Cardiopulmonary Interactions during Positive Pressure Ventilation

Positive pressure ventilation (PPV) may lead to significant hemodynamic alterations. The cardiocirculatory effects of PPV occur through alterations in the loading conditions of the right and left ventricle and are mediated by changes in intrathoracic pressures and in lung volume. However, the net effect of PPV on cardiac output and hemodynamics is not always predictable. PPV may lead to either a decrease or an increase in cardiac performance. The cardiac consequences of PPV are also dependent on baseline loading conditions and contractile function of the heart

The mapping of emotions in a respiratory illness: transferability of illness experience from Pulmonary Arterial Hypertension to COVID-19

Objectives: Covid-19 poses an existential threat that has increased death anxiety at the individual and societal levels. In prior work, we have examined existential conversations in patients with Pulmonary Arterial Hypertension (PAH), an incurable respiratory disease with symptom overlap. In this mixed method study, we analyse the emotional qualities of these conversations in PAH. By understanding the emotions in PAH, we may learn something about the feelings that can also be evoked in people coping with Covid-19. Methods: We interviewed 30 PAH patients from 2016-2018 about the meaning and impact of illness on their lives. We analysed transcripts and audio recordings for heightened emotional moments and categorised the emotional responses and topics that were discussed. A multiple correspondence analysis was conducted to identify the associations between emotions and topics. Clini cal illustrations are provided for interpretation. Results: Mean age and illness duration was 52 and 6 years, and 77% were female. Participants had a mean of 5 emotional moments, each lasting on average 20 seconds. Half occurred in the first 20 minutes. Coping with diagnosis and the healthcare system was accompanied by feelings of shock and unfairness; relational issues involving close others evoked complicated feelings of isolation, worthlessness, and self-blame; and the experience of physical limitations and mortality salience elicited much anger and fear. Conclusion: People confronted by the threat of mortality from disease may have powerful feelings that they would benefit from sharing. These emotions are readily expressed because opportunities to discuss them are rare. Psychoeducation about illness experiences may help healthy people to relate to the medically ill and destigmatise the discussion of illness-related concerns. Research on coping with existential distress may be applied to the illness experience of Covid-19

Clinically important deep vein thrombosis in the intensive care unit: a survey of intensivists

INTRODUCTION: Outside the intensive care unit (ICU), clinically important deep vein thrombosis (DVT) is usually defined as a symptomatic event that leads to objective radiologic confirmation and subsequent treatment. The objective of the present survey is to identify the patient factors and radiologic features of lower limb DVT that intensivists consider more or less likely to make a DVT clinically important in ICU patients. METHODS: Our definition of clinically important DVT was a DVT likely to result in short-term or long-term morbidity or mortality if left untreated, as opposed to a DVT that is unlikely to have important consequences. We asked respondents to indicate the likelihood that patient factors and ultrasonographic features make a DVT clinically important using a five-point scale (from 1 = much less likely to 5 = much more likely). RESULTS: Of the 71 Canadian intensivists who responded, 70 (99%) rated three patient factors as most likely to make a DVT clinically important: clinical suspicion of pulmonary embolism (mean score 4.6), acute or chronic cardiopulmonary morbidity that might limit a patient's ability to tolerate pulmonary embolism (score 4.5), and leg symptoms (score 4.2). Of the ultrasound features, proximal (score 4.7), large (score 4.2), and totally occlusive (score 3.9) thrombi were considered the three most important. CONCLUSION: When labeling a DVT as clinically important, intensivists rely on different patient specific factors and thrombus characteristics than are used to assess the clinical importance of DVT outside the ICU. The clinical importance of DVT is influenced by unique factors such as cardiopulmonary reserve among mechanically ventilated patients

