Blood laboratory analyses preceding in-hospital cardiac arrest: A matched case-control study.

BACKGROUND: Whether blood laboratory analyses differ in patients who later suffer in-hospital cardiac arrest (IHCA) compared to other hospitalised patients remains unknown. The aim of this study was to describe pre-arrest sampling frequencies, results, and trends in blood laboratory analyses in patients with IHCA compared to controls. METHODS: This study was a matched case-control study using national registries in Denmark. Cases were defined as patients with IHCA from 2017 to 2021. Controls were defined as hospitalised patients and were matched on age, sex, and date and length of admission. Data on a total of 51 different blood laboratory analyses were obtained. The laboratory analyses of primary interest were lactate, sodium, potassium, and haemoglobin. The index time for cases was defined as the time of cardiac arrest, and a corresponding index time was defined for controls based on the time to cardiac arrest for their corresponding case. Blood sampling frequencies were reported for blood laboratory analyses obtained either within the last 24 h before the index time or between the time of hospital admission and the index time. Blood sampling results were reported for blood laboratory analyses obtained within the last 24 h before the index time. RESULTS: A total of 9268 cases and 92,395 controls were included in this study. Cases underwent more frequent sampling of all blood laboratory analyses compared to controls. This higher sampling frequency was more pronounced for lactate compared to sodium, potassium, or haemoglobin. The last measured lactate was higher in cases (median [IQR]: 2.3 [1.3, 4.9]) compared to controls (median [IQR]: 1.3 [0.9, 2.0]). Differences in sodium, potassium, and haemoglobin were negligible. The proportion of abnormally elevated levels of lactate and potassium increased as time to cardiac arrest decreased; no such effect was seen in controls. No temporal trend was evident for sodium or haemoglobin. CONCLUSIONS: Patients with IHCA undergo more frequent blood sampling prior to IHCA and have higher levels of lactate compared to matched controls.

Characteristics and outcomes for general anesthesia in Denmark.

BACKGROUND: General anesthesia is common, but concerns regarding post-operative complications and mortality remain. No study has described the Danish patient population undergoing general anesthesia on a national level. The aim of this study was to describe the characteristics and outcomes of patients undergoing general anesthesia in Denmark. METHODS: This study was a registry-based observational cohort study of adult patients (≥18 years) undergoing general anesthesia in Denmark during 2020 and 2021. Data from nationwide registries covering patient characteristics, anesthesia and procedure information, and patient outcomes were combined. Descriptive statistics were used to present findings, both overall and in subgroups based on the American Society of Anesthesiologists (ASA) classification. RESULTS: We identified 453,133 cases of general anesthesia in 328,951 unique patients. The median age was 57 years (quartiles: 41, 71), and 242,679 (54%) were females. Data on ASA classification were missing for less than 1% of the population, and ASA II was the most prevalent ASA classification (49%). Among cases of general anesthesia, 0.1% experienced a stroke, 0.2% had in-hospital cardiac arrest, and 3.9% had a stay in the intensive care unit within 30 days. Mortality at 30 days and 1 year were 1.8% and 6.3%, respectively, increasing with a higher ASA classification. CONCLUSION: This study offers the first comprehensive overview of adult patients undergoing general anesthesia in Denmark. Post-anesthesia complications were few and increased with ASA classification.

Sodium Bicarbonate and Calcium Chloride for the Treatment of Hyperkalemia-Induced Cardiac Arrest: A Randomized, Blinded, Placebo-Controlled Animal Study.

