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Driving Pressure and Survival in the Acute Respiratory Distress Syndrome Marcelo B.P. Amato, M.D., Maureen O. Meade, M.D., Arthur S. Slutsky, M.D., Laurent Brochard, M.D., Eduardo L.V. Costa, M.D., David A. Schoenfeld, Ph.D., Thomas E. Stewart, M.D., Matthias Briel, M.D., Daniel Talmor, M.D., M.P.H., Alain Mercat, M.D., Jean-Christophe M. Richard, M.D., Carlos R.R. Carvalho, M.D., and Roy G. Brower, M.D. N Engl J Med 2015; 372:747-755 February 19, 2015 DOI: 10.1056/NEJMsa1410639 BACKGROUND Mechanical-ventilation strategies that use lower end-inspiratory (plateau) airway pressures, lower tidal volumes (V T ), and higher positive end-expiratory pressures (PEEPs) can improve survival in patients with the acute respiratory distress syndrome (ARDS), but the relative importance of each of these components is uncertain. Because respiratory-system compliance (C RS ) is strongly related to the volume of aerated remaining functional lung during disease (termed functional lung size)...
Hepatopulmonary syndrome: Due to vascular dilation at the pre- and post-capillary level therefore decreased VQ ratio Intrapulmonary vasodilation with R to left shunting mainly affecting the basal area,so it worsen with sitting up due to increas basal blood flow Diagnostic criteria: Chronic liver disease +\- chirosis Arterial hypoxaemia PaO2 < 75 or Aa gradient > 20 Intrapulmonary vascular dilation Diagnose with contrast echo. Agitated saline injected IV. Immediate visualisation in L heart intracardiac shunt. Delayed visualisation means intrapleural shunt Medical management disappointing It s indication for transplant with resolution usual in the months afterwards. However, the more hypoxic the greater the perioperative risk Porto-pulmonary hypertension: Diagnostic criteria: Portal hypertension Mean pulmonary artery pressure > 25 Pulmonary...
An association between HIV infection and pulmonary arterial hypertension was first reported in 1991. ► In population studies in which ECHO was used to estimate PA pressure, the incidence of PH ~0.5 % among patients with HIV infection ► a rate 6 to 12 times as high as in the general population. ► prevalence has not changed since 1991 despite the introduction of HAART The occurrence of pulmonary arterial hypertension is independent of the CD4 cell count, but it appears to be related to the duration of HIV infection. Many of these patients also have foreign-body emboli as a result of the use of intravenous drugs or portal hypertension due to a concomitant infection with hepatitis B or C. Still under discussion if HIV does directly infect endothelial cells, the mech...
Injury Mechanism Minimisation Strategy Volutrauma Non-homogenous lung injury Over-distension of normal alveolar units to trans- pulmonary pressures above ~30 cm H 2 O (that corresponds to approximate total lung volume) causes basement membrane stretch and stress on intracellular junctions. Avoid over-distending the “baby lung” of ARDS: (a) Maintain Plateau Airway pressure under 30 cm H20 (b) Use Tidal volumes 6ml/kg (4- 8ml/kg) Good evidence to support this strategy (ARDSNet) Barotrauma Increasing the trans-pulmonary pressures above 50 cm H 2 O will cause disruption of the basement membranes with classical barotrauma Biotrauma Mechanotransduction and tissue disruption leads to upregulation and release of chemokines and cytokines with subsequent WBC attraction and activation resulting in pulmonary and systemic inflammatory response and multi-organ dysfunction ...
Tracheostomy has a mortality rate of <1% but has a total complications rate as high as 40%. The complication rate is higher in the ICU and emergency patients. The complications can be divided into: 1- Immediate *Hemorrhage *Tube misplacement (e.g. into main bronchus) *Occlusion of tube by cuff herniation *Occlusion of the tube tip against carina or tracheal wall *Pneumnothorax 2-Delayed *Blockage of the tube by secretions which can be sudden or gradual; this is rare with adequate humidification and suction *Infection of the stoma *Overinflation of the cuff leads to ulceration and distension of the trachea *Mucosal ulceration because of excessive cuff pressures, asymmetrical inflation of the cuff or tube migration 3-Late *Granulomata of the trachea may cause respiratory difficulty after extubation *Persistent sinus at the tracheostomy site *Tracheal dilation *Trache...
Physiological Variables Associated with Successful Resuscitation Variables Amount Myocardial blood flow 15-20 mL/min/100 g Arterial diastolic pressure 40 mm Hg Coronary perfusion pressure 15-25 mm Hg End-tidal carbon dioxide >10 mm Hg
There is a general belief that PN formulations require tapering. Rebound hypoglycemia is rarely seen but is often discussed in the clinical setting . The risk is very low, even in patients with diabetes mellitus, as they are somewhat “protected” by inherent insulin deficiency. Stopping PN is the same as stopping an independent insulin drip; remember, the half-life of regular insulin is only 5 minutes (although, somewhat longer if the patient is in renal failure). A taper down of PN is not needed, especially if the patient is receiving another dependable source of carbohydrate. If a particular patient is prone to hypoglycemia, tapering PN over 1–2 hours before discontinuation is justified and can avoid this problem. Eisenberg PG, Gianino S, Clutter WE, et al. Abrupt discontinuation of cycled parenteral nutrition is safe. Dis Colon Rectum, 1995; 38 (9):933-939. Krzywda EA, Andris DA, Whipple JK, et al. Glucose response to abrupt initiation and discont...
