E-cylinder-powered mechanical ventilation may adversely impact anesthetic management and efficiency

Anesthesiologists often administer care outside the operating room. These locations may depend on gas cylinders for their oxygen source more than the operating suites supplied by dedicated central pipelines. Using full E-cylinders, we determined the oxygen consumption of two often used, pneumatically driven anesthesia ventilators to answer three questions: How much time is available when mechanically ventilating patients in the setting of absent or malfunctioning central oxygen pipeline? How much oxygen is used by the ventilator to drive the bellows? How does changing the inspiratory to expiratory ratio and the inspiratory flow (Narkomed ventilator only) influence oxygen use? At a ventilation of 5 L/min, we found that mechanical ventilation consumes between 59% and 85% of the available oxygen in an E-cylinder to drive the ventilator at fresh gas flows ranging from 1 to 10 L/min. The time span until the low oxygen alarm sounded ranged from 38 to 99 min. Alteration of the inspiratory flow but not the inspiratory to expiratory ratio had a significant impact. Clinicians must recognize that mechanical ventilation using E-cylinders rapidly depletes this sole oxygen source and could jeopardize patient safety. Conversely, manual or spontaneous ventilation with low fresh gas flows minimizes oxygen depletion. IMPLICATIONS: The time available to ventilate patients with an E-cylinder tank as the sole oxygen source was found to be as short as 38 min. Clinicians must recognize that mechanical ventilation using oxygen cylinders rapidly depletes oxygen and could jeopardize patient safety.     

The role of non-invasive ventilation in blunt chest trauma: systematic review and meta-analysis

Purpose

Respiratory support is the mainstay for the management of patients with pulmonary contusion following blunt chest trauma. In patients not requiring immediate intubation and ventilation, the optimal respiratory management strategy is not clear. This systematic review and meta-analysis aimed to determine the efficacy of non-invasive ventilation (NIV), as compared to traditional respiratory support strategies (i.e., high-flow facemask oxygen or pre-emptive intubation and ventilation), in adult patients with blunt chest trauma.

Methods

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing NIV to traditional forms of respiratory support (i.e., facemask oxygen or intubation and ventilation) in an adult trauma population. For each eligible trial, we extracted the outcomes of all-cause mortality, length of intensive care unit (ICU) stay, length of hospital stay, and pneumonia.

Results

We identified 643 citations, selected 17 for full-text evaluation, and identified three eligible RCTs. Patients receiving NIV had a non-significant reduction in the risk of death (OR 0.55; 95 % CI 0.18–1.70; I ² = 0 %), but significant reductions in length of ICU stay (mean difference ?2.45 days; 95 % CI ?4.27 to ?0.63; I ² = 66 %), length of hospital stay (mean difference ?4.60 days; 95 % CI ?8.81 to ?0.39; I ² = 85 %), and risk of pneumonia (OR 0.20; 95 % CI 0.09–0.47; I ² = 0 %).

Conclusion

This meta-analysis suggests that NIV is superior to both high-flow facemask oxygen or pre-emptive intubation and ventilation in patients with blunt chest trauma who have no contraindication to NIV.     

Lebensbedrohlicher Bronchospasmus bei Narkoseeinleitung

This article reports a case of live-threatening respiratory failure during induction of anesthesia. An 18-year-old female was admitted to hospital for an axillary abscess incision on a public holiday. The patient had a history of asthmatic episodes and an allergy to milk protein and 2 years previously an asthmatic attack had possibly been treated by mechanical ventilation. Retrospectively, this event turned out to be a cardiac arrest with mechanical ventilation for 24?h. During induction of anesthesia the patient suddenly developed massive bronchospasms and ventilation was impossible for minutes. Oxygen saturation fell below 80% over a period of 12?min with a lowest measurement of 13%. The patient was treated with epinephrine, prednisolone, antihistamine drugs, ?(2)-agonists, s-ketamine and methylxanthines and 15?min later the oxygen saturation returned to normal values. After mild therapeutic hypothermia for 24?h mechanical ventilation was still required for another 4 days. The patient recovered completely and was discharged home on day 19. Initially propofol was suspected of having caused an anaphylactic shock but in retrospect, the diagnosis of near fatal asthma was more likely. The onset of the event was facilitated by the patient playing down the history of asthmatic episodes due to a strong wish for independency and negation of the severity of the disease.     