OBJECTIVES: Current international guidelines recommend administrating calcium chloride and sodium bicarbonate to patients with hyperkalemia-induced cardiac arrest, despite limited evidence. The aim of this study was to evaluate the efficacy of calcium chloride and sodium bicarbonate on return of spontaneous circulation (ROSC) in a pig model of hyperkalemia-induced cardiac arrest. DESIGN: A randomized, blinded, placebo-controlled experimental pig study. Hyperkalemia was induced by continuous infusion of potassium chloride over 45 minutes followed by a bolus. After a no flow period of 7 minutes, pigs first received 2 minutes of basic cardiopulmonary resuscitation and subsequently advanced life support. The first intervention dose was administered after the fifth rhythm analysis, followed by a defibrillation attempt at the sixth rhythm analysis. A second dose of the intervention was administered after the seventh rhythm analysis if ROSC was not achieved. In case of successful resuscitation, pigs received intensive care for 1 hour before termination of the study. SETTING: University hospital laboratory. SUBJECTS: Fifty-four female Landrace/Yorkshire/Duroc pigs (38-42 kg). INTERVENTIONS: The study used a 2 × 2 factorial design, with calcium chloride (0.1 mmol/kg) and sodium bicarbonate (1 mmol/kg) as the interventions. MEASUREMENTS AND MAIN RESULTS: Fifty-two pigs were included in the study. Sodium bicarbonate significantly increased the number of animals achieving ROSC (24/26 [92%] vs. 13/26 [50%]; odds ratio [OR], 12.0; 95% CI, 2.3-61.5; p = 0.003) and reduced time to ROSC (hazard ratio [HR] 3.6; 95% CI, 1.8-7.5; p < 0.001). There was no effect of calcium chloride on the number of animals achieving ROSC (19/26 [73%] vs. 18/26 [69%]; OR, 1.2; 95% CI, 0.4-4.0; p = 0.76) or time to ROSC (HR, 1.5; 95% CI, 0.8-2.9; p = 0.23). CONCLUSIONS: Administration of sodium bicarbonate significantly increased the number of animals achieving ROSC and decreased time to ROSC. There was no effect of calcium chloride on the number of animals achieving ROSC or time to ROSC.

Animal research in cardiac arrest.

The purpose of this narrative review is to provide an overview of lessons learned from experimental cardiac arrest studies, limitations, translation to clinical studies, ethical considerations and future directions. Cardiac arrest animal studies have provided valuable insights into the pathophysiology of cardiac arrest, the effects of various interventions, and the development of resuscitation techniques. However, there are limitations to animal models that should be considered when interpreting results. Systematic reviews have demonstrated that animal models rarely reflect the clinical condition seen in humans, nor the complex treatment that occurs during and after a cardiac arrest. Furthermore, animal models of cardiac arrest are at a significant risk of bias due to fundamental issues in performing and/or reporting critical methodological aspects. Conducting clinical trials targeting the management of rare cardiac arrest causes like e.g. hyperkalemia and pulmonary embolism is challenging due to the scarcity of eligible patients. For these research questions, animal models might provide the highest level of evidence and can potentially guide clinical practice. To continuously push cardiac arrest science forward, animal studies must be conducted and reported rigorously, designed to avoid bias and answer specific research questions. To ensure the continued relevance and generation of valuable new insights from animal studies, new approaches and techniques may be needed, including animal register studies, systematic reviews and multilaboratory trials.

The effects of methylene blue during and after cardiac arrest in a porcine model; a randomized, blinded, placebo-controlled study.

PURPOSE: To evaluate the effect of methylene blue administered as a bolus on return of spontaneous circulation (ROSC), lactate levels, vasopressor requirements, and markers of neurological injury in a clinically relevant pig model of cardiac arrest. MATERIALS AND METHODS: 40 anesthetized pigs were subjected to acute myocardial infarction and 7 min of untreated cardiac arrest. Animals were randomized into three groups: one group received saline only (controls), one group received 2 mg/kg methylene blue and saline (MB + saline), and one group received two doses of 2 mg/kg methylene blue (MB + MB). The first intervention was given after the 3rd rhythm analysis, while the second dose was administered one hour after achieving ROSC. Animals underwent intensive care and observation for six hours, followed by cerebral magnetic resonance imaging (MRI). The primary outcome for this study was development in lactate levels after cardiac arrest. Categorical data were compared using Fisher's exact test and pointwise data were analyzed using one-way analysis of variance (ANOVA) or equivalent non-parametric test. Continuous data collected over time were analyzed using a linear mixed effects model. A value of p < .05 was considered statistically significant. RESULTS: Lactate levels increased in all groups after cardiac arrest and resuscitation, however lactate levels in the MB + MB group decreased significantly faster compared with the control group (p = .007) and the MB + saline group (p = .02). The proportion of animals achieving initial ROSC was similar across groups: 11/13 (85%) in the control group, 10/13 (77%) in the MB + saline group, and 12/14 (86%) in the MB + MB group (p = .81). Time to ROSC did not differ between groups (p = .67). There was no significant difference in accumulated norepinephrine dose between groups (p = .15). Cerebral glycerol levels were significantly lower in the MB + MB group after resuscitation compared with control group (p = .03). However, MRI data revealed no difference in apparent diffusion coefficient, cerebral blood flow, or dynamic contrast enhanced MR perfusion between groups. CONCLUSION: Treatment with a bolus of methylene blue during cardiac arrest and after resuscitation did not significantly improve hemodynamic function. A bolus of methylene blue did not yield the neuroprotective effects that have previously been described in animals receiving methylene blue as an infusion.

