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Background

A major barrier to the analysis of ventilation waveform data collected during CPR is the presence of artefacts caused by chest compressions. This study describes the development and evaluation of an algorithm to extract parameters regarding ventilation volume, pressure, and frequency from pneumotachography waveform data collected during ongoing simulated CPR.

Method

Ventilation waveform data was collected from a pneumotachograph connected to the respiratory circuit of a ventilator and a test lung. Both regular ventilation and ventilation during simulated CPR were used to develop the algorithm. A grid search was employed to optimize the algorithm parameters compared to the ventilator settings. The parameters were then manually tuned using clinical data from ventilation during CPR. The performance of the algorithm was described in terms of the median error vs. the known ventilator settings in the simulated data.

Results

Compared to the ventilator settings, the largest systematic errors of the algorithm was an overestimation of peak pressures during asynchronous CPR (median error of 3 (IQR 0.3–5.8) cmH₂O), and an underestimation of inspiratory volumes during synchronous CPR (median error 46 (IQR −76 to 10) ml).

Conclusion

In an experimental setting, the developed algorithm provides a novel solution to measure ventilation parameters during ongoing chest compressions. The algorithm is freely available under an open-source licence for use and further development. Further studies will be needed to validate the algorithm.

Background: Patients in the intensive care unit (ICU) often receive analgesic and sedative drugs. There is limited knowledge about the resulting drug concentrations in blood in the critically ill patient, and how these concentrations change after death. In this single-centre prospective study of deceased patients from a general ICU, the aim was to describe blood concentrations and post-mortem redistribution for ten common analgesic and sedative drugs.

Methods: We included 46 patients who died during intensive care. Blood samples were collected pre-mortem (before death), peri-mortem (within one hour after death) and post-mortem (through aortic arch sampling at the morgue or during clinical or forensic autopsy). Samples were analysed for clonidine, dexmedetomidine, fentanyl, ketamine, ketobemidone, morphine, midazolam, paracetamol, propofol and thiopental.

Results: Post-mortem redistribution was significant for fentanyl, with a mean concentration increase from 3.1 ng/ g to 5.2 ng/g (p = 0.002). There was no correlation between neither cumulative fentanyl dose nor post-mortem interval and post-mortem concentration changes. For the other drugs, the changes during the post-mortem interval were not significant. Median peri-mortem concentrations were 2.3-9 times higher than observed concentrations in a larger cohort of living ICU patients.

Conclusion: In conclusion, of the investigated drugs, only fentanyl showed a predominant positive post-mortem redistribution, whereas for the other drugs, post-mortem changes were unpredictable. We also conclude that concentrations from the living may not be comparable to those obtained even shortly after death. These concentration differences, as well as the observed post-mortem changes, can influence toxicological interpretation.

Cardiovascular perturbations are frequently encountered during the perioperative period and remain a major contributor to the perioperative morbidity and mortality. A thorough knowledge of pathophysiologic changes that lead to cardiac arrest as well as management strategies to optimize organ perfusion and the chance of survival after circulatory arrest is therefore of utmost importance to all anesthesia providers and perioperative physicians. Improvement of patient survival and neurologic outcome is critically dependent on the implementation of the resuscitation guidelines that have been developed and continuously updated by experts within the fields of anesthesiology, cardiology, medicine, neurology, and reanimatology, and based on a thorough review of the experimental and clinical research data and available experience. In this chapter, we review relevant clinical and pathophysiological components of cardiopulmonary resuscitation and advanced cardiac life support, as well as key points from the most recent recommendations and guidelines by the American Heart Association and the European Resuscitation Council and the related literature and evidence.

BACKGROUND:

The ongoing TANGO2 (Telephone Assisted CPR. AN evaluation of efficacy amonGst cOmpression only and standard CPR) trial is designed to evaluate whether compression-only cardiopulmonary resuscitation (CPR) by trained laypersons is noninferior to standard CPR in adult out-of-hospital cardiac arrest. This pilot study assesses feasibility, safety, and intermediate clinical outcomes as part of the larger TANGO2 survival trial.