Critical care procedure logging using handheld computers

INTRODUCTION: We conducted this study to evaluate the feasibility of implementing an internet-linked handheld computer procedure logging system in a critical care training program. METHODS: Subspecialty trainees in the Interdepartmental Division of Critical Care at the University of Toronto received and were trained in the use of Palm handheld computers loaded with a customized program for logging critical care procedures. The procedures were entered into the handheld device using checkboxes and drop-down lists, and data were uploaded to a central database via the internet. To evaluate the feasibility of this system, we tracked the utilization of this data collection system. Benefits and disadvantages were assessed through surveys. RESULTS: All 11 trainees successfully uploaded data to the central database, but only six (55%) continued to upload data on a regular basis. The most common reason cited for not using the system pertained to initial technical problems with data uploading. From 1 July 2002 to 30 June 2003, a total of 914 procedures were logged. Significant variability was noted in the number of procedures logged by individual trainees (range 13–242). The database generated by regular users provided potentially useful information to the training program director regarding the scope and location of procedural training among the different rotations and hospitals. CONCLUSION: A handheld computer procedure logging system can be effectively used in a critical care training program. However, user acceptance was not uniform, and continued training and support are required to increase user acceptance. Such a procedure database may provide valuable information that may be used to optimize trainees' educational experience and to document clinical training experience for licensing and accreditation

Prophylactic anticoagulation to prevent venous thromboembolism in traumatic intracranial hemorrhage: a decision analysis

Abstract Introduction Patients with intracranial hemorrhage due to traumatic brain injury are at high risk of developing venous thromboembolism including deep vein thrombosis (DVT) and pulmonary embolism (PE). Thus, there is a trade-off between the risks of progression of intracranial hemorrhage (ICH) versus reduction of DVT/PE with the use of prophylactic anticoagulation. Using decision analysis modeling techniques, we developed a model for examining this trade-off for trauma patients with documented ICH. Methods The decision node involved the choice to administer or to withhold low molecular weight heparin (LMWH) anticoagulation prophylaxis at 24 hours. Advantages of withholding therapy were decreased risk of ICH progression (death, disabling neurologic deficit, non-disabling neurologic deficit), and decreased risk of systemic bleeding complications (death, massive bleed). The associated disadvantage was greater risk of developing DVT/PE or death. Probabilities for each outcome were derived from natural history studies and randomized controlled trials when available. Utilities were obtained from accepted databases and previous studies. Results The expected value associated with withholding anticoagulation prophylaxis was similar (0.90) to that associated with the LMWH strategy (0.89). Only two threshold values were encountered in one-way sensitivity analyses. If the effectiveness of LMWH at preventing DVT exceeded 80% (range from literature 33% to 82%) our model favoured this therapy. Similarly, our model favoured use of LMWH if this therapy increased the risk of ICH progression by no more than 5% above the baseline risk. Conclusions Our model showed no clear advantage to providing or withholding anticoagulant prophylaxis for DVT/PE prevention at 24 hours after traumatic brain injury associated with ICH. Therefore randomized controlled trials are justifiable and needed to guide clinicians

The Characteristics of Treated Pulmonary Arterial Hypertension Patients in Ontario

Background. There are no Canadian prevalence studies on pulmonary arterial hypertension (PAH) to date. We described the characteristics of treated PAH patients and the healthcare utilization and costs associated with PAH in a population of public drug plan beneficiaries in Ontario, Canada. Methods. A retrospective cross-sectional analysis was conducted between April 2010 and March 2011 to identify treated PAH patients using population-based health administrative databases. We investigated demographic and clinical characteristics of treated PAH patients and conducted a cohort study to determine treatment patterns, healthcare utilization, and associated costs, over a one-year follow-up period (March 2012). Results. We identified 326 treated PAH cases in Ontario’s publicly funded drug plan. Overall mean age was 59.4 years (±20.3 years) and over 77% of cases were women (n=251). Combination therapy was used to treat 22.9% (n=69) of cases, costing an average of $4,569 (SD$1,544) per month. Median monthly healthcare costs were $264 (IQR$96–$747) for those who survived and$2,021 (IQR $993–$6,399) for those who died over a one-year period, respectively (p<0.01). Conclusions. PAH care in Ontario is complex and has high healthcare costs. This data may help guide towards improved patient management

The Pressure-Adjusted Rate (PAR) a simple and valid descriptor of the cardiovascular dysfunction of mods

123AIntroduction: Description of altered cardiovascular function in the Multiple Organ Dysfunction Syndrome (MODS) has been unsatisfactory. By analogy to the PaO2/FIO2 ratio as a measure of physiologic derangement corrected for therapy, we developed a simple composite measure termed the PAR, the product of the heart rate and the ratio of the mean arterial to central venous pressure (HRxCVP/MAP). We evaluated the PAR as a measure of cardiovascular dysfunction in the ICU