Bicarbonate, calcium, and magnesium for in-hospital cardiac arrest - An instrumental variable analysis.

INTRODUCTION: Bicarbonate, calcium, and magnesium are commonly used during in-hospital cardiac arrest. Whether these drugs are associated with survival in cardiac arrest patients is uncertain. METHODS: This was an observational study using data from the Get With The Guidelines registry. Adult patients with an in-hospital cardiac arrest between January 2008 and December 2021 were included. An instrumental variable approach was used based on hospital preferences for bicarbonate, calcium, and magnesium, respectively. The primary outcome was survival to hospital discharge. RESULTS: A total of 319,230 patients were included. The median age was 66 years, 59% patients were male, and 85% patients presented with a non-shockable rhythm. Bicarbonate was administered in 58% patients, calcium in 33% patients, and magnesium in 10% patients. When considering drug use in the previous cardiac arrest patient at a given hospital as an instrument, the absolute difference in survival to hospital discharge was estimated at -14.2% (95% CI, -19.9 to -8.6) for bicarbonate, -3.0% (95% CI, -8.6 to 2.6) for calcium, and 10.7% (95% CI, -0.8 to 22.2) for magnesium as compared to no drug. When considering the proportion of drug use within the past year at a given hospital as an instrument, the confidence intervals were very wide, making the results difficult to interpret. CONCLUSIONS: In this analysis, the results for bicarbonate, calcium, and magnesium were inconclusive due to wide confidence intervals and inconsistencies in estimates across instrumental variables. Randomized trials are needed to investigate the effect of these drugs on patient outcomes.

Vasopressin and methylprednisolone and hemodynamics after in-hospital cardiac arrest - A post hoc analysis of the VAM-IHCA trial.

INTRODUCTION: The Vasopressin and Methylprednisolone for In-Hospital Cardiac Arrest (VAM-IHCA) trial demonstrated a significant improvement in return of spontaneous circulation (ROSC) with no clear effect on long-term outcomes. The objective of the current manuscript was to evaluate the hemodynamic effects of intra-cardiac arrest vasopressin and methylprednisolone during the first 24 hours after ROSC. METHODS: The VAM-IHCA trial randomized patients with in-hospital cardiac arrest to a combination of vasopressin and methylprednisolone or placebo during the cardiac arrest. This study is a post hoc analysis focused on the hemodynamic effects of the intervention after ROSC. Post-ROSC data on the administration of glucocorticoids, mean arterial blood pressure, heart rate, blood gases, vasopressor and inotropic therapy, and sedation were collected. Total vasopressor dose between the two groups was calculated based on noradrenaline-equivalent doses for adrenaline, phenylephrine, terlipressin, and vasopressin. RESULTS: The present study included all 186 patients who achieved ROSC in the VAM IHCA-trial of which 100 patients received vasopressin and methylprednisolone and 86 received placebo. The number of patients receiving glucocorticoids during the first 24 hours was 22/86 (26%) in the placebo group and 14/100 (14%) in the methylprednisolone group with no difference in the cumulative hydrocortisone-equivalent dose. There was no significant difference between the groups in the mean cumulative noradrenaline-equivalent dose (vasopressin and methylprednisolone: 603 ug/kg [95CI% 227; 979] vs. placebo: 651 ug/kg [95CI% 296; 1007], mean difference -48 ug/kg [95CI% -140; 42.9], p = 0.30), mean arterial blood pressure, or lactate levels. There was no difference between groups in arterial blood gas values and vital signs. CONCLUSION: Treatment with vasopressin and methylprednisolone during cardiac arrest caused no difference in mean arterial blood pressure, vasopressor use, or arterial blood gases within the first 24 hours after ROSC when compared to placebo.

Temperature control after adult cardiac arrest: An updated systematic review and meta-analysis.

