Outcome in patients perceived as receiving excessive care across different ethical climates: a prospective study in 68 intensive care units in Europe and the USA.

PURPOSE: Whether the quality of the ethical climate in the intensive care unit (ICU) improves the identification of patients receiving excessive care and affects patient outcomes is unknown. METHODS: In this prospective observational study, perceptions of excessive care (PECs) by clinicians working in 68 ICUs in Europe and the USA were collected daily during a 28-day period. The quality of the ethical climate in the ICUs was assessed via a validated questionnaire. We compared the combined endpoint (death, not at home or poor quality of life at 1 year) of patients with PECs and the time from PECs until written treatment-limitation decisions (TLDs) and death across the four climates defined via cluster analysis. RESULTS: Of the 4747 eligible clinicians, 2992 (63%) evaluated the ethical climate in their ICU. Of the 321 and 623 patients not admitted for monitoring only in ICUs with a good (n = 12, 18%) and poor (n = 24, 35%) climate, 36 (11%) and 74 (12%), respectively were identified with PECs by at least two clinicians. Of the 35 and 71 identified patients with an available combined endpoint, 100% (95% CI 90.0-1.00) and 85.9% (75.4-92.0) (P = 0.02) attained that endpoint. The risk of death (HR 1.88, 95% CI 1.20-2.92) or receiving a written TLD (HR 2.32, CI 1.11-4.85) in patients with PECs by at least two clinicians was higher in ICUs with a good climate than in those with a poor one. The differences between ICUs with an average climate, with (n = 12, 18%) or without (n = 20, 29%) nursing involvement at the end of life, and ICUs with a poor climate were less obvious but still in favour of the former. CONCLUSION: Enhancing the quality of the ethical climate in the ICU may improve both the identification of patients receiving excessive care and the decision-making process at the end of life.

Esophageal pressure: research or clinical tool?

Esophageal manometry has traditionally been utilized for respiratory physiology research, but clinicians have recently found numerous applications within the intensive care unit. Esophageal pressure (PEs) is a surrogate for pleural pressures (PPl), and the difference between airway pressure (PAO) and PEs provides a good estimate for the pressure across the lung also known as the transpulmonary pressure (PL). Differentiating the effects of mechanical ventilation and spontaneous breathing on the respiratory system, chest wall, and across the lung allows for improved personalization in clinical decision making. Measuring PL in acute respiratory distress syndrome (ARDS) may help set positive end expiratory pressure (PEEP) to prevent derecruitment and atelectrauma, while assuring peak pressures do not cause over distension during tidal breathing and recruitment maneuvers. Monitoring PEs allows improved insight into patient-ventilator interactions and may help in decisions to adjust sedation and paralytics to correct dyssynchrony. Intrinsic PEEP (auto-PEEP) may be monitored using esophageal manometry, which may also improve patient comfort and synchrony with the ventilator. Finally, during weaning, PEs may be used to better predict weaning success and allow for rapid intervention during failure. Improved consistency in definition and terminology and further outcomes research is needed to encourage more widespread adoption; however, with clear clinical benefit and increased ease of use, it appears time to reintroduce basic physiology into personalized ventilator management in the intensive care unit.

An Official American Thoracic Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine Clinical Practice Guideline: Mechanical Ventilation in Adult Patients with Acute Respiratory Distress Syndrome

