Hemorrhagic Shock: Blood Marker Sequencing and Pulmonary Gas Exchange.

BACKGROUND: The early identification of internal hemorrhage in critically ill patients may be difficult. Besides circulatory parameters, hemoglobin and lactate concentration, metabolic acidosis and hyperglycemia serve as laboratory markers for bleeding. In this experiment, we examined pulmonary gas exchange in a porcine model of hemorrhagic shock. Moreover, we sought to investigate if a chronological order of appearance regarding hemoglobin, lactatemia, standard base excess/deficit (SBED) and hyperglycemia exists in early severe hemorrhage. METHODS: In this prospective, laboratory study, twelve anesthetized pigs were randomly allocated to exsanguination or a control group. Animals in the exsanguination group (n = 6) endured a 65% blood loss over 20 min. No intravenous fluids were administered. Measurements were taken before, immediately after, and at 60 min after the completed exsanguination. Measurements included pulmonary and systemic hemodynamic variables, hemoglobin concentration, lactate, base excess (SBED), glucose concentration, arterial blood gases, and a multiple inert gas assessment of pulmonary function. RESULTS: At baseline, variables were comparable. Immediately after exsanguination, lactate and blood glucose were increased (p = 0.001). The arterial partial pressure of oxygen was increased at 60 min after exsanguination (p = 0.04) owing to a decrease in intrapulmonary right-to-left shunt and less ventilation-perfusion inequality. SBED was different to the control only at 60 min post bleeding (p < 0.001). Hemoglobin concentration did not change at any time (p = 0.97 and p = 0.14). CONCLUSIONS: In experimental shock, markers of blood loss became positive in chronological order: lactate and blood glucose concentrations were raised immediately after blood loss, while changes in SBED lagged behind and became significant one hour later. Pulmonary gas exchange is improved in shock.

Clinical relevance of lung transplantation for COVID-19 ARDS: a nationwide study.

BACKGROUND: Although the number of lung transplantations (LTx) performed worldwide for COVID-19 induced acute respiratory distress syndrome (ARDS) is still low, there is general agreement that this treatment can save a subgroup of most severly ill patients with irreversible lung damage. However, the true proportion of patients eligible for LTx, the overall outcome and the impact of LTx to the pandemic are unknown. METHODS: A retrospective analysis was performed using a nationwide registry of hospitalised patients with confirmed severe acute respiratory syndrome coronavirus type 2 (SARS-Cov-2) infection admitted between January 1, 2020 and May 30, 2021 in Austria. Patients referred to one of the two Austrian LTx centers were analyzed and grouped into patients accepted and rejected for LTx. Detailed outcome analysis was performed for all patients who received a LTx for post-COVID-19 ARDS and compared to patients who underwent LTx for other indications. RESULTS: Between January 1, 2020 and May 30, 2021, 39.485 patients were hospitalised for COVID-19 in Austria. 2323 required mechanical ventilation, 183 received extra-corporeal membrane oxygenation (ECMO) support. 106 patients with severe COVID-19 ARDS were referred for LTx. Of these, 19 (18%) underwent LTx. 30-day mortality after LTx was 0% for COVID-19 ARDS transplant recipients. With a median follow-up of 134 (47-450) days, 14/19 patients are alive. CONCLUSIONS: Early referral of ECMO patients to a LTx center is pivotal in order to select patients eligible for LTx. Transplantation offers excellent midterm outcomes and should be incorporated in the treatment algorithm of post-COVID-19 ARDS.

Vasopressor Therapy in Cardiac Surgery-An Experts' Consensus Statement.

Hemodynamic conditions with reduced systemic vascular resistance commonly are observed in patients undergoing cardiac surgery and may range from moderate reductions in vascular tone, as a side effect of general anesthetics, to a profound vasodilatory syndrome, often referred to as vasoplegic shock. Therapy with vasopressors is an important pillar in the treatment of these conditions. There is limited guidance on the appropriate choice of vasopressors to restore and optimize systemic vascular tone in patients undergoing cardiac surgery. A panel of experts in the field convened to develop statements and evidence-based recommendations on clinically relevant questions on the use of vasopressors in cardiac surgical patients, using a critical appraisal of the literature following the GRADE system and a modified Delphi process. The authors unanimously and strongly recommend the use of norepinephrine and/or vasopressin for restoration and maintenance of systemic perfusion pressure in cardiac surgical patients; despite that, the authors cannot recommend either of these drugs with respect to the risk of ischemic complications. The authors unanimously and strongly recommend against using dopamine for treating post-cardiac surgery vasoplegic shock and against using methylene blue for purposes other than a rescue therapy. The authors unanimously and weakly recommend that clinicians consider early addition of a second vasopressor (norepinephrine or vasopressin) if adequate vascular tone cannot be restored by a monotherapy with either norepinephrine or vasopressin and to consider using vasopressin as a first-line vasopressor or to add vasopressin to norepinephrine in cardiac surgical patients with pulmonary hypertension or right-sided heart dysfunction.

Cerebral oxygenation in 45-degree trendelenburg position for robot-assisted radical prostatectomy: a single-center, open, controlled pilot study.