AIM: To perform an updated systematic review and meta-analysis on temperature control in adult patients with cardiac arrest. METHODS: The review is an update of a previous systematic review published in 2021. An updated search including PubMed, Embase, and the Cochrane Central Register of Controlled Trials was performed on May 31, 2023. Controlled trials in humans were included. The population included adult patients with cardiac arrest. The review included all aspects of temperature control including timing, temperature, duration, method of induction and maintenance, and rewarming. Two investigators reviewed trials for relevance, extracted data, and assessed risk of bias. Data were pooled using random-effects models. Certainty of evidence was evaluated using GRADE. RESULTS: The updated systematic search identified six new trials. Risk of bias in the trials was assessed as intermediate for most of the outcomes. For temperature control with a target of 32-34 °C vs. normothermia or 36 °C, two new trials were identified, with seven trials included in an updated meta-analysis. Temperature control with a target of 32-34 °C did not result in an improvement in survival (risk ratio: 1.06 [95%CI: 0.91, 1.23]) or favorable neurological outcome (risk ratio: 1.27 [95%CI: 0.89, 1.81]) at 90-180 days after the cardiac arrest (low certainty evidence). Subgroup analysis according to location of cardiac arrest (in-hospital vs. out-of-hospital) found similar results. A sensitivity analysis of nine trials comparing temperature control at 32-34 °C to normothermia or 36 °C for favorable neurological outcome at any time point also did not show an improvement in outcomes (risk ratio: 1.14 [95%CI 0.98, 1.34]). New individual trials comparing a target of 31-34 °C, temperature control for 12-24 hours to 36 hours, a rewarming rate of 0.25-0.5 °C/hour, and the effect of temperature control with fever prevention found no differences in outcomes. CONCLUSIONS: This updated systematic review showed no benefit of temperature control at 32-34 °C compared to normothermia or 36 °C, although the 95% confidence intervals cannot rule out a potential beneficial effect. Important knowledge gaps exist for topics such as hypothermic temperature targets, rewarming rate, and fever control.

Intravenous vs. intraosseous vascular access during out-of-hospital cardiac arrest - protocol for a randomised clinical trial.

Objective: During cardiac arrest, current guidelines recommend attempting intravenous access first and to consider intraosseous access if intravenous access is unsuccessful or impossible. However, these recommendations are only based on very low-certainty evidence. Therefore, the "Intravenous vs Intraosseous Vascular Access During Out-of-Hospital Cardiac Arrest" (IVIO) trial aims to determine whether there is a difference in patient outcomes depending on the type of vascular access attempted during out-of-hospital cardiac arrest. This current article describes the clinical IVIO trial. Methods: The IVIO trial is an investigator-initiated, randomised trial of intravenous vs. intraosseous vascular access during adult non-traumatic out-of-hospital cardiac arrest in Denmark. The intervention will consist of minimum two attempts (if unsuccessful on the first attempt) to successfully establish intravenous or intraosseous vascular access during cardiac arrest. The intraosseous group will be further randomised to the humeral or tibial site. The primary outcome is sustained return of spontaneous circulation and key secondary outcomes include survival and survival with a favourable neurological outcome at 30 days. A total of 1,470 patients will be included. Results: The trial started in March 2022 and the last patient is anticipated to be included in the spring of 2024. The primary results will be reported after 90-day follow-up and are anticipated in mid-2024. Conclusion: The current article describes the design of the Danish IVIO trial. The findings of this trial will help inform future guidelines for selecting the optimal vascular access route during out-of-hospital cardiac arrest.

Mild Hypercapnia or Normocapnia after Out-of-Hospital Cardiac Arrest.