Evolution of the Use of Noninvasive Mechanical Ventilation in Chronic Obstructive Pulmonary Disease in a Spanish Region, 1997–2010

IntroductionNoninvasive mechanical ventilation (NIV) appeared in the 1980s as an alternative to invasive mechanical ventilation (IMV) in patients with acute respiratory failure. We evaluated the introduction of NIV and the results in patients with acute exacerbation of chronic obstructive pulmonary disease in the Region of Murcia (Spain).Subjects and methodsA retrospective observational study based on the minimum basic hospital discharge data of all patients hospitalised for this pathology in all public hospitals in the region between 1997 and 2010. We performed a time trend analysis on hospital attendance, the use of each ventilatory intervention and hospital mortality through JoinPoint regression.ResultsWe identified 30 027 hospital discharges. JoinPoint analysis: downward trend in attendance (annual percentage change [APC]=?3.4, 95% CI: ?4.8 to ?2.0, P<.05) and in the group without ventilatory intervention (APC=?4.2%, ?5.6 to ?2.8, P<.05); upward trend in the use of NIV (APC=16.4, 12.0–20.9, P<.05), and downward trend that was not statistically significant in IMV (APC=?4.5%, ?10.3 to 1.7). We observed an upward trend without statistical significance in overall mortality (APC=0.5, ?1.3 to 2.4) and in the group without intervention (APC=0.1, ?1.6 to 1.9); downward trend with statistical significance in the NIV group (APC=?7.1, ?11.7 to ?2.2, P<.05) and not statistically significant in the IMV group (APC=?0.8, ?6, 1–4.8). The mean stay did not change substantially.ConclusionsThe introduction of NIV has reduced the group of patients not receiving assisted ventilation. No improvement in results was found in terms of mortality or length of stay.     

Early tracheostomy decreases ventilation time but has no impact on mortality of intensive care patients: a randomized study

Background

Long-term ventilation in intensive care units (ICUs) is associated with several problems such as increased mortality, increased rates of ventilator-associated pneumonia (VAP), and prolonged time of hospitalization, and thus leads to enormous healthcare expenditure. While the influence of tracheostomy on VAP incidence, duration of ventilation, and time of hospitalization has already been analyzed in several studies, the timing of the tracheostomy procedure on patient’s mortality is still controversial. The aim of our study was to investigate whether early tracheostomy improved outcome in critically ill patients.

Materials and methods

Within 2?years, 100 critically ill, predominantly surgical patients entered this prospective randomized study. A percutaneous dilatational tracheostomy was performed either early (≤4?days, 2.8?days median) or late (≥6?days, 8.1?days median) after intubation.

Results

We could demonstrate that mortality was not significantly reduced in the early tracheostomy (ET) group in contrast to the late tracheostomy (LT) group. ET was associated with decreased VAP incidence (ET 38% vs. LT 64%), decreased duration of ventilation (ET 367.5?h vs LT 507.5?h), and shorter time of hospitalization both in hospital (ET 31.5?days vs LT 68?days) and in ICU (ET 21.5?days vs LT 27?days).

Conclusion

Despite many advantages like reduced time of ventilation and hospitalization, early tracheostomy is not associated with decreased mortality in critically ill patients.     

Trends in intubation rates and durations in ventilated severely injured trauma patients: an analysis from the TraumaRegister DGU®

Background

Endotracheal intubation in severely injured patients is known to be a risk factor for systemic complications. We aimed to examine the changes in intubation rates and durations in severely injured trauma patients, and rates of the systemic complications associated with ventilation changes by using a large trauma registry over the period of 13 years.

Methods

Patient demographics, Injury Severity Score (ISS), ventilation days, ventilation free days (VFD), and prevalence of systemic complications (sepsis and multiple organ failure (MOF)) were obtained from the TraumaRegister DGU® and were compared over the study period.

Results

During the study period (2002 – 2014), 35,232 patients were recorded in TraumaRegister DGU®. 72.7 % of patients (n?=?25,629) were intubated, and 27.3 % (n?=?9603) of patients did not require mechanical ventilation throughout their hospital stay. The mean age was 48?±?21 years, mean ISS was 27.9?±?11.5, mean length of ICU stay was 11.7?±?13.8 days, mean time on mechanical ventilator was 7.1?±?11.3 days, and mean ventilation free days (spontaneous respiration) was 19.5?±?11.9 days. We observed a reduction in the intubation rates (87.5 % in 2002 versus 63.6 % in 2014), and early extubation (10 ventilation days in 2002, and 5.9 days in 2014) over time.

