Gut dysfunction and endoscopic lesions after out-of-hospital cardiac arrest

Extracerebral multiple organ dysfunction and interactions with brain injury after cardiac arrest

Cardiac arrest and successful resuscitation cause whole-body ischemia and reperfusion, leading to brain injury and extracerebral multiple organ dysfunction. Brain injury is the leading cause of death and long-term disability in resuscitated survivors, and was conceptualized and treated as an isolated injury, which has neglected the brain-visceral organ crosstalk. Extracerebral organ dysfunction is common and is significantly associated with mortality and poor neurological prognosis after resuscitation. However, detailed description of the characteristics of post-resuscitation multiple organ dysfunction is lacking, and the bidirectional interactions between brain and visceral organs need to be elucidated to explore new treatment for neuroprotection. This review aims to describe current concepts of post-cardiac arrest brain injury and specific characteristics of post-resuscitation dysfunction in cardiovascular, respiratory, renal, hepatic, adrenal, gastrointestinal, and neurohumoral systems. Additionally, we discuss the crosstalk between brain and extracerebral organs, especially focusing on how visceral organ dysfunction and other factors affect brain injury progression. We think that clarifying these interactions is of profound significance on how we treat patients for neural/systemic protection to improve outcome.

Impact of Hepatic Portal Venous Gas on the Prognosis of Traumatic Out-of-Hospital Cardiac Arrest: A Reason to Consider Terminating Cardiopulmonary Resuscitation

Background

We evaluated the prognosis of traumatic out-of-hospital cardiac arrest (OHCA) by assessing the presence of hepatic portal vein gas (HPVG) observed in ultrasound (US) or point-of-care ultrasonography (POCUS) performed during CPR. Furthermore, we aimed to understand the role of HPVG in decision-making regarding CPR discontinuation or withholding in traumatic OHCA.

Methods

The retrospective study was conducted at the level 1 trauma center of urban academic medical centers in South Korea. We included adult trauma OHCA patients who underwent CPR between January 1, 2020, and June 30, 2022. Data on traumatic OHCA patients who presented to the level I trauma center during this period were extracted from the hospital's electronic medical record system. The arrest data were separately managed through the hospital's electronic medical record system for quality control, specifically the arrest registry. US images or clips of the hepatic portal vasculature (HPV) during CPR were used to assess the presence of HPVG. These images were independently reviewed by two emergency medicine physicians with several years of US examination experience who were blinded to all clinical details and outcomes. We evaluated the prognosis of traumatic OHCA by assessing the presence of HPVG using the US. In addition, we analyzed the general characteristics and assessed the impact on the ROSC in traumatic OHCA.

Results

Among the 383 cardiac arrest patients, 318 traumatic OHCA patients were included. The mean age was 54.9 ± 19.4 years, and most patients were male. The initial rhythm was mainly asystole, and falls were the most frequent cause of injury. The overall ROSC rate was 18.8%, with a survival rate of 7.2% at hospital discharge. Among the 50 patients who underwent a US examination of HPV, 40 showed HPVG. The HPVG group had a significantly lower ROSC rate and survival rate at ED discharge and hospital discharge compared to the group without HPVG.

Conclusion

Traumatic OHCA with HPVG presents a significantly worse prognosis. This suggests that early consideration of termination or withholding of CPR may be appropriate in such cases.

Intestinal injury in cardiac arrest is associated with multiple organ dysfunction: A prospective cohort study

BACKGROUND

The impact of intestinal injury in cardiac arrest is not established. The first aim of this study was to assess associations between clinical characteristics in out-of-hospital cardiac arrest (OHCA) and a biomarker for intestinal injury, Intestinal Fatty Acid Binding Protein (IFABP). The second aim was to assess associations between IFABP and multiple organ dysfunction and 30-day mortality.

METHODS

We measured plasma IFABP in 50 patients at admission to intensive care unit (ICU) after OHCA. Demographic and clinical variables were analysed by stratifying patients on median IFABP, and by linear regression. We compared Sequential Organ Failure Assessment (SOFA) score, haemodynamic variables, and clinical-chemistry tests at day two between the "high" and "low" IFABP groups. Logistic regression was applied to assess factors associated with 30-day mortality.

