A randomized open label, parallel-group study to evaluate the hemodynamic effects of Cafedrine/Theodrenaline vs Noradrenaline in the treatment of intraoperative hypotension after induction of general anesthesia: the "HERO" study design and rationale

OBJECTIVE

Intraoperative arterial hypotension (IOH) is associated with poor patient outcome. This study aims to compare the hemodynamic effects of Cafedrine/Theodrenaline (C/T) and Noradrenaline (NA) for the treatment of hypotension in patients who develop IOH after anesthesia induction.

RESEARCH DESIGN AND METHODS

This is a national, randomized, parallel-group, multicenter, and open-label study. Adult patients (≥50 years, ASA-classification III-IV) who undergo elective surgery will be included. When IOH (MAP <70 mmHg) develops, C/T or NA will be given as a bolus injection ("bolus phase", 0-20 min after initial application) and subsequently as continuous infusion ("infusion phase", 21-40 min after initial application) to achieve MAP = 90 mmHg. Hemodynamic data are captured in real time by advanced hemodynamic monitoring.

RESULTS

Primary endpoints, i.e. the treatment-related difference in average mean arterial pressure (MAP) during the "infusion phase" and the treatment-related difference in average cardiac index during the "bolus phase" are assessed (fixed-sequence method). Non-inferiority of C/T compared to NA in achieving 90 mmHg (MAP) when applied as continuous infusion is hypothesized. In addition, superiority of C/T over NA, applied as bolus injection, in increasing cardiac index is postulated. It is estimated that 172 patients are required to establish statistical significance with a power of 90%. After adjusting for ineligibility and dropout rate, 220 patients will be screened.

CONCLUSION

This clinical trial will yield evidence for marketing authorization of C/T applied as continuous infusion. Additionally, the effects of C/T compared to NA on cardiac index will be assessed. First results of the "HERO"-study are expected in 2024. DRKS identifier: DRKS00028589. EudraCT identifier: 2021-001954-76.

Hemoadsorption in the critically ill-Final results of the International CytoSorb Registry

The aim of the current paper is to summarize the results of the International CytoSorb Registry. Data were collected on patients of the intensive care unit. The primary endpoint was actual in-hospital mortality compared to the mortality predicted by APACHE II score. The main secondary endpoints were SOFA scores, inflammatory biomarkers and overall evaluation of the general condition. 1434 patients were enrolled. Indications for hemoadsorption were sepsis/septic shock (N = 936); cardiac surgery perioperatively (N = 172); cardiac surgery postoperatively (N = 67) and "other" reasons (N = 259). APACHE-II-predicted mortality was 62.0±24.8%, whereas observed hospital mortality was 50.1%. Overall SOFA scores did not change but cardiovascular and pulmonary SOFA scores decreased by 0.4 [-0.5;-0.3] and -0.2 [-0.3;-0.2] points, respectively. Serum procalcitonin and C-reactive protein levels showed significant reduction: -15.4 [-19.6;-11.17] ng/mL; -17,52 [-70;44] mg/L, respectively. In the septic cohort PCT and IL-6 also showed significant reduction: -18.2 [-23.6;-12.8] ng/mL; -2.6 [-3.0;-2.2] pg/mL, respectively. Evaluation of the overall effect: minimal improvement (22%), much improvement (22%) and very much improvement (10%), no change observed (30%) and deterioration (4%). There was no significant difference in the primary outcome of mortality, but there were improvements in cardiovascular and pulmonary SOFA scores and a reduction in PCT, CRP and IL-6 levels. Trial registration: ClinicalTrials.gov Identifier: NCT02312024 (retrospectively registered).

(1 → 3)-β-D-Glucan-guided antifungal therapy in adults with sepsis: the CandiSep randomized clinical trial

Purpose

To investigate whether (1 → 3)-β-d-Glucan (BDG)-guidance shortens time to antifungal therapy and thereby reduces mortality of sepsis patients with high risk of invasive Candida infection (ICI).

Methods

Multicenter, randomized, controlled trial carried out between September 2016 and September 2019 in 18 intensive care units enrolling adult sepsis patients at high risk for ICI. Patients in the control group received targeted antifungal therapy driven by culture results. In addition to targeted therapy, patients in the BDG group received antifungals if at least one of two consecutive BDG samples taken during the first two study days was ≥ 80 pg/mL. Empirical antifungal therapy was discouraged in both groups. The primary endpoint was 28-day-mortality.

Results

339 patients were enrolled. ICI was diagnosed in 48 patients (14.2%) within the first 96 h after enrollment. In the BDG-group, 48.8% (84/172) patients received antifungals during the first 96 h after enrollment and 6% (10/167) patients in the control group. Death until day 28 occurred in 58 of 172 patients (33.7%) in the BDG group and 51 of 167 patients (30.5%) in the control group (relative risk 1.10; 95% confidence interval, 0.80–1.51; p = 0.53). Median time to antifungal therapy was 1.1 [interquartile range (IQR) 1.0–2.2] days in the BDG group and 4.4 (IQR 2.0–9.1, p < 0.01) days in the control group.

Conclusions

Serum BDG guided antifungal treatment did not improve 28-day mortality among sepsis patients with risk factors for but unexpected low rate of IC. This study cannot comment on the potential benefit of BDG-guidance in a more selected at-risk population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06733-x.

Validity of hospital ICD-10-GM codes to identify anaphylaxis

PURPOSE

Anaphylaxis (ANA) is an important adverse drug reaction. We examined positive predictive values (PPV) and other test characteristics of ICD-10-GM code algorithms for detecting ANA as used in a multinational safety study (PASS).

METHODS

We performed a cross-sectional study on routine data from a German academic hospital (2004-2019, age ≥ 18). Chart review was used for case verification. Potential cases were identified from the hospital administration system. The main outcome required at least one of the following: any type of specific in-hospital code (T78.2, T88.6, and T80.5) OR specific outpatient code in combination with a symptom code OR in-hospital non-specific code (T78.4, T88.7, and Y57.9) in combination with two symptom codes. PPV were calculated with 95% confidence interval. Sensitivity analyses modified type of codes, unit of analysis, verification criteria and time period. The most specific algorithm used only primary codes for ANA (numbers added in brackets).

RESULTS

Four hundred and sixteen eligible cases were evaluated, and 78 (37) potential ANA cases were identified. PPV were 62.8% (95% CI 51.1-73.5) (main) and 77.4% (58.9-90.4) (most specific). PPV from all modifications ranged from 12.9% to 80.6%. The sensitivity of the main algorithm was 66.2%, specificity 91.5%, and negative predictive value 92.6%. Corresponding figures for the most specific algorithm were 32.4%, 98.0%, and 87.0%.

CONCLUSIONS

The PPV of the main algorithm seems of acceptable validity for use in comparative safety research but will underestimate absolute risks by about a third. Restriction to primary discharge codes markedly improves PPV to the expense of reducing sensitivity.

Gemeindenotfallsanitäter als innovatives Einsatzmittel in der Notfallversorgung – erste Ergebnisse einer Beobachtungsstudie

Hintergrund

Rettungsdienst und Notaufnahmen werden zunehmend durch nichtlebensbedrohlich erkrankte Patienten belastet. In England und den USA wurden zur Versorgung vor Ort bereits vor einigen Jahren Community-paramedic-Systeme etabliert.

Auf diesen Konzepten basierend wurde ein an das deutsche Rettungswesen adaptierte System „Gemeindenotfallsanitäter“ (G-NFS) entwickelt. Das Ziel des G‑NFS ist, eine unnötige Disponierung höherwertiger Rettungsmittel zu reduzieren.

Ziel

Deskriptive Analyse der in den ersten 12 Monaten erhobenen Daten.

Methodik

Es handelt sich um eine retrospektive Beobachtungsstudie auf Basis der Einsatzdokumentation im Jahr 2019.

Ergebnisse

Es wurden 3703 Einsatzprotokolle ausgewertet. Das Durchschnittsalter betrug 62,2 ± 24,7 Jahre. Bei 2186 (61,1 %) Patienten wurde die Behandlungspriorität „0“ gewählt, d. h.: Es lag keine Dringlichkeit der Versorgung vor. 2134 (59 %) Patienten benötigten kein weiteres Rettungsmittel, eine ambulante Versorgung vor Ort war ausreichend. Am häufigsten wurde den Patienten die Vorstellung beim Hausarzt (n = 1422, 38 %) sowie die Vorstellung in der Notaufnahme (n = 1222, 33 %) empfohlen. Aus Sicht der G‑NFS wurden 3058 (85 %) Einsätze von den Leitstellendisponenten richtig kategorisiert.

