Levosimendan in intensive care and emergency medicine: literature update and expert recommendations for optimal efficacy and safety

The inodilator levosimendan, in clinical use for over two decades, has been the subject of extensive clinical and experimental evaluation in various clinical settings beyond its principal indication in the management of acutely decompensated chronic heart failure. Critical care and emergency medicine applications for levosimendan have included postoperative settings, septic shock, and cardiogenic shock. As the experience in these areas continues to expand, an international task force of experts from 15 countries (Austria, Belgium, China, Croatia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Spain, Sweden, Switzerland, and the USA) reviewed and appraised the latest additions to the database of levosimendan use in critical care, considering all the clinical studies, meta-analyses, and guidelines published from September 2019 to November 2021. Overall, the authors of this opinion paper give levosimendan a "should be considered" recommendation in critical care and emergency medicine settings, with different levels of evidence in postoperative settings, septic shock, weaning from mechanical ventilation, weaning from veno-arterial extracorporeal membrane oxygenation, cardiogenic shock, and Takotsubo syndrome, in all cases when an inodilator is needed to restore acute severely reduced left or right ventricular ejection fraction and overall haemodynamic balance, and also in the presence of renal dysfunction/failure.

[Perioperative care of patients with diastolic heart failure. Interface to anesthesia]

Diastolic heart failure leads to an increase in perioperative morbidity and mortality. The prevalence of this disease is rising and multiple risk factors have already been identified. Besides higher age and female gender, arterial hypertension, diabetes mellitus and coronary artery disease in particular have to be considered. Clinical examination and laboratory analyses are important for preoperative evaluation; however, echocardiography plays the most important role in the diagnostics of diastolic heart failure. The transmitral flow profile can be used to differentiate the grades of diastolic dysfunction using the ratio between early passive ventricular filling (E) and late active filling due to atrial contraction (A). Data concerning the ideal anesthesia technique are for the most part lacking; however, the application of thoracic epidural anesthesia seems to be beneficial. A great deal of attention has to be paid to the intraoperative volume status of patients with diastolic dysfunction as hypovolemia and hypervolemia can both have detrimental effects. Arrhythmias and major changes in blood pressure put this special group of patients at additional risks.

Platelet function testing to time surgery in patients on dual antiplatelet therapy?

In patients pretreated with P2Y12 receptor inhibitors who need to undergo non-emergent cardiac or major non-cardiac surgery, current guidelines of the European Society of Cardiology recommend postponing surgery for at least five days after last intake of clopidogrel or ticagrelor, and for seven days after last intake of prasugrel, unless there is high risk of ischemic events. However, a fixed five to seven days preoperative waiting period may be challenged, in the presence of inter-individual variability in on-treatment platelet reactivity. Therefore, Society of Thoracic Surgeons guidelines suggest to base decisions about a surgical delay on platelet function although both, the optimal platelet function assay and a bleeding cutoff have not yet been defined by large scale multicenter trials. This review aims to provide an overview on current knowledge of P2Y12 receptor induced platelet inhibition and surgery related bleeding and the potential role of platelet function analysis to time surgery.

[Peripartum aortic dissection]

A 29-year-old primagravida developed severe chest pains during labor. An emergency caesarean section was performed as the symptoms persisted. Imaging diagnosis immediately after delivery revealed an acute proximal (type A) aortic dissection. The patient was transferred to the nearest cardiothoracic surgery centre and successful emergency surgical aortic repair was performed. The perioperative course of a type A aortic dissection during pregnancy and labor is complicated by time pressure, diagnostic restrictions until delivery and potentially fatal uterine bleeding during cardiopulmonary bypass and hypothermic cardiac arrest. This case report describes the diagnosis and the surgical, anesthesiological and gynecological management of this life-threatening peripartum complication.

Arterial oxygen tension increase 2-3 h after hyperbaric oxygen therapy: a prospective observational study

BACKGROUND

Inhalation of hyperbaric oxygen (HBO) has been reported to decrease arterial oxygen tension (PaO(2)) in the early period after exposure. The current investigation aimed at evaluating whether and to what extent arterial blood gases were affected in mechanically ventilated intensive care patients within 6 h after HBO treatment.

