Nutritional support in the mechanically ventilated patient

In summary, nutritional management of the intubated patient requires several decision steps. Nutritional support should be strongly considered if the patient has evidence of malnutrition by nutritional assessment or has a high likelihood of becoming malnourished by virtue of a severe, prolonged critical illness. Nutrition can be administered enterally if good gut function exists or parenterally in patients unable to tolerate enteral feeding. Nutritional goals in the intensive care unit include maintenance of body weight and lean body mass. Proper nutritional therapy includes assessment of adequate caloric requirements as well as appropriate protein, carbohydrate, and fat composition of the nutritional support. Monitoring the efficacy of nutritional therapy includes evaluating nitrogen balance. Complications of both enteral and parenteral therapy exist. Nutritional therapy is but one link in the chain of therapeutic endeavors given a critically ill patient but, as with all other treatment modalities, requires knowledge of basic fundamentals.     

Sedation and analgesia in the mechanically ventilated patient

Sedation and analgesia are important components of care for the mechanically ventilated patient in the intensive care unit (ICU). An understanding of commonly used medications is essential to formulate a sedation plan for individual patients. The specific physiological changes that a critically ill patient undergoes can have direct effects on the pharmacology of drugs, potentially leading to interpatient differences in response. Objective assessments of pain, sedation, and agitation have been validated for use in the ICU for assessment and titration of medications. An evidence-based strategy for administering these drugs can lead to improvements in short- and long-term outcomes for patients. In this article, we review advances in the field of ICU sedation to provide an up-to-date perspective on management of the mechanically ventilated ICU patient.     

Transport of the mechanically ventilated pediatric patient

Children deserve quality care when they are critically ill or injured. Specialized pediatric services may be limited outside major medical centers. Transport by specialized pediatric and neonatal transport teams may be required to deliver patients to tertiary pediatric medical centers. In addition, in the past decade a cost-effective, organized, systematic approach to health care management has assumed greater importance, leading to the concept of the so-called medical home. In this model, a child with a complex medical problem is cared for in the environment in which he or she will receive the best care, with emphasis on providing rehabilitative and long-term care near the child's home. It is likely, then, that the field of pediatric transport medicine will assume greater importance in the coming decade.     

Successful management of CMV pneumonia in a mechanically ventilated patient.

We report a case of severe respiratory failure due to cytomegalovirus pneumonitis in a patient who underwent an allogeneic bone marrow transplant, who was successfully treated with the combination of ganciclovir and high-dose intravenous immune globulin. We also reviewed the rationale for the use of combination therapy with an antiviral agent and immunotherapy. Because of the bone marrow toxicity of ganciclovir, an aggressive diagnostic approach, including bronchoalveolar lavage and open lung biopsy, may be necessary to establish a definitive diagnosis prior to institution of therapy.     

Exhaled breath condensate collection in the mechanically ventilated patient

Collection of exhaled breath condensate (EBC) is a non-invasive means of sampling the airway-lining fluid of the lungs. EBC contains numerous measurable mediators, whose analysis could change the management of patients with certain pulmonary diseases. While initially popularized in investigations involving spontaneously breathing patients, an increasing number of studies have been performed using EBC in association with mechanical ventilation. Collection of EBC in mechanically ventilated patients follows basic principles of condensation, but is influenced by multiple factors. Effective collection requires selection of a collection device, adequate minute ventilation, low cooling temperatures, and sampling times of greater than 10?min. Condensate can be contaminated by saliva, which needs to be filtered. Dilution of samples occurs secondary to distilled water in vapors and humidification in the ventilator circuit. Dilution factors may need to be employed when investigating non-volatile biomarkers. Storage and analysis should occur promptly at -70?°C to -80?°C to prevent rapid degradation of samples. The purpose of this review is to examine and describe methodologies and problems of EBC collection in mechanically ventilated patients. A straightforward and safe framework has been established to investigate disease processes in this population, yet technical aspects of EBC collection still exist that prevent clinical practicality of this technology. These include a lack of standardization of procedure and analysis of biomarkers, and of normal reference ranges for mediators in healthy individuals. Once these procedural aspects have been addressed, EBC could serve as a non-invasive alternative to invasive evaluation of lungs in mechanically ventilated patients.     

Interhospital transport of the adult mechanically ventilated patient

Interhospital transport of the adult mechanically ventilated patient may be necessary for those who require specialized care. An experienced medical team can safely transport even the most critically ill patients if the care is optimized before departure. Patients with severe respiratory failure may have to remain on an ICU ventilator throughout the transport period, depending on the specific transport ventilator. Near-terminal ARDS can be treated with ECLS, and these patients also may be safely transported to a regional center.     

Intrahospital transport of the adult mechanically ventilated patient

As the diagnosis and treatment of critically ill patients continues to advance, the frequency of intrahospital transport of ventilator-dependent patients increases. Once the risks and benefits of transport are established, even the sickest ICU patient can be transported safely when adequate time is taken and preparations are made before beginning the transport. Patients should be stabilized as much as possible and monitored before, during, and after transport. Those responsible for the patient should be trained to provide a safe outcome. This necessitates that caregivers receive education in patient evaluation, potential risks, complications, interventions, equipment operation, and troubleshooting that may be necessary when caring for ventilated patients outside the ICU. All members of the transport team should communicate effectively and be aware of their roles in the transport process to minimize delays and mishaps during transport and at the final destination. Written policies that define the level of personnel, level of training, level of support, and equipment necessary can facilitate the transport process. When choosing a device to provide ventilation, the patient's clinical condition should be determine which method is used for transport.     