Delirium in the Critically Ill Delirium has been shown to be an independent predictor of mortality and can occur in up to 75% of critically ill patients. Whether preventing or treating delirium in the critically ill patient, consider the following: Minimize the use of anticholinergic medications (i.e. diphenhydramine, chlorpromazine) Ensure pain is adequately controlled (avoid meperidine and tramadol) Be careful with sedative medications; consider bolus dosing and daily interruption of continuous infusions Additional measures to treat delirious patients include reducing sensory deprivation, promoting normal sleep-wake cycles, early physical rehabilitation, and treating psychosis
There have been a number of publications looking at the pre-operative optimisation of oxygen delivery for high risk patients. They are based on studies showing that high-risk patients surviving major surgery achieved consistently higher postoperatrive oxygen delivery and cardiac index compared with non-survivors. Shoemaker showed the following values to be associated with survival: Cardiac Idex (CI) 4.5 l/min/m2 Oxygen delivery (DO2) 600 ml/min/m2 Oxygen consumption (VO2) 170 ml/min/m2 Shoemaker et al . in 1987 and Boyd et al . in 1993 showed that producing supranormal values of oxygen delivery(>600 ml/min/m2) resulted in a reduction in pot-operative mortality in high risk surgical patients. A paper in Critical Care Medicine in 2000 (prospective, randomized controlled trial of 412 patients undergoing major abdominal surgery in 13 hospitals from ...
Three subtypes of HIT: 1. Typical or classical onset HIT. Typically, the platelet count falls gradually starting 5 to 10 days (up to 2 weeks) after the initiation of heparin. Thrombocytopenic levels may not occur until several days later. 2. Early or rapid-onset HIT. In some cases, thrombocytopenia may occur abruptly within 5 days of heparin therapy. The rapid onset suggests exposure to heparin within the past 3 months and the presence of circulating HIT antibodies. Since the antibodies are already present, thrombocytopenia may occur promptly with heparin administration. 3. Delayed-onset HIT. Although rare, thrombocytopenia may occur from several days to more than a month after cessation of heparin. Such patients may have high titers of HIT antibody.
Blood pressure (BP) = Cardiac output (CO) x systematic vascular resistance (SVR) IS CO REDUCED? Yes No BP 90/70 mm Hg 90/40 mm Hg Skin Cool, blue Warm, pink Nail bed return Slow Rapid Heart sounds Muffled Crisp History/lab Hypervolemic or cardiogenic etiology or WBC and/or temperature Source of infection Immune compromise Severe liver disease Working diagnosis See next question Septic shock/endotoxemia IS THE HEART TOO FULL? Yes No Presentation Angina, dyspnea Hemorrhage, dehydration Signs Cardiomegaly Dry mucous membranes Extra heart sounds tissue turgor JVP Stool, gastric blood Lab ECG, x-ray hematocrit Echocardiogram BUN/creatinine Working diagnosis Cardiogenic shock Hypovolemic shock WHAT DOES NOT FIT? Cardiac tamponade Anaphylaxis Acute pulmonary hypertension Spinal shock Right ventricular infarction Adrenal insufficiency Overlapping multiple etiologies
Two recently presented abstracts at the 2012 Society of Critical Care Medicine conference suggest that the combination of vancomycin and piperacillin-tazobactam may lead to acute kidney injury (AKI) in the critically ill. There may also be evidence to suggest that piperacillin-tazobactam alone increases the risk of AKI. Both abstracts retrospectively compared patients who received either vancomycin alone or the combination of vancomycin and piperacillin-tazobactam. In both studies, the rates of AKI were significantly lower in patients treated with vancomycin alone as compared to patients receiving both vancomycin and piperacillin-tazobactam. Bottom line: Although the current evidence does not support a change in our clinical practice, more prospective studies exploring this topic are necessary. Min, et al. Acute Kidney Injury in Patients Recieving Concomitant Vancomycin and Piperacillin/Tazobactam . Critical Care Medicine. December 2011. 39(12); p 200 Hellwig, ...
Maybe it’s the surgeons who are tired of consulting us for “vent management,” and finding out we can’t get patients off the vent any faster than they can without our help. Anyway, some troublemakers in Germany (Dirk Schadler et al) found that among 300 patients in surgical intensive care units (SICUs), an automatically-weaning ventilator was as good as human beings using a ventilator weaning protocol at liberating patients from mechanical ventilation. What They Did Authors randomized 300 post-surgical patients at 3 SICUs at one hospital in Kiel, Germany after they had been on 9 hours of mechanical ventilation to one of two weaning strategies. Half were managed with standard ventilator-weaning protocols, managed by physicians and respiratory therapists. Half had a switch on their ventilators (Evita XL) flipped to enable the SmartCare software embedded into it. This software automatically adjusts the pressure support delivered in response to patient ef...