METHODS:

Emergency medical dispatch calls of suspected out-of-hospital cardiac arrest were screened for inclusion at 18 dispatch centers in Sweden between January 1, 2017, and March 12, 2020. Inclusion criteria were witnessed event, bystander on the scene with previous CPR training, age above 18 years of age, and no signs of trauma, pregnancy, or intoxication. Cases were randomized 1:1 at the dispatch center to either instructions to perform compression-only CPR (intervention) or instructions to perform standard CPR (control). Feasibility included evaluation of inclusion, randomization, and adherence to protocol. Safety measures were time to emergency medical service dispatch CPR instructions, and to start of CPR, intermediate clinical outcome was defined as 1-day survival.

RESULTS:

Of 11 838 calls of suspected out-of-hospital cardiac arrest screened for inclusion, 2168 were randomized and 1250 (57.7%) were out-of-hospital cardiac arrests treated by the emergency medical service. Of these, 640 were assigned to intervention and 610 to control. Crossover from intervention to control occurred in 16.3% and from control to intervention in 18.5%. The median time from emergency call to ambulance dispatch was 1 minute and 36 s (interquartile range, 1.1–2.2) in the intervention group and 1 minute and 30 s (interquartile range, 1.1–2.2) in the control group. Survival to 1 day was 28.6% versus 28.4% (P=0.984) for intervention and control, respectively.

CONCLUSIONS:

In this national randomized pilot trial, compression-only CPR versus standard CPR by trained laypersons was feasible. No differences in safety measures or short-term survival were found between the 2 strategies. Efforts to reduce crossover are important and may strengthen the ongoing main trial that will assess differences in long-term survival.

In Sweden 1600 patients/year survive cardiac arrest (30-day survival). Post-resuscitation care is complex and aims to stabilize organ function with focus on preventing secondary brain injury. In 2021 The European Resuscitation Council (ERC) and European Society of Intensive Care Medicine (ESICM) published joint guidelines on post-resuscitation care. In this article the Swedish Resuscitation Council summarizes the new guidelines with addition of more recent evidence to guide post-resuscitation care.

Vård efter hjärtstopp utgör en betydande andel av svensk intensivvård med ca 6 000 intensivvårdsdygn per år. 

Det finns i dag inga interventioner i intensivvården med hög evidens som har visat sig kunna minska de hjärnskador som uppkommer i samband med hjärtstopp. 

Rutinmässig koronarangiografi rekommenderas inte om patienten inte har ST-höjning på EKG. 

Temperaturkontroll med målet att hålla medvetslösa patienter feberfria i 72 timmar rekommenderas. 

Sedering i 24 timmar rekommenderas. 

Background: Standard dosages of analgesic and sedative drugs are given to intensive care patients. The resulting range of blood concentrations and corresponding clinical responses need to be better examined. The purpose of this study was to describe daily dosages, measured blood concentrations, and clinical responses in critically ill patients. The purpose was also to contribute to establishing whole blood concentration reference values of the drugs investigated.

Methods: A descriptive study of prospectively collected data from 302 admissions to a general intensive care unit (ICU) at a university hospital. Ten drugs (clonidine, fentanyl, morphine, dexmedetomidine, ketamine, ketobemidone, midazolam, paracetamol, propofol, and thiopental) were investigated, and daily dosages recorded. Blood samples were collected twice daily, and drug concentrations were measured. Clinical responses were registered using Richmond agitation-sedation scale (RASS) and Numeric rating scale (NRS).

Results: Drug dosages were within recommended dose ranges. Blood concentrations for all 10 drugs showed a wide variation within the cohort, but only 3% were above therapeutic interval where clonidine (57 of 122) and midazolam (38 of 122) dominated. RASS and NRS were not correlated to drug concentrations.

Conclusion: Using recommended dose intervals for analgesic and sedative drugs in the ICU setting combined with regular monitoring of clinical responses such as RASS and NRS leads to 97% of concentrations being below the upper limit in the therapeutic interval. This study contributes to whole blood drug concentration reference values regarding these 10 drugs.

