrolyte derangements. This review describes the physiologic response to trauma and highlights some of the important electrolyte abnormalities that can be encountered while caring for the injured patient.

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

INTRODUCTION

Trauma patients receiving massive transfusion protocol (MTP) are at risk of citrate-induced hypocalcemia and hyperkalemia. Here we evaluate potassium (K), ionized calcium (iCa), and K/iCa ratio as predictors of mortality.

METHODS

This retrospective study includes all adult trauma patients who received MTP within 1 h at our level I trauma center between 2014 and 2019. Receiver operating characteristic curve analysis assessed predictive accuracy of K/iCa ratio at admission on 120-day mortality.

RESULTS

Of 614 patients, 146 received MTP within 1 h and 38 expired. Patients who expired had higher K/iCa ratio than survivors (median [IQR] = 5.7 [3.8-7.2] vs 3.7 [3.1-4.9], p < 0.001). Area under the curve of K/iCa was 0.72 (95%CI = 0.62-0.82, p < 0.001) with sensitivity = 63.2% and specificity = 77.6%. At the optimum K/iCa cutoff (5.07), patients with high ratios had 4 times higher mortality risk (HR = 3.97, 95%CI = 1.89-8.32, p < 0.001).

CONCLUSION

Elevated K/iCa ratio was an independent predictor of mortality in trauma patients managed with MTP.

Supplementation of taurine improves ionic homeostasis and mitochondrial function in the rats exhibiting post-traumatic stress disorder-like symptoms

RATIONALE

Current pharmacotherapy for post-traumatic stress disorder (PTSD) is limited to few antidepressants. Mitochondrial dysfunction is observed in PTSD, along with altered potassium homeostasis. Nutritional supplementation of taurine can improve ionic homeostasis and thereby treat PTSD-like symptoms in rats.

AIM

The purpose is to study the pharmacological effect of taurine in stress re-stress-induced PTSD in rats.

METHODS

As per protocol, animals were restrained for 2 h then exposed to footshock (FS) (2 mA/10 s) followed by halothane-induced anesthesia. Behavioral assessments such as elevated plus maze (EPM) and Y-maze tests were performed on days 2, 8, and 32 of experimental protocol after re-stress. In addition, daily oral administration of taurine (100, 200, and 300 mg/kg) and paroxetine (PAX) (10 mg/kg) was done from D-8 to D-32 followed by re-stress. The plasma concentration of taurine, corticosterone, and potassium was measured on Day-32 along with mitochondrial function in discrete brain regions.

RESULTS

Sub-chronic administration of taurine in high and medium doses significantly ameliorated PTSD-like symptoms such as hyperarousal, anxiety, and improved spatial recognition memory. Taurine in all doses restored the plasma concentration of corticosterone and potassium. SRS-induced alterations in mitochondrial bioenergetics, complex enzyme activities, and reduced mitochondrial membrane potential in different brain regions were ameliorated by taurine.

CONCLUSION

Nutritional supplementation of taurine improves potassium ionic homeostasis, mitochondrial function, and attenuated PTSD-like symptoms in SRS subjected rats.

Reperfusion repercussions: A review of the metabolic derangements following resuscitative endovascular balloon occlusion of the aorta

BACKGROUND

Current resuscitative endovascular balloon occlusion of the aorta (REBOA) literature focuses on improving outcomes through careful patient selection, diligent catheter placement, and expeditious definitive hemorrhage control. However, the detection and treatment of post-REBOA ischemia-reperfusion injury (IRI) remains an area for potential improvement. Herein, we provide a review of the metabolic derangements that we have encountered while managing post-REBOA IRI in past swine experiments. We also provide data-driven clinical recommendations to facilitate resuscitation post-REBOA deflation that may be translatable to humans.

METHODS

We retrospectively reviewed the laboratory data from 25 swine across three varying hemorrhagic shock models that were subjected to complete REBOA of either 45 minutes, 60 minutes, or 90 minutes. In each model the balloon was deflated gradually following definitive hemorrhage control. Animals were then subjected to whole blood transfusion and critical care with frequent electrolyte monitoring and treatment of derangements as necessary.