RESULTS

Several markers of whole body ischaemia correlated with intestinal injury. Duration of arrest and lactate serum concentrations contributed to elevated IFABP in a multivariable model (p < 0.01 and p = 0.04, respectively). At day two, all seven patients who had died were in the "high" IFABP group, and all six patients who had been transferred to ward were in the "low" group. Of patients still treated in the ICU, the "high" group had higher total, renal and respiratory SOFA score (p < 0.01) and included all patients receiving inotropic drugs. IFABP predicted mortality (OR 16.9 per standard deviation increase, p = 0.04).

CONCLUSION

Cardiac arrest duration and lactate serum concentrations were risk factors for intestinal injury. High levels of IFABP at admission were associated with multiple organ dysfunction and mortality.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02648061.

Ischemic injury of the upper gastrointestinal tract after out-of-hospital cardiac arrest: a prospective, multicenter study

Background

The consequences of cardiac arrest (CA) on the gastro-intestinal tract are poorly understood. We measured the incidence of ischemic injury in the upper gastro-intestinal tract after Out-of-hospital CA (OHCA) and determined the risk factors for and consequences of gastrointestinal ischemic injury according to its severity.

Methods

Prospective, non-controlled, multicenter study in nine ICUs in France and Belgium conducted from November 1, 2014 to November 30, 2018. Included patients underwent an esophago-gastro-duodenoscopy 2 to 4 d after OHCA if still intubated and the presence of ischemic lesions of the upper gastro-intestinal tract was determined by a gastroenterologist. Lesions were a priori defined as severe if there was ulceration or necrosis and moderate if there was mucosal edema or erythema. We compared clinical and cardiac arrest characteristics of three groups of patients (no, moderate, and severe lesions) and identified variables associated with gastrointestinal ischemic injury using multivariate regression analysis. We also compared the outcomes (organ failure during ICU stay and neurological status at hospital discharge) of the three groups of patients.

Results

Among the 214 patients included in the analysis, 121 (57%, 95% CI 50–63%) had an upper gastrointestinal ischemic lesion, most frequently on the fundus. Ischemic lesions were severe in 55/121 (45%) patients. In multivariate regression, higher adrenaline dose during cardiopulmonary resuscitation (OR 1.25 per mg (1.08–1.46)) was independently associated with increased odds of severe upper gastrointestinal ischemic lesions; previous proton pump inhibitor use (OR 0.40 (0.14–1.00)) and serum bicarbonate on day 1 (OR 0.89 (0.81–0.97)) were associated with lower odds of ischemic lesions. Patients with severe lesions had a higher SOFA score during the ICU stay and worse neurological outcome at hospital discharge.

Conclusions

More than half of the patients successfully resuscitated from OHCA had upper gastrointestinal tract ischemic injury. Presence of ischemic lesions was independently associated with the amount of adrenaline used during resuscitation. Patients with severe lesions had higher organ failure scores during the ICU stay and a worse prognosis.

Clinical Trial RegistrationNCT02349074.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03939-9.

Post-Cardiac Arrest Syndrome Is Not Associated with An Early Bacterial Translocation

BACKGROUND

The aim of this study was to investigate bacterial translocation and its possible role in the development of post-resuscitation inflammatory response following Cardio-Pulmonary Resuscitation (CPR) after cardiac arrest.

METHODS

Munich female swine were employed for a model of cardiac arrest via application of electrical current. After 7 min, CPR was initiated, and animals were either successfully return to spontaneous circulation (ROSC) within 40 min or not (no-ROSC). At the end of experimental period and prior to sacrifice, samples from the intestine, mesenteric lymph nodes (MLN), liver and portal vein blood were obtained. Evaluation of inflammation and gut permeability was performed; MLN, liver and portal vein samples were analyzed for 16 s rRNA detection and cytokine mRNA expression.

RESULTS

A decreased expression of the tight junction protein Occludin, with higher levels of inflammation, greater epithelial disintegration, ulceration, loss of crypts and villi height were found in the intestines of the ROSC swine in comparison to no-ROSC. The macrophage surface antigen CD-14 staining was relatively more intense in the ROSC than in no-ROSC. Higher levels of TNF-α mRNA expression were present in the liver of the ROSC group. Finally, despite the inflammatory response and the gut mucosal alterations in ROSC group, no bacterial translocation was detected in liver, MLN and portal vein.