BACKGROUND: Ventilation during cardiopulmonary resuscitation (CPR) has long been a part of the standard treatment during cardiac arrests. Ventilation is usually given either during continuous chest compressions (CCC) or during a short pause after every 30 chest compressions (30:2). There is limited knowledge of how ventilation is delivered if it effects the hemodynamics and if it plays a role in the occurrence of lung injuries. The aim of this study was to compare ventilation parameters, hemodynamics, blood gases and lung injuries during experimental CPR given with CCC and 30:2 in a porcine model.

METHODS: Sixteen pigs weighing approximately 33 kg were randomized to either receive CPR with CCC or 30:2. Ventricular fibrillation was induced by passing an electrical current through the heart. CPR was started after 3 min and given for 20 min. Chest compressions were provided mechanically with a chest compression device and ventilations were delivered manually with a self-inflating bag and 12 l/min of oxygen. During the experiment, ventilation parameters and hemodynamics were sampled continuously, and arterial blood gases were taken every five minutes. After euthanasia and cessation of CPR, the lungs and heart were removed in block and visually examined followed by sampling of lung tissue which were examined using microscopy.

RESULTS: In the CCC group and the 30:2 group, peak inspiratory pressure (PIP) was 58.6 and 35.1 cmH₂O (p < 0.001), minute volume (MV) 2189.6 and 1267.1 ml (p < 0.001), peak expired carbon dioxide (PECO₂) 28.6 and 39.4 mmHg (p = 0.020), partial pressure of carbon dioxide (PaCO₂) 50.2 and 61.1 mmHg (p = 0.013) and pH 7.3 and 7.2 (p = 0.029), respectively. Central venous pressure (CVP) decreased more over time in the 30:2 group (p = 0.023). All lungs were injured, but there were no differences between the groups.

CONCLUSIONS: Ventilation during CCC resulted in a higher PIP, MV and pH and lower PECO₂ and PaCO₂, showing that ventilation mode during CPR can affect ventilation parameters and blood gases.

OBJECTIVES: This study aimed to describe the burden of illness and impact on health and working situation among former intensive care patients treated for COVID-19.

METHODS: A prospective cohort study was performed at one intensive care unit of a university hospital in Sweden during the first wave of COVID-19 in spring 2020. The burden of illness in health status, cognitive, physical, and psychological outcomes, and working situation were assessed at four and 12 months after discharge from intensive care, using nine validated instruments.

RESULTS: Forty-six participants treated for COVID-19 participated in both follow-ups and were included in this study. General fatigue was reported by 37 of 46 participants (82%) at both follow-ups (p = 1.000). For overall health status 28 (61%) participants at the first follow-up and 26 (57%) (p = 0.414) at the second reported lower values than the general population. Cognitive impairment was seen in 22 (52%) participants at four months and in 13 (31%) at 12 months (p = 0.029). The proportion of participants on sick-leave decreased between the first and second follow-up (24% vs 13%, p = 0.025), but the proportion of participants working full-time was almost the same at both follow-ups (35% vs 37%, p = 0.317).

CONCLUSIONS: The burden of illness of patients treated in intensive care due to COVID-19 included cognitive, physical, and psychological impacts. Cognitive functions were improved after 12 months, but no clear improvements could be distinguished in the physical or psychological outcome. Higher burden of illness was associated with inability to return to work.

IMPORTANCE: Some individuals experience persistent symptoms after initial symptomatic SARS-CoV-2 infection (often referred to as Long COVID).

OBJECTIVE: To estimate the proportion of males and females with COVID-19, younger or older than 20 years of age, who had Long COVID symptoms in 2020 and 2021 and their Long COVID symptom duration.

DESIGN, SETTING, AND PARTICIPANTS: Bayesian meta-regression and pooling of 54 studies and 2 medical record databases with data for 1.2 million individuals (from 22 countries) who had symptomatic SARS-CoV-2 infection. Of the 54 studies, 44 were published and 10 were collaborating cohorts (conducted in Austria, the Faroe Islands, Germany, Iran, Italy, the Netherlands, Russia, Sweden, Switzerland, and the US). The participant data were derived from the 44 published studies (10 501 hospitalized individuals and 42 891 nonhospitalized individuals), the 10 collaborating cohort studies (10 526 and 1906), and the 2 US electronic medical record databases (250 928 and 846 046). Data collection spanned March 2020 to January 2022.