BACKGROUND: Guidelines recommend normocapnia for adults with coma who are resuscitated after out-of-hospital cardiac arrest. However, mild hypercapnia increases cerebral blood flow and may improve neurologic outcomes. METHODS: We randomly assigned adults with coma who had been resuscitated after out-of-hospital cardiac arrest of presumed cardiac or unknown cause and admitted to the intensive care unit (ICU) in a 1:1 ratio to either 24 hours of mild hypercapnia (target partial pressure of arterial carbon dioxide [Paco2], 50 to 55 mm Hg) or normocapnia (target Paco2, 35 to 45 mm Hg). The primary outcome was a favorable neurologic outcome, defined as a score of 5 (indicating lower moderate disability) or higher, as assessed with the use of the Glasgow Outcome Scale-Extended (range, 1 [death] to 8, with higher scores indicating better neurologic outcome) at 6 months. Secondary outcomes included death within 6 months. RESULTS: A total of 1700 patients from 63 ICUs in 17 countries were recruited, with 847 patients assigned to targeted mild hypercapnia and 853 to targeted normocapnia. A favorable neurologic outcome at 6 months occurred in 332 of 764 patients (43.5%) in the mild hypercapnia group and in 350 of 784 (44.6%) in the normocapnia group (relative risk, 0.98; 95% confidence interval [CI], 0.87 to 1.11; P = 0.76). Death within 6 months after randomization occurred in 393 of 816 patients (48.2%) in the mild hypercapnia group and in 382 of 832 (45.9%) in the normocapnia group (relative risk, 1.05; 95% CI, 0.94 to 1.16). The incidence of adverse events did not differ significantly between groups. CONCLUSIONS: In patients with coma who were resuscitated after out-of-hospital cardiac arrest, targeted mild hypercapnia did not lead to better neurologic outcomes at 6 months than targeted normocapnia. (Funded by the National Health and Medical Research Council of Australia and others; TAME ClinicalTrials.gov number, NCT03114033.).

Extracorporeal Cardiopulmonary Resuscitation for Cardiac Arrest.

This JAMA Insights Clinical Update discusses the newer treatment option of extracorporeal cardiopulmonary resuscitation, particularly for patients with cardiac arrest who are not responsive to initial treatment.

Thiamine for the Treatment of Cardiac Arrest-Induced Neurological Injury: A Randomized, Blinded, Placebo-Controlled Experimental Study.

Background Thiamine supplementation has demonstrated protective effects in a mouse model of cardiac arrest. The aim of this study was to investigate the neuroprotective effects of thiamine in a clinically relevant large animal cardiac arrest model. The hypothesis was that thiamine reduces neurological injury evaluated by neuron-specific enolase levels. Methods and Results Pigs underwent myocardial infarction and subsequently 9 minutes of untreated cardiac arrest. Twenty minutes after successful resuscitation, the pigs were randomized to treatment with either thiamine or placebo. All pigs underwent 40 hours of intensive care and were awakened for assessment of functional neurological outcome up until 9 days after cardiac arrest. Nine pigs were included in both groups, with 8 in each group surviving the entire intensive care phase. Mean area under the curve for neuron-specific enolase was similar between groups, with 81.5 µg/L per hour (SD, 20.4) in the thiamine group and 80.5 µg/L per hour (SD, 18.3) in the placebo group, with an absolute difference of 1.0 (95% CI, -57.8 to 59.8; P=0.97). Likewise, there were no absolute difference in neurological deficit score at the end of the protocol (2 [95% CI, -38 to 42]; P=0.93). There was no absolute mean group difference in lactate during the intensive care period (1.1 mmol/L [95% CI, -0.5 to 2.7]; P=0.16). Conclusions In this randomized, blinded, placebo-controlled trial using a pig cardiac arrest model with myocardial infarction and long intensive care and observation for 9 days, thiamine showed no effect in changes to functional neurological outcome or serum levels of neuron-specific enolase. Thiamine treatment had no effect on lactate levels after successful resuscitation.

Extracorporeal cardiopulmonary resuscitation for cardiac arrest: An updated systematic review.

OBJECTIVES: To provide an updated systematic review on the use of extracorporeal cardiopulmonary resuscitation (ECPR) compared with manual or mechanical cardiopulmonary resuscitation during cardiac arrest. METHODS: This was an update of a systematic review published in 2018. OVID Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched for randomized trials and observational studies between January 1, 2018, and June 21, 2022. The population included adults and children with out-of-hospital or in-hospital cardiac arrest. Two investigators reviewed studies for relevance, extracted data, and assessed bias. The certainty of evidence was evaluated using GRADE. RESULTS: The search identified 3 trials, 27 observational studies, and 6 cost-effectiveness studies. All trials included adults with out-of-hospital cardiac arrest and were terminated before enrolling the intended number of subjects. One trial found a benefit of ECPR in survival and favorable neurological status, whereas two trials found no statistically significant differences in outcomes. There were 23 observational studies in adults with out-of-hospital cardiac arrest or in combination with in-hospital cardiac arrest, and 4 observational studies in children with in-hospital cardiac arrest. Results of individual studies were inconsistent, although many studies favored ECPR. The risk of bias was intermediate for trials and critical for observational studies. The certainty of evidence was very low to low. Study heterogeneity precluded meta-analyses. The cost-effectiveness varied depending on the setting and the analysis assumptions. CONCLUSIONS: Recent randomized trials suggest potential benefit of ECPR, but the certainty of evidence remains low. It is unclear which patients might benefit from ECPR.