Diskussion

Durch die gezielte Alarmierung der neu geschaffenen Ressource „Gemeindenotfallsanitäter“ können Patienten ambulant vor Ort versorgt werden und folglich die Institutionen der Notfallversorgung entlastet werden. Im weiteren Projektverlauf ist zu untersuchen, was die Einsatzindikationen bei den 1480 (41 %) Einsätzen mit einer Nachalarmierung von Rettungsmitteln sind und wie die Einschätzung der Leitstelle verbessert werden kann.

Current clinical use of intravenous fosfomycin in ICU patients in two European countries

PURPOSE

In Europe, intravenous fosfomycin (IV) is used particularly in difficult-to-treat or complex infections, caused by both Gram-positive and Gram-negative pathogens including multidrug-resistant strains. Here, we investigated the efficacy and safety of intravenous fosfomycin under real-life conditions.

METHODS

Prospective, multi-center, and non-interventional study in patients with bacterial infections from 20 intensive care units (ICU) in Germany and Austria (NCT01173575).

RESULTS

Overall, 209 patients were included (77 females, 132 males, mean age: 59 ± 16 years), 194 of which were treated in intensive care (APACHE II score at the beginning of fosfomycin therapy: 23 ± 8). Main indications (± bacteremia or sepsis) were infections of the CNS (21.5%), community- (CAP) and hospital-acquired pneumonia (HAP)/ventilator-associated pneumonia (VAP, 15.3%), bone and joint infections (BJI, 11%), abdominal infections (11%), and bacteremia (10.5%). Most frequently identified pathogens were S. aureus (22.3%), S. epidermidis (14.2%), Enterococcus spp. (10.8%), E. coli (12.3%) and Klebsiella spp. (7.7%). At least one multidrug-resistant (MDR) pathogen was isolated from 51 patients (24.4%). Fosfomycin was administered with an average daily dose of 13.7 ± 3.5 g over 12.4 ± 8.6 days, almost exclusively (99%) in combination with other antibiotics. The overall clinical success was favorable in 81.3% (148/182) of cases, and in 84.8% (39/46) of patients with ≥ 1 MDR pathogen. Noteworthy, 16.3% (34/209) of patients developed at least one, in the majority of cases non-serious, adverse drug reaction during fosfomycin therapy.

CONCLUSION

Our data suggest that IV fosfomycin is an effective and safe combination partner for the treatment of a broad spectrum of severe bacterial infections in critically ill patients.

Short-term incubation of gabapentin or pregabalin does not affect chemically induced injury in neuronal cell models in vitro

Purpose

Gabapentinoids are currently the mainstay of pharmacological treatments for patients with neuropathic pain. Little is known about the effects of this therapy on the integrity of neuronal networks, especially in patients with an already-damaged nervous system. Since gabapentinoids can worsen cognitive functions and recent studies have shown alterations in the brains of patients with neuropathic pain, it may be possible that these drugs have neurotoxic effects.

Methods

Rat clonal PC12 pheochromocytoma (autonomic) and primary sensory dorsal-root ganglion (DRG) neurons from newborn Wistar rats were employed for this study. To mimic neuronal damage, cells were exposed to cytotoxins using either hydrogen peroxide (H₂O₂) or vincristine.

Results

No direct cytotoxic effects were observed after incubating PC12 cells for 24 hours with increasing concentrations of gabapentin or pregabalin using MTT cytotoxicity assays. Even a 7-day incubation did not cause cellular damage. Furthermore, in preinjured PC12 and DRG neurons, neither gabapentin nor pregabalin prevented or enhanced the cytotoxic effects of H₂O₂ or vincristine after incubation for 24 hours and 7 days, respectively. Cell morphology and integrity of the cytoskeleton assessed by employing immunostaining of cytoskeletal proteins (α-tubulin, neurofilament L) remained intact and were not altered by gabapentinoids.

Conclusion

Based on these results, gabapentinoids are unlikely to be neurotoxic in cultured autonomic (PC12) and sensory DRG cells, even when cells are preinjured. These results are of high clinical relevance, as it seems unlikely that the morphological changes recently observed in the brains of neuropathic pain patients are caused or worsened by gabapentinoids.

The use of mid-regional proadrenomedullin to identify disease severity and treatment response to sepsis - a secondary analysis of a large randomised controlled trial

Background

This study assessed the ability of mid-regional proadrenomedullin (MR-proADM) in comparison to conventional biomarkers (procalcitonin (PCT), lactate, C-reactive protein) and clinical scores to identify disease severity in patients with sepsis.

Methods

This is a secondary analysis of a randomised controlled trial in patients with severe sepsis or septic shock across 33 German intensive care units. The association between biomarkers and clinical scores with mortality was assessed by Cox regression analysis, area under the receiver operating characteristic and Kaplan-Meier curves. Patients were stratified into three severity groups (low, intermediate, high) for all biomarkers and scores based on cutoffs with either a 90% sensitivity or specificity.

Results

1089 patients with a 28-day mortality rate of 26.9% were analysed. According to the Sepsis-3 definition, 41.2% and 58.8% fulfilled the criteria for sepsis and septic shock, with respective mortality rates of 20.0% and 32.1%. MR-proADM had the strongest association with mortality across all Sepsis-1 and Sepsis-3 subgroups and could facilitate a more accurate classification of low (e.g. MR-proADM vs. SOFA: N = 265 vs. 232; 9.8% vs. 13.8% mortality) and high (e.g. MR-proADM vs. SOFA: N = 161 vs. 155; 55.9% vs. 41.3% mortality) disease severity. Patients with decreasing PCT concentrations of either ≥ 20% (baseline to day 1) or ≥ 50% (baseline to day 4) but continuously high MR-proADM concentrations had a significantly increased mortality risk (HR (95% CI): 19.1 (8.0–45.9) and 43.1 (10.1–184.0)).

Conclusions

MR-proADM identifies disease severity and treatment response more accurately than established biomarkers and scores, adding additional information to facilitate rapid clinical decision-making and improve personalised sepsis treatment.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2001-5) contains supplementary material, which is available to authorized users.

A Computerized Information System for a Pain Clinic

The concept of the pain clinic constitutes a recent medical development requiring a thorough documentation of patient-related data in order to achieve reasonable standards in diagnosis and treatment, to ensure that the follow-up maintains these standards and to supply necessary data for research on the epidemiology, etiology, and therapy of chronic pain. We, therefore, developed a set of medical questionnaires for pain patients together with a microcomputer system for the storage and analysis of the data obtained. The main features of our approach are the problem-oriented medical records, the multi-user system and the immediate availability of the supplied data to every therapist using the system.

International registry on the use of the CytoSorb® adsorber in ICU patients : Study protocol and preliminary results

INTRODUCTION

The aim of this clinical registry is to record the use of CytoSorb® adsorber device in critically ill patients under real-life conditions.

METHODS

The registry records all relevant information in the course of product use, e. g., diagnosis, comorbidities, course of the condition, treatment, concomitant medication, clinical laboratory parameters, and outcome (ClinicalTrials.gov Identifier: NCT02312024). Primary endpoint is in-hospital mortality as compared to the mortality predicted by the APACHE II and SAPS II score, respectively.

RESULTS

As of January 30, 2017, 130 centers from 22 countries were participating. Data available from the start of the registry on May 18, 2015 to November 24, 2016 (122 centers; 22 countries) were analyzed, of whom 20 centers from four countries provided data for a total of 198 patients (mean age 60.3 ± 15.1 years, 135 men [68.2%]). In all, 192 (97.0%) had 1 to 5 Cytosorb® adsorber applications. Sepsis was the most common indication for CytoSorb® treatment (135 patients). Mean APACHE II score in this group was 33.1 ± 8.4 [range 15-52] with a predicted risk of death of 78%, whereas the observed mortality was 65%. There were no significant decreases in the SOFA scores after treatment (17.2 ± 4.8 [3-24]). However interleukin-6 levels were markedly reduced after treatment (median 5000 pg/ml before and 289 pg/ml after treatment, respectively).