BACKGROUND: This document provides evidence-based clinical practice guidelines on the use of mechanical ventilation in adult patients with acute respiratory distress syndrome (ARDS). METHODS: A multidisciplinary panel conducted systematic reviews and metaanalyses of the relevant research and applied Grading of Recommendations, Assessment, Development, and Evaluation methodology for clinical recommendations. RESULTS: For all patients with ARDS, the recommendation is strong for mechanical ventilation using lower tidal volumes (4-8 ml/kg predicted body weight) and lower inspiratory pressures (plateau pressure < 30 cm H2O) (moderate confidence in effect estimates). For patients with severe ARDS, the recommendation is strong for prone positioning for more than 12 h/d (moderate confidence in effect estimates). For patients with moderate or severe ARDS, the recommendation is strong against routine use of high-frequency oscillatory ventilation (high confidence in effect estimates) and conditional for higher positive end-expiratory pressure (moderate confidence in effect estimates) and recruitment maneuvers (low confidence in effect estimates). Additional evidence is necessary to make a definitive recommendation for or against the use of extracorporeal membrane oxygenation in patients with severe ARDS. CONCLUSIONS: The panel formulated and provided the rationale for recommendations on selected ventilatory interventions for adult patients with ARDS. Clinicians managing patients with ARDS should personalize decisions for their patients, particularly regarding the conditional recommendations in this guideline.

OS094. Subclinical left ventricular dysfunction in preeclamptic women with preserved left ventricular ejection fraction: A 2D speckle tracking imaging study.

INTRODUCTION: Patients with preeclampsia are at risk for cardiovascular disease [1,2]. Changes in cardiac function are subtle in preeclampsia and are quantitatively difficult with conventional imaging. Strain measurements using speckle-tracking echocardiography have been used to sensitively quantifyabnormalities in other disease settings [3]. OBJECTIVES: The objective of this study was to evaluate changes in myocardial strain using speckle tracking echocardiography in women with and without preeclampsia. We hypothesized that global left systolic strain measures would prove more sensitive than conventional left ventricular ejection fraction in detecting early changes in systolic LV function manifesting as subclinical disease prior to overt progression. METHODS: We evaluated the feasibility and sensitivity of strain imaging using speckle tracking echocardiography. Thirty-six women were enrolled in this pilot study; 28 were analyzed: 11 with preeclampsia and 17 without preeclampsia. Echocardiographic Ejection fraction and global peak longitudinal ,radial and circumferential strain were measured. RESULTS: Global Median longitudinal strain was significantly worsened in women with preeclampsia compared to women without preeclampsia (P<0.0001). Similar results were observed for global radial strain (P=0.006) and circumferential strain (P=0.03). There was no significant difference in ejection fraction between the groups (P=0.52) (Table 1). Data are presented as median (interquartile range). CONCLUSION: Myocardial strain imaging using speckle tracking is more sensitive than left ventricular ejection fraction to detect differences in left ventricular systolic function in women with and without preeclampsia.

Targeting transpulmonary pressure to prevent ventilator induced lung injury.

Acute respiratory distress syndrome (ARDS) and ventilator induced lung injury (VILI) continue to challenge clinicians who care for the critically ill. Current research in ARDS has focused on ventilator strategies to improve the outcome for these patients. In this review, we emphasize the limitations of managing ventilators based on airway pressures alone. Specifically, basic pulmonary mechanics including chest wall compliance and transpulmonary pressure are reviewed. This review suggests that perturbations in chest wall compliance and transpulmonary pressure may explain the lack of efficacy observed in recent clinical trials of ventilator management. We present a method for estimating pleural and transpulmonary pressures from esophageal manometry. Quantifying these variables and individualizing ventilator management based on individual patient physiology may be useful to intensive care clinicians who treat patients with ARDS.

Persistent hypoxia after diagnosis and treatment of pulmonary thromboembolism.

Acute respiratory failure in the perioperative period represents a frequent challenge to the anesthesiologist. The differential diagnosis is extensive and includes alterations on the pulmonary parenchyma, pulmonary vessels, airway, and cardiac system. Occasionally, two or more pathophysiological process superimpose. We present a patient who suffered from a left pulmonary embolism that was appropriately diagnosed and treated. However, the hypoxemia persisted and a second pathology was suspected. After careful evaluation and differential diagnosis, we drained a right pleural effusion, which had been present preoperatively, with resolution of the hypoxemia. There is controversy in the literature as to the role of drainage of pleural effusions on improving oxygenation. We present this case as an example of successful management of perioperative respiratory failure by thoracentesis in the presence of a second concurrent pathologic process.