RESULTS

Plasma lactate peaked and pH nadired long after balloon deflation in all swine in the 45-minute, 60-minute, and 90-minute occlusion models (onset of peak lactate, 32.9 ± 6.35 minutes, 38.8 ± 10.55 minutes, and 49.5 ± 6.5 minutes; pH nadir, 4.3 ± 0.72 minutes, 26.9 ± 12.32 minutes, and 42 ± 7.45 minutes after balloon deflation in the 45-, 60-, and 90-minute occlusion models, respectively). All models displayed persistent hypoglycemia for more than an hour following reperfusion (92.1 ± 105.5 minutes, 125 ± 114.9 minutes, and 96 ± 97.8 minutes after balloon deflation in the 45-, 60-, and 90-minute occlusion groups, respectively). Hypocalcemia and hyperkalemia occurred in all three groups, with some animals requiring treatment more than an hour after reperfusion.

CONCLUSION

Metabolic derangements resulting from REBOA use are common and may worsen long after reperfusion despite resuscitation. Vigilance is required to detect and proactively manage REBOA-associated IRI. Maintaining a readily available "deflation kit" of pharmacological agents needed to treat common post-REBOA electrolyte abnormalities may facilitate management.

LEVEL OF EVIDENCE

Level V.

NLRP3 inflammasomes are involved in the progression of postoperative cognitive dysfunction: from mechanism to treatment

Postoperative cognitive dysfunction (POCD) involves patient memory and learning decline after surgery. POCD not only presents challenges for postoperative nursing and recovery but may also cause permanent brain damage for patients, including children and the aged, with vulnerable central nervous systems. Its occurrence is mainly influenced by surgical trauma, anesthetics, and the health condition of the patient. There is a lack of imaging and experimental diagnosis; therefore, patients can only be diagnosed by clinical observation, which may underestimate the morbidity, resulting in decreased treatment efficacy. Except for symptomatic support therapy, there is a relative lack of effective drugs specific for the treatment of POCD, because the precise mechanism of POCD remains to be determined. One current hypothesis is that postoperative inflammation promotes the progression of POCD. Accumulating research has indicated that overactivation of NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasomes contribute to the POCD progression, suggesting that targeting NLRP3 inflammasomes may be an effective therapy to treat POCD. In this review, we summarize recent studies and systematically describe the pathogenesis, treatment progression, and potential treatment options of targeting NLRP3 inflammasomes in POCD patients.

Xenotransfusion with packed bovine red blood cells to a wildebeest calf (Connochaetes taurinus)

A 4-month-old female blue wildebeest (Connochaetes taurinus) was presented for bilateral pelvic limb fracture repair. Clinical examination under anaesthesia revealed a water-hammer pulse and a haematocrit of 0.13. A xenotransfusion was performed using bovine (Bos taurus) erythrocytes because of inability to acquire a wildebeest donor. Clinical parameters improved following transfusion and the post-operative haematocrit value was 0.31. The wildebeest remained physiologically stable with a gradually declining haematocrit for the next three days. On the third post-operative day, the wildebeest refractured its femur and was humanely euthanised because of the poor prognosis for further fracture repair. Xenotransfusion using blood from domestic ruminants represents a life-saving short-term emergency treatment of anaemic hypoxia in wild ungulates. Domestic goats could be used as blood donors for rare ungulates where allodonors are not available.

Fluids for Prevention and Management of Acute Kidney Injury

Fluids are the only known method of attenuating renal injury. Furthermore, whether for hydration, resuscitation or renal replacement therapy, fluid prescriptions must be tailored to the fluid and electrolyte, cardiovascular status and residual renal function of the patient. Different fluids have significantly different effects both on volume expansion as well as on the electrolyte and acid-base balance; while controversial, different fluids may even influence renal function differently. This systematic review focuses on fluids for prevention and management of acute kidney injury. We have reviewed the available evidence and have made recommendations for clinical practice and future studies.

Protocols for massive blood transfusion: when and why, and potential complications

PURPOSE

An update paper on massive bleeding after major trauma. A review of protocols to address massive bleeding, and its possible complications, including coagulation abnormalities, complications related to blood storage, immunosuppression and infection, lung injury associated with transfusion, and hypothermia is carried out.

