Pressure-Volume Loops for Reviewing Right Ventricular Physiology and Failure in the Context of Left Ventricular Assist Device Implantation

Right ventricular (RV) function is complex as a number of determinants beyond preload, inotropy and afterload play a fundamental role. In particular, arterial elastance (Ea), ventriculo-arterial coupling (VAC), and (systolic) ventricular interdependence play a vital role for the right ventricle. Understanding and actively visualizing these interactions in the failing RV as well as in the altered hemodynamic and morphological situation of left ventricular assist device (LVAD) implantation may aid clinicians in their understanding of RV dysfunction and failure. While, admittedly, hard data is scarce and invasive pressure-volume loop measurements will not become routine in cardiac surgery, we hope that clinicians will benefit from the comprehensive, simulation-based review of RV pathology. In particular, the aim of this article is to first, address and clarify the pathophysiologic hemodynamic factors that lead to RV dysfunction and then, second, expand upon this basis examining the changes occurring by LVAD implantation. This is illustrated using Harvi software which shows elastance, ventricular arterial coupling, and ventricular interdependence by simultaneously showing pressure volume loops of the right and left ventricle.

5-year results of a newly implemented mechanical circulatory support program for terminal heart failure patients in a Swiss non-cardiac transplant university hospital

Background

In Switzerland, long-term circulatory support programs have been limited to heart transplant centers. In 2014, to improve the management of patients with end-stage heart failure not eligible for transplantation, we implemented a left ventricular assist device (LVAD) program for destination therapy at the University Hospital of Basel.

Methods

We described the program set-up with practical aspects. Patients aged 65 and above with therapy refractory end-stage heart failure without major contraindication for LVAD implantation were included. Younger patients with bridge-to-candidacy profile were also considered. Using the Kaplan-Meier estimate, we retrospectively analyzed the overall survival and freedom from major adverse events after LVAD implantation. We compared our results to internationally reported data.

Results

Between October 2014 and September 2019, 16 patients received an LVAD in our center. The mean age at implantation was 67.1 years. The mean EuroSCORE II was 24.4% and the median INTERMACS level was 4. Thirteen patients received an LVAD as destination therapy and three patients as bridge-to-candidacy. The overall survival was 87.5 and 70% at 1 and 2 years, respectively. Freedom from stroke was 81.3% at 1 and 2 years. Freedom from device infection was 67.7 and 58.7% at 1 and 2 years, respectively. Freedom from gastrointestinal bleeding was 75 and 56.3% at 1 and 2 years, respectively. Freedom from readmission was 50 and 31.3% and at 6 months and 1 year, respectively.

Conclusions

The Basel experience demonstrated the possible implementation of an LVAD program for destination therapy or bridge-to-candidacy in a non-transplant comprehensive heart-failure center with midterm survival results and freedom from major adverse events comparable to international registries. Patient selection remains crucial.

Trial registration

This study was registered on the ClinicalTrials.gov database (NCT04263012).

Thoracoscopic epicardial left ventricular bipolar lead implantation with the use of automated titanium fasteners (Cor-Knot®)

Background

Pacemaker implantation techniques using thoracoscopy have been described since about 25 years. However, the published reports concerning types of electrodes refer mostly to monopolar screw-in leads. We report our experience of thoracoscopic implantation of a bipolar suture-on epicardial electrode with monofilamentous sutures tightened by automated fasteners to avoid hand-tied knots.

Case presentation

A 69-year-old Caucasian female patient with a cardiac resynchronization therapy – defibrillator (CRT-D) due to dilated cardiomyopathy required the implantation of a supplementary left ventricluar resynchronization electrode. Because of unfavorable venous access, we chose a thoracoscopic approach. A bipolar suture-on epicardial electrode, was implanted by means of polypropylene monofilament 2–0 threads and automated titanium fasteners (Cor-Knot®). The intervention was uneventful. The correct function of the device was confirmed postoperatively and the patient was dismissed within 3 days from hospital. Six months after implantation the cardiologic control asserted regular device function and restitution of normal ejection fraction (EF 60%).

Conclusion

This case demonstrates the feasibility, safety and effectiveness of automated fasteners in the setting of thoracoscopic implantation of epicardial bipolar suture-on leads.