CONCLUSIONS

This third interim report demonstrates the feasibility of the registry with excellent data quality and completeness from 20 study centers. The results must be interpreted with caution, since the numbers are still small; however the disease severity is remarkably high and suggests that adsorber treatment might be used as an ultimate treatment in life-threatening situations. There were no device-associated side effects.

Effect of a multifaceted educational intervention for anti-infectious measures on sepsis mortality: a cluster randomized trial

PURPOSE

Guidelines recommend administering antibiotics within 1 h of sepsis recognition but this recommendation remains untested by randomized trials. This trial was set up to investigate whether survival is improved by reducing the time before initiation of antimicrobial therapy by means of a multifaceted intervention in compliance with guideline recommendations.

METHODS

The MEDUSA study, a prospective multicenter cluster-randomized trial, was conducted from July 2011 to July 2013 in 40 German hospitals. Hospitals were randomly allocated to receive conventional continuous medical education (CME) measures (control group) or multifaceted interventions including local quality improvement teams, educational outreach, audit, feedback, and reminders. We included 4183 patients with severe sepsis or septic shock in an intention-to-treat analysis comparing the multifaceted intervention (n = 2596) with conventional CME (n = 1587). The primary outcome was 28-day mortality.

RESULTS

The 28-day mortality was 35.1% (883 of 2596 patients) in the intervention group and 26.7% (403 of 1587 patients; p = 0.01) in the control group. The intervention was not a risk factor for mortality, since this difference was present from the beginning of the study and remained unaffected by the intervention. Median time to antimicrobial therapy was 1.5 h (interquartile range 0.1-4.9 h) in the intervention group and 2.0 h (0.4-5.9 h; p = 0.41) in the control group. The risk of death increased by 2% per hour delay of antimicrobial therapy and 1% per hour delay of source control, independent of group assignment.

CONCLUSIONS

Delay in antimicrobial therapy and source control was associated with increased mortality but the multifaceted approach was unable to change time to antimicrobial therapy in this setting and did not affect survival.

Retrospective analysis of a surgical innovation using the IDEAL framework: radical cystectomy with epidural anaesthesia

Objectives

To retrospectively analyse experience of radical cystectomy using spinal/epidural anaesthesia and to classify this method using the IDEAL criteria.

Methods

Data from patients who had undergone radical cystectomy using spinal/epidural anaesthesia were evaluated retrospectively, focusing on clinical data, intraoperative and perioperative parameters and postoperative complications. Current literature reporting on this technique was reviewed and, together with the present study, evaluated according to the IDEAL recommendations.

Results

Three male patients aged 66–79 years who had undergone radical cystectomy with epidural anaesthesia were identified. The operating time ranged from 159–261 min and only minor complications occurred. Between 2013 and 2015, three published studies reported experiences with radical cystectomy with epidural/spinal anaesthesia; one was prospective and two were retrospective in nature and they included a total of 55 patients. According to the IDEAL classification, the present study corresponds to stage 1 (idea) and overall the surgical technique can be ranked as stage 2a (development).

Conclusions

Radical cystectomy with epidural anaesthesia is feasible and applicable for those who are not fit for general anaesthesia. The present study confirmed the functional results of this technique, which can be classified as IDEAL stage 2a on the basis of published studies.

Argon does not affect cerebral circulation or metabolism in male humans

OBJECTIVE

Accumulating data have recently underlined argon´s neuroprotective potential. However, to the best of our knowledge, no data are available on the cerebrovascular effects of argon (Ar) in humans. We hypothesized that argon inhalation does not affect mean blood flow velocity of the middle cerebral artery (Vmca), cerebral flow index (FI), zero flow pressure (ZFP), effective cerebral perfusion pressure (CPPe), resistance area product (RAP) and the arterio-jugular venous content differences of oxygen (AJVDO2), glucose (AJVDG), and lactate (AJVDL) in anesthetized patients.

MATERIALS AND METHODS

In a secondary analysis of an earlier controlled cross-over trial we compared parameters of the cerebral circulation under 15 minutes exposure to 70%Ar/30%O2 versus 70%N2/30%O2 in 29 male patients under fentanyl-midazolam anaesthesia before coronary surgery. Vmca was measured by transcranial Doppler sonography. ZFP and RAP were estimated by linear regression analysis of pressure-flow velocity relationships of the middle cerebral artery. CPPe was calculated as the difference between mean arterial pressure and ZFP. AJVDO2, AJVDG and AJVDL were calculated as the differences in contents between arterial and jugular-venous blood of oxygen, glucose, and lactate. Statistical analysis was done by t-tests and ANOVA.

RESULTS

Mechanical ventilation with 70% Ar did not cause any significant changes in mean arterial pressure, Vmca, FI, ZFP, CPPe, RAP, AJVDO2, AJVDG, and AJVDL.

DISCUSSION

Short-term inhalation of 70% Ar does not affect global cerebral circulation or metabolism in male humans under general anaesthesia.

Effect of Hydrocortisone on Development of Shock Among Patients With Severe Sepsis: The HYPRESS Randomized Clinical Trial

IMPORTANCE

Adjunctive hydrocortisone therapy is suggested by the Surviving Sepsis Campaign in refractory septic shock only. The efficacy of hydrocortisone in patients with severe sepsis without shock remains controversial.

OBJECTIVE

To determine whether hydrocortisone therapy in patients with severe sepsis prevents the development of septic shock.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind, randomized clinical trial conducted from January 13, 2009, to August 27, 2013, with a follow-up of 180 days until February 23, 2014. The trial was performed in 34 intermediate or intensive care units of university and community hospitals in Germany, and it included 380 adult patients with severe sepsis who were not in septic shock.

INTERVENTIONS

Patients were randomly allocated 1:1 either to receive a continuous infusion of 200 mg of hydrocortisone for 5 days followed by dose tapering until day 11 (n = 190) or to receive placebo (n = 190).

MAIN OUTCOMES AND MEASURES

The primary outcome was development of septic shock within 14 days. Secondary outcomes were time until septic shock, mortality in the intensive care unit or hospital, survival up to 180 days, and assessment of secondary infections, weaning failure, muscle weakness, and hyperglycemia (blood glucose level >150 mg/dL [to convert to millimoles per liter, multiply by 0.0555]).

RESULTS

The intention-to-treat population consisted of 353 patients (64.9% male; mean [SD] age, 65.0 [14.4] years). Septic shock occurred in 36 of 170 patients (21.2%) in the hydrocortisone group and 39 of 170 patients (22.9%) in the placebo group (difference, -1.8%; 95% CI, -10.7% to 7.2%; P = .70). No significant differences were observed between the hydrocortisone and placebo groups for time until septic shock; mortality in the intensive care unit or in the hospital; or mortality at 28 days (15 of 171 patients [8.8%] vs 14 of 170 patients [8.2%], respectively; difference, 0.5%; 95% CI, -5.6% to 6.7%; P = .86), 90 days (34 of 171 patients [19.9%] vs 28 of 168 patients [16.7%]; difference, 3.2%; 95% CI, -5.1% to 11.4%; P = .44), and 180 days (45 of 168 patients [26.8%] vs 37 of 167 patients [22.2%], respectively; difference, 4.6%; 95% CI, -4.6% to 13.7%; P = .32). In the hydrocortisone vs placebo groups, 21.5% vs 16.9% had secondary infections, 8.6% vs 8.5% had weaning failure, 30.7% vs 23.8% had muscle weakness, and 90.9% vs 81.5% had hyperglycemia.

CONCLUSIONS AND RELEVANCE

Among adults with severe sepsis not in septic shock, use of hydrocortisone compared with placebo did not reduce the risk of septic shock within 14 days. These findings do not support the use of hydrocortisone in these patients.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00670254.

Effect of Sodium Selenite Administration and Procalcitonin-Guided Therapy on Mortality in Patients With Severe Sepsis or Septic Shock: A Randomized Clinical Trial

IMPORTANCE

High-dose intravenous administration of sodium selenite has been proposed to improve outcome in sepsis by attenuating oxidative stress. Procalcitonin-guided antimicrobial therapy may hasten the diagnosis of sepsis, but effect on outcome is unclear.

