Haitham Mutlak

Complications associated with the prehospital use of laryngeal tubes—A systematic analysis of risk factors and strategies for prevention

OBJECTIVE With the increasing spread of laryngeal tubes (LT) in emergency medicine, complications and side-effects are observed. We sought to identify complications associated with the use of LTs in emergency medicine, and to develop strategies to prevent these incidents. METHODS In a prospective clinical study, all patients who had their airways managed in the field with a LT and who were admitted through the emergency department of the Frankfurt University Hospital during a 6 year period were evaluated using anonymised data collection sheets. A team of experts was available 24/7 and was requested whenever a patient was admitted with a LT in place. This team evaluated the condition of the patients with respect to prehospital airway management and was responsible for further advanced airway management. All complications were analysed, and strategies for prevention developed. RESULTS One hundred eighty nine patients were included and analysed. The initial cuff pressure of the LTs was 10 0 cm H₂O on the median. Complications consisted of significant tongue swelling (n=73; 38.6%), resulting in life-threatening cannot ventilate, cannot intubate scenarios in two patients (1.0%) and the need for surgical tracheostomy in another patient, massive distension of the stomach (n=20, 10.6%) with ventilation difficulties when LTs without gastric drainage were used; malposition of the LT in the piriform sinus (n=1, 0.5%) and significant bleeding from soft tissue injuries (n=4, 2.1%). CONCLUSIONS The prehospital use of LTs may result in severe and even life-threatening complications. Likely, such complications could have been prevented by using gastric drainage and cuff pressure adjustment. Both, prehospital health care providers and emergency department staff should develop a greater awareness of such complications to best avoid them in the future.

Comparison of the TruView infant EVO2 PCD™ and C-MAC video laryngoscopes with direct Macintosh laryngoscopy for routine tracheal intubation in infants with normal airways.

OBJECTIVE: Videolaryngoscopy has mainly been developed to facilitate difficult airway intubation. However, there is a lack of studies demonstrating this methods efficacy in pediatric patients. The aim of the present study was to compare the TruView infant EVO2 and the C-MAC videolaryngoscope with conventional direct Macintosh laryngoscopy in children with a bodyweight ≤10 kg in terms of intubation conditions and the time to intubation. METHODS: In total, 65 children with a bodyweight ≤10 kg (0-22 months) who had undergone elective surgery requiring endotracheal intubation were retrospectively analyzed. Our database was screened for intubations with the TruView infant EVO2, the C-MAC videolaryngoscope, and conventional direct Macintosh laryngoscopy. The intubation conditions, the time to intubation, and the oxygen saturation before and after intubation were monitored, and demographic data were recorded. Only children with a bodyweight ≤10 kg were included in the analysis. RESULTS: A total of 23 children were intubated using the C-MAC videolaryngoscope, and 22 children were intubated using the TruView EVO2. Additionally, 20 children were intubated using a standard Macintosh blade. The time required for tracheal intubation was significantly longer using the TruView EVO2 (52 sec vs. 28 sec for C-MAC vs. 26 sec for direct LG). However, no significant difference in oxygen saturation was found after intubation. CONCLUSION: All devices allowed excellent visualization of the vocal cords, but the time to intubation was prolonged when the TruView EVO2 was used. The absence of a decline in oxygen saturation may be due to apneic oxygenation via the TruView scope and may provide a margin of safety. In sum, the use of the TruView by a well-trained anesthetist may be an alternative for difficult airway management in pediatric patients.

Prednisolone as preservation additive prevents from ischemia reperfusion injury in a rat model of orthotopic lung transplantation.

