Interstitial lung opacities in patients with severe COVID-19 pneumonia by bedside high-resolution ultrasound in association to CO2 retention

BACKGROUND

Coronavirus disease 2019 (COVID-19) can cause acute respiratory distress syndrome (ARDS).

OBJECTIVE

This single centre cross-section study aimed to grade the severity of pneumonia by bed-side lung ultrasound (LUS).

METHODS

A scoring system discriminates 5 levels of lung opacities: A-lines (0 points),≥3 B-line (1 point), coalescent B-lines (2 points), marked pleural disruptions (3 points), consolidations (4 points). LUS (convex 1-5 MHz probe) was performed at 6 defined regions for each hemithorax either in supine or prone position. A lung aeration score (LAS, maximum 4 points) was allocated for each patient by calculating the arithmetic mean of the examined lung areas. Score levels were correlated with ventilation parameters and laboratory markers.

RESULTS

LAS of 20 patients with ARDS reached from 2.58 to 3.83 and was highest in the lateral right lobe (Mean 3.67). Ferritin levels (Mean 1885μg/l; r = 0.467; p = 0.051) showed moderate correlation in spearman roh calculation. PaCO2 level (Mean 46.75 mmHg; r = 0.632; p = 0.005) correlated significantly with LAS, while duration of ventilation, Horovitz index, CRP, LDH and IL-6 did not.

CONCUSIONS

The proposed LAS describes severity of lung opacities in COVID-19 patients and correlates with CO2 retention in patients with ARDS.

[Perioperative dexamethasone]

Dexamethasone is a synthetic steroid that has been used for many years in the clinical routine due to its anti-inflammatory, anti-allergic and immunosuppressive properties. Furthermore, dexamethasone has been used for a long time for prophylaxis and treatment of chemotherapy-induced nausea and vomiting. In the meantime dexamethasone has been approved as standard for the prophylaxis and treatment of postoperative nausea and vomiting (PONV). This review article outlines the indications and side effects of the perioperative administration of dexamethasone.

[Perioperative management for CRS and HIPEC : Anesthesiological aspects]

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are therapeutic options for the treatment of intra-abdominal neoplasms. Following the resection of all visible tumor areas by CRS, microscopic tumor areas are treated with HIPEC. This procedure increases the quality of life and survival. The CRS with HIPEC is a complex surgical procedure in which the mainly younger and often otherwise healthy patients undergo several pathophysiological changes during the operation. The main concern of the anesthesiologist is the massive volume loss, volume shift and metabolic alterations. Patients with a high comorbidity should undergo preoperative optimization to reduce the perioperative morbidity and mortality especially by protracted interventions.

[Perioperative management for CRS and HIPEC : Anesthesiological aspects]

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are therapeutic options for the treatment of intra-abdominal neoplasms. Following the resection of all visible tumor areas by CRS, microscopic tumor areas are treated with HIPEC. This procedure increases the quality of life and survival. The CRS with HIPEC is a complex surgical procedure in which the mainly younger and often otherwise healthy patients undergo several pathophysiological changes during the operation. The main concern of the anesthesiologist is the massive volume loss, volume shift and metabolic alterations. Patients with a high comorbidity should undergo preoperative optimization to reduce the perioperative morbidity and mortality especially by protracted interventions.

[Analysis and options for optimization of preoperative assessment for anesthesia at a university hospital]

BACKGROUND

Risk assessment prior to elective surgery is an important tool in the context of perioperative patient care; however, only a few studies have been carried out to address the processes and problems during preoperative assessment for anesthesia.

AIM

Over a period of several weeks all preoperative anesthesia evaluations prior to elective surgery were prospectively recorded in order to generate a data pool with a view to identifying options for process optimization.