Utilization of echocardiography in Intensive Care Units: results of an online survey in Germany

BACKGROUND

In patients with hemodynamic instability echocardiography has been recommended as the preferred modality to evaluate the underlying pathophysiology. However, due to the fact that recent scientific data on the utilization of echocardiography in German Intensive Care Units (ICU) are scarce, we sought to investigate current practice.

METHODS

A structured, web-based, anonymized survey was performed from May until July 2015 among members of the German Interdisciplinary Association of Critical Care and Emergency Medicine (DIVI) consisting of 14 questions. Descriptive data analysis was performed.

RESULTS

One hundred four intensivists participated in the survey. Two-thirds of participants (66%) used echocardiography regularly for hemodynamic monitoring and stated that it changed the therapy in 26-50% of the cases irrespective of the time performed after ordering the examination. Transthoracic (TTE) were more frequently used than transesophageal (TEE) examinations. Twenty-six percent of the participants held an echocardiography certificate with a formal examination, 27% completed a structured training without an examination and almost half of the questioned ICU personnel (47%) did not complete a comprehensive training.

CONCLUSIONS

The results of this survey demonstrate a widespread utilization of echocardiography as part of routine diagnostic on frequent number of operative ICUs. However, there might be a lack of structured echocardiographic training especially for anesthesiologists.

The timing of extraction of non-restorable first permanent molars: a systematic review

AIM

To identify the ideal timing of first permanent molar extraction to reduce the future need for orthodontic treatment.

MATERIALS AND METHODS

A computerised database and subsequent manual search was performed using Medline database, Embase and Ovid, covering the period from January 1946 to February 2013. Two reviewers (JE and ME) extracted the data independently and evaluated if the studies matched the inclusion criteria. Inclusion criteria were specification of the follow-up with clinical examination or analysis of models, specification of the chronological age or dental developmental stage at the time of extraction, no treatment in between, classification of the treatment result into perfect, good, average and poor. The search was limited to human studies and no language limitations were set.

RESULTS

The search strategy resulted in 18 full-text articles, of which 6 met the inclusion criteria. By pooling the data from maxillary sites, good to perfect clinical outcome was estimated in 72% (95% confidence interval 63%-82%). Extractions at the age of 8-10.5 years tended to show better spontaneous clinical outcomes compared to the other age groups. By pooling the data from mandibular sites, extractions performed at the age of 8-10.5 and 10.5-11.5 years showed significantly superior spontaneous clinical outcome with a probability of 50% and 59% likelihood, respectively, to achieve good to perfect clinical result (p<0.05) compared to the other age groups (<8 years of age: 34%, >11.5 years of age: 44%).

CONCLUSION

Prevention of complications after first permanent molars extractions is an important issue. The overall success rate of spontaneous clinical outcome for maxillary extraction of first permanent molars was superior to mandibular extraction. Extractions of mandibular first permanent molars should be performed between 8 and 11.5 years of age in order to achieve a good spontaneous clinical outcome. For the extraction in the maxilla, no firm conclusions concerning the ideal extraction timing could be drawn.

Rare case of generalised aggressive periodontitis in the primary dentition

BACKGROUND

Generalised aggressive periodontitis (AP) in the prepubescent age is an exceptionally rare disease in the primary dentition of otherwise healthy children. Characteristics of AP are gingival inflammation, deep periodontal pockets, bone loss, tooth mobility and even tooth loss. The most common way of treating this disease is the extraction of all the involved primary teeth.

CASE REPORT

A 4-year-old girl presented with signs of severe gingival inflammation. Clinical examination revealed deep pockets, increased tooth mobility and bone loss. Microbiological testing revealed the presence of a typical periopathogenic flora consisting of Aggregatibacter actinomycetemcomitans and the typical members of the red complex (Porphyromonas gingivalis, Prevotella intermedia and Treponema denticola). The patient underwent tooth extraction of all primary teeth except the primary canines, followed by thorough root debridement and treatment with systemic antibiotics (amoxicillin plus metronidazole).

FOLLOW-UP

Regular clinical and microbiological examinations over 4 years showed no signs of recurrence of a periodontitis, even in the erupted permanent teeth.

CONCLUSION

Early diagnosis and consequent early treatment of aggressive periodontitis can stop the disease and therefore avoid the development of a periodontal disease in the permanent dentition. A close collaboration between specialists of different disciplines is required for a favourable outcome.