Conclusion

Our study reveals a reduction in intubation rates and ventilation duration during the observation period. Moreover, we were able to observe decreased incidence of systemic complications such as sepsis over the 13 year study period, while no changes in incidence of MOF were registered. The exact relationship can not be proven in our study. This needs to be addressed in further analysis.

     

Erste Erfahrungen mit der Superponierten Hochfrequenz-Jetventilation in der Intensivmedizin

The study aimed to evaluate whether superimposed high-frequency jet ventilation (SHFJV) is a useful tool in intensive care medicine to ventilate patients with pulmonary insufficiency. Methods. SHFJV is the simultaneous application of low- and high-frequency jet ventilation performed using a specially designed ventilator. SHFJV versus conventional mechanical ventilation (CMV) was were applied in three groups of patients. Group?1 (Gr?1) included patients without pulmonary insufficiency; group?2 (Gr?2) patients had moderate and those in group?3 (Gr?3) had severe pulmonary insufficiency. Results. In Gr?1 and Gr?2, SHFJV was associated with a significant decrease in mean airway pressure (mPAW 12.9 vs. 13.3?mm?Hg, P<0.05). In Gr?3 oxygenation was significantly better with SHFJV (mean paO₂ 140.1 vs. 109.9?mm?Hg, P<0.05; mean FiO₂ 0.66 vs. 0.86, P<0.05). Other parameters, such as maximum airway pressure (Pmax) and mean Paw, were significantly lower with SHFJV than CMV (mean Pmax 29.6 vs. 40.1?mm?Hg, mean Paw 18 vs. 21.9?mm?Hg, P<0.05). Intrapulmonary shunt fractions showed a significant decrease with SHFJV (24.6 vs. 34.4, P<0.05). Conclusions. Significant differences were observed primarily in Gr?3 patients, indicating that patients with severe pulmonary insufficiency may benefit from SHFJV. SHFJV may thus represent an alternative mode of ventilation in critically ill patients.     

Veno-venöse extrakorporale Membranoxygenierung (ECMO) mit heparinbeschichtetem Bypass-System Eine effektive Erweiterung bei der Behandlung des akuten Lungenversagens (ARDS)

Mortality of severe acute respiratory distress syndrome (ARDS) in Germany is about 60%. Respiratory therapy can make the lung injury worse by high positive airway pressures, high tidal volumes and high inspiratory oxygen concentrations. Extracorporeal membrane oxygenation (ECMO) was employed to reduce aggressive mechanical ventilation, but it has not been proved to be superior to conventional ventilation. However, encouraged by recently developed improvements in the technique and concept of ECMO, we introduced this therapy into our program for the treatment of ARDS. Patients and methods. All patients with severe ARDS (lung injury score >2.5) admitted to our multidisciplinary intensive care unit from March 1992 to March 1995 were evaluated prospectively. After admission, the patients first underwent a conventional therapeutic approach, including pressure-controlled inverse-ratio ventilation, permissive hypercapnia, changes in body position (in particular, the prone position), negative fluid balance, antibiotics, and low-dose hydrocortisone infusion. ECMO via a covalently heparin-coated, venovenous bypass-system with a vortex pump and two membrane lungs was performed if ARDS did not improve after 24–96?h of conventional therapy and if two of three of the slow-entry criteria for ECMO were fulfilled: (1) PaO₂/FiO₂ <150?mmHg at PEEP >5?mbar; (2) semistatic compliance <30?ml/mbar; (3) right-left shunt >30%. Only in cases of life-threatening hypoxemia (PaO₂ <50?mmHg at FiO₂ 1.0 and PEEP >5?mbar for >2?h (fast-entry criteria) was ECMO instituted immediately. Results. Sixty patients fulfilled the entry criteria for our study. Thirty-nine patients were treated with a conventional protocol, 37 after improvement of ARDS and 2 who had not improved but in whom there were contraindications to the use of ECMO. ECMO was performed in 10 patients who had not improved, but who fulfilled the slow-entry criteria and in 11 primarily hypoxemic patients who fulfilled the fast-entry criteria. The survival rate was 30/39 (77%) for the conventional therapy group, 6/10 (60%) for the slow-entry group, and 11/11 (100%) for the fast-entry group. The onset of ECMO allowed a significant decrease in peak and mean airway pressures, tidal volume, ventilatory rate, minute volume and inspiratory oxygen concentration. Sufficient gas exchange was provided, and pulmonary artery pressures significantly decreased on bypass. The most frequent complications on bypass were pneumothorax (15/21 patients) and bleeding (7/21 patients). Conclusion. In comparison with the historical results at our own institution, the present study demonstrates an improvement in the survival rate from 56% to 78% since ECMO has become available. We conclude that venovenous ECMO with a heparin-bonded bypass circuit is an effective additional option for the treatment of patients with severe ARDS.     