OBJECTIVE

To determine whether high-dose intravenous sodium selenite treatment and procalcitonin-guided anti-infectious therapy in patients with severe sepsis affect mortality.

DESIGN, SETTING, AND PARTICIPANTS

The Placebo-Controlled Trial of Sodium Selenite and Procalcitonin Guided Antimicrobial Therapy in Severe Sepsis (SISPCT), a multicenter, randomized, clinical, 2 × 2 factorial trial performed in 33 intensive care units in Germany, was conducted from November 6, 2009, to June 6, 2013, including a 90-day follow-up period.

INTERVENTIONS

Patients were randomly assigned to receive an initial intravenous loading dose of sodium selenite, 1000 µg, followed by a continuous intravenous infusion of sodium selenite, 1000 µg, daily until discharge from the intensive care unit, but not longer than 21 days, or placebo. Patients also were randomized to receive anti-infectious therapy guided by a procalcitonin algorithm or without procalcitonin guidance.

MAIN OUTCOMES AND MEASURES

The primary end point was 28-day mortality. Secondary outcomes included 90-day all-cause mortality, intervention-free days, antimicrobial costs, antimicrobial-free days, and secondary infections.

RESULTS

Of 8174 eligible patients, 1089 patients (13.3%) with severe sepsis or septic shock were included in an intention-to-treat analysis comparing sodium selenite (543 patients [49.9%]) with placebo (546 [50.1%]) and procalcitonin guidance (552 [50.7%]) vs no procalcitonin guidance (537 [49.3%]). The 28-day mortality rate was 28.3% (95% CI, 24.5%-32.3%) in the sodium selenite group and 25.5% (95% CI, 21.8%-29.4%) (P = .30) in the placebo group. There was no significant difference in 28-day mortality between patients assigned to procalcitonin guidance (25.6% [95% CI, 22.0%-29.5%]) vs no procalcitonin guidance (28.2% [95% CI, 24.4%-32.2%]) (P = .34). Procalcitonin guidance did not affect frequency of diagnostic or therapeutic procedures but did result in a 4.5% reduction of antimicrobial exposure.

CONCLUSIONS AND RELEVANCE

Neither high-dose intravenous administration of sodium selenite nor anti-infectious therapy guided by a procalcitonin algorithm was associated with an improved outcome in patients with severe sepsis. These findings do not support administration of high-dose sodium selenite in these patients; the application of a procalcitonin-guided algorithm needs further evaluation.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00832039.

Influence of isoflurane on the diastolic pressure-flow relationship and critical occlusion pressure during arterial CABG surgery: a randomized controlled trial

The effects of isoflurane on the determinants of blood flow during Coronary Artery Bypass Graft (CABG) surgery are not completely understood. This study characterized the influence of isoflurane on the diastolic Pressure-Flow (P-F) relationship and Critical Occlusion Pressure (COP) during CABG surgery. Twenty patients undergoing CABG surgery were studied. Patients were assigned to an isoflurane or control group. Hemodynamic and flow measurements during CABG surgery were performed twice (15 minutes after the discontinuation of extracorporeal circulation (T15) and again 15 minutes later (T30)). The zero flow pressure intercept (a measure of COP) was extrapolated from a linear regression analysis of the instantaneous diastolic P-F relationship. In the isoflurane group, the application of isoflurane significantly increased the slope of the diastolic P-F relationship by 215% indicating a mean reduction of Coronary Vascular Resistance (CVR) by 46%. Simultaneously, the Mean Diastolic Aortic Pressure (MDAP) decreased by 19% mainly due to a decrease in the systemic vascular resistance index by 21%. The COP, cardiac index, heart rate, Left Ventricular End-Diastolic Pressure (LVEDP) and Coronary Sinus Pressure (CSP) did not change significantly. In the control group, the parameters remained unchanged. In both groups, COP significantly exceeded the CSP and LVEDP at both time points. We conclude that short-term application of isoflurane at a sedative concentration markedly increases the slope of the instantaneous diastolic P-F relationship during CABG surgery implying a distinct decrease with CVR in patients undergoing CABG surgery.

Impact of compliance with infection management guidelines on outcome in patients with severe sepsis: a prospective observational multi-center study

Introduction

Current sepsis guidelines recommend antimicrobial treatment (AT) within one hour after onset of sepsis-related organ dysfunction (OD) and surgical source control within 12 hours. The objective of this study was to explore the association between initial infection management according to sepsis treatment recommendations and patient outcome.

Methods

In a prospective observational multi-center cohort study in 44 German ICUs, we studied 1,011 patients with severe sepsis or septic shock regarding times to AT, source control, and adequacy of AT. Primary outcome was 28-day mortality.

Results

Median time to AT was 2.1 (IQR 0.8 – 6.0) hours and 3 hours (-0.1 – 13.7) to surgical source control. Only 370 (36.6%) patients received AT within one hour after OD in compliance with recommendation. Among 422 patients receiving surgical or interventional source control, those who received source control later than 6 hours after onset of OD had a significantly higher 28-day mortality than patients with earlier source control (42.9% versus 26.7%, P <0.001). Time to AT was significantly longer in ICU and hospital non-survivors; no linear relationship was found between time to AT and 28-day mortality. Regardless of timing, 28-day mortality rate was lower in patients with adequate than non-adequate AT (30.3% versus 40.9%, P < 0.001).

Conclusions

A delay in source control beyond 6 hours may have a major impact on patient mortality. Adequate AT is associated with improved patient outcome but compliance with guideline recommendation requires improvement. There was only indirect evidence about the impact of timing of AT on sepsis mortality.

Effect of empirical treatment with moxifloxacin and meropenem vs meropenem on sepsis-related organ dysfunction in patients with severe sepsis: a randomized trial

CONTEXT

Early appropriate antimicrobial therapy leads to lower mortality rates associated with severe sepsis. The role of empirical combination therapy comprising at least 2 antibiotics of different mechanisms remains controversial.

OBJECTIVE

To compare the effect of moxifloxacin and meropenem with the effect of meropenem alone on sepsis-related organ dysfunction.

DESIGN, SETTING, AND PATIENTS

A randomized, open-label, parallel-group trial of 600 patients who fulfilled criteria for severe sepsis or septic shock (n = 298 for monotherapy and n = 302 for combination therapy). The trial was performed at 44 intensive care units in Germany from October 16, 2007, to March 23, 2010. The number of evaluable patients was 273 in the monotherapy group and 278 in the combination therapy group.

INTERVENTIONS

Intravenous meropenem (1 g every 8 hours) and moxifloxacin (400 mg every 24 hours) or meropenem alone. The intervention was recommended for 7 days and up to a maximum of 14 days after randomization or until discharge from the intensive care unit or death, whichever occurred first.

MAIN OUTCOME MEASURE

Degree of organ failure (mean of daily total Sequential Organ Failure Assessment [SOFA] scores over 14 days; score range: 0-24 points with higher scores indicating worse organ failure); secondary outcome: 28-day and 90-day all-cause mortality. Survivors were followed up for 90 days.

RESULTS

Among 551 evaluable patients, there was no statistically significant difference in mean SOFA score between the meropenem and moxifloxacin group (8.3 points; 95% CI, 7.8-8.8 points) and the meropenem alone group (7.9 points; 95% CI, 7.5-8.4 points) (P = .36). The rates for 28-day and 90-day mortality also were not statistically significantly different. By day 28, there were 66 deaths (23.9%; 95% CI, 19.0%-29.4%) in the combination therapy group compared with 59 deaths (21.9%; 95% CI, 17.1%-27.4%) in the monotherapy group (P = .58). By day 90, there were 96 deaths (35.3%; 95% CI, 29.6%-41.3%) in the combination therapy group compared with 84 deaths (32.1%; 95% CI, 26.5%-38.1%) in the monotherapy group (P = .43).

CONCLUSION

Among adult patients with severe sepsis, treatment with combined meropenem and moxifloxacin compared with meropenem alone did not result in less organ failure.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00534287.

[Effects of advanced haemodynamic monitoring on perioperative outcome in high-risk patients]

Advanced haemodynamic monitoring provides information on blood flow, volume status, and oxygen supply to demand ratio. Together with related therapeutic algorithms these variables can be used to optimize cardiac preload and oxygen delivery in the perioperative period. There is increasing evidence that a goal-directed therapy can improve perioperative outcome. In this review we will briefly describe different target variables and their relevance for the haemodynamic optimization of high-risk surgical patients.