METHODS

Literature review and discussion with authors' experience.

RESULTS

Massive bleeding is an acute life-threatening complication of major trauma, and consequently its prompt diagnosis and treatment is of overwhelming importance. Treatment requires rapid surgical management together with the massive infusion of colloid and blood.

CONCLUSIONS

Since massive transfusion provokes further problems in patients who are already severely traumatized and anaemic, once this course of action has been decided upon, a profound knowledge of its potential complications, careful monitoring and proper follow-up are all essential. To diagnose this bleeding, most authors favour, as the main first choice tool, a full-body CT scan (head to pelvis), in non-critical severe trauma cases. In addition, focused abdominal sonography for trauma (FAST, an acronym that highlights the necessity of rapid performance) is a very important diagnostic test for abdominal and thoracic bleeding. Furthermore, urgent surgical intervention should be undertaken for patients with significant free intraabdominal fluid and haemodynamic instability. Although the clinical situation and the blood haemoglobin concentration are the key factors considered in this rapid decision-making context, laboratory markers should not be based on a single haematocrit value, as its sensitivity to significant bleeding may be very low. Serum lactate and base deficit are very sensitive markers for detecting and monitoring the extent of bleeding and shock, in conjunction with repeated combined measurements of prothrombin time, activated partial thromboplastin time, fibrinogen and platelets.

Outcomes After Post-Traumatic AKI Requiring RRT in United States Military Service Members

BACKGROUND AND OBJECTIVES

Mortality and CKD risk have not been described in military casualties with post-traumatic AKI requiring RRT suffered in the Iraq and Afghanistan wars.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This is a retrospective case series of post-traumatic AKI requiring RRT in 51 military health care beneficiaries (October 7, 2001-December 1, 2013), evacuated to the National Capital Region, documenting in-hospital mortality and subsequent CKD. Participants were identified using electronic medical and procedure records.

RESULTS

Age at injury was 26±6 years; of the participants, 50 were men, 16% were black, 67% were white, and 88% of injuries were caused by blast or projectiles. Presumed AKI cause was acute tubular necrosis in 98%, with rhabdomyolysis in 72%. Sixty-day all-cause mortality was 22% (95% confidence interval [95% CI], 12% to 35%), significantly less than the 50% predicted historical mortality (P<0.001). The VA/NIH Acute Renal Failure Trial Network AKI integer score predicted 60-day mortality risk was 33% (range, 6%-96%) (n=49). Of these, nine died (mortality, 18%; 95% CI, 10% to 32%), with predicted risks significantly miscalibrated (P<0.001). The area under the receiver operator characteristic curve for the AKI integer score was 0.72 (95% CI, 0.56 to 0.88), not significantly different than the AKI integer score model cohort (P=0.27). Of the 40 survivors, one had ESRD caused by cortical necrosis. Of the remaining 39, median time to last follow-up serum creatinine was 1158 days (range, 99-3316 days), serum creatinine was 0.85±0.24 mg/dl, and eGFR was 118±23 ml/min per 1.73 m(2). No eGFR was <60 ml/min per 1.73 m(2), but it may be overestimated because of large/medium amputations in 54%. Twenty-five percent (n=36) had proteinuria; one was diagnosed with CKD stage 2.

CONCLUSIONS

Despite severe injuries, participants had better in-hospital survival than predicted historically and by AKI integer score. No patient who recovered renal function had an eGFR<60 ml/min per 1.73 m(2) at last follow-up, but 23% had proteinuria, suggesting CKD burden.

The clinical relevance of plasma potassium abnormalities on admission in trauma patients: a retrospective observational study

Background

Abnormalities in potassium levels can lead to several clinical difficulties in trauma patients admitted to the ICU. However, the significance of potassium abnormalities soon after admission in trauma patients has not yet been clearly delineated. The objective of this study was to describe the plasma potassium abnormalities in trauma patients on admission and to examine the clinical outcomes associated with these abnormalities.