Effect of epidural analgesia in patients with traumatic rib fractures: a systematic review and meta-analysis of randomized controlled trials

Purpose

A consensus group recently proposed epidural analgesia as the optimal analgesic modality for patients with multiple traumatic rib fractures. However, its beneficial effects are not consistently recognized in the literature. We performed a systematic review and a meta-analysis of randomized controlled trials (RCT) of epidural analgesia in adult patients with traumatic rib fractures.

Methods

A systematic search strategy was applied to MEDLINE, EMBASE, the Cochrane Library and to the annual meeting of relevant societies (up to July 2008). All randomized controlled trials comparing epidural analgesia with other analgesic modalities in adult patients with traumatic rib fractures were included. Primary outcomes were mortality, ICU length of stay (LOS), hospital LOS and duration of mechanical ventilation.

Results

Eight studies (232 patients) met eligibility criteria. Epidural analgesia did not significantly affect mortality (odds ratio [OR] 1.6, 95% CI, 0.3, 9.3, 3 studies, n = 89), ICU LOS (weighted mean difference [WMD] ?3.7 days, 95% CI, ?11.4, 4.0, 4 studies, n = 135), hospital LOS (WMD ?6.7, 95% CI, ?19.8, 6.4, 4 studies, n = 140) or duration of mechanical ventilation (WMD ?7.5, 95% CI, ?16.3, 1.2, 3 studies, n = 101). Duration of mechanical ventilation was decreased when only studies using thoracic epidural analgesia with local anesthetics were evaluated (WMD ?4.2, 95% CI, ?5.5, ?2.9, 2 studies, n = 73). However, hypotension was significantly associated with the use of thoracic epidural analgesia with local anesthetics (OR 13.76, 95% CI, 2.89, 65.51, 3 studies, n = 99).

Conclusions

No significant benefit of epidural analgesia on mortality, ICU and hospital LOS was observed compared to other analgesic modalities in adult patients with traumatic rib fractures. However, there may be a benefit on the duration of mechanical ventilation with the use of thoracic epidural analgesia with local anesthetics. Further research is required to evaluate the benefits and harms of epidural analgesia in this population before being considered as a standard of care therapy.     

First experience with the ultra compact mobile extracorporeal membrane oxygenation system Cardiohelp in interhospital transport

In patients with severe cardiopulmonary failure extracorporeal assist devices are to support patients during resuscitation, for transportation, until organ recovery, and as bridge to further therapeutic modalities. We report on our first experience with the new Cardiohelp system for interhospital transfer of cardiopulmonarily compromised patients. The Cardiohelp system was used for transportation and in-house treatment in six male patients with a mean age of 41±17?years. Five patients suffered respiratory failure; one patient with acute myocardial infarction was in profound cardiogenic shock. Accordingly, the Cardiohelp system was implanted as a venovenous extracorporeal membrane oxygenation (ECMO) in five patients and as a venoarterial system in one patient. The preECMO ventilation time was 0.5-4?days. The patients were transported to our institution by car (n=1) or helicopter (n=5) over a distance of 80-5850?km. The subsequent in-house ECMO support was continued with the Cardiohelp and lasted for 5-13?days. PostECMO ventilation was one to 25 days. A 100% survival was achieved. The portable Cardiohelp system allows location-independent stabilization of cardiopulmonary compromised patients with consecutive interhospital transfer and in-house treatment. The integrated sensors, which register arterial and venous line pressure, blood temperature, hemoglobin as well as SvO(2), greatly alleviate its management and considerably increase safety.     