Continuous monitoring of ScvO(2) by a new fibre-optic technology compared with blood gas oximetry in critically ill patients: a multicentre study

OBJECTIVE

The aim of this study was to compare the accuracy of the CeVOX monitor measuring continuous central venous saturation (ScvO(2)) with laboratory blood gas oximetry under clinical circumstances.

DESIGN

Prospective, multicentre, observational study.

SETTING

Five adult general intensive care units.

PATIENTS AND PARTICIPANTS

Fifty-three critically ill patients.

INTERVENTIONS

The fibre-optic probe was inserted into an ordinary central venous catheter's distal lumen. Blood samples were taken from this line via a Y-adapter every 8 h and ScvO(2) was measured with a laboratory co-oximeter. Patients were observed for a maximum of 5 days. Results were compared using linear regression and the Bland and Altman plots.

MEASUREMENTS AND RESULTS

The 526 matched pairs of ScvO(2) showed a significant correlation between the two methods (r = 0.79, p< 0.001). Bland-Altman plots showed an overall mean bias of -0.3% and moderate agreement (lower and upper levels of agreement: -13.2% and 12.5%). Correlation for the first time point, and for differences between the first two time points for each method revealed good correlation: (n = 53): r = 0.79, p< 0.001; (n = 50): r = 0.58, p< 0.001, respectively.

CONCLUSION

These results in a heterogeneous group of critically ill patients show that continuous ScvO(2) monitoring by the CeVOX technology yielded results comparable with those obtained by laboratory co-oximetry and therefore can be relied on in everyday clinical practice.

Instantaneous diastolic pressure–flow relationship in arterial coronary bypass grafts

OBJECTIVE

The objective of this study was to describe the diastolic pressure-flow relationship and to assess critical occlusion pressure in arterial coronary bypass grafts in human beings.

METHODS AND RESULTS

Fifteen patients were studied following elective surgical coronary artery bypass grafting. Flow in the left internal mammary artery bypass to the left anterior descending artery was measured and simultaneously, aortic pressure, coronary sinus pressure and left ventricular end-diastolic pressure were recorded. The zero-flow pressure intercept as a measure of critical occlusion pressure was extrapolated from the linear regression analysis of the instantaneous diastolic pressure-flow relationship. Mean diastolic flow was 46 +/- 17 mL min(-1), mean diastolic aortic pressure was 60.5 +/- 10.0 mmHg. Diastolic blood flow was linearly related to the respective aortic pressure in all patients (R-values 0.7-0.99). The regression lines had a mean slope of 2.1 +/- 1.2 mL min(-1) mmHg(-1). Mean critical occlusion pressure was 32.3 +/- 9.9 mmHg and exceeded mean coronary sinus pressure and mean left ventricular end-diastolic pressure by factors of 3.1 and 2.6, respectively.

CONCLUSIONS

Our data demonstrate the presence of a vascular waterfall phenomenon in the coronary circulation after internal mammary artery bypass grafting. Critical occlusion pressure in arterial grafts considerably exceeds coronary sinus pressure as well as left ventricular end-diastolic pressure and should thus be used as the effective downstream pressure when calculating coronary perfusion pressure. Our data further suggest that the slope of diastolic pressure-flow relationships provides a more rational approach to assess regional coronary vascular resistance than conventional calculations of coronary vascular resistance.

Intra- and extravascular volume status in patients undergoing mitral valve replacement

BACKGROUND AND OBJECTIVE

Cardiopulmonary bypass is associated with changes of intra- and extravascular volume status often resulting in cardiopulmonary dysfunction. The purpose of this prospective double-blind study was to evaluate the influence of different priming solutions of the extracorporeal circuit on intra- and extravascular volume status and haemodynamics in patients undergoing elective mitral valve replacement.

METHODS

Twenty-two patients with mitral valve insufficiency were randomly allocated into two equal groups. In Group 1 cardiopulmonary bypass was primed with a nearly isooncotic solution consisting of 4% albumin. The second group received a pure crystalloid priming solution. The thermo-dye indicator dilution technique was used for the assessment of cardiac output, central and pulmonary blood volume, right ventricular end-diastolic volume and total blood volume.

RESULTS

Patients in the crystalloid group showed increased intraoperative fluid requirements. Significantly more fluid was accumulated in the extravascular space whereas total blood volume was decreased after surgery. Stroke volume index (SVI) was significantly decreased in the immediate postoperative period when compared to baseline. As indicated by the increase in extravascular fluid content after surgery, both colloid and crystalloid priming volumes were transferred to the extravascular space.

CONCLUSION

The use of colloid priming solutions in patients with mitral valve insufficiency leads to less fluid requirements and significantly reduced fluid shift in the interstitium. However, these changes are not associated with changes in haemodynamic parameters or short term outcome.

Influence of intra-aortic balloon pumping on cerebral blood flow pattern in patients after cardiac surgery

BACKGROUND AND OBJECTIVE

The effects of intra-aortic balloon pumping (IABP) on cerebral perfusion are still a matter of debate. End-diastolic reversal of blood flow in cerebral arteries has been observed in a small number of patients. We prospectively investigated the incidence and the amount of transient cerebral artery blood flow reversal during balloon pumping in patients recovering from cardiac surgery.

METHODS

In 23 patients receiving IABP support, blood flow velocities in the right middle cerebral artery were assessed by transcranial Doppler-sonography. Additionally, systemic haemodynamics were monitored. In each patient, measurements were performed at three different pump settings: without support, assist ratio 1 : 1 and assist ratio 1 : 2.

RESULTS

In 8 of 23 patients, balloon pumping caused a transient diastolic reversal of blood flow in the middle cerebral artery during balloon deflation. Antegrade mean flow velocity in the middle cerebral artery significantly increased from 57 +/- 27 to 61 +/- 26 (assist ratio 1 : 1) and 61 +/- 29 cm s(-1) (assist ratio 1 : 2) (P < 0.05). Taking transient blood flow reversal into account, net mean flow velocity did not increase with balloon pump support. Systemic haemodynamic parameters remained unchanged.

CONCLUSION

Left ventricular support with IABP significantly changed flow patterns in basal cerebral arteries of our patients. In 35% of patients, support resulted in a transient reversal of intracranial blood flow which counterbalanced a slight increase in mean antegrade flow.

Cerebral inflammatory response during and after cardiac surgery

BACKGROUND AND OBJECTIVE

Neurological dysfunction is a common problem after cardiac surgery with cardiopulmonary bypass (CPB). Cerebral ischaemia associated with the use of CPB may result in a release of neuronal-ischaemic markers and a subsequent cerebral inflammatory response which may additionally release inflammatory cytokines. In order to locate the origin and to quantify the release of neuronal-ischaemic markers and cytokines we investigated arterial-cerebral venous concentration gradients during and after CPB in a clinical setting.

METHODS

In twenty-five patients scheduled for coronary artery bypass grafting surgery we measured the plasma concentration of neuron-specific enolase, S-100beta protein as well as interleukins (IL) IL-6, IL-8 and IL-10 from arterial and cerebral venous blood samples prior to surgery (baseline), during hypothermic CPB at 32 degrees C, after termination of bypass, as well as 2, 4 and 6 h after admission to the intensive care unit.

RESULTS

Arterial-cerebral venous concentration gradients of neuron-specific enolase, S-100beta, IL-6, IL-8 and IL-10 were neither detectable during nor after CPB. Compared to the baseline period, S-100beta and neuron-specific enolase significantly increased during hypothermic CPB. After termination of CPB, neuronal-ischaemic markers as well as cytokines were increased and remained elevated during the investigated time course without reaching baseline values.

CONCLUSIONS

Although we found an overall increase in plasma concentrations of neuronal-ischaemic markers, IL-6, IL-8 and IL-10 during and after CPB, arterial-cerebral venous gradients were not detectable for any of these parameters. Our results suggest that the increase of investigated parameters associated with the use of CPB are not primarily caused by a cerebral inflammatory response but rather reflect a release from other sources in the systemic circulation.