MATERIAL AND METHODS

All preoperative evaluations over a period of 38 working days at the University Medical Center Regensburg were recorded and analyzed with respect to waiting time for the patient and the duration of the preoperative consultation on medication. Also documented were the patient age, ASA score, the faculty carrying out the operation, type and risk of surgery, planned time of surgery, professional experience of the anesthesiologist and the approval status for surgery. In addition, all problems which occurred during the preoperative anesthesia evaluation were documented using a questionnaire.

RESULTS

Overall 2233 preoperative assessments for anesthesia were recorded and analyzed. The number of patients attending the preoperative assessment clinic differed markedly in the course of a day and was lower at the end of the week. Approval for surgery with no reservations was given more frequently by anesthesiologists with more than 5 years professional experience and consultants compared to younger colleagues. The main reason for approval with reservations or no approval was the lack of patient records and test results, which should have been presented according to the in-house standard for preoperative assessment for anesthesia. The mean waiting time was 58.6 ± 30.3 min, the mean duration of the patient documentation review and physician-patient consultation together was 33.6 ± 16.3 min. Anesthesiologists with 2-5 years professional experience needed significantly less time for patient documentation reviews and physician-patient consultations than younger and more experienced colleagues. The duration of the preoperative assessment for anesthesia correlated with the ASA score and risks of surgery.

CONCLUSION

The analysis of processes and problems in the context of preoperative assessment for anesthesia revealed several options for optimization. Major efforts should be the implementation of an appointment system for the preoperative assessment clinic in order to generate a homogeneous distribution of patients during the course of a day. Furthermore, surgeons and case managers should be requested to refer patients to the preoperative assessment clinic only with complete records and test results according to the in-house standard.

[Secondary sclerosing cholangitis after multiple trauma and long-term intensive care treatment: case report of a characteristic course]

This article reports on a patient who needed intensive care treatment because of multiple trauma. The patient had no preexisting liver disease but developed secondary sclerosing cholangitis and finally died. The etiology, diagnosis and therapeutic options of this clinical picture are discussed and a review of the literature is presented.

Emergency cricothyrotomy in infants--evaluation of a novel device in an animal model

BACKGROUND

According to different algorithms of airway management, emergency cricothyrotomy is the final step in managing an otherwise not accessible airway. As an alternative to an open surgical procedure, minimally invasive approaches exist. Quicktrach baby™ is a commercially available set for a minimal invasive cricothyrotomy in infants. The set consists of a plastic cannula over a metal needle for direct placement in the trachea. So far, this device has not been evaluated for its intended use.

OBJECTIVES

We hypothesize that Quicktrach baby™ allows the establishment of an emergency airway. The aim was to prove that the device is easy to handle and the cricothyrotomy fast to perform.

METHODS

After approval of the local ethics committee, the study was performed on the cadavers of 10 adult rabbits. Cricothyrotomy was performed with Quicktrach baby™. Successful placement, performance time, and complication rate were documented. Possible ventilation with a breathing bag was evaluated. Data are reported as mean and interquartile range.

RESULTS

Successful placement of Quicktrach baby™ was possible in all attempts. The placement took 31 [23-43] s. In two cases, a fracture of the cricoid's cartilage was seen. In one animal, damage to the posterior wall mucosa was observed. In all cases, sufficient ventilation was possible.

CONCLUSIONS

Quicktrach™ baby proved to be a reliable technique. In the animal model, it is easy and fast to perform. Only a few minor complications occurred. Sufficient ventilation was possible in all attempts.

[Regional anesthesia and neurological diseases]

Modern anesthesia is handling an increasing number of patients with neurological diseases who require narcosis. Regional anesthesia techniques offer qualities which might be advantageous for this group particularly for childbirth. The number of pregnant women with neurological diseases has increased significantly in the recent years due to improved diagnostics and therapy. A more careful approach to regional anesthesia in patients with neurological diseases is necessary as the drugs themselves possess neurotoxic effects and the procedure might worsen the underlying neurological diseases. Additionally, performing regional anesthesia might be more complicated and the resulting blockade might be different from the expected neuronal block. Published data concerning regional anesthesia in this patient group are limited and mainly restricted to case reports. In this review general considerations regarding regional anesthesia, techniques, drugs and methods in these patient groups will be discussed. In the second part the practical approach to regional anesthesia for some of the most important neurological diseases is highlighted.

