[Tracheal rupture following endotracheal intubation for an emergency cesarean]. / Trachealriss nach Intubation bei Notsectio.

This is a case report of a 45-year-old patient, 39 weeks of gestation, who was intubated via rapid sequence induction (RSI) for an emergency cesarean. The indication for emergency cesarean was a pathological cardiotocography during the ejection phase following labor induction.Despite the primary use of a video laryngoscope, there was difficulty aligning the laryngeal axis. Therefore, an internal stylet was used to heavily angulate the endotracheal tube (ETT) to a hockey stick shape to enter the larynx.Postoperative dyspnea and extensive facial swelling were initially diagnosed as an allergic reaction. Only 22 h later the diagnosis of tracheal rupture was confirmed following computer tomography.We hypothesized that the mechanism of injury was due to excessive pressure transmitted to the tip of the ETT. This probably occurred due to a leverage effect caused by the withdrawal of the heavily bent stylet from the ETT, forcing an intratracheal cranial movement of the ETT.By conducting an experiment on a pig's trachea, we were able to visualize this mechanism of injury. In addition, we were able to demonstrate that bending the stylet to a similar angle as the laryngoscope blade led to minimal movement of the tip of the ETT.Therefore, when using a stylet during intubation, we recommend bending the ETT and stylet to the shape of the used laryngoscope blade and retracting the stylet at a similar angle to avoid complications, such as tracheal rupture.

[Iatrogenic anisocoria after using a scopolamine patch for PONV prophylaxis]. / Iatrogene Anisokorie nach Scopolaminpflaster zur PONV-Prophylaxe.

This is a case report of a 29-year-old female patient who developed unilateral mydriasis following the use of a scopolamine patch for the prevention of postoperative nausea and vomiting (PONV).Given a medical history showing multiple risk factors for PONV, a preauricular scopolamine patch was applied prior to the induction of anesthesia. General anesthesia was induced with 150 mg propofol and 25 µg sufentanil and maintained with total intravenous anesthesia, using propofol (5 mg/kg per h) and remifentanil (2-3 µg/kg per h).Following an uneventful surgery of 90min duration, the patient was extubated and transferred to the recovery room, where the patch was removed. During the orthopedic ward round the following day, the clinical examination revealed anisocoria of the left eye in the form of unilateral mydriasis. In order to determine the cause of this clinical presentation, further neurological and ophthalmological examinations and investigations were carried out. In addition, magnetic resonance imaging was conducted to rule out a central nervous cause. The results of the investigations were negative and no pathology was identified. In addition, the symptoms resolved within 24 h of onset without any therapeutic intervention. Therefore, a suspected diagnosis of a pharmacologically induced anisocoria from the scopolamine patch was made, whereby the substance accidentally reached the affected left eye.Previous studies showed that scopolamine patches may reduce early emetic symptoms. Case reports describing the occurrence of anisocoria following the application of scopolamine patches have been previously published. In all of these cases the patches were used to prevent PONV and each case was comprehensively investigated using various diagnostic and clinical tools. It should be noted, however, that a dysfunctional accommodation is listed as a common side effect of the drug, affecting more than 1 in 10 patients.Even though the efficacy of scopolamine patches for the prevention of PONV is proven, clinicians should be aware of the common ophthalmological side effect. Particularly with respect to various surgical disciplines, where anisocoria may indicate an underlying surgery-related complication, the application of scopolamine patches should be well- considered.

[Epidural anesthesia for fetoscopy : Retrospective analysis of a one-year cohort]. / Peridurale Anästhesie zur Fetoskopie : Retrospektive Analyse einer Einjahreskohorte.

