The Incidence of Perioperative Hypotension in Patients Undergoing Major Abdominal Surgery with the Use of Arterial Waveform Analysis and the Hypotension Prediction Index Hemodynamic Monitoring-A Retrospective Analysis.

Intraoperative hypotension (IH) is common in patients receiving general anesthesia and can lead to serious complications such as kidney failure, myocardial injury and increased mortality. The Hypotension Prediction Index (HPI) algorithm is a machine learning system that analyzes the arterial pressure waveform and alerts the clinician of an impending hypotension event. The purpose of the study was to compare the frequency of perioperative hypotension in patients undergoing major abdominal surgery with different types of hemodynamic monitoring. The study included 61 patients who were monitored with the arterial pressure-based cardiac output (APCO) technology (FloTrac group) and 62 patients with the Hypotension Prediction Index algorithm (HPI group). Our primary outcome was the time-weighted average (TWA) of hypotension below < 65 mmHg. The median TWA of hypotension in the FloTrac group was 0.31 mmHg versus 0.09 mmHg in the HPI group (p = 0.000009). In the FloTrac group, the average time of hypotension was 27.9 min vs. 8.1 min in the HPI group (p = 0.000023). By applying the HPI algorithm in addition to an arterial waveform analysis alone, we were able to significantly decrease the frequency and duration of perioperative hypotension events in patients who underwent major abdominal surgery.

Cerebral Perfusion Pressure-Guided Therapy in Patients with Subarachnoid Haemorrhage-A Retrospective Analysis.

BACKGROUND: Prevention and treatment of haemodynamic instability and increased intracranial pressure (ICP) in patients with subarachnoid haemorrhage (SAH) is vital. This study aimed to evaluate the effects of protocolised cerebral perfusion pressure (CPP)-guided treatment on morbidity and functional outcome in patients admitted to the intensive care unit (ICU) with SAH. METHODS: We performed a retrospective study comparing 37 patients who received standard haemodynamic treatment (control group) with 17 individuals (CPP-guided group) who were on the CPP-guided treatment aimed at maintaining CPP > 70 mmHg using both optimisations of ICP and mean arterial pressure (MAP). RESULTS: MAP, cumulative crystalloid doses and fluid balance were similar in both groups. However, the incidence of delayed cerebral ischaemia was significantly lower in the CPP-guided group (14% vs. 64%, p < 0.01), and functional outcome as assessed by the Glasgow Outcome Scale at 30 days after SAH was improved (29.0% vs. 5.5%, p = 0.03). CONCLUSIONS: This preliminary analysis showed that implementing a CPP-guided treatment approach aimed at maintaining a CPP > 70 mmHg may reduce the occurrence of delayed cerebral ischaemia and improve functional outcomes in patients with SAH. This observation merits further prospective investigation of the use of CPP-guided treatment in patients with SAH.

Monitoring Treatment, Risks and Side Effects.

Inflammation plays a key role in the pathophysiology of organ dysfunction in the critically ill patients and is triggered by an overwhelming host response resulting in the overproduction of various cytokines. Regaining immune homeostasis over the dysregulated immune response through broad removal of cytokines using extracorporeal blood purification therapies has recently gained increasing attention. Nonetheless, many questions remain regarding the appropriate monitoring treatment, its potential risks, and side effects. The CytoSorb blood purification, the most extensively investigated device, has been shown to effectively remove an array of cytokines that may lead to rapid hemodynamic stabilization as indicated by reduced vasopressor need during the treatment, as well as an improvement in vital organ function. However, reported survival benefits have been fairly inconsistent. The therapy has also been confirmed as being safe and well tolerated. Despite several questions remaining such as the right timing, duration, frequency, concomitant antibiotic use, and most appropriate patient group with the highest change of benefit, the additional use as adjuvant therapy in hyperinflammatory states and/or in patients refractory to best standard care seems reasonable. Of note, there are several randomized controlled trials currently registered and ongoing that hopefully will provide answers to some of the above questions in the not-too-distant future.

Intraoperative Hypotension Prediction-A Proactive Perioperative Hemodynamic Management-A Literature Review.

Intraoperative hypotension (IH) is a frequent phenomenon affecting a substantial number of patients undergoing general anesthesia. The occurrence of IH is related to significant perioperative complications, including kidney failure, myocardial injury, and even increased mortality. Despite advanced hemodynamic monitoring and protocols utilizing goal directed therapy, our management is still reactive; we intervene when the episode of hypotension has already occurred. This literature review evaluated the Hypotension Prediction Index (HPI), which is designed to predict and reduce the incidence of IH. The HPI algorithm is based on a machine learning algorithm that analyzes the arterial pressure waveform as an input and the occurrence of hypotension with MAP <65 mmHg for at least 1 min as an output. There are several studies, both retrospective and prospective, showing a significant reduction in IH episodes with the use of the HPI algorithm. However, the level of evidence on the use of HPI remains very low, and further studies are needed to show the benefits of this algorithm on perioperative outcomes.