EXPOSURES: Symptomatic SARS-CoV-2 infection.

MAIN OUTCOMES AND MEASURES: Proportion of individuals with at least 1 of the 3 self-reported Long COVID symptom clusters (persistent fatigue with bodily pain or mood swings; cognitive problems; or ongoing respiratory problems) 3 months after SARS-CoV-2 infection in 2020 and 2021, estimated separately for hospitalized and nonhospitalized individuals aged 20 years or older by sex and for both sexes of nonhospitalized individuals younger than 20 years of age.

RESULTS: A total of 1.2 million individuals who had symptomatic SARS-CoV-2 infection were included (mean age, 4-66 years; males, 26%-88%). In the modeled estimates, 6.2% (95% uncertainty interval [UI], 2.4%-13.3%) of individuals who had symptomatic SARS-CoV-2 infection experienced at least 1 of the 3 Long COVID symptom clusters in 2020 and 2021, including 3.2% (95% UI, 0.6%-10.0%) for persistent fatigue with bodily pain or mood swings, 3.7% (95% UI, 0.9%-9.6%) for ongoing respiratory problems, and 2.2% (95% UI, 0.3%-7.6%) for cognitive problems after adjusting for health status before COVID-19, comprising an estimated 51.0% (95% UI, 16.9%-92.4%), 60.4% (95% UI, 18.9%-89.1%), and 35.4% (95% UI, 9.4%-75.1%), respectively, of Long COVID cases. The Long COVID symptom clusters were more common in women aged 20 years or older (10.6% [95% UI, 4.3%-22.2%]) 3 months after symptomatic SARS-CoV-2 infection than in men aged 20 years or older (5.4% [95% UI, 2.2%-11.7%]). Both sexes younger than 20 years of age were estimated to be affected in 2.8% (95% UI, 0.9%-7.0%) of symptomatic SARS-CoV-2 infections. The estimated mean Long COVID symptom cluster duration was 9.0 months (95% UI, 7.0-12.0 months) among hospitalized individuals and 4.0 months (95% UI, 3.6-4.6 months) among nonhospitalized individuals. Among individuals with Long COVID symptoms 3 months after symptomatic SARS-CoV-2 infection, an estimated 15.1% (95% UI, 10.3%-21.1%) continued to experience symptoms at 12 months.

CONCLUSIONS AND RELEVANCE: This study presents modeled estimates of the proportion of individuals with at least 1 of 3 self-reported Long COVID symptom clusters (persistent fatigue with bodily pain or mood swings; cognitive problems; or ongoing respiratory problems) 3 months after symptomatic SARS-CoV-2 infection.

BACKGROUND: The remaining symptoms in patients with coronavirus disease 2019 (COVID-19) treated in intensive care unit are limited described. Therefore, we assessed patient's perception of their COVID-19 disease, stay in intensive care, and remaining symptoms three to six months after intensive care.

METHODS: Prospective cohort study was performed in one intensive care unit of a university hospital in Sweden during the first wave. A questionnaire with open-ended questions and closed-ended questions was used. Data were analyzed using qualitative and quantitative content analysis and descriptive statistics.

RESULTS: Out of 123 patients treated for COVID-19, 64 answered the questionnaire 3-6 months after discharge from intensive care. Memories from illness and hospital stay revealed in three categories; awareness of the illness, losing anchor to reality and being cared for in a dynamic environment. Information was perceived as spare by 48% and they wanted the information to be more personal. The diary was perceived as personal and was received by 33% patients. The relationship with family was affected among 39% and 13% of the patients indicated that they had not resumed their daily life. A large amount, 84%, indicated that they had remaining symptoms from COVID-19. The dominated symptoms were impaired strength and energy both physically and mentally.

CONCLUSION: Patients reported a variety of physical and mental symptoms, and revealed memories from the ICU, and specific awareness of other patients' health. It illustrates the need for screening patients for remaining symptoms after COVID-19 disease and ICU care and may affect resuming patients' daily life.