Inefficacy of simulator-based training on anaesthesiologists' non-technical skills

BACKGROUND

Analysis of critical incidents in anaesthesia practice emphasizes the important role of non-technical skills (NTS) in improving patient safety. Therefore, debriefing with regard to NTS has been added to medical management (MM) simulator training to improve acute crisis competencies of anaesthesiologists. The purpose of this study was to compare the NTS and MM performance of two groups of anaesthesiologists in a simulated anaesthesia crisis after undergoing different types of training.

METHODS

Forty-two anaesthesiologists were randomly assigned to two different training groups, with each group participating in two simulation training sessions. One group's (NTS+MMG) training included extensive debriefing of NTS (resource management, planning, leadership and communication) and MM, while the other group (MMG) received a simpler debriefing that focused solely on MM. The quality and quantity of NTS and quality of MM performance were rated by reviewing the videotapes of the scenarios.

RESULTS

NTS+MMG did not prove superior to MMG with regard to behavioural and MM markers. The quality of NTS performances correlated significantly (P<0.01) with the quantity of NTS demonstration, and also correlated significantly with the MM actions (P<0.01) in both groups.

CONCLUSION

A single session of training including debriefing of NTS and MM did not improve the NTS performances of anaesthesiologists when compared with anaesthesiologists who only received MM training. This might indicate that a more frequent or individual training is needed to improve participants' NTS performance.

Ketamine

There are two optical isomers of the 2-(2-chlorophenyl)-2-(methylamino)-cyclohexanone ketamine: S(+) ketamine and R(-) ketamine. Effects of this drug are mediated by N-methyl-d-aspartate (NMDA), opioid, muscarinic and different voltage-gated receptors. Clinically, the anaesthetic potency of the S(+)-isomer is approximately three to four times that of the R(-)-isomer, which is attributable to the higher affinity of the S(+)-isomer to the phencyclidine binding sites on the NMDA receptors. Ketamine is water- and lipid-soluble, allowing it to be administered conveniently via various routes and providing extensive distribution in the body. Ketamine metabolism is mediated by hepatic microsomal enzymes. It causes bronchodilation and stimulation of the sympathetic nervous system and cardiovascular system. In clinics, ketamine and particularly S(+)-ketamine are used for premedication, sedation, and induction and maintenance of general anaesthesia, which is than termed "dissociative anaesthesia". Ketamine and its S(+)-isomer are ideal anaesthetic agents for trauma victims, patients with hypovolemic and septic shock and patients with pulmonary diseases. Even subanaesthetic doses of this drug have analgesic effects, so ketamine is also recommended for post-operative analgesia and sedation. The combination of ketamine with midazolam or propofol can be extremely useful and safe for sedation and pain relief in intensive care patients, especially during sepsis and cardiovascular instability. In the treatment of chronic pain ketamine is effective as a potent analgesic or substitute together with other potent analgesics, whereby it can be added by different methods. There are some important patient side-effects, however, that limit its use, whereby psycho-mimetic side-effects are most common.