Admission Lactate Concentration, Base Excess, and Alactic Base Excess Predict the 28-Day Inward Mortality in Shock Patients.

Base excess (BE) and lactate concentration may predict mortality in critically ill patients. However, the predictive values of alactic BE (aBE; the sum of BE and lactate), or a combination of BE and lactate are unknown. The study aimed to investigate whether BE, lactate, and aBE measured on admission to ICU may predict the 28-day mortality for patients undergoing any form of shock. In 143 consecutive adults, arterial BE, lactate, and aBE were measured upon ICU admission. Receiver Operating Curve (ROC) characteristics and Cox proportional hazard regression models (adjusted to age, gender, forms of shock, and presence of severe renal failure) were then used to investigate any association between these parameters and 28-day mortality. aBE < −3.63 mmol/L was found to be associated with a hazard ratio of 3.19 (HR; 95% confidence interval (CI): 1.62−6.27) for mortality. Risk of death was higher for BE < −9.5 mmol/L (HR: 4.22; 95% CI: 2.21−8.05), particularly at lactate concentrations > 4.5 mmol/L (HR: 4.62; 95% CI: 2.56−8.33). A 15.71% mortality rate was found for the combined condition of BE > cut-off and lactate < cut-off. When BE was below but lactate above their respective cut-offs, the mortality rate increased to 78.91%. The Cox regression model demonstrated that the predictive values of BE and lactate were mutually independent and additive. The 28-day mortality in shock patients admitted to ICU can be predicted by aBE, but BE and lactate deliver greater prognostic value, particularly when combined. The clinical value of our findings deserves further prospective evaluation.

SepsEast Registry indicates high mortality associated with COVID-19 caused acute respiratory failure in Central-Eastern European intensive care units.

The coronavirus disease (COVID-19) pandemic caused unprecedented research activity all around the world but publications from Central-Eastern European countries remain scarce. Therefore, our aim was to characterise the features of the pandemic in the intensive care units (ICUs) among members of the SepsEast (Central-Eastern European Sepsis Forum) initiative. We conducted a retrospective, international, multicentre study between March 2020 and February 2021. All adult patients admitted to the ICU with pneumonia caused by COVID-19 were enrolled. Data on baseline and treatment characteristics, organ support and mortality were collected. Eleven centres from six countries provided data from 2139 patients. Patient characteristics were: median 68, [IQR 60-75] years of age; males: 67%; body mass index: 30.1 [27.0-34.7]; and 88% comorbidities. Overall mortality was 55%, which increased from 2020 to 2021 (p = 0.004). The major causes of death were respiratory (37%), cardiovascular (26%) and sepsis with multiorgan failure (21%). 1061 patients received invasive mechanical ventilation (mortality: 66%) without extracorporeal membrane oxygenation (n = 54). The rest of the patients received non-invasive ventilation (n = 129), high flow nasal oxygen (n = 317), conventional oxygen therapy (n = 122), as the highest level of ventilatory support, with mortality of 50%, 39% and 22%, respectively. This is the largest COVID-19 dataset from Central-Eastern European ICUs to date. The high mortality observed especially in those receiving invasive mechanical ventilation renders the need of establishing national-international ICU registries and audits in the region that could provide high quality, transparent data, not only during the pandemic, but also on a regular basis.

The effect of volatile anesthetics on cellular responses in the microcirculation of free tissue transfers.

The purpose of this review was to summarize the anti-inflammatory and immunosuppressive properties of volatile anesthetics and present their potential impact on the outcomes of major surgical procedures as well as microsurgical cases of free tissue transfer. Inhaled anesthetics are commonly used as a component of general anesthesia in interventional procedures, reconstructive surgery, free tissue transfers and transplantation. Experimental and clinical studies have shown that volatile anesthetics such as halothane, sevoflurane, isoflurane or desflurane can affect the immune system of patients exposed to general anesthesia. In patients with no serious systemic diseases, this effect is transient and mostly clinically irrelevant. However, in patients subjected to the inflammatory response due to the active disease, cardiac or pulmonary failure or advanced age, the prognosis may improve or worsen following inhalation anesthesia depending on the type of systemic pathology. The available data from reported clinical trials, as well as the in vitro and in vivo experimental studies, have often reported conflicting statements regarding the impact of inhalation anesthetics on outcomes of surgical procedures. These differences may be due to the heterogeneity of the evaluated patients, the extent and duration of surgical procedures, and different experimental design and methodologies applied for assessment of the reported clinical and research studies. In this review, based on the available literature reports we have summarized the anti-inflammatory and immunosuppressive effects as well as cellular responses of inhalation anesthetics at the microcirculatory level and discussed their potential clinical implications for the outcomes of surgical procedures of free tissue transfers.