Timing of tracheostomy

Currently, tracheostomy represents an established procedure for airway management in critically ill patients who require long-term respiratory support, and it is one of the most frequently performed surgical procedures in critically ill patients. It offers a number of practical and theoretical advantages when compared to conventional translaryngeal oro- or nasotracheal intubation, but is also associated with a number of serious complications. In the last 20 years, several retrospective studies, randomized prospective trials, and meta-analyses have been published to determine the best timing for tracheostomy. However, these studies presented conflicting results. All studies performed so far in a prospective randomized fashion were relatively small and underpowered. Currently, several large controlled randomized studies are underway that will hopefully help physicians make better evidence-based decisions on the timing of tracheostomy. Based on our current knowledge, the following recommendations might be made on a low level of evidence: on day 2 or 3 after onset of mechanical ventilation (>48 h of mechanical ventilation or need for an artificial airway) tracheostomy should be seriously considered. Before decisions are made, several questions should be answered: Is the situation suitable for tracheostomy? Are there relevant contraindications for the performance of a tracheostomy? What is the most likely course of the underlying respiratory insufficiency? What is the likelihood the patient will stay in need of invasive mechanical ventilation for more than a week, either because of an ongoing impairment of oxygenation, weaning failure, upper airway obstruction, coma or a swallowing disorder? If no relevant contraindication is present and if the need for invasive mechanical ventilation can be expected to last for more than one week, tracheostomy should be planned and performed within the next 2 days.     

Ventilatory strategies in septic patients

Background

Mortality in intensive care unit (ICU) patients is affected by multiple variables. The possible impact of the mode of ventilation has not yet been clarified; therefore, a secondary analysis of the “epidemiology of sepsis in Germany” study was performed. The aims were (1) to describe the ventilation strategies currently applied in clinical practice, (2) to analyze the association of the different modes of ventilation with mortality and (3) to investigate whether the ratio between arterial partial pressure of oxygen and inspired fraction of oxygen (PF ratio) and/or other respiratory variables are associated with mortality in septic patients needing ventilatory support.

Methods

A total of 454 ICUs in 310 randomly selected hospitals participated in this national prospective observational 1-day point prevalence of sepsis study including 415 patients with severe sepsis or septic shock according to the American College of Chest Physicians/Society of Critical Care Medicine criteria.

Results

Of the 415 patients, 331 required ventilatory support. Pressure controlled ventilation (PCV) was the most frequently used ventilatory mode (70.6 %) followed by assisted ventilation (AV 21.7 %) and volume controlled ventilation (VCV 7.7 %). Hospital mortality did not differ significantly among patients ventilated with PCV (57 %), VCV (71 %) or AV (51 %, p?=?0.23). A PF ratio equal or less than 300 mmHg was found in 83.2 % of invasively ventilated patients (n?=?316). In AV patients there was a clear trend to a higher PF ratio (204?±?70 mmHg) than in controlled ventilated patients (PCV 179?±?74 mmHg, VCV 175?±?75 mmHg, p?=?0.0551). Multiple regression analysis identified the tidal volume to pressure ratio (tidal volume divided by peak inspiratory airway pressure, odds ratio OR?=?0.94, 95 % confidence interval 95% CI?=?0.89–0.99), acute renal failure (OR?=?2.15, 95% CI?=?1.01–4.55) and acute physiology and chronic health evaluation (APACHE) II score (OR?=?1.09, 95% CI?=?1.03–1.15) but not the PF ratio (univariate analysis OR?=?0.998, 95 % CI?=?0.995–1.001) as independent risk factors for in-hospital mortality.

Conclusions

This representative survey revealed that severe sepsis or septic shock was frequently associated with acute lung injury. Different ventilatory modes did not affect mortality. The tidal volume to inspiratory pressure ratio but not the PF ratio was independently associated with mortality.     

Intraoperative Kontrastechokardiographie zum Nachweis eines funktionell offenen Foramen ovale unter Durchführung eines Provokationstests mit PEEP-Beatmung