Effect of calcium in patients with pulseless electrical activity and electrocardiographic characteristics potentially associated with hyperkalemia and ischemia-sub-study of the Calcium for Out-of-hospital Cardiac Arrest (COCA) trial.

OBJECTIVE: The Calcium for Out-of-hospital Cardiac Arrest (COCA) trial was recently conducted and published. This pre-planned sub-study evaluated the effect of calcium in patients with pulseless electrical activity (PEA) including subgroup analyses based on electrocardiographic characteristics potentially associated with hyperkalemia and ischemia. METHODS: Patients aged ≥ 18 years were included if they had a non-traumatic out-of-hospital cardiac arrest and received adrenaline. The trial drug consisted of calcium chloride (5 mmol) or saline placebo given after the first, and again after the second, dose of adrenaline for a maximum of two doses. This sub-study analyzed patients with PEA as their last known rhythm prior to receiving the trial drug. Outcomes were return of spontaneous circulation and survival at 30 days. RESULTS: 104 patients were analyzed. In the calcium group, 9 patients (20 %) achieved return of spontaneous circulation vs 23 patients (39 %) in the placebo group (risk ratio 0.51; 95 %CI 0.26, 1.00). Subgroup analyses based on electrocardiographic characteristics potentially associated with hyperkalemia and ischemia showed similar results. At 30 days, 1 patient (2.2 %) was alive in the calcium group while 8 patients (13.6 %) were alive in the placebo group (risk ratio 0.16; 95 %CI 0.02, 1.26). CONCLUSION: In adults with out-of-hospital cardiac arrest presenting with PEA, effect estimates suggested harm of calcium administration as compared to placebo but with wide confidence intervals. Results were consistent for patients with electrocardiographic characteristics potentially associated with hyperkalemia and ischemia. The results do not support calcium administration based strictly on electrocardiographic findings seen during out-of-hospital cardiac arrest.

Cerebral monitoring in a pig model of cardiac arrest with 48 h of intensive care.

BACKGROUND: Neurological injury is the primary cause of death after out-of-hospital cardiac arrest. There is a lack of studies investigating cerebral injury beyond the immediate post-resuscitation phase in a controlled cardiac arrest experimental setting. METHODS: The aim of this study was to investigate temporal changes in measures of cerebral injury and metabolism in a cardiac arrest pig model with clinically relevant post-cardiac arrest intensive care. A cardiac arrest group (n = 11) underwent 7 min of no-flow and was compared with a sham group (n = 6). Pigs underwent intensive care with 24 h of hypothermia at 33 °C. Blood markers of cerebral injury, cerebral microdialysis, and intracranial pressure (ICP) were measured. After 48 h, pigs underwent a cerebral MRI scan. Data are presented as median [25th; 75th percentiles]. RESULTS: Return of spontaneous circulation was achieved in 7/11 pigs. Time to ROSC was 4.4 min [4.2; 10.9]. Both NSE and NfL increased over time (p < 0.001), and were higher in the cardiac arrest group at 48 h (NSE 4.2 µg/L [2.4; 6.1] vs 0.9 [0.7; 0.9], p < 0.001; NfL 63 ng/L [35; 232] vs 29 [21; 34], p = 0.02). There was no difference in ICP at 48 h (17 mmHg [14; 24] vs 18 [13; 20], p = 0.44). The cerebral lactate/pyruvate ratio had secondary surges in 3/7 cardiac arrest pigs after successful resuscitation. Apparent diffusion coefficient was lower in the cardiac arrest group in white matter cortex (689 × 10-6 mm2/s [524; 765] vs 800 [799; 815], p = 0.04) and hippocampus (854 [834; 910] vs 1049 [964; 1180], p = 0.03). N-Acetylaspartate was lower on MR spectroscopy in the cardiac arrest group (- 17.2 log [- 17.4; - 17.0] vs - 16.9 [- 16.9; - 16.9], p = 0.03). CONCLUSIONS: We have developed a clinically relevant cardiac arrest pig model that displays cerebral injury as marked by NSE and NfL elevations, signs of cerebral oedema, and reduced neuron viability. Overall, the burden of elevated ICP was low in the cardiac arrest group. A subset of pigs undergoing cardiac arrest had persisting metabolic disturbances after successful resuscitation.