Methods

We performed a retrospective observational study of plasma potassium levels in trauma patients admitted to the Fukuyama City Hospital between January 1, 2010 and December 31, 2013. Five hundred twenty consecutive trauma patients were included and categorized into six groups according to their plasma potassium level on admission (<3.0, 3.0–<3.5, 3.5–<4.0, 4.0–<4.5, 4.5–<5.0, and ≥5.0 mEq/L). After adjusting for covariates, including age, gender, the Revised Trauma Score, and the Injury Severity Score, logistic regression analysis was used to examine the association between plasma potassium levels and outcomes, including life-saving interventions and in-hospital mortality.

Results

Two hundred twenty-seven patients (43.7 %) presented with hypokalemia (<3.5 mEq/L), while seven patients (1.3 %) presented with hyperkalemia (≥5.0 mEq/L). Patients in the lowest potassium group (<3.0 mEq/L, n = 36 [6.9 %]) were significantly associated with craniotomy (adjusted odds ratio 5.25 [95 % confidence interval 2.06–13.40]; p < 0.001) and showed an increased trend toward in-hospital mortality. In the second lowest potassium group (3.0–< 3.5 mEq/L, n = 191 [36.7 %]), the adjusted odds ratio for craniotomy was significantly higher (2.03 [95 % confidence interval 1.01–4.07]; p = 0.048) compared to the reference group.

Conclusions

Trauma patients presenting with hypokalemia (<3.5 mEq/L) on admission may be associated with severe head trauma requiring life-saving craniotomy.

Cardiopulmonary arrest due to early hyperkalemia after liver injury

Hyperkalemia due to crush syndrome after trauma is a well known fatal clinical condition, but early hyperkalemia with hemorrhage after trauma is a rare phenomenon. We report on a 5-year-old boy who bruised from the lumbers, had cardiopulmonary arrest caused by hyperkalemia, and underwent perihepatic packing twice before being discharged without any neurologic deficits. Clinicians should be vigilant for signs of hyperkalemia accompanying hemorrhagic shock, even in the early phase of trauma.

Monitoring systems and quantitative measurement of biomolecules for the management of trauma

Continued high morbidity and complications due to trauma related hemorrhage underscores the fact that our understanding of the detailed molecular events of trauma are inadequate to bring life-saving changes to practice. The current state of efficacy and advances in biomedical microdevice technology for trauma diagnostics concerning hemorrhage and hemorrhagic shock was considered with respect to vital signs and metabolic biomarkers. Tachycardia and hypotension are markers of hemorrhagic shock in decompensated trauma patients. Base deficit has been predicative of injury severity at hospital admission. Tissue oxygen saturation has been predicative of onset of multiple organ dysfunction syndrome. Blood potassium levels increase with onset of hemorrhagic shock. Lactate is a surrogate for tissue hypoxia and its clearance predicts mortality. Triage glucose measurements have been shown to be specific in predicting major injuries. No vital sign has yet to be proven effective as an independent predictor of trauma severity. Point of care (POC) devices allow for rapid results, easy sample preparation and processing, small sample volumes, small footprint, multifunctional analysis, and low cost. Advances in the field of in-vivo biosensors has provided a much needed platform by which trauma related metabolites can be monitored easily, rapidly and continuously. Multi-analyte monitoring biosensors have the potential to explore areas still undiscovered in the realm of trauma physiology.

Pathophysiological effects and changes in potassium, ionised calcium, glucose and haemoglobin early after severe blunt chest trauma

BACKGROUND

Severe lung contusion is often observed after blunt chest trauma due to traffic accidents or fall from heights, but may also occur after a non-penetrating ballistic impact against body armour. Such trauma has been designated behind armour blunt trauma (BABT). Our aim in the present study has been to evaluate pathophysiological changes and compensatory mechanisms that occur early after such severe lung contusion.

METHODS

Twelve pigs wearing body armour were shot with a 7.62mm assault rifle to produce a standardised pulmonary contusion. Exposed animals were compared with five control animals shot with blank ammunition. Physiological parameters and levels of potassium, glucose, haemoglobin, calcium, lactate and pH were monitored for two hours after the shot.

RESULTS

The impact induced severe pulmonary contusion with apnoea, desaturation and hypotension in all exposed animals. Increased haemoglobin, glucose and severe hyperkalaemia were seen shortly after impact. Seven of twelve animals died due to the trauma. Dense cardiac tissue was observed during post mortem examination in six of the animals that died during the experimental course.

