The limits of succinylcholine for critically ill patients.

BACKGROUND: Urgent tracheal intubations are common in intensive care units (ICU), and succinylcholine is one of the first-line neuromuscular blocking drugs used in these situations. Critically ill patients could be at high risk of hyperkalemia after receiving succinylcholine because one or more etiologic factors of nicotinic receptor upregulation can be present, but there are few data on its real risk. Our objectives in this study were to determine the factors associated with arterial potassium increase (ΔK) and to assess the occurrence of acute hyperkalemia ≥6.5 mmol/L after succinylcholine injection for intubation in the ICU. METHODS: In a prospective, observational study, all critically ill patients intubated with succinylcholine in an ICU were screened. Only intubations with arterial blood gases and potassium measurements before and after (K(after)) a succinylcholine injection were studied. RESULTS: During 18 months, 131 critically ill patients were intubated after receiving succinylcholine with arterial potassium before and after intubation (K(after)) for a total of 153 intubations. After multivariate analysis, the only factor associated with ΔK was the length of ICU stay before intubation (ρ = 0.561, P < 0.001). The factors associated with K(after) ≥6.5 mmol/L (n = 11) were the length of ICU stay (P < 0.001) and the presence of acute cerebral pathology (P = 0.047). The threshold of 16 days was found highly predictive of acute hyperkalemia ≥6.5 with 37% (95% confidence interval: 19%-58%) of K(after) ≥6.5 after the 16th day compared with only 1% (95% confidence interval: 0%-4%) of K(after) ≥6.5 when succinylcholine was injected during the first 16 days. CONCLUSIONS: This study shows that the risk of ΔK after succinylcholine injection is strongly associated with the length of ICU stay. The risk of acute hyperkalemia ≥6.5 mmol/L is highly significant after 16 days.

Prone positioning in acute respiratory distress syndrome after abdominal surgery: a multicenter retrospective study : SAPRONADONF (Study of Ards and PRONe position After abDOmiNal surgery in France).

BACKGROUND: The recent demonstration of prone position's strong benefit on patient survival has rendered proning a major therapeutic intervention in severe ARDS. Uncertainties remain as to whether or not ARDS patients in the postoperative period of abdominal surgery should be turned prone because of the risk of abdominal complications. Our aim was to investigate the prevalence of surgical complications between patients with and without prone position after abdominal surgery. METHODS: This study was a multicenter retrospective cohort of patients with ARDS in a context of recent abdominal surgery. Primary outcome was the number of patients who had at least one surgical complication that could be induced or worsened by prone position. Secondary outcomes included effects of prone position on oxygenation. Data from the prone group were compared with those from the supine group (not having undergone at least a prone position session). RESULTS: Among 98 patients included, 36 (37%) had at least one prone position session. The rate of surgical complications induced or worsened by prone position did not differ between prone and supine groups [respectively, 14 (39%) vs 27 (44%); p = 0.65]. After propensity score application, there was no significant difference between the two groups (OR 0.72 [0.26-2.02], p = 0.54). Revision surgery did not differ between the groups. The first prone session significantly increased PaO2/FiO2 ratio from 95 ± 47 to 189 ± 92 mmHg, p < 0.0001. CONCLUSION: Prone position of ARDS patients after abdominal surgery was not associated with an increased rate of surgical complication. Intensivists should not refrain from proning these patients.

Chest trauma: First 48hours management.

Chest trauma remains an issue for health services for both severe and apparently mild trauma management. Severe chest trauma is associated with high mortality and is considered liable for 25% of mortality in multiple traumas. Moreover, mild trauma is also associated with significant morbidity especially in patients with preexisting conditions. Thus, whatever the severity, a fast-acting strategy must be organized. At this time, there are no guidelines available from scientific societies. These expert recommendations aim to establish guidelines for chest trauma management in both prehospital an in hospital settings, for the first 48hours. The "Société française d'anesthésie réanimation" and the "Société française de médecine d'urgence" worked together on the 7 following questions: (1) criteria defining severity and for appropriate hospital referral; (2) diagnosis strategy in both pre- and in-hospital settings; (3) indications and guidelines for ventilatory support; (4) management of analgesia; (5) indications and guidelines for chest tube placement; (6) surgical and endovascular repair indications in blunt chest trauma; (7) definition, medical and surgical specificity of penetrating chest trauma. For each question, prespecified "crucial" (and sometimes also "important") outcomes were identified by the panel of experts because it mattered for patients. We rated evidence across studies for these specific clinical outcomes. After a systematic Grade® approach, we defined 60 recommendations. Each recommendation has been evaluated by all the experts according to the DELPHI method.

