Time to change the times? Time of recurrence of ventricular fibrillation during OHCA.

AIM OF THE STUDY: For out-of-hospital-cardiac-arrest (OHCA) due to ventricular fibrillation (VF) guidelines recommend early defibrillation followed by chest compressions for two minutes before analyzing shock success. If rhythm analysis reveals VF again, it is obscure whether VF persisted or reoccurred within the two-minutes-cycle of chest compressions after successful defibrillation. We investigated the time of VF-recurrence in OHCA. METHODS: We examined all cases of OHCA presenting with initial VF rhythm at arrival of ALS-ambulance (Marburg-Biedenkopf-County, 246.648 inhabitants) from January 2014 to March 2018. Three independent investigators analyzed corpuls3® ECG-recordings. We included ECG-data from CPR-beginning until four minutes after the third shock. VF termination was defined as the absence of a VF-waveform within 5 s of shock delivery. VF recurrence was defined as the presence of a VF-waveform in the interval 5 s post shock delivery. RESULTS: We included 185 shocks in 82 patients. 74.1% (n = 137) of all shocks terminated VF, but VF recurred in 81% (n = 111). The median (IQR) time of VF-recurrences was 27 s (13.5 s/80.5 s) after shock. 51.4% (n = 57) of VF-recurrence occurred 5-30 s after shock, 13.5% (n = 15) VF-recurrence occurred 31-60 s after shock, 21.6% (n = 24) of VF-recurrence occurred 61-120 s after shock, 13.5% (n = 15) of VF-recurrence occurred 121-240 s after shock. CONCLUSIONS: Although VF was terminated by defibrillation in 74.1%, VF recurred in 81% subsequent to the chest compression interval. Thus, VF reappears frequently and early. It is unclear to which extend chest compressions influence VF-relapse. Further studies need to re-evaluate the algorithm, timing of antiarrhythmic therapy or novel defibrillation strategies to minimize refibrillation during shockable OHCA.

Hidden charge states in soft-x-ray laser-produced nanoplasmas revealed by fluorescence spectroscopy.

Highly charged ions are formed in the center of composite clusters by strong free-electron laser pulses and they emit fluorescence on a femtosecond time scale before competing recombination leads to neutralization of the nanoplasma core. In contrast to mass spectrometry that detects remnants of the interaction, fluorescence in the extreme ultraviolet spectral range provides fingerprints of transient states of high energy density matter. Spectra from clusters consisting of a xenon core and a surrounding argon shell show that a small fraction of the fluorescence signal comes from multiply charged xenon ions in the cluster core. Initially, these ions are as highly charged as the ions in the outer shells of pure xenon clusters with charge states up to at least 11+.

Nanoplasma dynamics of single large xenon clusters irradiated with superintense x-ray pulses from the linac coherent light source free-electron laser.

The plasma dynamics of single mesoscopic Xe particles irradiated with intense femtosecond x-ray pulses exceeding 10(16) W/cm2 from the Linac Coherent Light Source free-electron laser are investigated. Simultaneous recording of diffraction patterns and ion spectra allows eliminating the influence of the laser focal volume intensity and particle size distribution. The data show that for clusters illuminated with intense x-ray pulses, highly charged ionization fragments in a narrow distribution are created and that the nanoplasma recombination is efficiently suppressed.

Explosions of xenon clusters in ultraintense femtosecond x-ray pulses from the LCLS free electron laser.

Explosions of large Xe clusters ( ~ 11,000) irradiated by femtosecond pulses of 850 eV x-ray photons focused to an intensity of up to 10(17) W/cm(2) from the Linac Coherent Light Source were investigated experimentally. Measurements of ion charge-state distributions and energy spectra exhibit strong evidence for the formation of a Xe nanoplasma in the intense x-ray pulse. This x-ray produced Xe nanoplasma is accompanied by a three-body recombination and hydrodynamic expansion. These experimental results appear to be consistent with a model in which a spherically exploding nanoplasma is formed inside the Xe cluster and where the plasma temperature is determined by photoionization heating.

Ultrafast x-ray scattering of xenon nanoparticles: imaging transient states of matter.