Activation of mitogen-activated protein kinases in human heart during cardiopulmonary bypass.

Mitogen-activated protein kinases (MAPKs) have been shown to be activated in both in vitro and in vivo models of cardiac tissue in response to ischemia/reperfusion injury. We investigated whether MAPKs are activated in human heart during coronary artery bypass grafting (CABG) surgery. During elective CABG surgery of 8 patients, 3 right atrial appendage biopsies were obtained at baseline, at the end of cross-clamping, and after coronary reperfusion. The expression of the p38-MAPK, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinases (ERK1/2) MAPKs was not altered during CABG. The phosphorylation and activation of both ERK1/2 and p38-MAPK were increased approximately 2-fold by ischemia and even more (8- and 4-fold, respectively) by reperfusion. Although the ischemic period did not result in a significant activation of JNK, an approximately 6-fold increase in JNK activity could be observed after reperfusion. In conclusion, distinct activation patterns of ERK1/2, p38, and JNK MAPKs can be observed in human heart during CABG.

Inhibition of cyclooxygenase 2 by nimesulide decreases prostaglandin E2 formation but does not alter brain edema or clinical recovery after closed head injury in rats.

Recently, the enzyme cyclooxygenase (COX) has been recognized to exist as constitutive (COX-1) and inducible isoforms (COX-2). In previous studies, drugs that were inhibitors of both COX-1 and COX-2 failed to decrease brain edema formation or improve Neurological Severity Score (NSS) after closed head trauma (CHT), although some did decrease prostaglandin-E2 (PGE2) formation. The present study examined whether or not a specific inhibitor of COX-2 (nimesulide) exerts a beneficial effect after CHT in rats. Halothane-anesthetized rats (n = 8 in each group) were randomly assigned to one of four groups: surgery, no CHT, no drug (group 1); surgery, no CHT, nimesulide 30 mg/kg intraperitoneally (IP) (group 2); surgery, CHT, no drug (group 3); and surgery, CHT, nimesulide 30 mg/kg IP (group 4). NSS was determined at 1 and 24 h, and brain tissue PGE2 concentration and water content were determined after killing at 24 h. Treatment with nimesulide did not improve NSS (NSS at 24 h = 11+/-6 [median +/- range] in group 3 and 12+/-4 in group 4) or edema formation (brain water content at 24 h = 84.3+/-1.8% [mean +/- SD] in group 3 and 83.8+/-1.9% in group 4). However, nimesulide did decrease cortical and hypothalamic PGE2 formation by 41% and 47%, respectively during the first hour of incubation after brain tissue sampling. The authors conclude that although nimesulide does reduce tissue PGE2 formation, it does not exert a beneficial effect on brain tissue edema or functional activity after CHT in rats.

Albumin or hetastarch improves neurological outcome and decreases volume of brain tissue necrosis but not brain edema following closed-head trauma in rats.

The present study examined whether hemodilution with 20% human serum albumin (HSA) or 10% hydroxyethyl starch (HES) improved the outcome from closed-head trauma (CHT) in rats. Rats anesthetized with halothane were given one of three hemodilution solutions (i.e., 20% HSA, 10% HES, or control [0.9% saline]) after CHT or sham surgery. CHT was delivered using a weight drop impact of 0.5 J onto the closed cranium. The hemodilution solution (volume = 1% of body weight) was given just after determining the neurological severity score (NSS) at 1 hour following CHT. The NSS was determined again at 24, 48, and 72 hours following CHT. At 72 hours, brains were removed, and brain edema and brain tissue necrosis volume were determined. Solutions of 20% HSA and 10% HES significantly improved brain tissue necrosis volume (143 +/- 72 mm3 and 104 +/- 53 mm3 as compared to 271 +/- 65 mm3 in controls, mean +/- SD) and NSS (12 +/- 2 and 9 +/- 2 as compared to 15 +/- 2 in controls at 72 hours, median +/- range) but not brain edema. The hematocrit decreased similarly in all groups during hemodilution. Hemodilution with 20% HSA and 10% HES following CHT in rats did not decrease brain edema but did decrease brain tissue necrosis volume and NSS (improved neurological function), suggesting that the beneficial effect of hemodilution resulted not from decreased edema formation but rather from effects not measured in this study such as improved perfusion of the salvageable brain tissue surrounding the core injury.