CONCLUSION

In conclusion, this study has shown that life-threatening hyperkalaemia occurs early after severe lung contusion. Moreover, dense cardiac tissue and early increase of haemoglobin and glucose are intriguing findings that should be investigated in future studies.

Potassium in hemorrhagic shock: a potential marker of tissue hypoxia

BACKGROUND

This study was designed to evaluate serum potassium level variation in a porcine model of hemorrhagic shock (HS).

METHODS

Eight pigs were studied in a controlled hemorrhage model of HS. Blood withdrawal began at a 50 mL/min to 70 mL/min rate, adjusted to reach a mean arterial pressure (MAP) level of 60 mm Hg in 10 minutes. When MAP reached 60 mm Hg, the blood withdrawal rate was adjusted to maintain a MAP decrease rate of 10 mm Hg every 2 minutes to 4 minutes. Arterial and mixed venous blood samples were collected at MAP levels of 60 mm Hg, 50 mm Hg, 40 mm Hg, 30 mm Hg, 20 mm Hg, and 10 mm Hg and analyzed for oxygen saturation, Po2, Pco2, potassium, lactate, bicarbonate, hemoglobin, pH, and standard base excess.

RESULTS

Significant increase in serum potassium occurred early in all animals. The rate of rise in serum potassium and its levels accompanied the hemodynamic deterioration. Hyperkalemia (K >5 mmol/L) incidence was 12.5% at 60 mm Hg and 50 mm Hg, 62.5% at 40 mm Hg, 87.5% at 30 mm Hg, and 100% at 20 mm Hg. Strong correlations were found between potassium levels and lactate (R = 0.82), SvO2 (R = 0.87), DeltapH (R = 0.83), and DeltaPco2 (R = 0.82).

CONCLUSIONS

Serum potassium increase accompanies the onset of HS. The rise in serum potassium was directly related to the hemodynamic deterioration of HS and strongly correlated with markers of tissue hypoxia.

Complications of massive transfusion

Massive transfusion (MT) is a lifesaving treatment of hemorrhagic shock, but can be associated with significant complications. The lethal triad of acidosis, hypothermia, and coagulopathy associated with MT is associated with a high mortality rate. Other complications include hypothermia, acid/base derangements, electrolyte abnormalities (hypocalcemia, hypomagnesemia, hypokalemia, hyperkalemia), citrate toxicity, and transfusion-associated acute lung injury. Blood transfusion in trauma, surgery, and critical care has been identified as an independent predictor of multiple organ failure, systemic inflammatory response syndrome, increased infection, and increased mortality in multiple studies. Once definitive control of hemorrhage has been established, a restrictive approach to blood transfusion should be implemented to minimize further complications.

Hyperkalemia accompanies hemorrhagic shock and correlates with mortality

OBJECTIVE

This study was designed to evaluate the effects of terlipressin versus fluid resuscitation with normal saline, hypertonic saline or hypertonic-hyperoncotic hydroxyethyl starch, on hemodynamics, metabolics, blood loss and short-term survival in hemorrhagic shock.

METHOD

Twenty-nine pigs were subjected to severe liver injury and treated 30 min later with either: (1) 2 mg terlipressin in a bolus, (2) placebo-treated controls, (3) 4 mL/kg 7.5% hypertonic NaCl, (4) 4 mL/kg 7.2% hypertonic-hyperoncotic hydroxyethyl starch 200/0.5, or (5) normal saline at three times lost blood volume.

RESULTS

The overall mortality rate was 69%. Blood loss was significantly higher in the hypertonic-hyperoncotic hydroxyethyl starch and normal saline groups than in the terlipressin, hypertonic NaCl and placebo-treated controls groups (p<0.005). Hyperkalemia (K>5 mmol/L) before any treatment occurred in 66% of the patients (80% among non-survivors vs. 22% among survivors, p=0.019). Post-resuscitation hyperkalemia occurred in 86.66% of non-survivors vs. 0% of survivors (p<0.001). Hyperkalemia was the first sign of an unsuccessful outcome for the usual resuscitative procedure and was not related to arterial acidemia. Successfully resuscitated animals showed a significant decrease in serum potassium levels relative to the baseline value.