CONCLUSIONS

We show that resuscitation from cardiac arrest induces inflammatory response and intestinal permeability in swine 4h after resuscitation, but not a bacterial translocation. Bacterial translocation is not an early phase phenomenon but probably part of the pathophysiologic sequelae.

Non-occlusive mesenteric ischemia: Diagnostic challenges and perspectives in the era of artificial intelligence

Acute mesenteric ischemia (AMI) is a severe condition associated with poor prognosis, ultimately leading to death due to multiorgan failure. Several mechanisms may lead to AMI, and non-occlusive mesenteric ischemia (NOMI) represents a particular form of AMI. NOMI is prevalent in intensive care units in critically ill patients. In NOMI management, promptness and accuracy of diagnosis are paramount to achieve decisive treatment, but the last decades have been marked by failure to improve NOMI prognosis, due to lack of tools to detect this condition. While real-life diagnostic management relies on a combination of physical examination, several biomarkers, imaging, and endoscopy to detect the possibility of several grades of NOMI, research studies only focus on a few elements at a time. In the era of artificial intelligence (AI), which can aggregate thousands of variables in complex longitudinal models, the prospect of achieving accurate diagnosis through machine-learning-based algorithms may be sought. In the following work, we bring you a state-of-the-art literature review regarding NOMI, its presentation, its mechanics, and the pitfalls of routine work-up diagnostic exams including biomarkers, imaging, and endoscopy, we raise the perspectives of new biomarker exams, and finally we discuss what AI may add to the field, after summarizing what this technique encompasses.

Levosimendan Ameliorates Post-Resuscitation Acute Intestinal Microcirculation Dysfunction Partly Independent of Its Effects on Systemic Circulation: A Pilot Study On Cardiac Arrest In A Rat Model

BACKGROUND

Cardiac arrest (CA) is recognized as a life-threatening disease; however, the initial resuscitation success rate has increased due to advances in clinical treatment. Levosimendan has shown potential benefits in CA patients. However, its exact function on intestinal and systemic circulation in CA or post-cardiac arrest syndrome (PCAS) remained unclear. This study preliminarily investigated the link between dynamic changes in intestine and systemic hemodynamics post-resuscitation after levosimendan administration.

METHODS

Twenty-five rats were randomized into three groups: 1) sham control group (n = 5), 2) levosimendan group (n = 10), and 3) vehicle group (n = 10). Intestinal microcirculation was observed using a sidestream dark-field imaging device at baseline and each hour of the return of spontaneous circulation (≤6 h). Systemic hemodynamics, serum indicators of cardiac injury, and tissue perfusion/metabolism were measured by echo-cardiography, a biological signal acquisition system, and an enzyme-linked immunosorbent assay (ELISA), respectively.

RESULTS

Myocardial injury and global and intestinal perfusion/metabolism were significantly improved by levosimendan treatment. There was no statistically significant difference in the mean arterial pressure values between the vehicle and levosimendan groups (P > 0.05). The intestinal and systemic circulation measurements showed poor correlation (Pearson r-value of variable combinations in the levosimendan group was much less than 0.75; P < 0.01, levosimendan vs. vehicle group).

CONCLUSIONS

Levosimendan significantly reduced the cardiac injury and corrected the metabolic status in an experimental rat model of ventricular fibrillation (VF) induced CA and CPR. Levosimendan may ameliorate PCAS-induced intestinal microcirculation dysfunction, partly independent of its effects on macrocirculation.

Mortality in patients with hepatic gas on point-of-care ultrasound in cardiac arrest: Does location matter?

PURPOSE

Prior research has suggested an association of hepatic venous gas with mortality in cardiac arrest. As point of care ultrasound (POCUS) is frequently used in the context of resuscitation, we sought to evaluate if the presence of hepatic gas on POCUS had a similar mortality association.

METHODS

A retrospective review was conducted of patients who experienced nontraumatic cardiac arrest. Archived ultrasound images were independently reviewed to determine the presence of gas in the hepatic parenchyma and vasculature. Electronic medical records were then reviewed to collect remaining clinical data.