Treatments to support blood pressure increases bleeding and/or decreases survival in a rat model of closed head trauma combined with uncontrolled hemorrhage.

UNLABELLED: Hemorrhagic hypotension may aggravate the detrimental effects of head trauma on neurologic outcome. Our study examined whether using phenylephrine or large volumes of saline IV to increase mean arterial blood pressure (MAP) to 70, 80, or 90 mm Hg during the combination of head trauma and uncontrolled hemorrhage would improve neurologic outcome. Rats were assigned to one of 17 groups. In Groups 1-5, the variables were head trauma (yes/no), hemorrhage (yes/no), 0 or 3 mL saline per milliliter of blood lost, and no target MAP. In Groups 6-11, hemorrhage was or was not combined with head trauma, and large volumes of saline were given IV to achieve target MAPs of 70, 80, or 90 mm Hg. Groups 12-17 were similar to Groups 6-11 except that phenylephrine was used rather than saline to achieve target MAPs. Saline increased blood loss at 2 h to approximately 16 and 25 mL at a MAP of 80 and 90 mm Hg respectively, increased (worsened) the neurodeficit score but not cerebral edema at 24 h, and decreased survival rate at 2 and 24 h. Because phenylephrine was fatal for 62 of 63 rats, group mean values for blood loss, neurodeficit score, and brain tissue specific gravity could not be calculated. We conclude that supporting MAP with either phenylephrine or large volumes of saline worsened the neurodeficit score and/or survival and did not affect cerebral edema formation in our rat model of head trauma combined with hemorrhage. IMPLICATIONS: The results of this study indicate that maintaining mean arterial blood pressure at 70, 80, or 90 mm Hg with either phenylephrine or large volumes of saline worsened the neurodeficit score and/or survival and did not affect cerebral edema formation in our rat model of head trauma combined with hemorrhage.

Phenylephrine-induced hypertension does not improve outcome after closed head trauma in rats.

UNLABELLED: Phenylephrine-induced hypertension (increase of 30-35 mm Hg for 15 min) is reported to increase cerebral perfusion pressure and collateral flow to ischemic areas of the brain in a rat model of focal cerebral ischemia. In the present study, we examined whether phenylephrine-induced hypertension of similar magnitude and duration was beneficial in a rat model of closed head trauma (CHT). Forty-eight rats were randomized into four experimental conditions: CHT at time 0 min (yes/no), plus phenylephrine-induced hypertension (increase of 30-35 mm Hg for 15 min) at 65 min (yes/no). CHT was delivered using a weight-drop device (0.5 J). Outcome measures were neurological severity score (NSS) at 1, 4, and 24 h, and brain tissue specific gravity (microgravimetry) and injury volume (2,3,5-triphenyltetrazoium chloride) at 24 h. After CHT, NSS at 24 h (median +/- range) and brain tissue specific gravity (mean +/- SD, injured hemisphere) were 7+/-2 and 1.033+/-0.007 without phenylephrine and 8+/-2 and 1.035+/-0.005 with phenylephrine (P = 0.43), respectively. Tissue injury volume (mean +/- SD) was 335+/-92 mm3 without phenylephrine and 357+/-154 mm3 with phenylephrine (P > 0.62). The results of our study indicate that postinjury treatment with 15 min of phenylephrine-induced hypertension does not attenuate brain edema, reduce tissue injury volume, or improve neurological outcome after CHT in rats. IMPLICATIONS: Phenylephrine-induced hypertension is reported to increase cerebral perfusion pressure and blood flow in a rat model of focal cerebral ischemia. In our study, phenylephrine-induced hypertension did not decrease brain edema or tissue injury volume or improve neurological outcome in a rat model of closed head trauma.