Extrapolation to zero-flow pressure in cerebral arteries to estimate intracranial pressure

BACKGROUND

Cerebral perfusion pressure (CPP) is commonly calculated from the difference between arterial blood pressure (AP) and intracranial pressure (ICP). ICP can be considered the effective downstream pressure of the cerebral circulation. Consequently, cerebral circulatory arrest would occur when AP equals ICP. Estimation of AP for zero-flow pressure (ZFP) may thus allow estimation of ICP. We estimated ZFP from cerebral pressure-flow velocity relationships so that ICP could be measured by transcranial Doppler sonography.

METHODS

We studied 20 mechanically ventilated patients with severe head injury, in whom ICP was monitored by epidural pressure transducers. AP was measured with a radial artery cannula. Blood flow velocity in the middle cerebral artery (V(MCA)) ipsilateral to the site of ICP measurement was measured with a 2 MHz transcranial Doppler probe. All data were recorded by a microcomputer from analogue-digital converters. ZFP was extrapolated by regression analysis of AP-V(MCA) plots and compared with simultaneous measurements of ICP.

RESULTS

ZFP estimated from AP-V(MCA) plots was linearly related to ICP over a wide range of values (r=0.93). There was no systematic difference between ZFP and ICP. Limit of agreement (2 SD) was 15.2 mm Hg. Short-term variations in ICP were closely followed by changes in ZFP.

CONCLUSION

Extrapolation of cerebral ZFP from instantaneous AP-V(MCA) relationships enables detection of severely elevated ICP and may be a useful and less invasive method for CPP monitoring than other methods.

[A comparison of the Proseal laryngeal mask to the standard laryngeal mask on anesthesized, non-relaxed patients]

It was our goal to compare the Proseal-laryngeal mask airway (PLMA) with the classical laryngeal mask airway (LMA) in a german multicenter trial. Handling of the instruments and application criteria were to be tested. 7 anaesthesia departments were able to take part in this study. 280 patients could be investigated after approval of the ethics committee of the medical faculty of the university of Goettingen. 145 patients received the PLMA and 135 the LMA. The surgical interventions were small to moderate procedures with a duration of at least 20 minutes in the sections general surgery, trauma/orthopedic surgery, urology, vascular surgery, gynecology, ENT-surgery and ophthalmology. There was equivalence of the two instruments PLMA and LMA concerning duration and ease of insertion, endoscopic position check, observations on emergence, potential for injury and some postoperative complaints. This equivalence could be confirmed statistically. Laryngospasm was observed in three, Bronchospasm in two patients with the PLMA, in no one with the LMA. In one case of laryngospasm and another of bronchospasm a mechanism of supraglottic laryngeal stenosis has been involved which may occur in rare instances with the PLMA. This mechanism is due to the double cuff of the PLMA with the instruments proximity to the laryngeal inlet. The seal pressure in both groups differs significantly (p = 0.001). The mean value for the seal pressure was 29,3 +/- 0,21 mbar for the PLMA and 20,9 +/- 0,21 mbar for the LMA. In the PLMA the gastric tube could be positioned with the first attempt in 118 patients, with the second attempt in 17 cases. In 10 patients the gastric tube could not be placed. Contrary to the LMA the tip of the PLMA cuff may be bent in some cases with loss of airway safety and positioning of the gastric tube. The symptoms sore throat and painful swallowing on the first postoperative day were more frequent with LMA application. These differences could be confirmed statistically (sore throat p = 0.01, painful swallowing p = 0.04). They may be explained by the more rigid LMA compared to the PLMA and by the fact that the LMA in this study was older than the PLMA, loosing plasticizer. The drainage tube within the PLMA offers safety from aspiration in patients with no primary aspiration risk, additional reassurance for a correct position and a better stability of the airway. Our data may support a wider indication range for the PLMA compared with the LMA. The PLMA may be applied in laparoscopies and lower abdominal surgical interventions. Careful clinical observation will show, if the minimal invasiveness of the PLMA offers an advantage for these patients. The PLMA should not be applied in patients with increased aspiration risk.

Relationship between intracranial pressure and critical closing pressure in patients with neurotrauma

BACKGROUND

The driving pressure gradient for cerebral perfusion is the difference between mean arterial pressure (MAP) and critical closing pressure (CCP = zero flow pressure). Therefore, determination of the difference between MAP and CCP should provide an appropriate monitoring of the effective cerebral perfusion pressure (CPP(eff)). Based on this concept, the authors compared conventional measurements of cerebral perfusion pressure by MAP and intracranial pressure (CPP(ICP)) with CPP(eff).

METHODS

Simultaneous synchronized recordings of pressure waveforms of the radial artery and blood flow velocities of the middle cerebral artery were performed in 70 head trauma patients. CCP was calculated from pressure-flow velocity plots by linear extrapolation to zero flow.

RESULTS

Intracranial pressure measured by intraventricular probes and CCP ranged from 3 to 71 and 4 to 70 mmHg, respectively. Linear correlation between ICP and CCP was r = 0.91. CPP(ICP) was 77 +/- 20 mmHg and did not differ from CPP(eff); linear correlation was r = 0.92. However, limits of agreement were only +/- 16.2 mmHg. Therefore, in 51.4% of the patients, CPP(ICP) overestimated CPP(eff) by 19.8 mmHg at most.

CONCLUSION

Assuming that CPP(eff) (MAP - CCP) takes into account more determinants of cerebral downstream pressure, in individual cases, the actual gold standard of CPP determination (MAP - ICP) might overestimate the CPP(eff) of therapeutic significance.

Assessment of cardiac preload by indicator dilution and transoesophageal echocardiography

BACKGROUND AND OBJECTIVE

Assessment of cardiac preload is of major importance in the management of critically ill patients. Echocardiographic determined left ventricular end-diastolic area and indicator dilution derived intrathoracic blood volume are used as surrogates for cardiac preload. However, no controlled comparison studies on the relationship between induced changes in end-diastolic area and intrathoracic blood volume and concomitant changes in stroke volume index are available.

METHODS

The effects of a change in body position on these variables were investigated in 10 anaesthetized patients.

RESULTS

Intrathoracic blood volume and end-diastolic area decreased by 18 +/- 11% and 27 +/- 13% respectively. Stroke volume index concomitantly decreased by 19 +/- 11%. Correlation analysis revealed a close relation between stroke volume index and intrathoracic blood volume (r=0.75) and end-diastolic area (r=0.76).

CONCLUSIONS

Within the observed range of data, intrathoracic blood volume and end-diastolic area are equivalent indices of cardiac preload.

Reliability of cerebral blood flow measurements by transcerebral double-indicator dilution technique

BACKGROUND AND OBJECTIVE

The recently developed transcerebral double-indicator dilution technique has proven to be a feasible monitoring alternative to measure global cerebral blood flow at the bedside. However, the short-term repeatability of transcerebral double-indicator dilution measurements has not yet been investigated. The present study was designed to investigate the accuracy in terms of reliability for repeated transcerebral double-indicator dilution measurements to assess global cerebral blood flow during a definite carbon dioxide challenge in a clinical trial.

METHODS

The investigation was performed in 10 patients scheduled for elective coronary artery bypass grafting. After induction of anaesthesia, repeated cerebral blood flow measurements using transcerebral double-indicator dilution were performed during target normocapnia, hypocapnia and hypercapnia. For transcerebral double-indicator dilution measurements, a bolus injection of ice-cold indocyanine green was administered into a central vein. The resulting thermal dye dilution curves were recorded simultaneously in the aorta and the jugular bulb using combined fibreoptic thermistor catheters. Cerebral blood flow was calculated from the mean transit times of the indicators through the brain. Additionally, transcranial Doppler sonography was simultaneously performed to measure transient changes in the cerebral blood flow velocity.

RESULTS

Transcerebral double-indicator dilution measurements revealed a reasonable coefficient of repeatability with 9.1, 9.7 and 20.2 mL min-1 100 g-1 during normo-, hypo- and hypercapnic conditions, respectively. However, a total of 20% of the administered measurements had to be rejected for methodological reasons.

CONCLUSIONS

Repeated measurements with the transcerebral double-indicator dilution method show a reasonable repeatability. With consideration to the limitations of the transcerebral double-indicator dilution technique, this new method proves to be a reliable monitoring tool to measure global cerebral blood flow at the bedside.