BACKGROUND: Within the last decade, robotically-assisted laparoscopic prostatectomy (RALP) has become the standard for treating localized prostate cancer, causing a revival of the 45° Trendelenburg position. In this pilot study we investigated effects of Trendelenburg position on hemodynamics and cerebral oxygenation in patients undergoing RALP. METHODS: We enrolled 58 patients undergoing RALP and 22 patients undergoing robot-assisted partial nephrectomy (RAPN) (control group) in our study. Demographic patient data and intraoperative parameters including cerebral oxygenation and cerebral hemodynamics were recorded for all patients. Cerebral function was also assessed pre- and postoperatively via the Mini Mental Status (MMS) exam. Changes in parameters during surgery were modelled by a mixed effects model; changes in the MMS result were evaluated using the Wilcoxon signed rank test. RESULTS: Preoperative assessment of patient characteristics, standard blood values and vital parameters revealed no difference between the two groups. CONCLUSIONS: Applying a 45° Trendelenburg position causes no difference in postoperative brain function, and does not alter cerebral oxygenation during a surgical procedure lasting up to 5 h. Further studies in larger patient cohorts will have to confirm these findings. TRIAL REGISTRATION: German Clinical Trial Registry; DRKS00005094; Registered 12th December 2013-Retrospectively registered; https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00005094 .

Supplemental Intraoperative Oxygen Does Not Promote Acute Kidney Injury or Cardiovascular Complications After Noncardiac Surgery: Subanalysis of an Alternating Intervention Trial.

BACKGROUND: Perioperative hyperoxia has been recommended by the World Health Organization and the Centers for Disease Control and Prevention for the prevention of surgical site infections. Based on animal studies and physiological concerns, the kidneys and heart may be at risk from hyperoxia. We therefore conducted 2 unplanned subanalyses of a previous alternating cohort trial in which patients having colorectal surgery were assigned to either 30% or 80% inspired intraoperative oxygen. Specifically, we tested 2 coprimary hypotheses: (1) hyperoxia increases the incidence of acute kidney injury (AKI) within 7 postoperative days (PODs); and (2) hyperoxia worsens a composite of myocardial injury, in-hospital cardiac arrest, and 30-day mortality. METHODS: The underlying controlled trial included 5749 colorectal surgeries in 4481 patients, with the exposure alternating between 30% and 80% fraction of inspired oxygen (FIO2) during general anesthesia at 2-week intervals over a period of 39 months. AKI was defined as a 1.5-fold increase in creatinine from the preoperative level to the highest value measured during the initial 7 PODs. Myocardial injury was defined by fourth-generation troponin-T level >0.03 ng/mL. We assessed the effect of 80% vs 30% oxygen on the outcomes using generalized estimating equation (GEE) logistic models that adjusted for the possible within-patient correlation across multiple potential operations for a patient on different visits. RESULTS: For the AKI outcome, 2522 surgeries were allocated to 80% oxygen and 2552 to 30% oxygen. Hyperoxia had no effect on the primary outcome of postoperative AKI, with an incidence of 7.7% in the 80% oxygen group and 7.7% in the 30% oxygen group (relative risk = 0.99; 95% confidence interval [CI], 0.82-1.2; P = .95). One thousand six hundred forty-seven surgeries (all with scheduled troponin monitoring) were analyzed for the composite cardiovascular outcome. Hyperoxia had no effect on the collapsed composite of myocardial injury, cardiac arrest, and 30-day mortality, nor on any of its components (estimated relative risk = 0.71; 95% CI, 0.44-1.16; P = .17). CONCLUSIONS: We found no evidence that intraoperative hyperoxia causes AKI or cardiovascular complications in adults undergoing colorectal surgery. Consequently, we suggest that clinicians select intraoperative inspired oxygen fraction based on other considerations.

Use of Levosimendan in Intensive Care Unit Settings: An Opinion Paper.

Levosimendan is an inodilator that promotes cardiac contractility primarily through calcium sensitization of cardiac troponin C and vasodilatation via opening of adenosine triphosphate-sensitive potassium (KATP) channels in vascular smooth muscle cells; the drug also exerts organ-protective effects through a similar effect on mitochondrial KATP channels. This pharmacological profile identifies levosimendan as a drug that may have applications in a wide range of critical illness situations encountered in intensive care unit medicine: hemodynamic support in cardiogenic or septic shock; weaning from mechanical ventilation or from extracorporeal membrane oxygenation; and in the context of cardiorenal syndrome. This review, authored by experts from 9 European countries (Austria, Belgium, Czech republic, Finland, France, Germany, Italy, Sweden, and Switzerland), examines the clinical and experimental data for levosimendan in these situations and concludes that, in most instances, the evidence is encouraging, which is not the case with other cardioactive and vasoactive drugs routinely used in the intensive care unit. The size of the available studies is, however, limited and the data are in need of verification in larger controlled trials. Some proposals are offered for the aims and designs of these additional studies.

Landiolol for managing atrial fibrillation in post-cardiac surgery.

Landiolol is an intravenous ultra-short acting beta-blocker which has been used in Japan for many years to prevent and/or to treat post-operative atrial fibrillation following cardiac surgery. The drug is now available in Europe. This article is a systematic review of literature regarding the use of landiolol in that specific surgical setting.