RESULTS

From 1 January 2017 through 16 June 2019, 87 patients met inclusion criteria. Among them, 68 (78.2%) patients died. Among those who died, 40 (58.8%) had hepatic gas, while 28 (41.2%) had none. Only a single survivor demonstrated hepatic venous gas (11%). While the difference in mortality with respect to presence of undifferentiated hepatic gas was not significant (P = .37), there was a significant difference with respect to the presence of venous gas (P = .004).

CONCLUSION

Our study demonstrated that the incidence of postarrest hepatic gas on POCUS was common, and that the presence of hepatic venous gas during cardiac resuscitation was associated with increased mortality, while hepatic parenchymal gas alone was not.

Comparison of the Protective Effect of Different Mild Therapeutic Hypothermia Temperatures on Intestinal Injury After Cardiopulmonary Resuscitation in Rats

BACKGROUND

Therapeutic temperature management (TTM) is the standard treatment protocol for unconscious post-resuscitation patients. However, there is still controversy about the ideal targeted temperature of mild hypothermia therapy. Additionally, studies about protective therapy for post-resuscitation intestinal injury are very limited. Therefore, this study was performed to explore: whether mild hypothermia therapy can exert a protective effect on post-resuscitation intestinal injury; the protective effect of different targeted temperatures on post-resuscitation intestinal injury and the ideal targeted temperature; the potential protective mechanism of mild hypothermia therapy for post-resuscitation intestinal injury.

METHODS

Ventricular fibrillation was electrically induced and untreated for 6 min while defibrillation was attempted after 8 min of cardiopulmonary resuscitation in 15 rats. After successful resuscitation, animals were randomized into three groups: control; TTM-35; TTM-33. In animals of the control group, temperature was maintained at 37 ± 0.2°C for 6 h. In animals of the two TTM groups, temperature was maintained at 33 ± 0.2°C or 35 ± 0.2°C for 6 h, respectively. During mild hypothermia therapy, intestinal microcirculation was measured at 60, 240, and 360 min after resuscitation. Animals were euthanized 6.5 h after resuscitation. The morphological changes in the intestinal tissue, systemic and local inflammatory factors, and intestinal injury markers were measured and analyzed. The tight junction proteins in the intestinal epithelium, cell-cell contact protein E-cadherin expression, myosin light chain (MLC) and myosin light chain kinase levels, and the NF-κB p65 signaling pathway were analyzed by western blotting.

RESULTS

Compared with results in the control group, mild hypothermia therapy (TTM-33 and TTM-35 groups) significantly improved post-resuscitation intestinal microcirculation and pathological scores, decreased systemic and local intestinal tissue inflammatory factor levels, inhibited the NF-κB signaling pathway and downstream MLC phosphorylation, and significantly decreased MLC phosphorylation-associated loss of intestinal tight junction proteins and E-cadherin (P < 0.05). A 33°C target temperature could exert more protective effects than 35°C on post-resuscitation intestinal injury, such as improving intestinal microcirculation, decreasing intestinal ischemia factor iFABP, and plasma endotoxin levels, inhibiting the NF-κB signaling pathway and downstream MLC phosphorylation, and suppressing the loss of intestinal tight junctions and E-cadherin (P < 0.05).

CONCLUSIONS

Mild hypothermia therapy can improve post-resuscitation intestinal injury, and a targeted temperature of 33°C may confer more benefit for mitigation of intestinal injury as compared with a targeted temperature of 35°C.

Frequency, risk factors, and outcomes of non-occlusive mesenteric ischaemia after cardiac arrest

PURPOSE

Mesenteric ischaemia after successfully resuscitated cardiac arrest (CA) has been insufficiently studied. We aimed to assess the frequency, risk factors, and outcomes of non-occlusive mesenteric ischaemia (NOMI) after CA.

METHODS

We retrospectively included patients admitted to a CA centre with sustained return of spontaneous circulation between 2007 and 2017. NOMI was suspected based on clinical symptoms and classified as possible if no tests were feasible or the only test was a negative abdominal computed tomography (CT) scan and as confirmed if diagnosed by endoscopy, CT, or surgery.