Intraoperative paradoxical air embolism may occur even if a patent foramen ovale (PFO) is excluded by contrast transoesophagal echocardiography (TEE) under 20?cmH₂O positive airway pressure. It is questionable whether the combination of PEEP and ventilation with a large tidal volume increases the sensivity of contrast TEE in detecting a PFO. Methods. Eighty healthy patients (ASA status I, II) scheduled for surgery in the supine position and ranging from 25 to 72 years of age were investigated by TEE, which was performed in the biatrial viewing mode (short axis). Echocardiographic contrast (10?ml agitated gelatine solution) was injected during two different ventilation manoeuvres. Manoeuvre I: Contrast injection during the application of 20?cmH₂O positive airway pressure for 5?s. The pressure was released when the right atrium became completely opacified by echo targets. The injected bolus was observed throughout the ventilatory cycle, with special attention being given to early expiration and systole. A right-to-left shunt was assumed if five echo targets were observed in the left atrium. Manoeuvre II: Contrast injection during ventilation with PEEP (15?cmH₂O), a tidal volume of 1,200?ml, and a respiratory rate of 6/min. Results. The frequency of a PFO causing a right-to-left interatrial shunt was 8.7% (7 cases) in manoeuvre I and 15% (12 cases) in manoeuvre II. In one case a PFO was diagnosed intraoperatively by chance. Discussion. The use of provocation manoeuvres including ventilation with PEEP and high tidal volumes might improve the ability to detect a PFO presenting with right-to-left interatrial shunt by intraoperative contrast TEE, but does not have 100% sensitivity. However, our results clearly indicate that ventilation with PEEP and high tidal volumes may predispose to paradoxical embolism.     

Spontaneous breathing during high-frequency oscillatory ventilation improves regional lung characteristics in experimental lung injury

Background: Maintenance of spontaneous breathing is advocated in mechanical ventilation. This study evaluates the effect of spontaneous breathing on regional lung characteristics during high‐frequency oscillatory (HFO) ventilation in an animal model of mild lung injury. Methods: Lung injury was induced by lavage with normal saline in eight pigs (weight range 47–64 kg). HFO ventilation was applied, in runs of 30 min on paralyzed animals or on spontaneous breathing animals with a continuous fresh gas flow (CF) or a custom‐made demand flow (DF) system. Electrical impedance tomography (EIT) was used to assess lung aeration and ventilation and the occurrence of hyperinflation. Results: End expiratory lung volume (EELV) decreased in all different HFO modalities. HFO, with spontaneous breathing maintained, showed preservation in lung volume in the dependent lung regions compared with paralyzed conditions. Comparing DF with paralyzed conditions, the center of ventilation was located at 50% and 51% (median, left and right lung) from anterior to posterior and at 45% and 46% respectively, P<0.05. Polynomial coefficients using a continuous flow were ?0.02 (range ?0.35 to 0.32) and ?0.01 (?0.17 to 0.23) for CF and DF, respectively, P=0.01. Conclusions: This animal study demonstrates that spontaneous breathing during HFO ventilation preserves lung volume, and when combined with DF, improves ventilation of the dependent lung areas. No significant hyperinflation occurred on account of spontaneous breathing. These results underline the importance of maintaining spontaneous breathing during HFO ventilation and support efforts to optimize HFO ventilators to facilitate patients' spontaneous breathing.     

Notfallnarkose, Atemwegsmanagement und Beatmung beim Polytrauma

Patients with multiple trauma presenting with apnea or a gasping breathing pattern (respiratory rate? <?6/min) require prehospital endotracheal intubation (ETI) and ventilation. Additional indications are hypoxia (S_pO₂? <?90% despite oxygen insufflation and after exclusion of tension pneumothorax), severe traumatic brain injury [Glasgow Coma Scale (GCS)? <?9], trauma-associated hemodynamic instability [systolic blood pressure (SBP)? <?90?mmHg] and severe chest trauma with respiratory insufficiency (respiratory rate ?>?29/min). The induction of anesthesia after preoxygenation is conducted as rapid sequence induction (analgesic, hypnotic drug, neuromuscular blocking agent). With the availability of ketamine as a viable alternative, the use of etomidate is not encouraged due to its side effects on adrenal function. An electrocardiogram (ECG), blood pressure measurement and pulse oximetry are needed to monitor the emergency anesthesia and the secured airway. Capnography is absolutely mandatory to confirm correct placement of the endotracheal tube and to monitor tube dislocations as well as ventilation in the prehospital and hospital setting. Because airway management is often complicated in trauma patients, alternative devices need to be available preclinical and a fiber-optic endoscope should be available within the hospital. Use of these alternative measures for airway management and ventilation should be considered at the latest after a maximum of three unsuccessful endotracheal intubation attempts. Emergency medical service (EMS) physicians should to be trained in emergency anesthesia, ETI and alternative methods of airway management on a regular basis. Within hospitals ETI, emergency anesthesia and ventilation are to be conducted by trained and experienced anesthesiologists. When a difficult airway or induction of anesthesia is expected, endotracheal intubation should be supervised or conducted by an anesthesiologist. Normoventilation should be the goal of mechanical ventilation. After arrival in the resuscitation room the ventilation will be controlled and guided with the help of arterial blood gas analyses. After temporary removal of a cervical collar, the cervical spine needs to be immobilized by means of manual in-line stabilization when securing the airway.     