Influence of levosimendan on organ dysfunction in patients with severely reduced left ventricular function undergoing cardiac surgery

OBJECTIVES

Levosimendan is an inotropic drug with organ-protective properties due to its activation of mitochondrial K(ATP) channels. This prospective, randomized, double-blind, placebo-controlled study investigated whether administration of levosimendan prior to cardiopulmonary bypass could reduce organ dysfunction and influence subsequent secondary endpoints.

PATIENTS AND METHODS

Patients with left ventricular ejection fraction <30% scheduled for elective coronary artery bypass surgery (with or without valve surgery) received either levosimendan (12.5 mg, 0.1 µg kg(-1) per min; n = 17) or placebo (n = 16) central venous infusion, immediately after anaesthesia induction, as add-on medication to a goal-orientated treatment algorithm.

RESULTS

A total of 33 patients completed the study. There were no statistically significant differences in Sequential Organ Failure Assessment scores, survival, haemodynamic parameters, time to extubation, time in intensive care unit, need for haemodialysis or health-related quality-of-life at 6 months post operation. The levosimendan group compared with the placebo group had significantly lower use of epinephrine (35% versus 81%) and nitroglycerine (6% versus 44%) 24 h postoperation, and significantly less frequent serious adverse events (13% versus 47%).

CONCLUSIONS

These preliminary results show that timely perioperative levosimendan treatment is feasible, has a favourable safety profile safe and may help to prevent low cardiac output syndrome. However, organ function was not preserved. Further studies, using larger sample sizes, are required.

[DGAI-certified seminar series: anaesthesia focussed echocardiography: module 4 cardiosonography]

The use of ultrasonography in perioperative medicine has developed rapidly within the last decade. Today ultrasonic techniques are established methods for peripheral and central venous access as well as for regional anaesthesia. However, transthoracic ultrasonography by non-cardiologists has not yet been routinely established perioperatively, in intensive care medicine or in emergency medicine. With the current module 4: Cardiosonography of the DGAI-certified seminar series in Anaesthesia Focussed Sonography (AFS) it is intended to provide a basis for a quality assured training and implementation of transthoracic sonography in anaesthesia, intensive care medicine and emergency medicine.

S3 guidelines for intensive care in cardiac surgery patients: hemodynamic monitoring and cardiocirculary system

Hemodynamic monitoring and adequate volume-therapy, as well as the treatment with positive inotropic drugs and vasopressors are the basic principles of the postoperative intensive care treatment of patient after cardiothoracic surgery. The goal of these S3 guidelines is to evaluate the recommendations in regard to evidence based medicine and to define therapy goals for monitoring and therapy. In context with the clinical situation the evaluation of the different hemodynamic parameters allows the development of a therapeutic concept and the definition of goal criteria to evaluate the effect of treatment. Up to now there are only guidelines for subareas of postoperative treatment of cardiothoracic surgical patients, like the use of a pulmonary artery catheter or the transesophageal echocardiography. The German Society for Thoracic and Cardiovascular Surgery (Deutsche Gesellschaft für Thorax-, Herz- und Gefässchirurgie, DGTHG) and the German Society for Anaesthesiology and Intensive Care Medicine (Deutsche Gesellschaft für Anästhesiologie und lntensivmedizin, DGAI) made an approach to ensure and improve the quality of the postoperative intensive care medicine after cardiothoracic surgery by the development of S3 consensus-based treatment guidelines. Goal of this guideline is to assess the available monitoring methods with regard to indication, procedures, predication, limits, contraindications and risks for use. The differentiated therapy of volume-replacement, positive inotropic support and vasoactive drugs, the therapy with vasodilatators, inodilatators and calcium sensitizers and the use of intra-aortic balloon pumps will also be addressed. The guideline has been developed following the recommendations for the development of guidelines by the Association of the Scientific Medical Societies in Germany (AWMF). The presented key messages of the guidelines were approved after two consensus meetings under the moderation of the Association of the Scientific Medical Societies in Germany (AWMF).