Ketamine

There are two optical isomers of the 2-(2-chlorophenyl)-2-(methylamino)-cyclohexanone ketamine: S(+) ketamine and R(-) ketamine. Effects of this drug are mediated by N-methyl-d-aspartate (NMDA), opioid, muscarinic and different voltage-gated receptors. Clinically, the anaesthetic potency of the S(+)-isomer is approximately three to four times that of the R(-)-isomer, which is attributable to the higher affinity of the S(+)-isomer to the phencyclidine binding sites on the NMDA receptors. Ketamine is water- and lipid-soluble, allowing it to be administered conveniently via various routes and providing extensive distribution in the body. Ketamine metabolism is mediated by hepatic microsomal enzymes. It causes bronchodilation and stimulation of the sympathetic nervous system and cardiovascular system. In clinics, ketamine and particularly S(+)-ketamine are used for premedication, sedation, and induction and maintenance of general anaesthesia, which is than termed "dissociative anaesthesia". Ketamine and its S(+)-isomer are ideal anaesthetic agents for trauma victims, patients with hypovolemic and septic shock and patients with pulmonary diseases. Even subanaesthetic doses of this drug have analgesic effects, so ketamine is also recommended for post-operative analgesia and sedation. The combination of ketamine with midazolam or propofol can be extremely useful and safe for sedation and pain relief in intensive care patients, especially during sepsis and cardiovascular instability. In the treatment of chronic pain ketamine is effective as a potent analgesic or substitute together with other potent analgesics, whereby it can be added by different methods. There are some important patient side-effects, however, that limit its use, whereby psycho-mimetic side-effects are most common.

[Dolasetron and shivering. A prospective randomized placebo-controlled pharmaco-economic evaluation]

BACKGROUND AND GOAL

Forced by the current economical situation, German hospitals have to reconsider their clinical productivity. When caregivers introduce new therapeutic concepts medical quality should either be improved without increasing costs or when reducing costs medical quality should be maintained. In the surgical field postoperative shivering reduces both patient comfort and medical quality. We therefore investigated the clinical pathway prevention of shivering with dolasetron in a prospective, randomized, placebo-controlled analysis of cost-effectiveness.

MATERIAL AND METHODS

After written informed consent we randomized 40 patients scheduled for lumbar disc hernia repair or head and neck surgery into two groups: patients of group D received dolasetron 1 mg/kg body weight during surgery whereas patients of group K received 100 ml saline as placebo. Primary endpoints were the incidence of shivering, the length of stay in the postanesthesia care unit and process-associated costs. Secondary endpoint was the influence on perioperative thermoregulation.

RESULTS

We observed postanesthetic shivering in 5 patients belonging to group D in comparison to 15 patients receiving the placebo (p<0.05). The length of stay in the postanesthesia care unit was shorter in patients allocated to dolasetron (mean+/-SD; group D: 43+/-16 min, group K 62+/-18 min, p<0.05). There was a significant saving in process-associated personnel costs (personnel costs in group D EUR 41.26+/-14, personnel costs in group K EUR 53.15+/-15) but in contrast the process-associated material costs were significantly increased (group D EUR 17.16+/-3, group K EUR 0.73+/-1, p<0.05).

CONCLUSIONS

The optimization of the clinical process and medical quality induced by a prophylaxis against shivering and postoperative nausea and vomiting compensates for the increased use of pharmaceutical resources in our setting.

Simulation as an additional tool for investigating the performance of standard operating procedures in anaesthesia

BACKGROUND

In medicine, the use of standard operating procedures (SOPs) is often evaluated using questionnaires (QUES). However, QUES can have limitations with regard to method, thus leading to errors. Simulation (SIM) offers another opportunity for evaluation. We hypothesized that medical errors in the evaluation of SOPs using QUES could be detected by SIM, and that SIM is better qualified to demonstrate applied medicine.

METHODS

We investigated the use of SOPs in anaesthesia, rapid sequence induction (RSI), by means of a QUES (n=42) or SIM (n=42) among 84 anaesthesiologists. Seven measures for preventing aspiration during induction of anaesthesia were examined and evaluated according to a predetermined points system.

RESULTS

The average number of times that precautionary measures to prevent aspiration were mentioned in the QUES [4.8 (0.9)] or performed during SIM [5.0 (1.1)] did not differ between the two groups. Pre-oxygenation was the most frequently described or performed measure (95% vs 93%). However, other measures, such as avoidance of positive pressure ventilation (45% vs 85%), differed significantly between the two groups.