The lung is, more than other solid organs, susceptible for ischemia reperfusion injury after orthotopic transplantation. Corticosteroids are known to potently suppress pro-inflammatory processes when given in the post-operative setting or during rejection episodes. Whereas their use has been approved for these clinical indications, there is no study investigating its potential as a preservation additive in preventing vascular damage already in the phase of ischemia. To investigate these effects we performed orthotopic lung transplantations (LTX) in the rat. Prednisolone was either added to the perfusion solution for lung preservation or omitted and rats were followed for 48 hours after LTX. Prednisolone preconditioning significantly increased survival and diminished reperfusion edema. Hypoxia induced vasoactive cytokines such as VEGF were reduced. Markers of leukocyte invasiveness like matrix metalloprotease (MMP)-2, or common pro-inflammatory molecules like the CXCR4 receptor or the chemokine (C-C motif) ligand (CCL)-2 were downregulated by prednisolone. Neutrophil recruitment to the grafts was only increased in Perfadex treated lungs. Together with this, prednisolone treated animals displayed significantly reduced lung protein levels of neutrophil chemoattractants like CINC-1, CINC-2α/β and LIX and upregulated tissue inhibitor of matrix metalloproteinase (TIMP)-1. Interestingly, lung macrophage invasion was increased in both, Perfadex and prednisolone treated grafts, as measured by MMP-12 or RM4. Markers of anti-inflammatory macrophage transdifferentiation like MRC-1, IL-13, IL-4 and CD163, significantly correlated with prednisolone treatment. These observations lead to the conclusion that prednisolone as an additive to the perfusion solution protects from hypoxia triggered danger signals already in the phase of ischemia and thus reduces graft edema in the phase of reperfusion. Additionally, prednisolone preconditioning might also lead to macrophage polarization as a beneficial long-term effect.

Multiple Electrode Aggregometry for the Assessment of Acquired Platelet Dysfunctions during Extracorporeal Circulation

BACKGROUND There have been many reports on how the usage of extracorporeal circulation (ECC) is independently associated with the induction of platelet dysfunctions. The aim of the present investigation was to study the capability of the multiple electrode aggregometry (MEA) using the Multiplate (Roche AG, Grenzach, Germany) device to reflect the extent of ECC-associated platelet dysfunctions. PATIENTS AND METHODS The study population consisted of patients who were treated with either hypothermic (cardiopulmonary bypass [CPB]) or normothermic (extracorporeal membrane oxygenation) ECC. Hemostatic analyses included conventional laboratory coagulation tests and aggregometric measures following stimulation with different agonists using MEA. The area under the aggregation curve in the ADPtest (ex vivo adenosine diphosphate induced platelet aggregation) of the MEA was defined as the primary end point. The analyses were performed before the usage of ECC (baseline) and 90 minutes (T1), 120 minutes (T2), 150 minutes (T3), and 180 minutes (T4) after the usage of ECC. In the hypothermic ECC group, additional hemostatic analyses were performed after the patients postoperative admission to the intensive care unit (T5). Periprocedural data and results of other hemostatic testing were defined as secondary end points. RESULTS A total of n = 40 patients were assessed for eligibility and n = 25 patients were finally enrolled into the study (hypothermic ECC group: n = 20; normothermic ECC group: n = 5). The extent of ADP-induced platelet aggregation decreased significantly between baseline and consecutive measuring points during hypothermic ECC and remained unchanged between T4 and T5. In the normothermic ECC group, ADP-induced aggregability was significantly lower at T1 compared with baseline and remained unchanged from T1 onward. CONCLUSION Data from the present study indicate that ex vivo ADP-induced platelet aggregation in MEA reflects the time-dependent extent of ECC-induced platelet dysfunction.

The Impact of Tracheostomy Timing on Clinical Outcome and Adverse Events in Poor-Grade Subarachnoid Hemorrhage.