Dosing of Extracorporeal Cytokine Removal In Septic Shock (DECRISS): protocol of a prospective, randomised, adaptive, multicentre clinical trial.

INTRODUCTION: Sepsis and septic shock have mortality rates between 20% and 50%. In sepsis, the immune response becomes dysregulated, which leads to an imbalance between proinflammatory and anti-inflammatory mediators. When standard therapeutic measures fail to improve patients' condition, additional therapeutic alternatives are applied to reduce morbidity and mortality. One of the most recent alternatives is extracorporeal cytokine adsorption with a device called CytoSorb. This study aims to compare the efficacy of standard medical therapy and continuous extracorporeal cytokine removal with CytoSorb therapy in patients with early refractory septic shock. Furthermore, we compare the dosing of CytoSorb adsorber device changed every 12 or 24 hours. METHODS AND ANALYSIS: It is a prospective, randomised, controlled, open-label, international, multicentre, phase III study. Patients fulfilling the inclusion criteria will be randomly assigned to receive standard medical therapy (group A) or-in addition to standard treatment-CytoSorb therapy. CytoSorb treatment will be continuous and last for at least 24 hours, CytoSorb adsorber device will be changed every 12 (group B) or 24 hours (group C). Our primary outcome is shock reversal (no further need or a reduced (≤10% of the maximum dose) vasopressor requirement for 3 hours) and time to shock reversal (number of hours elapsed from the start of the treatment to shock reversal).Based on sample size calculation, 135 patients (1:1:1) will need to be enrolled in the study. A predefined interim analysis will be performed after reaching 50% of the planned sample size, therefore, the corrected level of significance (p value) will be 0.0294. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Scientific and Research Ethics Committee of the Hungarian Medical Research Council (OGYÉI/65049/2020). Results will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT04742764; Pre-results.

An acid-base disorders analysis with the use of the Stewart approach in patients with sepsis treated in an intensive care unit.

BACKGROUND: Patients with sepsis admitted to the intensive care unit often present with acid-base disorders. As the traditional interpretation might be clinically misleading, an alternative approach described by Stewart may allow one to quantify the individual components of acid-base abnormalities and provide an insight into their pathogenesis. The aim of our study was to compare the traditional and Stewart approaches in the analysis of acid-base disturbance. METHODS: We analyzed arterial blood gases (ABG) taken from 43 ICU septic patients from admission to discharge categorising them according to SBE values. The traditional concept analysis was compared with the physicochemical approach using the Stewart equations. RESULTS: 990 ABGs were analysed. In the SBE < -2 mEq L⁻¹ group, hyperlactatemia was observed in 34.7% ABG, hypoalbuminemia in 100% and SIG acidosis in 42% ABG. Moreover, a Cl/Na ratio > 0.75 was present in 96.9% ABG. In the normal range SBE group, elevated lactates were present in 21.3% ABG, SIG acidosis in 14.9%, elevated Cl/Na ratio in 98.4% and hypoalbuminemia in all 324 ABG. In the metabolic alkalosis group (SBE > +2 mEq L⁻¹), hyperlactatemia was observed in 18.4% ABG, SIG acidosis in 5% ABG, Cl/Na ratio> 0.75 in 88.8%, while 99.1% samples revealed hypoalbuminemia. CONCLUSION: The use of the Stewart model may improve our understanding of the underlying pathophysiological mechanism and the true etiology of the derangements of acid-base disorders. Indeed, it proves that patients may suffer from mixed arterial blood gas disorders hidden under normal values of SBE and pH.

Theorethical principles of fluid managment according to physicochemical Stewart approach.