Ketamine attenuates the interleukin-6 response after cardiopulmonary bypass.

UNLABELLED: Cardiopulmonary bypass (CPB) has been proposed as a model for studying the inflammatory cascade associated with the systemic inflammatory response syndrome. Serum interleukin-6 (IL-6) concentration seems to be a good indicator of activation of the inflammatory cascade and predictor of subsequent organ dysfunction and death. Prolonged increases of circulating IL-6 are associated with morbidity and mortality after cardiac operations. In the present study, we compared the effects of adding ketamine 0.25 mg/kg to general anesthesia on serum IL-6 levels during and after elective coronary artery bypass grafting (CABG). Thirty-one patients undergoing elective CABG were randomized to one of two groups and prospectively studied in a double-blind manner. The patients received either ketamine 0.25 mg/kg or a similar volume of isotonic sodium chloride solution in addition to large-dose fentanyl anesthesia. Blood samples for analysis of serum IL-6 levels were drawn before the operation; after CPB; 4, 24, and 48 h after surgery; and daily for 6 days beginning the third day postoperatively. Ketamine suppressed the serum IL-6 response immediately after CPB and 4, 24, and 48 h postoperatively (P < 0.05). During the first 7 days after surgery, the serum IL-6 levels in the ketamine group were significantly lower than those in the control group (P < 0.05). On Day 8 after surgery, IL-6 levels were no different from baseline values in both groups. A single dose of ketamine 0.25 mg/kg administered before CPB suppresses the increase of serum IL-6 during and after CABG. IMPLICATIONS: In this randomized, double-blind, prospective study of patients during and after coronary artery bypass surgery, we examined whether small-dose ketamine added to general anesthesia before cardiopulmonary bypass suppresses the increase of the serum interleukin-6 (IL-6) concentration. Serum IL-6 levels correlate with the patient's clinical course during and after coronary artery bypass. Ketamine suppresses the increase of serum IL-6 during and after coronary artery bypass surgery.

0.45% saline and 5% dextrose in water, but not 0.9% saline or 5% dextrose in 0.9% saline, worsen brain edema two hours after closed head trauma in rats.

UNLABELLED: In this study, we examined the effect of four i.v. fluids (250 mL/kg) on blood glucose and osmolality and brain tissue specific gravity after closed head trauma (CHT) in rats. CHT was delivered at Time 0; blood was sampled at 60 min; fluid infusion began at 75 min and ended at 105 min. Blood was again sampled at 105 and 120 min, and brain tissue specific gravity was determined at 120 min. Five groups (one control and four fluid-treated groups) received CHT, and five other groups (one control and four fluid-treated) did not (n = 9 in each group). 0.45% saline (1/2 NS) and 5% dextrose in water (D5W) accentuated the decrease of brain tissue specific gravity (1.0366 +/- 0.0025 and 1.0368 +/- 0.0028, respectively; mean +/- SD) caused by CHT (1.0395 +/- 0.0036), but 5% dextrose in 0.9% saline (D5NS) and 0.9% saline (NS) did not (1.0431 +/- 0.0042 and 1.0389 +/- 0.0049, respectively). In addition, 1/2 NS decreased blood osmolality (248 +/- 6 mOsm/L), D5W increased blood glucose (1095 +/- 173 mg/dL), D5NS increased blood osmolality (350 +/- 5 mOsm/L) and glucose (1695 +/- 76 mg/dL), and NS caused no significant change. We conclude that administering hypoosmolar i.v. fluids after CHT causes a significant worsening of cerebral edema 2 h after CHT. IMPLICATIONS: We previously reported worse neurological outcome and/or mortality after closed head trauma in rats when 5% dextrose in water or 0.45% saline was given i.v. compared with 0.9% saline or 5% dextrose in 0.9% saline. The present results and our previous findings indicate that worsening of outcome after closed head trauma in rats may be caused more by edema formation than by hyperglycemia.