CONCLUSIONS

QUES and SIM are powerful instruments for evaluating the implementation of SOPs such as RSI. SIM demonstrates automated behaviours and thus more clearly represents behaviours used in clinical practice than is possible to demonstrate using QUES. Using a combination of these two instruments, method errors resulting from the individual instruments can be reduced.

Myotoxizität von Lokalanästhetika

Intramuscular injections of local anaesthetic agents regularly result in reversible muscle damage, with a dose-dependent extent of the lesions. All local anaesthetic agents that have been examined are myotoxic, whereby procaine produces the least and bupivacaine the most severe muscle injury. The histological pattern and the time course of skeletal muscle injury appear relatively uniform: hypercontracted myofibrils become evident directly after injection, followed by lytic degeneration of striated muscle sarcoplasmic reticulum myocyte edema and necrosis. Intriguingly, in most cases myoblasts, basal laminae and connective tissue elements remain intact which subsequently ensures complete muscular regeneration. Subcellular pathomechanisms of local anaesthetic myotoxicity are still not understood in detail. Increased intracellular Ca(2+) levels are suggested to be the most important element in myocyte injury, since denervation, inhibition of sarcolemmal Na(+) channels and direct toxic effects on myofibrils have been excluded as sites of action. Although experimental myotoxic effects are impressively intense and reproducible, only few case reports of myotoxic complications in patients after local anaesthetic administration have been published. In particular, the occurrence of clinically relevant myopathy and myonecrosis has been described after continuous peripheral blockades, infiltration of wound margins, trigger point injections, peribulbar and retrobulbar blocks.

GABAmimetic intravenous anaesthetics inhibit spontaneous Ca2+ -oscillations in cultured hippocampal neurons

BACKGROUND

Spontaneous Ca2+ -oscillations are a possible mechanism of Ca2+ -mediated signal transduction in neurons. They develop by a periodical interplay of Ca2+, which enters the neuron from the extracellular medium and triggers Ca2+ release from the endoplasmic reticulum (ER). Ca2+ -oscillations are terminated by reuptake into the ER or plasmalemmal extrusion. Spontaneous Ca2+ -oscillations are glutamate dependent and appear to be responsible for neuronal plasticity and integration of information. Here, we examined the role of the gamma-aminobutyric acid (GABAA) receptor on spontaneous Ca2+ -oscillations and studied the effects of the anaesthetics midazolam, thiopental and the non-anesthetic barbituric acid on spontaneous Ca2+ -oscillations.

METHODS

Hippocampal neuronal cell cultures of 19-day-old embryonic Wistar rats 17-18 days in culture were loaded with the Ca2+ -sensitive dye Fura-2AM. Experiments were performed using dual wave-length excitation fluorescence microscopy and calibration constants were obtained from in situ calibration.

RESULTS

Spontaneous Ca2+ -oscillations are influenced by the GABAA receptor. The intravenous anaesthetics midazolam and thiopental suppressed the amplitude and frequency reversibly in a dose-dependent manner with EC50 in clinically relevant concentrations. This effect was mediated via the GABAA receptor as it could be reversed by the GABAA receptor antagonist bicuculline. In contrast, the application of barbituric acid had no effects on the spontaneous Ca2+ -oscillations.

CONCLUSION

Spontaneous Ca2+ -oscillations are influenced by the GABAA receptor. Spontaneous Ca2+ -oscillations might represent an interesting model system to study anaesthetic mechanisms on neuronal information processing.