Changes in cardiac output and intrathoracic blood volume: a mathematical coupling of data?

BACKGROUND

Measurements of intrathoracic blood volume (ITBV) provide volumetric information about cardiac preload and are used to investigate the cause of alterations in cardiac output (CO). On the other hand, CO is required to calculate ITBV. Thus, concerns have been raised with respect to a mathematical coupling of data. The aim of this prospective, clinical study was to investigate whether a variation in CO induced by high-dose beta-blockade influences thermodilution measurements of ITBV in the absence of changes in intravascular volume in patients undergoing minimally invasive coronary artery bypass grafting.

METHODS

Sixteen patients undergoing elective minimally invasive direct coronay artery bypass (MIDCAB) surgery were studied. Transpulmonary thermodilution measurements of ITBV and CO were simultaneously performed before bypass grafting, during beta-blockade induced by high-dose esmolol and at the end of surgery.

RESULTS

During esmolol administration, CO significantly decreased by 33%, whereas ITBV remained unchanged compared to control values (876+/-46 ml m-2 during control versus 860+/-61 ml m-2 during esmolol administration). After the end of esmolol administration, CO significantly increased by 79%. Again, ITBV remained virtually unchanged (860+/-61 ml m-2 during esmolol administration versus 911+/-38 ml m-2 after esmolol administration).

CONCLUSIONS

The results of the present study demonstrate that substantial alterations in CO as a consequence of high-dose esmolol infusion are not associated with changes in ITBV. Because haemodynamic changes were induced by factors other than variation of preload, these findings suggest that changes in cardiac output do not influence thermodilution measurements of ITBV in this setting.

Doppler-sonographic evidence of cerebral microembolism originating from a biventricular assist device

The use of extracorporeal assist devices in heart failure is associated with the risk of thromboembolic complications [1]. Prove of thromboembolic material in the ventricles and tubes of the assist devices is difficult, and the clinical relevance of thrombotic material in the tubes is not clear. Here, we report on a patient with severe heart failure caused by endstage dilated cardiomyopathy who was bridged to transplantation using a biventricular assist device (BVAD). Five weeks after implantation, transcranial Doppler sonography (TCD) revealed high intensity transient signals (HITS) in basal cerebral arteries, suggesting continued cerebral microembolism. Apart from a correlation of these Doppler sonographic findings with neurological symptoms, macroscopic evidence of fibrin thrombi in the artificial ventricle, and post mortem confirmation of cerebral infarction could be proved.

Cerebrovascular tone rather than intracranial pressure determines the effective downstream pressure of the cerebral circulation in the absence of intracranial hypertension

Cerebral perfusion pressure is commonly calculated from the difference between mean arterial pressure and intracranial pressure because intracranial pressure is known to represent the effective downstream pressure of the cerebral circulation. Studies of other organs, however, have shown that effective downstream pressure is determined by a critical closing pressure located at the arteriolar level. This study was designed to investigate the effects of PCO2-induced variations in cerebrovascular tone on the effective downstream pressure of the cerebral circulation. Sixteen patients recovering from head injury were studied. Intracranial pressure was assessed by epidural pressure transducers. Blood flow velocity in the middle cerebral artery was monitored by transcranial Doppler sonography. Effective downstream pressure was derived from the zero flow pressure as extrapolated by regression analysis of instantaneous arterial pressure/middle cerebral artery flow velocity relationships. PaCO2 was varied between 30 and 47 mm Hg in randomized sequence. Intracranial pressure decreased from 18.5+/-5.2 mm Hg during hypercapnia to 9.9+/-3.1 mm Hg during hypocapnia. In contrast, effective downstream pressure increased from 13.7+/-9.6 mm Hg to 23.4+/-8.6 mm Hg and exceeded intracranial pressure at hypocapnic PaCO2 levels. Our results demonstrate that, in the absence of intracranial hypertension, intracranial pressure does not necessarily represent the effective downstream pressure of the cerebral circulation. Instead, the tone of cerebral resistance vessels seems to determine effective downstream pressure. This suggests a modified model of the cerebral circulation based on the existence of two Starling resistors in a series connection.

Myocardial consequences of remifentanil in patients with coronary artery disease

Remifentanil may be an alternative to conventional opioids for minimally invasive direct coronary artery bypass surgery because of its extremely short duration of action. The aim of this study was to investigate the effects of remifentanil on myocardial blood flow, metabolism and systemic haemodynamic variables in patients with coronary artery disease. After approval by the local ethics committee, 12 male patients were investigated before elective coronary artery bypass grafting. Systemic haemodynamic variables, myocardial blood flow and metabolism were measured when patients were awake and when they were anaesthetized with high-dose remifentanil (2.0 micrograms kg-1 min-1), or with remifentanil 0.5 microgram kg-1 min-1 combined with propofol (target-controlled infusion aiming at a plasma concentration of 2.0 micrograms ml-1). Myocardial blood flow was measured using a modified Kety-Schmidt technique. High-dose remifentanil anaesthesia significantly reduced cardiac index (CI) (-25%) as a consequence of a decrease in stroke volume index (SVI) (-14%) and heart rate (-13%). Mean arterial pressure (MAP) was 30% lower than that in the awake patient. Myocardial blood flow and myocardial oxygen uptake (MVO2) decreased by 30% and 42%, respectively. In contrast to high-dose remifentanil anaesthesia, systemic vascular resistance index (-14%) during remifentanil/propofol anaesthesia was significantly lower than that in the awake patient. Other haemodynamic variables, and myocardial blood flow and MVO2, did not significantly differ from the high-dose remifentanil period. In conclusion, high-dose remifentanil reduces SVI, heart rate, MAP, myocardial blood flow and MVO2 and its effects do not differ from those of remifentanil/propofol anaesthesia.

Haemodynamic changes during minimally invasive coronary artery bypass surgery using high-dose esmolol

We aimed to investigate the effects of high-dose esmolol on haemodynamics and oxygen extraction in minimally invasive direct coronary artery bypass (MIDCAB) surgery patients.

METHODS

In 18 patients, heart rate (HR), mean arterial (MAP), central venous (CVP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO), and mixed venous oxygen saturation (Sv0(2)) were prospectively measured after induction of anaesthesia (T1), start of surgery (T2), during bypass grafting with beta-blockade (T3), and at the end of surgery (T4).

RESULTS

Mean esmolol dose at T3 was 0.44+/-0.2mgkg(-1)min(-1). HR was unchanged, whereas significant decreases in mean CO (3.1+/-0. 8 vs 4.8+/-1.0lmin(-1)m(-2), pre-esmolol), MAP (53+/-10 vs 89+/-14mmHg), and SvO(2) (65+/-10 vs 81+/-4%) were observed during esmolol administration. All haemodynamic parameters normalized immediately after termination of esmolol (T4).

CONCLUSIONS

Despite unchanged HR esmolol reduced CO and MAP suggesting a favorable reduction of myocardial oxygen consumption. Mean Sv0(2) during esmolol administration reflects an acceptable ratio of whole-body oxygen delivery and consumption. Haemodynamic changes with high-dose esmolol during MIDCAB surgery remain within safety margins.

Effects of the sitting position on the distribution of blood volume in patients undergoing neurosurgical procedures

The use of the sitting position in neurosurgery is often associated with decreased arterial pressure (MAP) and stroke volume index (SVI). A shift in blood from the intra- to the extrathoracic compartment may be responsible for this cardiovascular response. However, little is known of the amount of shift in blood volume after transfer from the supine to the sitting position. Therefore, we measured simultaneously changes in intrathoracic blood volume (ITBV) caused by a change in body position in anaesthetized patients. Measurements of cardiac index (CI), ITBV, pulmonary (PBV) and total circulating (TBVcirc) blood volumes were performed in the supine and sitting position. CI, ITBV, PBV and TBVcirc were measured using a thermodye dilution technique. Fluid input was restricted to 14 ml kg-1 before induction of anaesthesia. Change in body position caused a significant decrease in ITBV and was accompanied by a significant decrease in CI, SVI and MAP. Changes in ITBV correlated (r = 0.78) with changes in SVI. Thus a change in blood volume distribution between the intra- and extrathoracic compartment occurred after a change from the supine to the sitting position. Indicator dilution enables quantification of this shift and may be helpful in guiding fluid therapy in selected patients.