Socioeconomic status and outcomes after in-hospital cardiac arrest.

AIM: To investigate the association between socioeconomic status and outcomes after in-hospital cardiac arrest in Denmark. METHODS: We conducted an observational cohort study based on nationwide registries and prospectively collected data on in-hospital cardiac arrest from 2017 and 2018 in Denmark. Unadjusted and adjusted analyses using regression models were performed to assess the association between socioeconomic status and outcomes after in-hospital cardiac arrest. Outcomes included return of spontaneous circulation (ROSC), survival to 30 days, survival to one year, and the duration of resuscitation among patients without ROSC. RESULTS: A total of 3,223 patients with in-hospital cardiac arrest were included in the study. In the adjusted analyses, high household assets were associated with 1.20 (95 %CI: 0.96, 1.51) times the odds of ROSC, 1.49 (95 %CI: 1.14, 1.96) times the odds of survival to 30 days, 1.40 (95 %CI: 1.04, 1.90) times the odds of survival to one year, and 2.8 (95 %CI: 0.9, 4.7) minutes longer duration of resuscitation among patients without ROSC compared to low household assets. Similar albeit attenuated associations were observed for education. While high household income was associated with better outcomes in the unadjusted analyses, these associations largely disappeared in the adjusted analyses. CONCLUSIONS: In this study of patients with in-hospital cardiac arrest, we found that high household assets were associated with a higher odds of survival and a longer duration of resuscitation among patients without ROSC compared to low household assets. However, the effect size may potentially be small. The results varied based on socioeconomic status measure, outcome of interest, and across adjusted analyses.

Intraoperative respiratory and hemodynamic strategies for reducing nausea, vomiting, and pain after surgery: Systematic review and meta-analysis.

BACKGROUND: Despite improved medical treatment strategies, postoperative pain, nausea, and vomiting remain major challenges. This systematic review investigated the relationship between perioperative respiratory and hemodynamic interventions and postoperative pain, nausea, and vomiting. METHODS: PubMed and Embase were searched on March 8, 2021 for randomized clinical trials investigating the effect of perioperative respiratory or hemodynamic interventions in adults undergoing non-cardiac surgery. Investigators reviewed trials for relevance, extracted data, and assessed risk of bias. Meta-analyses were performed when feasible. GRADE was used to assess the certainty of the evidence. RESULTS: This review included 65 original trials; of these 48% had pain, nausea, and/or vomiting as the primary focus. No reduction of postoperative pain was found in meta-analyses when comparing recruitment maneuvers with no recruitment, high (80%) to low (30%) fraction of oxygen, low (5-7 ml/kg) to high (9-12 ml/kg) tidal volume, or goal-directed hemodynamic therapy to standard care. In the meta-analysis comparing recruitment maneuvers with no recruitment maneuvers, patients undergoing laparoscopic gynecological surgery had less shoulder pain 24 h postoperatively (mean difference in the numeric rating scale from 0 to 10: -1.1, 95% CI: -1.7, -0.5). In meta-analyses, comparing high to low fraction of inspired oxygen and goal-directed hemodynamic therapy to standard care in patients undergoing abdominal surgery, the risk of postoperative nausea and vomiting was reduced (odds ratio: 0.45, 95% CI: 0.24, 0.87 and 0.48, 95% CI: 0.27, 0.85). The certainty in the evidence was mostly very low to low. The results should be considered exploratory given the lack of prespecified hypotheses and corresponding risk of Type 1 errors. CONCLUSION: There is limited evidence regarding the impact of intraoperative respiratory and hemodynamic interventions on postoperative pain or nausea and vomiting. More definitive trials are needed to guide clinical care within this area.