BACKGROUND: The introduction of routine prenatal screening using ultrasound has led to a substantial increase in diagnoses of fetal disorders that are amenable to intrauterine treatment. While an ultrasound guided insertion of small bore cannulas can be performed under local anesthesia, insertion of a fetoscope usually requires anesthetic management for the mother and the fetus. Additionally, the fetus' intrauterine position may have to be manipulated in order to enable access. Such manoeuvres depend on relaxation of the mother's abdominal wall. General anesthesia has been the preferred method, but it involves substantial risks both to the mother and possibly the fetus, especially when combined with aggressive uterine relaxation. Epidural anesthesia (EA) may provide an alternative. Only little systematic data on the efficacy, requirements or untoward effects of epidural anesthesia for fetoscopy exists in the literature, yet a high rate of arterial hypotension following EA has been reported. We therefore aimed to assess the hemodynamic reaction to EA in a mixed population of pregnant women undergoing fetoscopy for a variety of fetal conditions and performed a retrospective analysis of a one-year cohort in a single university hospital. METHODS: The local ethics committee approved this retrospective analysis and waived patient consent (local study identifier 304/14). We extracted anesthesiologic and hemodynamic data from the anesthesia charts of 23 consecutive cases of elective fetoscopic procedures requiring anesthesia between May 2011 and 2012 at a German university medical centre. RESULTS: Twenty-three cases of fetoscopy were included in this study. Indications for fetoscopy were congenital diaphragmatic hernia (n = 9), aortic valve stenosis (n = 8), and feto-fetal transfusion syndrome (n = 6). Median gestational age was 26 (8, interquartile range) weeks. Lumbar epidural catheters were injected with a median dose of 0.09 (0.02, interquartile range) ml ropivacaine 0.75% per cm maternal height. In 11 patients, EA was titrated to a sufficient height whereas 12 patients received a single dose with a median volume of 0.08 (0.02) ml/cm maternal height. After injection, systolic arterial pressure did not change significantly, mean arterial pressure dropped from 93 (14) mm Hg to 88 (15) mm Hg (p = 0.03). Heart rate fell from 96 (29) to 89 (20) beats per minute (p = 0.02). At incision, neither blood pressure nor heart rate changed significantly. For hemodynamic support during the procedure, cafedrine/theodrenaline (Akrinor™) was injected in five patients (median dose in these patients 0.5 (1.5) ml). One patient carrying a fetus with a poor prognosis and who underwent two separate procedures demanded additional sedation, for which we chose remifentanil. Another patient was hypotensive after intravenous administration of the tocolytic drug atosiban. A stable hemodynamic condition was quickly restored in this patient with administration of cafedrine/theodrenaline and i. v. fluids. All procedures were performed without conversion to general anaesthesia. CONCLUSION: This retrospective study demonstrates that fetoscopic procedures under EA in the range of indications treated in our institution can be performed safely. EA was associated with stable hemodynamic conditions in this mixed cohort of pregnant women. EA appears thus to be a suitable technique for fetoscopy, avoiding the risks inherent to general anesthesia in pregnant women.

Performance of a new pulse contour method for continuous cardiac output monitoring: validation in critically ill patients.

BACKGROUND: A new calibrated pulse wave analysis method (VolumeView™/EV1000™, Edwards Lifesciences, Irvine, CA, USA) has been developed to continuously monitor cardiac output (CO). The aim of this study was to compare the performance of the VolumeView method, and of the PiCCO2™ pulse contour method (Pulsion Medical Systems, Munich, Germany), with reference transpulmonary thermodilution (TPTD) CO measurements. METHODS: This was a prospective, multicentre observational study performed in the surgical and interdisciplinary intensive care units of four tertiary hospitals. Seventy-two critically ill patients were monitored with a central venous catheter, and a thermistor-tipped femoral arterial VolumeView™ catheter connected to the EV1000™ monitor. After initial calibration by TPTD CO was continuously assessed using the VolumeView-CCO software (CCO(VolumeView)) during a 72 h period. TPTD was performed in order to obtain reference CO values (COREF). TPTD and arterial wave signals were transmitted to a PiCCO2™ monitor in order to obtain CCO(PiCCO) values. CCO(VolumeView) and CCO(PiCCO) were recorded over a 5 min interval before assessment of CO(TPTD). Bland-Altman analysis, %(errors), and concordance (trend analysis) were calculated. RESULTS: A total of 338 matched sets of data were available for comparison. Bias for CCO(VolumeView)-CO(REF) was -0.07 litre min(-1) and for CCO(PiCCO)-CO(REF) +0.03 litre min(-1). Corresponding limits of agreement were 2.00 and 2.48 litre min(-1) (P<0.01), %(errors) 29 and 37%, respectively. Trending capabilities were comparable for both techniques. CONCLUSIONS: The performance of the new VolumeView™-CCO method is as reliable as the PiCCO2™-CCO pulse wave analysis in critically ill patients. However, an improved precision was observed with the VolumeView™ technique. CLINICALTRIALS.GOV IDENTIFIER: NCT01405040.