Objective: The value of optimal timing of tracheostomy in patients with subarachnoid hemorrhage is controversially debated. This study investigates whether early or late tracheostomy is associated with beneficial outcome or reduced rates of adverse events. Design: Retrospective observational multicentric on patients prospectively inserted into a database. Setting: Neurologic ICUs of one academic hospital and two secondary hospitals in Germany. Patients: Data of all patients admitted to the Goethe University Hospital between 2006 and 2011 with poor-grade subarachnoid hemorrhage were prospectively entered into a database. All patients who underwent tracheostomy were included for analysis. Follow-up was maintained in primary and secondary ICUs. Interventions: Patients underwent tracheostomy upon expected long-term ventilation. Early tracheostomy was defined as performed on days 1–7 and late tracheostomy on days 8–20 after admission. Measurement and Main Results: We compared 148 consecutive patients admitted with poor-grade (World Federation of Neurosurgical Societies, 3–5) subarachnoid hemorrhage. Early tracheostomy was performed in 39 patients and late tracheostomy in 109 patients. In early versus late tracheostomy groups, no significant differences were observed with regard to ICU mortality (7.7% vs 7.3%; p = 0.93) and median modified Rankin Scale after 6 months (3 vs 3; p = 0.94). Of the early group, pneumonia developed in 19 patients, whereas in the late group, pneumonia developed in 75 patients (48.7% vs 68.8%; p = 0.03; odds ratio, 2.32; 95% CI, 1.1–4.9). Six patients of the early group (15.4%) and 36 patients of the late group (33%) suffered from respiratory adverse event (p = 0.04; odds ratio, 2.71; 95% CI, 1.04–7.06). Mechanical ventilation was shorter (17.4 vs 22.3 d; p < 0.05) and decannulation occurred earlier (42 vs 54 d; p = 0.039) in the early tracheostomy group. Conclusions: Tracheostomy within 7 days of critical care admission is a feasible and safe procedure for patients with poor-grade subarachnoid hemorrhage. Early tracheostomy was not associated with an improvement in mortality or neurologic outcome but associated with fewer respiratory adverse events.

A radiographic comparison of human airway anatomy and airway manikins--Implications for manikin-based testing of artificial airways.

OBJECTIVE The aim of this prospective, single-center, observational study was to investigate the accuracy of modeling and reproduction of human anatomical dimensions in manikins by comparing radiographic upper airway measurements of 13 different models with humans. METHODS 13 commonly used airway manikins (male or female anatomy based) and 47 controls (adult humans, 37 male, 10 female) were investigated using a mediosagittal and axial cervical spine CT scan. For anatomical comparison six human upper airway target structures, the following were measured: Oblique diameter of the tongue through the center, horizontal distance between the center point of the tongue and the posterior pharyngeal wall, horizontal distance between the vallecula and the posterior pharyngeal wall, distance of the upper oesophageal orifice length of epiglottis distance at the narrowest part of the trachea. Furthermore, the cross-section of the trachea in axial view and the cross-section of the upper oesophageal orifice in the same section was calculated. All measurements were compared gender specific, if the gender was non-specified with the whole sample. RESULTS None of the included 13 different airway manikins matched anatomy in human controls (n = 47) in all of the six measurements. The Laerdal Airway Management Trainer, however, replicated human airway anatomy at least satisfactorily. CONCLUSION This investigation showed that all of the examined manikins did not replicate human anatomy. Manikins should therefore be selected cautiously, depending on the type of airway securing procedure. Their widespread use as a replacement for in vivo trials in the field of airway management needs to be reconsidered.

[Valvular heart disease: anesthesia in non-cardiac surgery].

The probability of treating patients with valvular heart disease during non-cardiac surgery increases with the age of the patient. The prevalence of valvular heart disease is approximately 2.5% and increases further in the patient group aged over 75 years old. Patients with valvular heart disease undergoing non-cardiac surgery have an increased perioperative cardiovascular risk depending on the severity of the disease. Knowledge of the hemodynamic alterations and compensation mechanisms which accompany diseases of the valve apparatus is essential for a suitable treatment of patients with such pre-existing diseases. The most common valvular heart diseases lead to volume (mitral valve insufficiency) or pressure load (aortic stenosis) of the left ventricle and in the case of mitral stenosis to a pressure load on the left atrium. Depending on the underlying disease and the type of surgery planned a corresponding choice of anesthesia procedure and medication must be made. In the present review article the pathophysiology of the relevant valvular heart diseases and the implications for perioperative anesthesia management will be presented. An individually tailored extended perioperative monitoring allows hemodynamic alterations to be rapidly recognized and adequately treated.

The fibrinopeptide bβ15-42 reduces inflammation in mice subjected to polymicrobial sepsis.