Arztbegleiteter Patiententransport

Introduction

To relieve existing interhospital transfer systems, a novel transfer vehicle was introduced in Bavaria in 2009. Its aim was to transfer patients who need care by an emergency physician but are not considered intensive care patients.

Method

Logistic data (time, duration, location, distance, hospital units) and relevant medical data (urgency, medication, ventilation, special monitoring) were documented. Simultaneously the transport volume of the existing systems were evaluated after the introduction of the novel vehicle.

Results

A total of 1762 transfers were documented (on average 1.6/day): 84?% took place weekdays and 85?% during daytime. Intensive care procedures like invasive hemodynamic monitoring, ventilation, and continuous medication were performed in 51?% of patients. In 20?%, discontinuous medication was needed. In 16?%, an indication for monitoring by a physician existed. Due to an overall increasing transfer volume no relevant relief was seen for the existing systems.

Discussion

There seems to be a need for physician-staffed interhospital transfers especially weekdays during the daytime. In half of the transfers, intensive care-related procedures were performed. Only one third of the patients fulfilled the criteria defined at introduction of the novel vehicle. Therefore a revision of the system seems necessary.

     

Methohexital zur Analgosedierung bei beatmeten Intensivpatienten

Background

Delirium is defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR) as a potentially reversible disturbance of consciousness and a change of cognition caused by a medical condition, drug intoxication, or medication side effect. Delirium affects up to 80?% of intensive care unit (ICU) patients and is associated with increased morbidity and mortality. One risk factor for development of delirium in ventilated intensive care unit patients is sedation. The German S3 guidelines on “Analgesie, Sedierung und Delirmanagement in der Intensivmedizin” (analgesia, sedation and delirium management in intensive care medicine) of the DGAI (German Society for Anesthesiology and Intensive Care Medicine) and the DIVI (German Interdisciplinary Association for Intensive Care and Emergency Medicine) recommend midazolam and propofol for sedation, although both drugs are associated with a high incidence of delirium.

Aim

Within the framework of this study the question arose whether the barbiturate methohexital could be associated with a lower incidence of delirium in comparison to midazolam or propofol in analgosedated and ventilated ICU patients.

Material and methods

This was a prospective nonrandomized observational cohort study in a mixed medical surgical intensive care unit. Patients ventilated within 72 h after admittance were consecutively allocated to either propofol/remifentanil versus methohexital/remifentanil (expected ventilation duration ≤?7 days) or midazolam/fentanyl versus methohexital/fentanyl (expected ventilation duration >?7 days) by the attending senior consultant anesthetist at the time of admission and/or intubation. Primary endpoint was delirium at any time during the ICU stay. Delirium was checked every 8 h by ICU nurses using the intensive care delirium screening checklist (ICDSC), with delirium defined as ICDSC ≥?4 points. Before evaluation of the ICDSC the Richmond agitation sedation scale (RASS) score and the visual analogue scale for pain (VAS target ≤?4) were measured. To assure reliable evaluation of the ICDSC, the RASS score of the patient at the time of evaluation had to be ≥???2. Assuming an incidence of delirium in the midazolam group of 70?% and in the methohexital group of 35?%, 16 patients were needed each in the midazolam/fentanyl and the methohexital/fentanyl cohorts (p?=?0.05, β =?0.1). Assuming an incidence of delirium in the propofol group of 50?% and in the methohexital group again of 35?%, 94 patients were needed in the propofol/remifentanil and methohexital/remifentanil groups, respectively (p?=?0.05, β =?0.1).

Results

A total of 222 patients were evaluated, 34 in the methohexital vs. midazolam group and 188 in the methohexital vs. propofol group. Out of 16 patients sedated with midazolam, 15 developed delirium (94?%) in contrast to only 5 out of 18 patients sedated with methohexital (28?%). Thus compared to midazolam the sedation with methohexital reduced the incidence of delirium by 66?% (p?<?0.001) corresponding to a number needed to treat (NNT) of 1.5. Out of 94 patients in the propofol/remifentanil group, 64 developed delirium (68?%) in contrast to only 23 out of 94 in the methohexital/remifentanil group (24?%). Thus compared to propofol the sedation with methohexital reduced the incidence of delirium by 44?% (p?<?0.001), corresponding to an NNT of 2.5.