Femtosecond x-ray laser flashes with power densities of up to 10(14) W/cm(2) at 13.7 nm wavelength were scattered by single xenon clusters in the gas phase. Similar to light scattering from atmospheric microparticles, the x-ray diffraction patterns carry information about the optical constants of the objects. However, the high flux of the x-ray laser induces severe transient changes of the electronic configuration, resulting in a tenfold increase of absorption in the developing nanoplasma. The modification in opaqueness can be correlated to strong atomic charging of the particle leading to excitation of Xe(4+). It is shown that single-shot single-particle scattering on femtosecond time scales yields insight into ultrafast processes in highly excited systems where conventional spectroscopy techniques are inherently blind.

The neural basis of the P300 potential. Focus on the time-course of the underlying cortical generators.

The locations and time-courses of the neural generators of the event-related P300 potential have been well described using intracranial recordings. However, this invasive method is not adequate for usage in healthy volunteers or psychiatric patients and not all brain regions can be covered well with this approach. With functional MRI, a non-invasive method with high spatial resolution, most of these locations could be found again. However, the time-course of these activations can only be roughly determined with this method, even if an event-related fMRI design has been chosen. Therefore, we have now tried to analyse the time-course of the activations using EEG data providing a better time resolution. We have used Low Resolution Electromagnetic Tomography (LORETA) in the analysis of P300 data (27 electrodes) of healthy volunteers (n = 50) in the time frame 230-480 ms and found mainly the same activations that have been described using intracranial recordings or fMRI, i. e. the inferior parietal lobe/temporo-parietal junction (TPJ), the supplementary motor cortex (SMA) and the anterior cingulate cortex (ACC), the superior temporal gyrus (STG), the insula and the dorsolateral prefrontal cortex. In these selected regions, an analysis of the activation time-courses has been performed.

[Drugs for supplementation in cataract surgery with a laryngeal mask]. / Supplementierungsmedikamente beim Einsatz der Larynxmaske in der Kataraktchirurgie.

BACKGROUND: We compared intraocular pressure (IOP), vitreous pressure and several anaesthesiological parameters for patients who underwent cataract surgery with propofol anaesthesia, laryngeal mask and different supplementations with reference to the effect of S-ketamin in particular. PATIENTS AND METHODS: In 4 groups with 15 patients cataract surgery (phacoemulsification) was carried out using anaesthesia with propofol, laryngeal masks and spontaneous breathing if possible, supplementation with propofol (0.6 mg/kg, group 1), S-ketamin (0.3 mg/kg, group 2), ketamin (0.6 mg/kg, group 3) or fentanyl (0.5 microgram/kg, group 4); IOP measurement with tonopen XL and scoring vitreous pressure at different times during anaesthesia (score 0-3). RESULTS: For IOP and vitreous pressure, none of the different supplementations showed a significant difference. Insertion of the laryngeal mask did not cause a rise in intraocular pressure. The number of patients with spontaneous breathing during the operation in group 4 was significantly lower than in groups 1-3. No significant differences were observed between the different anaesthesiological parameters. CONCLUSION: S-Ketamin had no significant effect on IOP and vitreous pressure during phacoemulsification. It offers a safe "handling" of patients because of a high spontaneous breathing rate and lower concentration compared to Ketamin.

Laparoscopic fluorometry: a new minimally invasive tool for investigation of the intestinal microcirculation.

The aim of this study was to develop and establish a new system of laparoscopic fluorometry for the purpose of investigating the intestinal microcirculation. In 25 pigs (German Landrace, 16-25 kg body weight), ischemia was established in two segments (A, irreversible; B, reversible ischemia; C, internal control) of the small intestine by a laparoscopic technique. Microcirculation in the segments was assessed by laparoscopy at a second-look operation 24 h later by means of the fluorescence system Endoscan. The fluorescence of the three bowel segments was measured by arbitrary dye fluorescence units (DFU) 15 min after starting reperfusion, before and after injection of sodium fluorescein (NaFlu, 0.25 mg/kg body weight). The dividing line between viable and nonviable bowel tissue was established from the inflow and outflow rates of NaFlu with the aid of ROC (receiver operating characteristic) curves. The specificity and sensitivity of the new method were evaluated by correlating the results with the viability of each intestinal segment as predicted by three laparoscopically experienced surgeons and by histological examination. By means of the calculated separation sharpness (fluorescence index at 2 min >0.5, outflow factor of NaFlu at 10 min >20%), the overall predictions of intestinal viability in all 25 animals achieved a sensitivity of 93.5% and a specificity of 94.1% by laparoscopic fluorometry, versus a sensitivity of 70.8% and a specificity of 87.5% for the prediction of bowel viability by ordinary laparoscopic technique. Used as an adjunct to conventional laparoscopy, laparoscopic fluorometry brought significant gains in sensitivity and specificity in the distinction between reversible and irreversible intestinal ischemia.