Interpreting acid base disturbances according to the physicochemical Stewart approach allows the cause of such abnormalities to be discovered. This method is based on three independent variables: SID (strong ion difference), mainly sodium and chloride; weak acids concentration - Atot, mainly albumins and phosphate; and carbon dioxide tension - pCO2. These three independent variables are responsible for the change of water dissociation and for the change in H+ concentration and, consequently, the change in serum pH value. The SID value of the fluids administered to a patient is responsible for the change of serum SID value and therefore causes a change in the patient's acid base status. During the infusion of a given fluid, the SID value of the serum becomes closer to the SID value of that fluid; on the other hand, the infusion causes a decrease in Atot concentration. In order to avoid acid base disturbances connected with fluid administration, the SID value of fluids being administered should be greater than 0 and lower then the serum SID. It has been suggested that fluids should be given of which the SID value is as close as possible to the actual serum HCO3 concentration. Knowing the SID value of the fluid administered, and the serum HCO3 concentration, one can expect a change of serum pH after a fluid infusion. Administering a fluid with a SID greater than the HCO3 concentration causes a pH increase towards alkalosis. Likewise, administering a a fluid with a SID lower than the HCO3 concentration causes a pH decrease towards acidosis. It seems that knowledge of the electrolyte concentration and the SID value of an administered fluid is an important factor regarding acid base disturbances.

Acid-base disorder analysis during diabetic ketoacidosis using the Stewart approach--a case report.

This case report presents a 49 year-old female with type 1 diabetes admitted to the intensive care unit with acute respiratory failure and severe diabetic ketoacidosis with an initial measurement of blood glucose level of 1,200 mg L⁻¹, pH 6.78, serum HCO3 ⁻ 3.2 mmoL L⁻¹ and BE -31.2 mmoL L⁻¹. Analysis of the blood gasometric parameters with the Stewart approach and the traditional Henderson-Hasselbalch concept enabled the discovery of metabolic acidosis caused by unidentified anions (mainly ketons). A treatment protocol with intensive fluid management with 0.9% NaCl, intensive intravenous insulin therapy, and potassium supplementation was administered. Analysis of the gasometric parameters after 12 hours of treatment according to the Stewart approach compared to the Henderson-Hasselbalch concept disclosed that metabolic acidosis caused by the unidentified anions has resolved almost completely and been replaced by metabolic hyperchloremic acidosis. The hyperchloremic acidosis was caused by the intensive fluid resuscitation with 0.9% NaCl, which contains a high chloride load, exceeding the chloride levels observed in human serum. Fluid management with balanced fluids other than saline was continued, together with intravenous insulin infusion, potassium supplementation, and 5% glucose administration. Analysis of this case study revealed the advantages of the Stewart approach to acid base abnormalities compared to the traditional Henderson-Hasselbalch concept. The Stewart approach allows the diagnosis of the exact causes of severe life-threatening metabolic acidosis and the appropriate modification of the therapeutic mangement of patients with diabetic ketoacidosis.

Glycemic profile and effectiveness and safety of insulin therapy in septic patients: is the blood glucose level sufficient?

INTRODUCTION: Hyperglycemia in sepsis is managed by intensive insulin therapy, which can cause hypoglycemia. OBJECTIVES: The aim of the study was to evaluate the glycemic profile as well as safety and effectiveness of a nurse-controlled insulin therapy protocol in patients with severe sepsis and septic shock. PATIENTS AND METHODS: The study included 16 septic patients who died (nonsurvivors) and 61 septic patients who survived. Glycemia was measured every 4 h, and the dose of insulin infusion was adjusted to maintain glycemia of 4.4 mmol/l to 8.3 mmol/l. We analyzed glycemia levels and daily variations, insulin dose, episodes of hypo- and hyperglycemia. RESULTS: Nonsurvivors and survivors had similar mean glycemia levels (7.38 vs. 7.08 mmol/l; p = 0.20) and insulin requirements (median [Me] = 26.9 vs. 23.9 units/d; p = 0.22; Me = 1.7 vs. 1.4 units/h; p = 0.25). Daily glycemia variation (Me = 4.81 vs. 3.03 mmol/l; p <0.001), episodes of hypoglycemia (18.8% vs. 3.3%; p = 0.02), spontaneous severe hypoglycemia (12.5% vs. 0%; p = 0.006) and hyperglycemia (75.0% vs. 45.9%; p = 0.04) were higher and more frequent in nonsurvivors. Three of 5393 blood samples (0.05%) met severe insulin-induced hypoglycemia criteria, and 74.4% of samples met the recommended range of 4.4-8.3 mmol/l. CONCLUSIONS: Patients who died experienced more episodes of hyperglycemia, spontaneous hypoglycemia and greater variation in the daily glycemia level. Daily glycemia variation is more reliable than a mean glycemic level in evaluating glucose homeostasis in septic patients. Few episodes of severe insulin-induced hypoglycemia occurred while using the nurse-controlled insulin therapy protocol.