RESULTS

Of 1343 patients, 82 (6%) had suspected NOMI, including 33 (2.5%) with confirmed NOMI. Investigations for suspected NOMI were done in 47/82 (57%) patients (CT, n = 30; lower digestive endoscopy, n = 14; and upper digestive endoscopy, n = 12); 11 patients underwent surgery. By multivariate analysis, factors associated with suspected NOMI were female sex (OR, 1.8; 95%CI, 1.1-2.9, p = 0.02), cardiovascular comorbidities (OR, 1.6; 95%CI, 1.0-2.7; p = 0.047), admission lactate >5 mmol/L (OR, 2.0; 95%CI, 1.2-3.4; p = 0.01), low flow >17 min (OR, 2.2; 95%CI, 1.3-3.8; p = 0.003), and inotropic score >7 μg/kg/min (OR, 1.8; 95%CI, 1.1-3.2; p = 0.03). ICU mortality was 96% (79/82), with 61% of patients dying from multi-organ failure (MOF) and 35% from post-anoxic brain injury. Of the eight patients who regained consciousness, 5 finally died from MOF, leaving 3 patients discharged alive from the ICU with a good neurologic outcome.

CONCLUSIONS

NOMI may affect 2.5-6% of patients after CA. Mortality was extremely high in patients, and very few survived with a good neurological outcome.

Epinephrine treatment but not time to ROSC is associated with intestinal injury in patients with cardiac arrest

AIM

Current guidelines suggest the use of epinephrine in patients with cardiac arrest (CA). However, evidence for increased survival in good neurological condition is lacking. In experimental settings, epinephrine-induced impairment of microvascular flow was shown. The aim of our study was to analyze the association between epinephrine treatment and intestinal injury in patients after CA.

METHODS

We have included 52 patients with return of spontaneous circulation (ROSC) after CA admitted to our medical intensive care unit (ICU). Blood was taken on admission and levels of circulating intestinal fatty acid binding protein (iFABP) were analyzed.

RESULTS

Patients were 64 (49.8-73.8) years old and predominantly male (76.9%). After six months, 50% of patients died and 38.5% of patients had a cerebral performance category (CPC)-score of 1-2. iFABP levels were lower in survivors (234 IQR 90-399 pg/mL) as compared to non-survivors (283, IQR 86-11500 pg/mL; p < 0.05). Plasma levels of iFABP were not associated with time to ROSC but correlated with epinephrine-dose (R = 0.32; p < 0.05). 40% of patients receiving ≥3 mg of epinephrine as compared to 10.5% of patients treated with <3 mg (p < 0.05) developed iFABP plasma levels >1500 pg/mL, which was associated with dramatically increased mortality (HR4.87, 95%CI 1.95-12.1; p < 0.001). iFABP levels predicted mortality independent from time to ROSC and the disease severity score SAPS II. In contrast to mortality, iFABP plasma levels were not associated with neurological outcome.

CONCLUSIONS

In this small, single centre study, cumulative dose of epinephrine used in cardiac arrest patients was associated with an increase in biomarker indicative of intestinal injury and 6-month mortality.

Characterization of neutrophil-neuronal co-cultures to investigate mechanisms of post-ischemic immune-mediated neurotoxicity

BACKGROUND

Immune-mediated reperfusion injury is a critical component of post-ischemic central nervous system (CNS) damage. In this context, the activation and recruitment of polymorphonuclear neutrophils (PMNs) to the CNS induces neurotoxicity in part through the release of degradative enzymes, cytokines, and reactive oxygen species. However, the extent to which close-range interactions between PMNs and neurons contribute to injury in this context has not been directly investigated.

NEW METHOD

We devised a co-culture model to investigate mechanisms of PMN-dependent neurotoxicity. Specifically, we established the effect of PMN dose, co-incident neuronal ischemia, lipopolysaccharide (LPS)-induced PMN priming, and the requirement for cell-cell contact on cumulative neuron damage.

RESULTS AND COMPARISON TO EXISTING METHOD(S)

Pre-exposure of day in vitro 10 primary cortical neurons to oxygen-glucose deprivation (OGD) enhanced PMN-dependent neuronal death. Likewise, LPS-induced priming of the PMN donor further increased PMN-induced toxicity in vitro compared to saline-injected controls. Compartmentalization of LPS-primed PMNs using net wells confirmed the requirement for close-range cell-cell interactions in the process of PMN-induced neuronal injury. Moreover, time-lapse imaging and quantitative neurite analyses implicate PMN-neurite interactions in this pathological response. These experiments establish a platform to investigate immune and neural factors that contribute to post-ischemic neurodegeneration.