Dose-dependent rate of nosocomial pulmonary infection in mechanically ventilated patients with brain oedema receiving barbiturates: A prospective case study

Summary In a prospective case study we investigated whether the application of barbiturates in artificially ventilated patients with brain oedema has dose-dependent effects on the rate of nosocomial pneumonia. Pneumonia developed within the first seven days of controlled ventilation in patients receiving barbiturates; furthermore, the rate of nosocomial pneumonia was significantly higher in patients receiving barbiturates than in the control group without barbiturates (7.7%; p<0.0181); thus a clear dose dependency was shown (high-dose group: 43.8%, low-dose group: 21.4%). In all patients with pneumonia, colonization of the respiratory tract with pathogenic organisms preceded the pulmonary infection by four days. Under barbiturate therapy colonization of the respiratory tract occurred in all patients and one or two days earlier than in the control group, in which only 70% of the patients were colonized. These differences were significant for each of the first six days after hospitalization (p<0.0001 -0.013). While in the high-dose group both colonization and pneumonia were caused mainly by gram-positive pathogens, mixed gram-positive and gram-negative pathogens were isolated in groups 2 and 3. Thus the higher rate of pneumonia of 43.8% in the high-dose group suggests a need for regular and semiquantitative monitoring of the causative agents and their antibiogram. Such measures could lead to early recognition with high predictability of the development of nosocomial pneumonia in colonized patients, allowing for timely application of the most appropriate antibiotics.

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Häufigkeit und Dosisabhängigkeit nosokomialer Pneumonien unter Barbiturat-Behandlung bei Patienten mit Hirnödem und künstlicher Beatmung

Zusammenfassung In einer prospektiven Fallstudie untersuchten wir die Frage, ob künstlich beatmete Patienten mit Hirnödem eine erhöhte Quote nosokomialer Pneumonien entwickeln, wenn sie eine hohe bzw. eine niedere Dosis von Barbituraten erhalten, als wenn sie ohne Barbiturate sediert werden. Die Untersuchung zeigte, daß sich nosokomiale Pneumonien innerhalb von sieben Tagen nach Beginn der Beatmung entwickelten, und daß die Quote signifikant höher lag bei der Gruppe der Patienten mit hoher Barbituratdosis (43,8%) gegenüber der Gruppe mit niedriger Barbituratdosis (21,4%) und der Kontrollgruppe ohne Barbituratapplikation (7,7%, p<0,0181). Bei allen Pneumonie-Patienten war eine Kolonisation der Atemwege mit pathogenen Keimen der Infektion um vier Tage vorausgegangen. Unter der Barbiturat-Therapie erschien die 100%ige Kolonisation der Atemwege ein bis zwei Tage früher als bei der Kontrollgruppe. Letztere wurde nur zu 70% kolonisiert. Unterschiede sind für jeden der ersten sechs Tage nach der Hospitalisierung mit p<0,0001 - 0,013 signifikant. Während in der Hochdosis-Gruppe sowohl die Kolonisation wie die Infektion der tiefen Atemwege hauptsächlich durch grampositive Erreger verursacht wurde, lag bei den Gruppen 2 und 3 meist eine Mischflora aus grampositiven und gramnegativen Erregern vor. Die hohe Pneumonierate von 43,8% in der Hochdosis-Gruppe verlangt in Zukunft nach einem regelmäßigen semiquantitativen Monitoring der ursächlichen Erreger und ihres Antibiogramms. Dies ermöglicht ein frühzeitiges Erkennen mit hoher Voraussagekraft einer sich entwickelnden nosokomialen Pneumonie aus der Gruppe der kolonisierten Patienten und den zeitgerechten Einsatz der geeigneten Antibiotika.

     

Fatal non-cardiogenic pulmonary oedema after intravenous non-ionic radiographic contrast

Life-threatening reactions to radiographic contrast media are rare. We describe a case of fatal non-cardiogenic pulmonary oedema, after use of iopamidol, a widely used, low osmolar, non-ionic, radiographic contrast medium. A woman with a history of bladder tumour who had haematuria was referred for an intravenous urogram. After intravenous injection of 100 mL iopamidol, the woman became short of breath, and a chest radiograph showed severe pulmonary oedema. She was treated but subsequently died. The pathogenesis of contrast-induced, non-cardiogenic pulmonary oedema is unclear, and treatment differs from that for cardiogenic pulmonary oedema.     

Anatomically localised re-expansion pulmonary oedema following pneumothorax drainage. Case report and literature review

We describe the 15th recorded case of ipsilateral pulmonary oedema following re-expansion of a pneumothorax. In contrast to previously described cases, the oedema was exclusively confined to the right middle and lower lobes, with complete sparing of the right upper lobe. This strict anatomical localisation can best be explained by the presence of a discrete temporary obstruction of the bronchus intermedius during the critical period of rapid pneumothorax re-expansion. We believe that this case lends strong support to previous contentions that bronchial occlusion plays a crucial role in the genesis of re-expansion oedema.     