[Haemodynamic monitoring in the perioperative phase. Available systems, practical application and clinical data]

A regular hydration status and compensated vascular filling are targets of perioperative fluid and volume management and, in parallel, represent precautions for sufficient stroke volume and cardiac output to maintain tissue oxygenation. The physiological and pathophysiological effects of fluid and volume replacement mainly depend on the pharmacological properties of the solutions used, the magnitude of the applied volume as well as the timing of volume replacement during surgery. In the perioperative setting surgical stress induces physiological and hormonal adaptations of the body, which in conjunction with an increased permeability of the vascular endothelial layer influence fluid and volume management. The target of haemodynamic monitoring in the operation room is to collect data on haemodynamics and global oxygen transport, which enable the anaesthetist to estimate the volume status of the vascular system. Particularly in high risk patients this may improve fluid and volume therapy with respect to maintaining cardiac output. A goal-directed volume management aiming at preventing hypovolaemia may improve the outcome after surgery. The objective of this article is to review the monitoring devices that are currently used to assess haemodynamics and filling status in the perioperative setting. Methods and principles for measuring haemodynamic variables, the measured and calculated parameters as well as clinical benefits and shortcomings of each device are described. Furthermore, the results for monitoring devices from clinical studies of goal-directed fluid and volume therapy which have been published will be discussed.

[Monitoring of perioperative fluid management in children]

Invasive monitoring is rarely used in children undergoing routine anaesthesia. Therefore the management of fluid therapy and its maintenance depends often on the experience of the anaesthetist. In situations of high volume uptake and during critical surgical procedures haemodynamic state can easily be underestimated and hypovolaemic episodes remain undetected. This article summarises recent developments of less invasive and continuous monitoring techniques available for paediatric use which probably represent a useful addition in optimising the perioperative haemodynamic performance.

[Guidelines for intensive care in cardiac surgery patients: haemodynamic monitoring and cardio-circulatory treatment guidelines of the German Society for Thoracic and Cardiovascular Surgery and the German Society of Anaesthesiology and Intensive Care Medicine]

Hemodynamic monitoring and adequate volume-therapy, as well as the treatment with positive inotropic drugs and vasopressors, are the basic principles of the postoperative intensive care treatment of patient after cardiothoracic surgery. The goal of these S3 guidelines is to evaluate the recommendations in regard to evidence based medicine and to define therapy goals for monitoring and therapy. In context with the clinical situation the evaluation of the different hemodynamic parameters allows the development of a therapeutic concept and the definition of goal criteria to evaluate the effect of treatment. Up to now there are only guidelines for subareas of postoperative treatment of cardiothoracic surgical patients, like the use of a pulmonary artery catheter or the transesophageal echocardiography. The German Society for Thoracic and Cardiovascular Surgery and the German Society for Anaesthesiology and Intensive Care Medicine made an approach to ensure and improve the quality of the postoperative intensive care medicine after cardiothoracic surgery by the development of S3 consensus-based treatment guidelines. Goal of this guideline is to assess available monitoring methods and their risks as well as the differentiated therapy of volume-replacement, positive inotropic support and vasoactive drugs, the therapy with vasodilators, inodilators and calcium-sensitizers and the use of intra-aortic balloon pumps. The guideline has been developed according to the recommendations for the development of guidelines by the Association of the Scientific Medical Societies in Germany (AWMF). The presented key messages of the guidelines were approved after two consensus meetings under the moderation of the Association of the Scientific Medical Societies in Germany (AWMF).

Current practice of hemodynamic monitoring and vasopressor and inotropic therapy in post-operative cardiac surgery patients in Germany: results from a postal survey

BACKGROUND

In Germany, more than 100,000 patients are monitored and treated in 80 intensive care units (ICUs) following cardiac surgery each year. The controversies concerning the different methods of hemodynamic monitoring and the appropriate agents for volume therapy and inotropic support are well known. However, little is known about how monitoring and treatment are currently performed.

METHODS

A questionnaire with 39 questions was sent to the leading physicians of 80 ICUs in Germany, treating patients after cardiac surgery. The questions to be answered covered the current practice of hemodynamic monitoring, volume replacement, inotropic/vasopressor support and transfusions in patients after cardiac surgery.