A modification to the Bouwer and Rice method of slug-test analysis for large-diameter, hand-dug wells.

The Bouwer and Rice method of estimating the saturated hydraulic conductivity (Ks) from slug-test data was evaluated for geometries typical of hand-dug wells. A two-dimensional, radially symmetric and variably saturated, ground water transport model was used to simulate well recovery given a range of well and aquifer geometries and unsaturated soil properties, the latter in terms of the van Genuchten parameters. The standard Bouwer and Rice method, when applied to the modeled recharge rates, underestimated Ks by factors ranging from 1.3 to 5.6, depending on the well geometry and the soil type. The Bouwer and Rice analytical solution was modified to better explain the recovery rates as predicted by the numerical model, which revealed a significant dependence on the unsaturated soil for the shallow and wide geometries that are typical of traditional wells. The modification introduces a new parameter to the Bouwer and Rice analysis that is a measure of soil capillarity which improves the accuracy of Ks estimates by tenfold for the geometries tested.

[The effect of needle type and immobilization on postspinal headache]. / Die Bedeutung von Nadeltyp und Immobilisation für den postspinalen Kopfschmerz.

UNLABELLED: Post-dural puncture headache (PDPH) is a significant complication of spinal anaesthesia. Diameter and tip of the needle as well as the patient's age have been proven to be important determinants. The question of whether post-operative recumbency can reduce the risk of PDPH has not been answered uniformly. And besides, some studies referring to this subject reveal methodical failures, for example, as to clear definition and exact documentation of post-operative immobilization. Furthermore, fine-gauge needles (26G or more) have not been investigated yet. The first aim of our study was therefore to examine the role of recumbency in the prevention of PDPH under controlled conditions using thin needles. Secondly, we wanted to confirm the reported prophylactic effect of needles with a modified, atraumatic tip (Whitacre and Atraucan) by comparing them to Quincke needles of identical diameter. Most of the former investigators compared Quincke with atraumatic needles of different size regardless of the known influence of the diameter on PDPH. PATIENTS AND METHODS: In a prospective study we included 481 consecutive patients undergoing a total of 500 orthopaedic operations under spinal anaesthesia. The latter was performed in a standardized manner (patient sitting, midline approach, needle with parallel bevel direction), using four different needles allocated randomly (26-gauge and 27-gauge needles with Quincke tip, 26-gauge Atraucan and 27-gauge Whitacre cannula). Half of the patients were instructed to stay in bed for 24 h (horizontal position without raising head), the others to get up as early as possible. An anaesthesiologist visited the patients on the fourth postoperative day or later and questioned them about headache and duration of recumbency. Additionally, the patients had to fill out a questionnaire 1 week after surgery. Any postural headache was considered as PDPH. RESULTS: The four groups of different needles had homogeneous demographic characteristics (see Table 1). A total of 47 patients (9.4%) developed PDPH. The incidence was highest after puncture with a 26-gauge Quincke cannula (17.6%) with a significant difference compared to the other needles (see Table 2). PDPH incidence correlated well with increasing age and number of dural punctures, but showed no relation to sex, patient's history of headache or experience of the anaesthesiologist. Only about half of the patients (60.5%) followed the instructions regarding mobilization or recumbency. The duration of strict bed rest did not influence the development of PDPH: The overall incidence was 9.4% in the recumbency group and 8.8% in the group of early ambulation. In all, 45 patients suffered from ordinary not posture-related headache. CONCLUSIONS: The significantly higher incidence of PDPH after spinal anaesthesia with 26-gauge Quincke needles compared to the 27-gauge Quincke and the 26-gauge Atraucan group confirmed the importance of both needle diameter and design of its tip. The Atraucan cannula has not been examined in a controlled study (in comparison with Quincke needle of the same diameter) before. In accordance with other investigators we found patient's age and number of puncture attempts as additional predictors of PDPH. Consequent bed rest, however, was not able to reduce its incidence. Our studies reveal the poor compliance of patients with regard to mobilization/immobilization, a problem which possibly has not been considered enough in former studies examining the influence of bed rest on PDPH. Based on the literature and the present findings, we recommend using thin needles with atraumatic tips for spinal anaesthesia if possible. Recumbency presents an avoidable stress for patients as well as medical staff and should no longer be ordered.