METHODS

Arterial blood gases were measured in 11 ventilated subjects [nine males, two females, synchronized intermittent mandatory ventilation (SIMV) mode] undergoing HBO therapy for necrotizing soft tissue infection (seven patients), burn injury (two patients), crush injury (one patient) and major abdominal surgery (one patient). Blood gases were obtained with the patients in the supine position under continuous analgesia and sedation before the hyperbaric session (baseline), during isopression, after decompression, after each transport, and 1, 2, 3 and 6 h after exposure. Heart rates and blood pressures were recorded. Intensive care unit (ICU) ventilator settings remained unchanged. Transport and chamber ventilator settings were adjusted to baseline with maintenance of tidal volumes and positive end-expiratory pressure (PEEP) levels. The hyperbaric protocol consisted of 222.9 kPa (2.2 absolute atmospheres) and a 50-min isopression phase. The paired Wilcoxon's test was used.

RESULTS

Major findings (median values, 25%/75% quartiles) as per cent change of baseline: PaO(2) values decreased by 19.7% (7.0/31.7, P < 0.01) after 1 h and were elevated over baseline by 9.3% (1.5/13.7, P < 0.05) after 3 h. SaO(2), alveolar-arterial oxygen tension difference and PaO(2)/FiO(2) ratio behaved concomitantly. Acid-base status and carbon dioxide tension were unaffected.

CONCLUSION

Arterial oxygen tension declines transiently after HBO and subsequently improves over baseline in intensive care patients on volume-controlled mechanical ventilation. The effectiveness of other ventilation modes or a standardized recruitment manoeuvre has yet to be evaluated.

Different effects of abciximab and cytochalasin D on clot strength in thrombelastography

Maximum amplitude (MA) in thrombelastography (TEG) consists of a plasmatic and a platelet component. To assess the magnitude of the plasmatic component, pharmacological approaches have been proposed to eliminate the platelet component. We evaluated the individual and combined effects of abciximab and cytochalasin D on the MA of TEG. Whole blood, platelet-rich plasma (PRP) and homologous platelet-poor plasma (PPP) from 20 healthy volunteers were spiked with abciximab or cytochalasin D or a combination of both and TEGs performed. Abciximab and cytochalasin D decreased MA in all samples. MA of whole blood (18.6 +/- 3.1 mm) and PRP (33.7 +/- 3.5 mm) spiked with abciximab or cytochalasin D alone (15.0 +/- 2.9 mm and 25.0 +/- 4.0 mm) were significantly higher when compared with abciximab and cytochalasin D combined (10.4 +/- 3.0 and 20.2 +/- 3.5 mm). While MA of PRP and homologous PPP were significantly (P < 0.001) different after individual administration of abciximab and cytochalasin D, combination of both abolished this difference (20.2 +/- 3.5 mm and 20.4 +/- 3.7 mm, P = 0.372). In whole blood of critically ill patients or patients undergoing major surgery there was also a significant difference of MA between abciximab alone and in combination with cytochalasin D (16.5 +/- 11.3 mm and 11.3 +/- 7.7 mm, P < 0.001). This indicates that in contrast to individual administration of abciximab or cytochalasin D, a combination of both compounds eliminates the platelet-specific effect on MA of TEG tracings.

Low potential of dobutamine and dopexamine to block intestinal peristalsis as compared with other catecholamines

OBJECTIVE

Catecholamines are frequently used in critically ill patients to restore stable hemodynamics and to improve organ perfusion. One effect of short-term or long-term administration of catecholamines may be inhibition of propulsive motility in the intestine. We therefore analyzed the effect of dopexamine, dobutamine, and dopamine on ileal peristalsis and compared their action with that of epinephrine and norepinephrine, which have long been known to suppress intestinal peristalsis.

DESIGN

In vitro study on excised guinea pig ileum segments.

SETTING

Laboratory for experimental studies at the University.

SUBJECTS

Isolated guinea pig ileum.

INTERVENTIONS

Segments of ileum excised from guinea pigs were mounted in a tissue bath in Krebs-Henseleit solution and bubbled with 95% oxygen/5% CO2. Luminal perfusion with the same solution was performed at a rate of 0.35 mL/min. The bath temperature was kept at 36.5 degrees C. Peristalsis was recorded via changes in the intraluminal pressure. The drugs under investigation (dopamine, epinephrine, norepinephrine, dobutamine, and dopexamine) were added to the tissue bath.