RESULTS

Sixty-nine per cent of the questionnaires were completed and returned. All ICUs used basic monitoring as recommended by the societies. The use of advanced hemodynamic monitoring included the pulmonary artery catheter (58.2%), transesophageal echocardiography (38.1%) and transpulmonary dilution techniques (13%). Crystalloids (21.2%) and colloids (73%) were used for volume replacement. Epinephrine (41.8%) and dobutamine (30.9%) were the first-choice inotropic drugs for the treatment of low cardiac output syndrome, followed by phosphodiesterase inhibitors (14.5%). Second-choice drugs for the treatment of low cardiac output syndrome were enoximone (29%), milrinone (25%) and dobutamine (25%). A written transfusion protocol and a transfusion threshold for red blood cells existed in 59% and 79% of ICUs, respectively.

CONCLUSION

Hemodynamic monitoring and the variability in clinical practice with regard to volume replacement, transfusion triggers and the use of vasopressors/inotropes in cardiac surgery patients tend to follow the results of traditional experience rather than current scientific knowledge. Guidelines are therefore necessary to help to improve the standards of intensive care after cardiac surgery and thus the outcome of patients.

A new microwave applicator with integrated cooling system for intracavitary hyperthermia of vaginal carcinoma

An improved design of a previously described intracavitary microwave hyperthermia applicator is presented. The applicator consists of a coaxial choke antenna designed to be positioned into a perspex obturator. The antenna can be fitted in the obturator in three defined positions depending on the specific clinical situation: the selected median, paramedian or lateral position can each provide differently directed heating patterns. This feature combined with the additional axial variability of the antenna position within the obturator can lead to a highly targeted heating of tumours and a reduced risk of unwanted heating of normal tissues. Various phantom studies were conducted using both liquid and solid phantoms. The saline phantom was used to check the typical action of the choke of the antenna where it was found that the antenna choke is efficiently working resulting in a heating pattern which is dependent of the insertion depth of the antenna. The solid phantom was used to measure the typical specific absorption rate (SAR) distribution of each antenna/obturator configuration.

[The characterization of semirigid coaxial antennae for interstitial and endocavitary microwave hyperthermia]

PURPOSE

The increased dissemination of interstitial hyperthermia techniques requires suitable action in quality assurance for the used applicators. This work presents physical-technical methods for complete characterisation of interstitial and endocavitary coaxial antennas used for microwave hyperthermia.

METHODS

After a short introduction about the antennas' physical principle 2 fundamental experiments for acquisition of specific absorption rate (SAR) are described: There are the thermometric method, especially the power pulse technique, using a static solid state phantom and the direct measurement of the amplitude square of emitted electric field using miniaturized E-field probes in a fluid phantom. Principal problems occurring during E-field measurements in the near field zone of insulated antennas in media (phantom fluid) are discussed in detail.

RESULTS

Characteristic relative SAR profiles were found for each tested applicator design. The profiles were described using the following parameters: depths of SAR maximum, effective heating lengths and lengths of the dead end of the antennas relative to the 50%-iso-SAR-surface. Antenna designs for endocavitary and interstitial purposes were measured at variable insertion depths. The changing SAR-patterns were discussed regarding the found measurement data. Additionally measurements of parallel and inclined antenna arrays consisting of 4 interstitial applicators are described.

CONCLUSION

The final discussion give future perspectives to forthcoming developments for interstitial and endocavitary microwave hyperthermia.

A review of data on measles cases from sentinel surveillance sites in north-western Nigeria

This review was carried out to evaluate the impact of the revised Expanded Programme on Immunisation (EPI) against measles in the six north-western states of Nigeria through the sentinel surveillance system. The revised EPI was launched in all states by 1985, with a strategy of phased acceleration to reach all local government areas by 1987, and to achieve 80% vaccine coverage of children under two years, with 50% reduction in EPI disease morbidity by 1990. Results of the review showed a dramatic decrease in measles cases in each state: 70% overall from 1985 to 1988. Of 918 cases with known measles vaccination status, 90.6% were unvaccinated and 9.4% had documented immunisation. One concern is that 19% of cases occur in unimmunised infants under nine months. Although a suitable vaccine for children under nine months is available, it is not yet in use in Nigeria and these cases are therefore not preventable. At present, our best strategy is to increase coverage through a vigorous EPI campaign, concentrating on underserviced and hard-to-reach areas, and to strengthen surveillance so that measles outbreaks are identified early and action taken.