Effect of triturator speed variation on physical properties of encapsulated glass-ionomer luting cements.

This in vitro study evaluated the effect of variation of triturator mixing speed on the physical properties of two encapsulated glass-ionomer luting cements. Physical properties evaluated were working time, setting time, film thickness, and 24-hour and 7-day compressive strengths. Encapsulated glass-ionomer luting cements were mixed at 3000, 3500, 4000 (control), and 4500 cycles per minute (cpm). An oscillating rheometer was used to determine working and setting times. Film thickness and compressive strength were determined using methods described in ANSI/ADA Specification No 66 for dental glass-ionomer cements. Results of the study indicated that decreased mixing speed may prolong working and setting times for Ketac-Cem Maxicap and Fuji Cap I. Within the range of 3500 to 4500 cpm, variations in mixing speed do not significantly affect compressive strength or film thickness values for either cement. Excessively slow mixing speed (3000 cpm) often resulted in the presence of unmixed powder expressed from the capsule nozzle prior to the expression of mixed cement. The presence of this unmixed powder results in a decreased powder/liquid ratio, which may have an adverse effect on the physical properties of the set cement.

[The value of mini-tracheotomy as a new interventional technique in treatment of postoperative tracheobronchial retention of secretions. Results of a prospective study of 152 surgical intensive care patients]. / Die Bedeutung der Minitracheotomie als neue interventionelle Technik zur Behandlung der postoperativen tracheobronchialen Sekretretention. Ergebnisse einer prospektiven Untersuchung mit 152 chirurgischen Intensivpatienten.

OBJECTIVE: Since minitracheotomy has been established in 1984 for prophylaxis and therapy of postoperative sputum retention, numerous publications represent technical descriptions, case reports or empirical results, but only few specific facts related to this method have been investigated. In this study we review the efficiency, complications and late follow-up results of minitracheotomy in a department of general surgery. DESIGN: Between 1987 and 1991 we prospectively included 152 intensive-care patients who received minitracheotomy. The average follow-up was 24.2 +/- 6.1 (4-50) months. RESULTS: Endotracheal secretion could be sucked off significantly more often after mini-tracheotomy. The rate of endotracheal suction increased from 5.9 +/- 4.5/d to 18.4 +/- 6.1/d (p < or = 0.01). The pulmonary gas exchange improved at the same time. PaO2 level of 78.9 +/- 9.9 mmHg that decreased to critical values of 60.7 +/- 8.9 mmHg, rose after minitracheotomy above the original levels. Although the PaCO2 level remained constant, a compensatory hyperventilation with a rate of 27.3 +/- 6.9/min was normalised by minitracheotomy. Furthermore, the various methods of minitracheotomy were opposed in this study. In the group of minitracheotomy by cricothyroideal stab incision (n = 55) we recorded 5.4% serious complications. In contrast minitracheotomy by the Seldinger technique (n = 87) could be accomplished without any disturbance. CONCLUSION: Minitracheotomy seems to be an effective and safe treatment for therapy and prophylaxis of postoperative complications due to tracheobronchial sputum retention in critically ill patients. Manipulation was simplified and rendered more safe by the technique of transcutaneous bouginage.

[Endometriosis of the inguinal ligament as a rare differential diagnosis of inguinal space-occupying lesion]. / Endometriose des Leistenbandes als seltene Differentialdiagnose einer inguinalen Raumforderung.

A case of endometriosis infiltrating the inguinal ligament is presented. As a rare condition involving of the extraperitoneal portion of the round ligament was not seen. Ultrasonography revealed a hypoechoic tumor with internal anechoic areas. Surgical exploration was carried out in the assumption of a relapse of an inguinal hernia. Microscopically, endometrial glands, fibrosis and old hemorrhage were seen. Laparoscopy revealed no evidence of pelvic endometriosis. We conclude that endometriosis must be considered in the differential diagnosis of palpable lesions of the groin in women of reproductive age. Surgery in cooperation with the gynecologist is the treatment of choice.