Neuroprotective effects of NPS 846, a novel N-methyl-D-aspartate receptor antagonist, after closed head trauma in rats.

OBJECT: The authors sought to determine whether 3,3-bis (3-fluorophenyl) propylamine (NPS 846), a novel noncompetitive N-methyl-D-aspartate receptor antagonist, alters outcome after closed head trauma in rats. METHODS: The experimental variables were: presence or absence of closed head trauma, treatment with NPS 846 or no treatment, and time at which the rats were killed (24 or 48 hours). The NPS 846 (1 mg/kg) was administered intraperitoneally at 1 and 3 hours after closed head trauma or sham operation. Outcome measures were the neurological severity score (NSS), ischemic tissue volume, hemorrhagic necrosis volume, and specific gravity, water content, and concentrations of calcium, sodium, potassium, and magnesium in brain tissue. The following closed head trauma-induced changes in the injured hemisphere (expressed as the mean +/- the standard deviation) were reversed by NPS 846: decreased specific gravity of 1.035 +/- 0.006 at 24 hours was increased to 1.042 +/- 0.004; the decreased potassium level of 0.583 +/- 0.231 mg/L at 48 hours and at 24 hours was increased to 2.442 +/- 0.860 mg/L; the increased water content of 84.7 +/- 2.6% at 24 hours was decreased to 79.8 +/- 2%; the increased calcium level of 0.592 +/- 0.210 mg/L at 24 hours was decreased to 0.048 +/- 0.029 mg/L; and the increased sodium level of 2.035 +/- 0.649 mg/L was decreased to 0.631 +/- 0.102 mg/L. Administration of NPS 846 also lowered the NSS (improved neurological status) at 48 hours (7 +/- 3) and caused no significant changes in ischemic tissue or hemorrhagic necrosis volumes in the injured hemisphere at 24 or 48 hours. CONCLUSIONS: In this model of closed head trauma, NPS 846 improved neurological outcome, delayed the onset of brain edema, and improved brain tissue ion homeostasis.

Effects of closed head trauma and lipopolysaccharide on body temperature, brain tissue water content, and PGE2 production in rats.

Closed head trauma (CHT) increases brain tissue prostaglandin E2 (PGE2) concentration, and that increase is associated with cerebral edema formation and worsening of the neurologic severity score (NSS). Injection of the bacterial endotoxin lipopolysacharride (LPS) increases cerebral and hypothalamic PGE2, and the hypothalamic increase is associated with increased body temperature. The present study determined (a) whether LPS-induced increase of PGE2 causes brain edema or worsens NSS and (b) whether CHT increases hypothalamic PGE2 and thereby increases body temperature. Halothane-anesthetized rats were divided into four groups: group 1 = surgery with no CHT and no LPS (n = 8); group 2 = surgery with LPS and no CHT (n = 8); group 3 = surgery with CHT and no LPS (n = 8); and group 4 = surgery with CHT plus LPS (n = 8). NSS was determined at 1 and 24 h after injury, and brain tissue PGE2 and edema were determined when animals were killed 24 h after injury. As compared with group 1, LPS alone, but not CHT or CHT plus LPS, increased rectal temperature. CHT and CHT plus LPS, but not LPS alone increased brain water content and worsened NSS. LPS, CHT, and CHT plus LPS all increased hypothalamic and cerebral PGE2 production. We conclude that although LPS and CHT increased PGE2 levels, LPS alone did not affect neurologic status or brain edema, CHT did not increase rectal temperature, and addition of LPS to CHT did not aggravate the sequelae of CHT.