[Does method of anesthesia modify postoperative ischemia incidence? A study of patients after aortocoronary bypass operations]

In the postoperative period after coronary artery bypass graft surgery, the physician's enhanced attention should be focused on the incidence of myocardial ischaemia. The increased stress in the awakening patient as well as the return of autonomous reflexes can be the cause of imbalances in myocardial oxygen supply and uptake. Therefore, a probable influence of the pharmacologic profile of the intraoperatively applied anaesthetics on the incidence of postoperative myocardial ischaemia is of importance for adapting therapy on ICU to minimize any ischaemic risk. After approval by the ethics committee, a prospective randomized study was performed in 40 male patients who underwent coronary artery bypass graft surgery. The aim of the study was to compare balanced anaesthetic techniques performed with fentanyl and halothane, isoflurane and enflurane, respectively, with total intravenous anaesthesia performed with fentanyl and midazolam. An index to classify detection of ischaemia into three categories (ischaemia, probable ischaemia, no ischaemia) was established, based on measurements of myocardial lactate extraction and ST-segment analysis. Simultaneously, measurements of haemodynamic parameters and serum concentrations of catecholamines and intraoperatively applied anaesthetics were taken. In 8% of all measurements (30% of all patients) ischaemia was detected in the observation period and in 37% of all measurements (72.5% of all patients) probable ischaemia was detected. No significant difference was found concerning the incidence of myocardial ischaemia between all groups. The results of this investigation indicate that the application of inhalational anaesthetics for maintaining anaesthesia in coronary artery bypass graft surgery does not increase the risk of postoperative myocardial ischaemia.

Comparison of cardiac output assessed by pulse-contour analysis and thermodilution in patients undergoing minimally invasive direct coronary artery bypass grafting

OBJECTIVE

To investigate the precision and accuracy of continuous pulse contour cardiac output (PCCO) compared with intermittent transcardiopulmonary (TCPCO) and pulmonary artery thermodilution (TDCO) measurements in patients undergoing minimally invasive coronary bypass surgery (MIDCAB).

DESIGN

Prospective, controlled, clinical study.

SETTING

University hospital.

PARTICIPANTS

Twelve patients undergoing MIDCAB.

INTERVENTIONS

Thirty-six measurements of PCCO and thermodilution cardiac output (CO) were simultaneously performed after the start of surgery, during bypass grafting, and at the end of surgery. TCPCO and TDCO were simultaneously assessed by three injections of ice-cold saline randomly spread over the respiratory cycle. The pulse contour device was initially calibrated with an additional set of aortic thermodilution measurements.

MEASUREMENTS AND MAIN RESULTS

Absolute values of CO ranged between 1.6 and 9.2 L/min. A close agreement among the three techniques was observed at all measurements. Mean bias between PCCO and TDCO and TCPCO was 0.003 L/min (2 SD of differences between methods = 1.26 L/min) and 0.27 L/min (2 SD of differences between methods = 1.16 L/min), respectively. The correlation coefficients were r2 = 0.90 for TCPCO versus PCCO and r2 = 0.88 for TDCO versus PCCO.

CONCLUSION

The results of the present study show that compared with thermodilution CO, pulse contour analysis enables accurate measurement of continuous CO in patients undergoing MIDCAB.

Effects of one minimum alveolar anesthetic concentration sevoflurane on cerebral metabolism, blood flow, and CO2 reactivity in cardiac patients

We investigated the cerebral hemodynamic effects of 1 minimum alveolar anesthetic concentration (MAC) sevoflurane anesthesia in nine male patients scheduled for elective coronary bypass grafting. For measurement of cerebral blood flow (CBF), a modified Kety-Schmidt saturation technique was used with argon as an inert tracer gas. Measurements of CBF were performed before the induction of anesthesia and 30 min after induction under normocapnic, hypocapnic, and hypercapnic conditions. Compared with the awake state under normocapnic conditions, sevoflurane reduced the mean cerebral metabolic rate of oxygen by 47% and the mean cerebral metabolic rate of glucose by 39%. Concomitantly, CBF was reduced by 38%, although mean arterial pressure was kept constant. Significant changes in jugular venous oxygen saturation were absent. Hypocapnia and hypercapnia caused a 51% decrease and a 58% increase in CBF, respectively. These changes in CBF caused by variation of Paco2 indicate that cerebrovascular CO2 reactivity persists during 1 MAC sevoflurane anesthesia.

IMPLICATIONS

We used a modified Kety-Schmidt saturation technique to investigate the effects of 1 minimum alveolar anesthetic concentration (MAC) sevoflurane on cerebral blood flow, metabolism, and CO2 reactivity in cardiac patients. We found that the global cerebral blood flow and global cerebral metabolic rate of oxygen remained coupled and that cerebrovascular CO2 reactivity is not impaired by the administration of 1 MAC sevoflurane.

Heart transplantation after successful donor postpartum pulmonary embolectomy

A fulminant pulmonary embolism can be treated surgically if thrombolytic therapy is contraindicated. A 31-year-old woman developed a fulminant pulmonary embolism after right-sided deep venous thrombosis 1 day after undergoing a cesarean section. A pulmonary embolectomy with cardiopulmonary bypass was performed, but the patient was brain-dead. After 2 days of echocardiographic observation, her heart was explanted for a 61-year-old man with ischemic cardiomyopathy. His right heart data were unremarkable, and he remains well 16 months after transplantation. Despite the sudden strain on the right ventricle that occurs with a pulmonary embolism, such a heart may be transplanted successfully after a pulmonary embolectomy.

Changes in central venous pressure and pulmonary capillary wedge pressure do not indicate changes in right and left heart volume in patients undergoing coronary artery bypass surgery

The value of pulmonary artery catheterization is a matter for discussion. Previous studies suggest that direct measurements of intravascular volume distribution and cardiac volume indices may be of greater relevance than central venous and pulmonary capillary wedge pressure. We therefore used a thermo-dye dilution technique for the quantification of central blood volume, right ventricular end-diastolic volume and left heart volume in patients undergoing coronary artery bypass surgery. Measurements were performed after the induction of anaesthesia as well as 1, 6 and 24 h after surgery. Central venous pressure was significantly increased at 1 and 6 h, whereas right ventricular end-diastolic volume was increased only at 6 h post-operatively. Pulmonary capillary wedge pressure showed a tendency to increase whereas left heart and central blood volume decreased significantly after surgery. The results of the present study suggest that changes in cardiac filling pressure do not indicate changes in indices of cardiac volume in patients after coronary bypass surgery.

Effects of respiratory alkalosis and acidosis on myocardial blood flow and metabolism in patients with coronary artery disease

BACKGROUND

Variation of the arterial carbon dioxide partial pressure (PaCO2) is not uncommon in anesthetic practice. However, little is known about the myocardial consequences of respiratory alkalosis and acidosis, particularly in patients with coronary artery disease. The aim of the current study was to investigate the effects of variation in PaCO2 on myocardial blood flow (MBF), metabolism, and systemic hemodynamics in patients before elective coronary artery bypass graft surgery.

METHODS

In 10 male anesthetized patients, measurements of MBF, myocardial contractility, metabolism, and systemic hemodynamics were made in a randomized sequence at PaCO2 levels of 30, 40, and 50 mmHg, respectively. The MBF was measured using the Kety-Schmidt technique with argon as a tracer. End-diastolic left ventricular pressure and the maximal increase of left ventricular pressure were assessed using a manometer-tipped catheter.

RESULTS

The cardiac index significantly changed with varying PaCO2 levels (hypocapnia, - 9%; hypercapnia, 13%). This reaction was associated with inverse changes in systemic vascular resistance index levels. The MBF significantly increased by 15% during hypercapnia, whereas no change was found during hypocapnia. Myocardial oxygen and glucose uptake and the maximal increase of left ventricular pressure were not affected by varying PaCO2 levels.

CONCLUSIONS

In anesthetized patients with coronary artery disease, short-term variations in PaCO2 have significant effects on MBF but do not influence global myocardial oxygen and glucose uptake. Changes in systemic hemodynamics associated with respiratory alkalosis and acidosis are caused by changes in systemic vascular resistance rather than by alterations in myocardial contractility.