[Measures for reducing the use of homologous blood. Effects on blood coagulation during total endoprosthesis]. / Fremdblutsparende Massnahmen. Auswirkungen auf die plasmatische Gerinnung bei totalendoprothetischen Eingriffen.

The influence of two different methods of autologous transfusion, preoperative donor plasmapheresis (Abbott Autotrans) and postoperative autotransfusion (intraoperative blood salvage, Dideco Autotrans), on the intravascular hemostatic system was investigated. Forty-two patients undergoing total hip surgery and preoperative donor plasmapheresis were prospectively randomized into three groups. For substitution of blood loss, patients in group 1 (control group, n = 12) received in addition to cristalloids and colloids only homologous blood, group 2 (n = 14) autologous blood, and group 3 (n = 16) additionally intra- and postoperative autologous fresh frozen plasma (FFP). The investigation included blood parameters (hemoglobin, hematocrit, thrombocytes), clotting status (prothrombin time, plasma thromboplastin time, thrombin time, fibrinogen, plasminogen, and antithrombin III), and immunological methods such as fibrinopeptide A (FPA), thrombin-antithrombin III (TAT), and protein C. No significant difference was found with respect to total amount of infusion, intraoperative blood loss, autologous transfusion, and blood parameters. Excellent quality of the autologous FFP was demonstrated by investigation of the specimens before administration. The autologous packed red cells showed high levels of TAT and FPA as an indicator of thrombin generation. Their administration caused a significant increase in TAT and FPA levels in groups 2 and 3 compared to group 1.(ABSTRACT TRUNCATED AT 250 WORDS)

[Endocrine reactions during acute normovolemic hemodilution]. / Endokrine Reaktionen bei akuter normovolämischer Hämodilution (ANH).

To investigate the influence of acute normovolemic hemodilution (ANH) on endocrine parameters in orthopedic surgery patients, 20 patients scheduled for total prosthetic replacement of the hip under epidural anesthesia with bupivacaine 0.5% were randomly allocated to the following groups: ANH group, (about 7.5 ml/kg body weight within 30 min) during substitution with 6% HES 200/0.5; Control group (without hemodilution). During a period before the onset of anesthesia and on the 1st day after the operation, MAP, HR, plasma concentrations of adrenaline and noradrenaline (by HPLC/ECD), and of ADH, ACTH and cortisol (by RIA) were determined at 8 points, as were glucose, lactate and free glycerol. Biometric data were comparable between the groups. MAP was significantly higher in the ANH group, and the intraoperative decrease was less pronounced. Adrenaline, ACTH, and cortisol revealed no specific influence of ANH and remained within the normal range in both groups. Noradrenaline was above the normal range in both groups and increased slightly (about 20%) during ANH. ADH was significantly higher in the control group. No specific influence of ANH was found with respect to glucose, lactate and free glycerol. In conclusion, ANH had no negative effects on the endocrine stress response during orthopedic surgery under epidural anesthesia. Sympatho-adrenergic reactions were only moderate and tolerable, even for patients with compensated cardiovascular disorders. Slight increases in endocrine parameters in the perioperative period documented adequate stress protection with epidural anesthesia.

Acute polyuric renal failure after aspirin intoxication.

Reversible acute polyuric renal failure was observed in a patient after the ingestion of an unusually large toxic (125 g) dose of aspirin. Renal dysfunction occurred in the absence of volume depletion or underlying renal impairment. These observations emphasize the need for careful monitoring of renal function in all patients with aspirin intoxication.

[Adrenergic cardiovascular responses during neuroleptanalgesia (author's transl)]. / Adrenerge Kreislaufreaktionen bei neuroleptanalgesien.

During major abdominal surgery with neuroleptanalgesia unexplainable increases of arterial blood pressure were observed several times without being objectified until now. Therefore the actual plasma catecholamines in connection with haemodynamic parameters like arterial blood pressure, heart rate and peripheral pulse amplitude were compared with synchronously measured concentrations of fentanyl in 31 patients undergoing standardized neuroleptanalgesia. From the data obtained it could be shown that the parameters of circulation do not always correlate with the concentration of the analgesic. Activation of the sympathetic nervous system was found in spite of sufficient analgesic medication. It was observed, with a sometimes particularly critical increase of pressure and decrease of pulse amplitude, mainly during the surgical stimulation in the upper abdomen. The causes of these increases and the possibilities of prevention also by other drugs are discussed.