[High resolution fluorescence microscopy in combination with mathematical modelling. First evidence of sub-cellular anesthetic effects on Ca2+ sparks in situ]

Volatile anesthetics used in daily clinical routine, are associated with a rare but life-threatening disease, malignant hyperthermia. To date it is well known that, with the exception of xenon and nitrous oxide, all volatile anesthetics have the potential to trigger calcium (Ca(2+)) release from the sarcoplasmic reticulum, thereby influencing the Ca(2+) homeostasis in muscle fibers. The effects of volatile anesthetics have been previously studied by recording Ca(2+)-activated force transients in muscle fibers and by quantifying the effects on isolated intracellular Ca(2+)-release channels (ryanodin receptors). The use of high resolution fluorescence microscopy methods in combination with spatio-temporal mathematical models allows the effects of volatile anesthetics on functional clusters of ryanodin receptors in mammalian skeletal muscle fibers to be studied in situ for the first time.Thus, the analysis of cellular Ca(2+)-activated force production and single channel properties in conjunction with mathematical models allows the quantification of the effects of volatile anesthetics on Ca(2+)-release in the natural physiological environment on the basis of the underlying molecular architecture. In addition to the basic understanding of alterations in the Ca(2+) homeostasis induced by volatile anesthetics in muscle and nerve cells, the results are also of direct clinical importance for the understanding of the pathogenesis of malignant hyperthermia,where ryanodin receptor mutations are currently thought to result in an increased Ca(2+) release under the influence of volatile anesthetics.

The effect of citalopram treatment on platelet serotonin function in panic disorders

We investigated the effect of the selective serotonin reuptake inhibitor (SSRI) citalopram after 6-8 weeks and 6 months of treatment on clinical and peripheral indexes for central serotonergic function: platelet [14C]serotonin uptake and [3H]paroxetine- and [3H]LSD-binding to platelets membranes in 33 patients with panic disorder. Basal data from patients were compared with data from a control material consisting of 33 healthy volunteers. Bmax for platelet [3H]paroxetine binding was significantly lower in patients than in controls. There were no differences in serotonin uptake or [3H]LSD-binding between patients and controls. The degree of anxiety and depression was assessed using the Beck Anxiety Inventory (BAI) and Beck Depression Inventory self-assessment scales, and the Clinical Anxiety Scale and the Montgomery Asberg Depression Rating Scale for clinical evaluation. Complete remission was found in one third of the patients after 6-8 weeks and in two-thirds after 6 months of treatment. The reduction in assessment scores was parallelled with similar reductions in platelet 5-HT2-receptor density, [3H]LSD affinity variable (Kd) and Vmax for platelet [14C]5-HT uptake. Citalopram treatment did not alter Bmax and Kd for platelet [3H]paroxetine-binding. A positive correlation was found between Vmax for the platelet [14C]5-HT uptake and BAI after 6 months citalopram treatment. The present study shows that citalopram has a therapeutic effect in panic disorders. A prerequisite of responding to treatment might be plasticity in the serotonergic system.

Continuous versus intermittent thermodilution cardiac output measurement during orthotopic liver transplantation

We evaluated intermittent and continuous thermodilution cardiac output data in 12 patients undergoing orthotopic liver transplantation. Measurements were performed at 16 predefined time points between induction of anaesthesia and 3 h after reperfusion of the liver graft. Cardiac output measurements yielded 192 data pairs (intermittent cardiac output range: 1.8-18.9 l.min-1, continuous cardiac output range: 3.3-20.0 l.min-1). During most of the procedure the correlation between intermittent and continuous cardiac output measurements was significant (r = 0.87, p < 0.0001), accompanied with a bias of -0.240 l.min-1 and a degree of precision of 1.789 l.min-1 (< 10.0 l.min-1:1.137 l.min-1, > or = 10.0 l.min-1:2.220 l.min-1). However, in the early phases after caval clamping and after reperfusion, accuracy was not acceptable. Only during these phases did the difference between the mean values of pulmonary artery blood temperature and rectal temperature increase (after caval clamping) or decrease (after reperfusion). In conclusion, despite acceptable levels of accuracy and precision between intermittent and continuous cardiac output measurement under stable conditions, both methods showed markedly decreased accuracy and precision in the early phases after caval clamping and after reperfusion, possibly owing to increased thermal noise.