Endothelial oxidative stress induced by serum from patients with severe trauma hemorrhage.

OBJECTIVE: Shock induces oxidative stress by ischemia-reperfusion phenomenon. Endothelial cells are involved in the inflammatory response and oxidative stress responsible for microcirculation impairment and organ failure. We examined the potential of serum from patients to induce in vitro reactive oxygen species production by cultured human umbilical vein endothelial cells (HUVECs). PATIENTS: Three groups were compared: hemorrhagic shock trauma patients, isolated brain injured patients, and healthy volunteers. METHODS: In the hemorrhagic shock group we sought a correlation between reactive oxygen species production and severity of shock. Serum was separated and perfused in an in vitro model of perfused HUVECs. Ex vivo reactive oxygen species production was assessed by fluorescence microscopy using dichlorodihydrofluorescein, an intracellular dye oxidized by H2O2. Results are expressed in proportional change from baseline and normalized by protidemia to control for variation related to hemodilution. RESULTS: Reactive oxygen species production by endothelial cells exposed to serum from hemorrhagic shock patients (46.2+/-24.9%) was significantly greater than in those with brain injury (3.9+/-35.1%) and in healthy volunteers (-6.8+/-5.8%). In the hemorrhagic shock group dichlorodihydrofluorescein fluorescence was strongly correlated positively to Simplified Acute Physiology Score II and lactatemia and negatively to [HCO3-]. CONCLUSIONS: Serum from trauma patients with hemorrhagic shock induces reactive oxygen species formation in naive endothelial cells which is correlated to shock severity.

Both passive leg raising and intravascular volume expansion improve sublingual microcirculatory perfusion in severe sepsis and septic shock patients.

PURPOSE: To assess sublingual microcirculatory changes following passive leg raising (PLR) and volume expansion (VE) in septic patients. METHODS: This prospective study was conducted in two university hospital intensive care units and included 25 mechanically ventilated patients with severe sepsis or septic shock who were eligible for VE in the first 24 h of their admission. Pulse pressure variation (ΔPP), cardiac output (CO) and sublingual microcirculation indices were assessed at five consecutive steps: (1) semi-recumbent position (Baseline 1), (2) during PLR manoeuvre (PLR), (3) after returning to semi-recumbent position (Baseline 2), (4) at the time when VE induced the same degree of preload responsiveness as PLR (VE(∆PP = PLR)) and (5) at the end of VE (VE(END)). At each step, five sublingual microcirculation sequences were acquired using sidestream darkfield imaging to assess functional capillary density (FCD), microcirculatory flow index (MFI), proportion of perfused vessels (PPV) and flow heterogeneity index (FHI). RESULTS: The PLR, VE(∆PP = PLR) and VE(END) induced a significant increase in CO and a significant decrease in ΔPP compared to Baseline 1 and Baseline 2 values. Both PLR and VE induced significant increases in FCD, MFI and PPV and a significant decrease in FHI compared to Baseline 1 and Baseline 2 values. CONCLUSIONS: In preload responsive severe septic patients examined within the first 24 h of their admission, both PLR and VE improved sublingual microcirculatory perfusion. At the level of volume infusion used in this study, these changes in sublingual microcirculation were not explained by changes in rheologic factors or changes in arterial pressure.

One-day quantitative cross-sectional study of family information time in 90 intensive care units in France.

RATIONALE: Providing family members with clear, honest, and timely information is a major task for intensive care unit physicians. Time spent informing families has been associated with effectiveness of information but has not been measured in specifically designed studies. OBJECTIVES: To measure time spent informing families of intensive care unit patients. METHODS: One-day cross-sectional study in 90 intensive care units in France. MEASUREMENTS: Clocked time spent by physicians informing the families of each of 951 patients hospitalized in the intensive care unit during a 24-hr period. MAIN RESULTS: Median family information time was 16 (interquartile range, 8-30) mins per patient, with 20% of the time spent explaining the diagnosis, 20% on explaining treatments, and 60% on explaining the prognosis. One third of the time was spent listening to family members. Multivariable analysis identified one factor associated with less information time (room with more than one bed) and seven factors associated with more information time, including five patient-related factors (surgery on the study day, higher Logistic Organ Dysfunction score, coma, mechanical ventilation, and worsening clinical status) and two family-related factors (first contact with family and interview with the spouse). Median information time was 20 (interquartile range, 10-39) mins when three factors were present and 106.5 (interquartile range, 103-110) mins when five were present. CONCLUSION: This study identifies factors associated with information time provided by critical care physicians to family members of critically ill patients. Whether information time correlates with communication difficulties or communication skills needs to be evaluated. Information time provided by residents and nurses should be studied.