CONCLUSIONS

Ischemic and immune priming enhance neurotoxicity in PMN-neuronal co-cultures. Moreover, cell-cell contact and neurite destruction are prominent features in the observed mechanism of post-ischemic neuronal death.

The post-cardiac arrest syndrome: A case for lung-brain coupling and opportunities for neuroprotection

Systemic inflammation and multi-organ failure represent hallmarks of the post-cardiac arrest syndrome (PCAS) and predict severe neurological injury and often fatal outcomes. Current interventions for cardiac arrest focus on the reversal of precipitating cardiac pathologies and the implementation of supportive measures with the goal of limiting damage to at-risk tissue. Despite the widespread use of targeted temperature management, there remain no proven approaches to manage reperfusion injury in the period following the return of spontaneous circulation. Recent evidence has implicated the lung as a moderator of systemic inflammation following remote somatic injury in part through effects on innate immune priming. In this review, we explore concepts related to lung-dependent innate immune priming and its potential role in PCAS. Specifically, we propose and investigate the conceptual model of lung-brain coupling drawing from the broader literature connecting tissue damage and acute lung injury with cerebral reperfusion injury. Subsequently, we consider the role that interventions designed to short-circuit lung-dependent immune priming might play in improving patient outcomes following cardiac arrest and possibly other acute neurological injuries.

Targeted temperature management using the "Esophageal Cooling Device" after cardiac arrest (the COOL study): A feasibility and safety study

BACKGROUND

Targeted temperature management (TTM) between 32 and 36°C is recommended after out-of-hospital cardiac arrest (OHCA). We aimed to assess the feasibility and safety of the "Esophageal Cooling Device" (ECD) in performing TTM.

PATIENTS AND METHODS

This single-centre, prospective, interventional study included 17 comatose OHCA patients. Main exclusion criteria were: delay between OHCA and return of spontaneous circulation (ROSC)>60min, delay between sustained ROSC and inclusion >360min, known oesophageal disease. A TTM between 32 and 34°C was performed using the ECD (Advanced Cooling Therapy, USA) connected to a heat exchanger console (Meditherm III^®, Gaymar, France), without cold fluids' use. Primary endpoint was feasibility of inducing, maintaining TTM, and rewarming using the ECD alone. Secondary endpoints were adverse events, focusing on potential digestive damages. Results were expressed as median (interquartiles 25-75).

RESULTS

Cooling rate to reach the Target Temperature (33°C-TT) was 0.26°C/h [0.19-0.36]. All patients reached the 32-34°C range with a time spent within the range of 26h [21-28] (3 patients did not reach 33°C). Temperature deviation outside the TT during TTM-maintenance was 0.10°C [0.03-0.20]. Time with deviation >1°C was 0h. Rewarming rate was 0.20°C/h [0.18-0.22]. Among the 16 gastrointestinal endoscopy procedures performed, 10 (62.5%) were normal. Minor oeso-gastric injuries (37.5% and 19%, respectively) were similar to usual orogastric tube injuries. One patient experienced severe oesophagitis mimicking peptic lesions, not cooling-related. No patient among the 9 alive at 3-month follow-up had gastrointestinal complains.

CONCLUSION

ECD seems an interesting, safe, accurate, semi-invasive cooling method in OHCA patients treated with 33°C-TTM, particularly during the maintenance phase.

Endotoxemia induces lung-brain coupling and multi-organ injury following cerebral ischemia-reperfusion

Post-ischemic neurodegeneration remains the principal cause of mortality following cardiac resuscitation. Recent studies have implicated gastrointestinal ischemia in the sepsis-like response associated with the post-cardiac arrest syndrome (PCAS). However, the extent to which the resulting low-grade endotoxemia present in up to 86% of resuscitated patients affects cerebral ischemia-reperfusion injury has not been investigated. Here we report that a single injection of low-dose lipopolysaccharide (50μg/kg, IP) delivered after global cerebral ischemia (GCI) induces blood-brain barrier permeability, microglial activation, cortical injury, and functional decline in vivo, compared to ischemia alone. And while GCI was sufficient to induce neutrophil (PMN) activation and recruitment to the post-ischemic CNS, minimal endotoxemia exhibited synergistic effects on markers of systemic inflammation including PMN priming, lung damage, and PMN burden within the lung and other non-ischemic organs including the kidney and liver. Our findings predict that acute interventions geared towards blocking the effects of serologically occult endotoxemia in survivors of cardiac arrest will limit delayed neurodegeneration, multi-organ dysfunction and potentially other features of PCAS. This work also introduces lung-brain coupling as a novel therapeutic target with broad effects on innate immune priming and post-ischemic neurodegeneration following cardiac arrest and related cerebrovascular conditions.