ABSTRACT Sepsis is still a leading cause of death on intensive care units. Despite intensive research, only few new therapies have been developed and used in the clinical setting. The fibrin fragment B&bgr;15-42 was already shown to preserve endothelial barrier function by binding to VE-cadherin and thus stabilize the interendothelial junctions. This was accompanied by reduced inflammation. Now we show that treatment with B&bgr;15-42 reduces inflammation in a murine polymicrobial sepsis model. Administration of B&bgr;15-42 reduced proinflammatory cytokine levels in the lung, liver, and blood and decreased neutrophil infiltration into the lung. Analysis alanine aminotransferase and aspartate aminotransferase further indicated reduced liver damage following polymicrobial sepsis. In vitro experiments using endothelial cells and macrophages further revealed that B&bgr;15-42 had no direct effect on Toll-like receptor–mediated inflammation. Therefore, we assume that attenuated inflammation is rather due to sustained vascular integrity and thus suppresses vascular leakage and subsequently leukocyte infiltration during sepsis.

Is Postoperative Imaging Mandatory after Meningioma Removal? Results of a Prospective Study

Background Routine postoperative imaging (PI) following surgery for intracranial meningiomas is common practice in most neurosurgical departments. The purpose of this study was to determine the role of routine PI and its impact on clinical decision making after resection of meningioma. Methods Patient and tumor characteristics, details of radiographic scans, symptoms and alteration of treatment courses were prospectively collected for patients undergoing removal of a supratentorial meningioma of the convexity, falx, tentorium, or lateral sphenoid wing at the authors’ institution between January 1st, 2010 and March 31st, 2012. Patients with infratentorial manifestations or meningiomas of the skull base known to be surgically difficult (e.g. olfactory groove, petroclival, medial sphenoid wing) were not included. Maximum tumor diameter was divided into groups of < 3cm (small), 3 to 6 cm (medium), and > 6 cm (large). Results 206 patients with meningiomas were operated between January 2010 and March 2012. Of these, 113 patients met the inclusion criteria and were analyzed in this study. 83 patients (73.5%) did not present new neurological deficits, whereas 30 patients (26.5%) became clinically symptomatic. Symptomatic patients had a change in treatment after PI in 21 cases (70%), while PI was without consequence in 9 patients (30%). PI did not result in a change of treatment in all asymptomatic patients (p<0.001) irrespective of tumor size (p<0.001) or localization (p<0.001). Conclusions PI is mandatory for clinically symptomatic patients but it is safe to waive it in clinically asymptomatic patients, even if the meningioma was large in size.

Cecum ligation and dissection: a novel modified mouse sepsis model.

BACKGROUND The fact that many sepsis therapeutics failed to be translated into the human indicates that there is still a serious need to reassess our models of sepsis research. We aimed to develop a novel modified model of sepsis in the mouse, which simulates the clinical situation more accurately. MATERIALS AND METHODS Sepsis was induced in C57Bl/6 mice by dissecting the cecum and placing the discontinued organ back into the abdomen (cecum ligation and dissection [CLD]). Septic animals were relaparotomized after 6 h, followed by peritoneal lavage, and antibiotic treatment. Results were compared with shams or the classic colon ligation and puncture (CLP) model. The postoperative lung impairment was assessed using neutrophil invasion as a surrogate. Proinflammatory cytokines were measured by either real-time polymerase chain reaction or Luminex technology, and liver damage was evaluated by aspartate transaminase and alanine transaminase measurements. RESULTS In CLD animals with relaparotomy after 6 h, lung interleukin (IL) 6, monocyte chemoattractant protein (MCP)-1 messenger RNA levels, and neutrophil invasion were significantly increased. Liver messenger RNA expression in CLD animals was significantly upregulated for IL-6, tumor necrosis factor alpha, IL-10, and MCP-1 compared with sham and CLP animals. Significantly higher levels of alanine transaminase were observed in CLD animals. Finally, systemic inflammation as measured by plasma IL-6, tumor necrosis factor alpha, IL-1β, IL-10, and MCP-1 was significantly increased in all CLD animals compared with shams, whereas CLP animals only showed an insignificant increase in the latter molecules. CONCLUSIONS Our modifications to the classic CLP model significantly produced organ inflammation, liver damage, and a similar mortality compared with a clinical setting, with a reliable onset of sepsis.