Selective substrates for non-neuronal monoamine transporters.

The recently identified transport proteins organic cation transporter 1 (OCT1), OCT2, and extraneuronal monoamine transporter (EMT) accept dopamine, noradrenaline, adrenaline, and 5-hydroxytryptamine as substrates and hence qualify as non-neuronal monoamine transporters. In the present study, selective transport substrates were identified that allow, by analogy to receptor agonists, functional discrimination of these transporters. To contrast efficiency of solute transport, stably transfected 293 cell lines, each expressing a single transporter, were examined side by side in uptake experiments with radiolabeled substrates. Normalized uptake rates indicate that tetraethylammonium, with a rate of about 0.5 relative to 1-methyl-4-phenylpyridinium (MPP+), is a good substrate for OCT1 and OCT2. It was not, however, accepted as substrate by EMT. Choline was transported exclusively by OCT1, with a rate of about 0.5 relative to MPP+. Histamine was a good substrate with a rate of about 0.6 relative to MPP+ for OCT2 and EMT, but was not transported by OCT1. Guanidine was an excellent substrate for OCT2, with a rate as high as that of MPP+. Transport of guanidine by OCT1 was low, and transport by EMT was negligible. With the guanidine derivatives cimetidine and creatinine, a pattern strikingly similar to guanidine was observed. Collectively, these substrates reveal key differences in solute recognition and turnover and thus challenge the concept of "polyspecific" organic cation transporters. In addition, our data, when compared with previous studies, suggest that OCT2 corresponds to the organic cation/H+ antiport mechanism in renal brush-border membrane vesicles, and that EMT corresponds to the guanidine/H+ antiport mechanism in membrane vesicles from placenta and intestine.

Transport of monoamine transmitters by the organic cation transporter type 2, OCT2.

The recently cloned apical renal transport system for organic cations (OCT2) exists in dopamine-rich tissues such as kidney and some brain areas (Gründemann, D., Babin-Ebell, J., Martel, F., Ording, N., Schmidt, A., and Schömig, E. (1997) J. Biol. Chem. 272, 10408-10413). The study at hand was performed to answer the question of whether OCT2 accepts dopamine and other monoamine transmitters as substrate. 293 cells were stably transfected with the OCT2r cDNA resulting in the 293OCT2r cell line. Expression of OCT2r in 293 cells induces specific transport of tritiated dopamine, noradrenaline, adrenaline, and 5-hydroxytryptamine (5-HT). Initial rates of specific 3H-dopamine, 3H-noradrenaline, 3H-adrenaline, and 3H-5-HT transport were saturable, the Km values being 2.1, 4.4, 1.9, and 3.6 mmol/liter. The corresponding Vmax values were 3.9, 1.0, 0. 59, and 2.5 nmol min-1.mg of protein-1, respectively. 1, 1'-diisopropyl-2,4'-cyanine (disprocynium24), a known inhibitor of OCT2 with a potent eukaliuric diuretic activity, inhibited 3H-dopamine uptake into 293OCT2r cells with an Ki of 5.1 (2.6, 9.9) nmol/liter. In situ hybridization reveals that, within the kidney, the OCT2r mRNA is restricted to the outer medulla and deep portions of the medullary rays indicating selective expression in the S3 segment of the proximal tubule. These findings open the possibility that OCT2r plays a role in renal dopamine handling.