CONCLUSION

Hyperkalemia accompanies hemorrhagic shock and, in addition to providing an early sign of the acute ischemic insult severity, may be responsible for cardiac arrest related to hemorrhagic shock.

Hyperkalemia after packed red blood cell transfusion in trauma patients

BACKGROUND

Published analyses of clinical outcomes for patients requiring large-volume blood transfusion conflict with respect to the impact upon plasma potassium levels. We analyzed a cohort of trauma patients to ascertain the impact of component product transfusion upon plasma potassium values.

METHODS

We performed an observational analysis of previously, prospectively collected clinical data on 131 noncrush trauma patients undergoing resuscitation during the initial 12 hours after admission to a combat support hospital. Comparisons were made between those who received packed red blood cell (PRBC) transfusion and those who did not. Primary outcome was hyperkalemia (plasma potassium level >5.5 mmol/L).

RESULTS

Ninety-six of one hundred thirty-one patients (73.3%) received PRBCs (mean number of PRBC units 11.2, range, 0-55.0). For transfusion versus nontransfusion patients, baseline plasma potassium value (3.7 +/- 0.57 mmol/L vs. 3.6 +/- 0.36 mmol/L, p = 0.22) rose significantly after transfusion (5.3 +/- 1.2 mmol/L, vs. 4.0 +/- 0.78 mmol/L, p < 0.001). During the study period, 38.5% of transfusion patients developed hyperkalemia, versus 2.9% of those who did not (p = 0.003). In multivariate logistic regression analysis, transfusion of greater than 7 units of PRBCs was independently associated with the development of hyperkalemia (RR 4.72, 95% CI 1.01-21.97, p = 0.048). Transfusion of other cell-based products, baseline base deficits, and plasma bicarbonate levels were not. Spearman's rank correlation coefficient for the relationship of number of transfused PRBC units to the highest recorded potassium value was 0.554 (p < 0.001). The predictive accuracy of the logistic regression model for hyperkalemia was 0.824 (95% CI 0.747-0.901, p < 0.001).

CONCLUSIONS

Hyperkalemia is common after PRBC transfusion, and often severe. PRBC transfusion is independently associated with the development of hyperkalemia. The findings suggest the need for interventional studies examining the impact of alternative resuscitative approaches after severe trauma.

Cardiac arrests associated with hyperkalemia during red blood cell transfusion: a case series

BACKGROUND

Transfusion-associated hyperkalemic cardiac arrest is a serious complication of rapid red blood cell (RBC) administration. We examined the clinical scenarios and outcomes of patients who developed hyperkalemia and cardiac arrest during rapid RBC transfusion.

METHODS

We retrospectively reviewed the Mayo Clinic Anesthesia Database between November 1, 1988, and December 31, 2006, for all patients who developed intraoperative transfusion-associated hyperkalemic cardiac arrest.

RESULTS

We identified 16 patients with transfusion-associated hyperkalemic cardiac arrest, 11 adult and 5 pediatric. The majority of patients underwent three types of surgery: cancer, major vascular, and trauma. The mean serum potassium concentration measured during cardiac arrest was 7.2 +/- 1.4 mEq/L (range, 5.9-9.2 mEq/L). The number of RBC units administered before cardiac arrest ranged between 1 (in a 2.7 kg neonate) and 54. Nearly all patients were acidotic, hyperglycemic, hypocalcemic, and hypothermic at the time of arrest. Fourteen (87.5%) patients received RBC via central venous access. Commercial rapid infusion devices (pumps) were used in 8 of 11 (72.7%) of the adult patients, but RBC units were rapidly administered (pressure bags, syringe pumped) in all remaining patients. Mean resuscitation duration was 32 min (range, 2-127 min). The in-hospital survival rate was 12.5%.

CONCLUSION

The pathogenesis of transfusion-associated hyperkalemic cardiac arrest is multifactorial and potassium increase from RBC administration is complicated by low cardiac output, acidosis, hyperglycemia, hypocalcemia, and hypothermia. Large transfusion of banked RBCs and conditions associated with massive hemorrhage should raise awareness of the potential for hyperkalemia and trigger preventative measures.