Conclusion

Sedation with methohexital compared to midazolam or propofol reduced the incidence of delirium by more than 50?% in ventilated ICU patients.     

Prähospitale nichtinvasive Ventilation in der Bundesrepublik Deutschland

Background and objectives

Non-invasive ventilation (NIV) is an evidence-based treatment of acute respiratory failure and can be helpful to reduce morbidity and mortality. In Germany national S3 guidelines for inhospital use of NIV based on a large number of clinical trials were published in 2008; however, only limited data for prehospital non-invasive ventilation (pNIV) and hence no recommendations for prehospital use exist so far.

Aim

In order to create a database for pNIV in Germany a nationwide survey was conducted to explore the status quo for the years 2005–2008 and to survey expected future developments including disposability, acceptance and frequency of pNIV.

Material and methods

A questionnaire on the use of pNIV was developed and distributed to 270 heads of medical emergency services in Germany.

Results

Of the 270 questionnaires distributed 142 could be evaluated (52?%). The pNIV was rated as a reasonable treatment option in 91?% of the respondents but was available in only 54 out of the 142 responding emergency medical services (38?%). Continuous positive airway pressure (98?%) and biphasic positive airway pressure (22?%) were the predominantly used ventilation modes. Indications for pNIV use were acute cardiogenic pulmonary edema (96?%), acute exacerbation of chronic obstructive pulmonary disease (89?%), asthma (32?%) and pneumonia (28?%). Adverse events were reported for panic (20?±??17%) and non-threatening heart rhythm disorders (8?±?5%), the rate of secondary intubation was low (reduction from 20 % to 10?%) and comparable to data from inhospital treatment.

Conclusion

Prehospital NIV in Germany was used by only one third of all respondents by the end of 2008. Based on the clinical data a growing application for pNIV is expected. Controlled prehospital studies are needed to enunciate evidence-based recommendations for pNIV.     

不同机械通气模式对老年腹部手术患者细胞因子的影响

目的探讨不同机械通气模式对于老年腹部手术患者细胞因子的影响。方法 72例择期进行腹部手术全麻机械通气的老年患者(年龄65岁)分为6组,每组12例。A组:VCV(Vt 6 m L/kg)+PEEP 8 mm Hg+auto-flow模式;B组:VCV(Vt 6 m L/kg)+PEEP 8 mm Hg+const-flow模式;C组:VCV(Vt 6 m L/kg)+PEEP 12 mm Hg+auto-flow模式;D组:VCV(Vt 6 m L/kg)+PEEP 12mm Hg+const-flow模式;E组:VCV(Vt 10 m L/kg)+auto-flow模式;F组:VCV(Vt 10 m L/kg)+const-flow模式。6组患者全身麻醉气管插管后,均予以VCV(Vt 6 m L/kg)+const-flow模式通气60 min,再按分组的通气模式进行通气,总通气时间大于5 h。在通气1 h及5 h两个时间点,抽取静脉血和支气管肺泡灌洗液检测IL-8、IL-10、MMP-9、SP-A以及SF浓度。结果大潮气量组(E、F两组)较小潮气量四组(A、B、C、D四组)通气5 h后,血与BALF中测定的IL-8、MMP-9浓度以及血中测定的SP-A、SF浓度明显升高(P0.05),血与BALF中测定的IL-10浓度以及BALF中测定的SP-A浓度明显降低(P0.05)。通气5 h后F组较E组,血及BALF中IL-8以及MMP-9、血SF、血SP-A更高(P0.05),而BALF中SP-A则更低(P0.05)。结论 (1)大潮气量机械通气较小潮气量机械通气而言,更有利于促进IL-8、MMP-9、SF的分泌,抑制IL-10的释放,BALF中SP-A下降,血中SP-A升高,进一步加剧了VILI的程度。(2)就老年(年龄65岁)腹部手术患者而言,围手术期以VCV(Vt6 m L/kg)+PEEP 12 mm Hg+auto-flow模式机械通气较其他五种通气模式,更有利于减轻肺组织急性炎症反应及氧化应激反应的激活,减轻机械通气所致生物伤,从而减轻VILI的程度。