VAP is defined as pneumonia that occurs more than 48 to 72 hours after endotracheal intubation. Although the incidence of VAP is poorly defined, an estimated 9 to 27% of all intubated patients develop VAP. The estimated risk of VAP is 3% per day during the first 5 days of ventilation, 2% per day during days 5 to 10, a and 1% per day thereafter. 2004 American Thoracic Society - Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia. Am. J. Respir. Crit. Care Med . 2005;171(4):388-416. Available at: http://www.ncbi.nlm.nih.gov/pubmed/15699079 [Accessed June 3, 2009].
Taking care of Drowning patient in ICU Treat drowning victims as ARDS patients, with low tidal-volume lung-protective mechanical ventilation. Not weaning mechanical ventilation for at least 24 hours, even if a drowning victim appears ready to extubate: the underlying pulmonary injury may result in recurrence of pulmonary edema, reintubation and increased risk of complications. Pneumonia is usually not present initially (12% in one series) and authors believe antibiotics may be over-prescribed and sometimes harmful; instead, use clinical evidence of infection or bronchoscopic / mini-BAL sampling to identify pneumonia and need for antibiotics. Swimming pool water in particular is unlikely to cause pneumonia. On the other hand, late-onset nosocomial pneumonias (i.e., ventilator-associated pneumonia) may be equally common among mechanically ventilated drowning victims as those with other causes of respiratory failure. Systemic inflammatory response syndrome (SIRS) can occur ...
Drowning is uncommon but by no means rare in the U.S.: it’s the second leading cause of death by injury in the U.S. among toddlers (3 per 100,000 among children aged 1 to 4), and you are 200 times more likely to die by drowning during a boat ride as to die from trauma during a trip by automobile. Drowning kills about 500,000 people a year worldwide, according to the WHO. What happens? We can only hold our breath for about a minute. Eventually, a person submerged in water gasps for air, aspirates water, and starts coughing as a reflex response; continued aspiration follows. Hypoxemia leads to unconsciousness, apnea, and cardiac decompensation: tachycardia, then bradycardia, pulseless electrical activity (PEA), then asystole. From the last breath of air to final cardiac arrest, drowning may take less than a minute, to several minutes. Colder water (hypothermia) slows the entire process. Patient in ER... Recognize that only 6% of people rescued by lifeguar...
Your patient has a central venous catheter inadvertently placed in his carotid. Do you pull-and-push? This small case series suggests leaving it in and getting vascular repair is a better approach. Below is the Summary.. Background Percutaneous catheterization is a frequently-used technique to gain access to the central venous circulation. Inadvertent arterial puncture is often without consequence, but can lead to devastating complications if it goes unrecognized and a large-bore dilator or catheter is inserted. The present study reviews our experience with these complications and the literature to determine the safest way to manage catheter-related cervicothoracic arterial injury (CRCAI). Methods We retrospectively identified all cases of iatrogenic carotid or subclavian injury following central venous catheterization at three large institutions in Montreal. We reviewed the French and English literature published from 1980 to 2006, in PubMed, and selected stu...
Central lines terminating in the superior vena cava (i.e. internal jugular and subclavian placement) can also be used to determine the central venous oxygenation (Scv O 2 ), as part of the EGDT protocol. An Scv O 2 of less than 70% would be an indicator that oxygen delivery to tissues is not matching the demand, and that further interventions are needed such as 1) Intubation to increase PaO 2 , 2) Blood transfusion to achieve a Hct of ≥ 30%, 3) Initiation of an inotrope, usually Dobutamine. While S cv O 2 was shown to correlate with mixed venous oxygenation Sv O 2 obtained from a pulmonary artery catheter, peripheral venous blood gases (VBG) are not good indicators of systemic oxygen extraction. Lactic acid has recently gained interest as a possible substitute for Scv O 2 to determine adequate delivery of oxygen to tissues. A study by Jones et al has shown that a lactic acid clearance of more than 10% at least ...
Sympathetic storming after traumatic brain injury remains one of the most dramatic clinical scene particularly in neurological units. It occurs due to uncontrolled sympathetic surge with a diminish or unmatch parasympathetic response. According to Baguley criteria 5 out of the 7 clinical features should be present - tachycardia, tachypnea, hyperthermia, hypertension, dystonia, posturing, and diaphoresis. Various agents have been used for treatment like clonidine and Benzos (article below) but haloperidol may worsen the symptoms. Dr. Blackman and coll. coined the term "PAID" - paroxysmal autonomic instability with dystonia- in Archives of Neurology March 2004. Please Click below to Read more about PAID.. Click Here