MEASUREMENTS AND MAIN RESULTS

Low concentrations of each catecholamine, except epinephrine, caused a decrease in the pressure threshold, which reflects a stimulatory effect on peristalsis. Higher catecholamine concentrations caused a concentration-related increase in the threshold, cumulating in a complete block of peristalsis. The rank order of inhibitory potency was epinephrine > norepinephrine > dopamine > dobutamine approximately dopexamine. Dobutamine and dopexamine were about 500-fold less active than epinephrine in suppressing peristalsis.

CONCLUSIONS

This study shows that dobutamine and dopexamine have the least potential to block propulsive motility in the intestine, whereas epinephrine demonstrates the most adverse inhibitory effect. Because at low concentrations dobutamine and dopexamine even stimulate peristalsis, these drugs appear to be superior compared with other catecholamines with regard to their direct effects on intestinal motility.

Operations on patients deemed "unfit for operation and anaesthesia": what are the consequences?

BACKGROUND

The decision "patient unfit for anaesthesia and operation" is likely to cause a delay of the scheduled operation. This retrospective evaluation was done: 1) to determine the correctness of preoperative tentative diagnoses of coexisting diseases making anaesthesia and operation excessively risky in relation to the physician's training status; 2) to examine the question of whether preoperative medical management modified according to the anaesthesiologist's suggestions had a positive impact on the perioperative course.

METHODS

The medical records of patients scheduled for elective non-cardiac surgery who were rated "unfit for operation and anaesthesia" were evaluated. The accuracy of the tentative diagnoses was examined for relation to the training status of the anaesthesiologists. The preoperative management was tested for its impact on postoperative outcome.

RESULTS

During the observation period 16,122 patients underwent preoperative anaesthesiological assessment; 1021 (6.3%) were initially considered to be unfit for operation and anaesthesia. The records of 807 patients were available for review. The accuracy of the tentative diagnoses was 70%, and was not significantly affected by the training status of the physicians (P = 0.022). Four hundred and seventeen patients were excluded from the second part of the investigation (discharged without operation, underwent operation using local anaesthesia or tentative diagnosis not confirmed). Three hundred and ninety patients were operated under general anaesthesia. Group I (n = 216) was managed according to the anaesthesiologist's suggestions and was found to have a significantly lower complication rate (18.1%) than group II (n = 174) in which the suggestions from the preoperative assessment were ignored (32.2%; P < 0.05). The perioperative mortality rate in group I was 2.3% compared with 5.2% in group II (n.s.; P > 0.05).

CONCLUSIONS

We conclude that the anaesthesiology decision "patient unfit for operation and anaesthesia" has a high accuracy, independent of the anaesthesiologist's training status, and that preoperative medical management significantly reduces complications.

Perioperative myocardial cell injury: the role of troponins

Early recognition of minor myocardial cell injury and appropriate treatment may prevent development of myocardial infarction as one of the most severe postoperative cardiac complications. Troponins have been shown to be sensitive biochemical markers for the assessment of myocardial cell injury. We investigated prospectively 67 cardiac risk patients undergoing elective non-cardiac surgery. Troponin T (TNT) concentrations were measured during the perioperative period, and in those patients with increased TNT (cut-off 0.2 ng ml-1), troponin I (TNI) concentrations were measured additionally (cut-off 0.6 ng ml-1). Patients were allocated to one of three groups: group I, all patients with normal TNT concentrations had a good cardiac outcome (80.5%). In those patients with increased TNT concentrations (19.5%) TNI was also positive; group II, patients (8.8%) with only slightly increased TNT concentrations (0.32-0.99 ng ml-1) also had a good outcome, indicating minor myocardial cell injury, whereas patients with cardiac complications (11.9%) had higher TNT concentrations (0.47-9.8 ng ml-1) (P < 0.05) (group III). With a TNT cut-off at 0.2 ng ml-1, the positive predictive value for adverse outcome was 61.5%; the negative predictive value was 100%. With a TNT cut-off at 0.6 ng ml-1, the positive predictive value for adverse outcome increased to 87.5%, but the negative predictive value was still high (98%). Most of the patients showed an increase in TNT content from the day of surgery until the third postoperative day. We conclude that serial troponin measurements during the perioperative period identify pre-, intra- and postoperative myocardial cell injury. The concentration of troponin T may reflect the degree of injury and help categorize the subsequent risk.