Is enteral feeding tolerated during therapeutic hypothermia?

OBJECTIVE

To determine whether patients undergoing therapeutic hypothermia following cardiac arrest tolerate early enteral nutrition.

METHODS

We undertook a single-centre longitudinal cohort analysis of the tolerance of enteral feeding by 55 patients treated with therapeutic hypothermia following resuscitation from cardiac arrest. The observation period was divided into three phases: (1) 24h at target temperature (32-34 °C); (2) 24h rewarming to 36.5 °C; and (3) 24h maintained at a core temperature below 37.5 °C.

RESULTS

During period 1, patients tolerated a median of 72% (interquartile range (IQR) 68.7%; range 31.3-100%) of administered feed. During period 2 (rewarming phase), a median of 95% (IQR 66.2%; range 33.77-100%) of administered feed was tolerated. During period 3 (normothermia) a median of 100% (IQR 4.75%; range 95.25-100%) of administered feed was tolerated. The highest incidence of vomiting or regurgitation of feed (19% of patients) occurred between 24 and 48 h of therapy.

CONCLUSIONS

Patients undergoing therapeutic hypothermia following cardiac arrest may be able to tolerate a substantial proportion of their daily nutritional requirements. It is possible that routine use of prokinetic drugs during this period may increase the success of feed delivery enterally and this could usefully be explored.

Markers of intestinal injury are associated with endotoxemia in successfully resuscitated patients

AIMS

Gut dysfunction is suspected to play a major role in the pathophysiology of post-resuscitation disease through an increase in intestinal permeability and endotoxin release. However this dysfunction often remains occult and is poorly investigated. The aim of this pilot study was to explore intestinal failure biomarkers in post-cardiac arrest patients and to correlate them with endotoxemia.

METHODS

Following resuscitation after cardiac arrest, 21 patients were prospectively studied. Urinary intestinal fatty acid-binding protein (IFABP), which marks intestinal permeability, plasma citrulline, which reflects the functional enterocyte mass, and whole blood endotoxin were measured at admission, days 1-3 and 6. We explored the kinetics of release and the relationship between IFABP, citrulline and endotoxin values.

RESULTS

IFABP was extremely high at admission and normalized at D3 (6668 pg/mL vs 39 pg/mL, p=0.01). Lowest median of citrulline (N=20-40 μmol/L) was attained at D2 (11 μmol/L at D2 vs 24 μmol/L at admission, p=0.01) and tended to normalize at D6 (21 μmol/L). During ICU stay, 86% of patients presented a detectable endotoxemia. Highest endotoxin level was positively correlated with highest IFABP level (R(2)=0.31, p=0.01) and was inversely correlated with lowest plasma citrulline levels (R(2)=0.55, p<0.001). Endotoxin levels increased between admission and D2 in patients with post-resuscitation shock, whereas it decreases in patients with no shock (median +0.33 EU vs -0.19 EU, p=0.03). Highest endotoxin level was positively correlated with D3 SOFA score (R(2)=0.45, p=0.004).

CONCLUSION

Biomarkers of intestinal injury are altered after cardiac arrest and are associated with endotoxemia. This could worsen post-resuscitation shock and organ failure.

Postresuscitation care

Cardiac arrest in infants and children is a rare but critical event that typically follows a period of respiratory or circulatory compromise and has a low survival rate. The only intervention demonstrated to increase survival rate is the provision of bystander CPR. This article examines the pathophysiology of the postarrest reperfusion state; postresuscitation care of the respiratory and cardiovascular systems; postresuscitation neurologic management; therapeutic hypothermia; blood glucose control; immunologic disturbances and infections; coagulation abnormalities; and gastrointestinal and hepatic dysfunction, among other topics.