Alteration of pulmonary oxygenation by pulmonary artery occluded pressure measurements in mechanically ventilated patients

A significant decrease in PaO2 occurs in some patients during PAOP measurements. To examine the incidence and the types of patients whose PaO2 decreases during PAOP measurements, we studied the changes of PaO2 in 101 anesthetized, mechanically ventilated adult patients. During a 2-min inflation of a PAC balloon, seven patients (6.9 percent) developed marked decrease in PaO2/FIo2 (more than 100 mm Hg). Neither age nor size of patients, decrease in end-tidal CO2, nor baseline value of PAP correlated with the decreases in PaO2. A decrease in PaO2/FIo2 (more than 50 mm Hg) was observed more frequently in female patients and in patients with cardiac disease, especially those whose PAP values were above normal. Although a significant decrease in PaO2 during PAOP measurements does not appear to occur often, our results suggest that the changes in PaO2 should be evaluated in patients with severely compromised pulmonary oxygenation.     

Indications for manual lung hyperinflation (MHI) in the mechanically ventilated patient with chronic obstructive pulmonary disease

Manual lung hyperinflation (MHI) can enhance secretion clearance, improve total lung/thorax compliance and assist in the resolution of acute atelectasis. To enhance secretion clearance in the intubated patient, the evidence highlights the need to maximize expiratory flow. Chronic pulmonary diseases such as chronic obstructive pulmonary disease (COPD) have often been cited as potential precautions and/or contra-indications to the use of manual lung hyperinflation (MHI). There is an absence of evidence on the effects of MHI in the patient with COPD. Research on the effects of mechanical ventilation in the patient with COPD provides a useful clinical examination of the effect of positive pressure on cardiac and pulmonary function. The potential effects of MHI in the COPD patient group were extrapolated on the basis of the MHI and mechanical ventilation literature. There is the potential for MHI to have both detrimental and beneficial effects on cardiac and pulmonary function in patients with COPD. The potential detrimental effects of MHI may include either, increased intrinsic peep through inadequate time for expiration by the breath delivery rate, tidal volume delivered or through the removal of applied external PEEP thereby causing more dynamic airway compression compromising downward expiratory flow, which may also retard bronchial mucus transport. MHI may also increase right ventricular after load through raised intrathoracic pressures with lung hyperinflation, and may therefore impair right ventricular function in patients with evidence of cor pulmonale. There is the potential for beneficial effects from MHI in the intubated COPD patient group (i.e., secretion clearance), but further research is required, especially on the effect of MHI on inspiratory and expiratory flow rate profiles in this patient group. The more controlled delivery of lung hyperinflation through the use of the mechanical ventilator may be a more optimal means of providing lung hyperinflation and should be further investigated.     

Medical management and therapy of bronchopleural fistulas in the mechanically ventilated patient

Bronchopleural fistulas are associated with high morbidity and mortality and are particularly challenging in the ventilated patient. Familiarity with both basic and more technical medical management techniques may lessen morbidity and improve survival. Prompt recognition of BPFs and appropriate placement of a chest tube with an adequate suction device are crucial to prevent potential tension pneumothorax and to drain an infected pleural space. The chest tube may be used therapeutically to decrease BPF air leak and to promote fistula repair. Appropriate conventional ventilator manipulations aimed at decreasing fistula air leak and maintaining adequate oxygenation and ventilation may fail and necessitate a trial of HFV. Definitive therapy by the bronchoscopic application of a sealing agent to occlude the fistula site can be used, particularly in the poor surgical candidate.     

Recurrent re-expansion pulmonary edema

A unique patient is described who experienced two episodes of pulmonary edema following re-expansion of two left pneumothoraces occurring months apart. Successful surgical treatment was carried out at thoracotomy. Factors regarding pathogenesis are discussed.     

Bilateral pleural effusion and a subsegmental infiltrate due to Chlamydia pneumoniae in a mechanically ventilated patient

A case of Chlamydia pneumoniae infection with bilateral pleural effusion and a subsegmental pulmonary infiltrate in an intubated and mechanically ventilated critically ill patient is described. Diagnosis was made by polymerase chain reaction on both pleural effusions.     

Pneumothorax due to ball-valve obstruction of an endotracheal tube in a mechanically ventilated patient.

Barotrauma is a well-known complication of mechanical ventilation, thought to be related to alveolar rupture from localized hyperinflation. Mishaps related to endotracheal intubation can lead to barotrauma such as inadvertent intubation of the right mainstem bronchus. In this report, we describe pneumothorax as a consequence of ball-valve occlusion, a previously undescribed endotracheal tube malfunction.     

Tracheal intubation in mechanically ventilated patients

Airway management is an important skill in the care of patients undergoing mechanical ventilation. This article reviews the available techniques of tracheal cannulation and describes common complications, preferred routes of intubation, and approaches to weaning.