Plasma-induced endothelial oxidative stress is related to the severity of septic shock.

OBJECTIVE: To estimate the capacity of plasma from septic shock patients to induce in vitro reactive oxygen species (ROS) production by endothelial cells and to analyze whether ROS production is related to the severity of the septic shock. DESIGN: Prospective, observational study. SETTING: Medical intensive care unit in a university hospital. PATIENTS: Twenty-one patients with septic shock. INTERVENTIONS: The in vitro capacity of plasma from septic shock patients to induce ROS production by naive human umbilical vein endothelial cells (HUVEC) was quantified by using a fluorescent probe (2',7'-dichlorodihydrofluorescein diacetate). MEASUREMENTS AND MAIN RESULTS: Blood samples were collected on day 1, day 3, and day 5 from 21 consecutive septic shock adult patients and from ten healthy volunteers. Patients mean age was 58 yrs old, mean Sequential Organ Failure Assessment (SOFA) score at admission was 12, mean severity illness assessed by Simplified Acute Physiology Score (SAPS) II was 53, and the mortality rate was 47%. In addition to assessment of in vitro ROS generation by HUVEC, oxidative stress in blood was evaluated by measuring lipid peroxidation products and enzymatic and nonenzymatic antioxidants. Septic shock was associated with oxidative stress and an imbalance in antioxidant status. As compared with controls, plasma-induced ROS production by naive HUVEC was significantly higher in septic shock. Moreover ROS production was significantly correlated with SAPS II (p = .028) and SOFA values (p = .0012) and was higher in nonsurvivors than in survivors. In contrast, no correlation was found between the severity of the septic shock and any of the levels of lipid peroxidation products or enzymatic and nonenzymatic antioxidants. CONCLUSION: Plasma from septic shock patients induces ROS formation by naive HUVEC, and the extent of ROS formation correlates with mortality and with criteria of the severity of septic shock as SOFA score and SAPS II.

Beta2-adrenergic agonist protects human endothelial cells from hypoxia/reoxygenation injury in vitro.

OBJECTIVE: Circulatory shock results in hypoxia/reoxygenation processes that lead to the release of reactive oxygen species, endothelial injury, and multiple organ failure. Previous data suggest that beta2-adrenergic agonists prevent endothelial dysfunction. The study aimed at determining whether the beta2-adrenergic agonist formoterol protects endothelial cells against hypoxia/reoxygenation injury in vitro. DESIGN: Prospective controlled trial. SETTING: University hospital research laboratory. SUBJECTS: Cultured human umbilical vein endothelial cells (HUVECs). INTERVENTIONS: Confluent HUVECs were sealed in a flow-through chamber mounted on an inverted microscope and perfused with a constant flow of Krebs medium. After 1 hr of equilibration, HUVECs underwent 2 hrs of hypoxia and 1 hr of reoxygenation. Cell death at the end of reoxygenation and reactive oxygen species formation were assessed with fluorescent probes propidium iodide and 2',7'-dichlorodihydrofluorescein diacetate, respectively. The effects of the beta2-adrenergic agonist formoterol, the beta2-adrenergic antagonist ICI 118,551 and the nitric oxide synthase inhibitor L-NNA were investigated. Statistical analysis was performed with analysis of variance followed by post hoc Fisher's test. MEASUREMENTS AND MAIN RESULTS: Hypoxia/reoxygenation increased cell death (hypoxia/reoxygenation 29 +/- 4% vs. control 1 +/- 5%, p < .05) and endothelial reactive oxygen species production (hypoxia/reoxygenation 126 +/- 4% vs. control 108 +/- 4%, p < .05). Formoterol reduced cell death in a concentration-dependent manner (EC95 = 10 mol/L) and reduced endothelial reactive oxygen species production (hypoxia/reoxygenation + formoterol EC95 109 +/- 4% vs. hypoxia/reoxygenation 126 +/- 4%, p < .05). When added to formoterol EC95, ICI 118,551 and L-NNA abolished the formoterol-induced cell protection and reduced reactive oxygen species production. CONCLUSIONS: These results indicate that formoterol reduces endothelial cell death and reactive oxygen species production in this in vitro hypoxia/reoxygenation model. These effects are beta2-adrenergic specific and are partially mediated by nitric oxide synthase.

Risk of post-traumatic stress symptoms in family members of intensive care unit patients.

RATIONALE: Intensive care unit (ICU) admission of a relative is a stressful event that may cause symptoms of post-traumatic stress disorder (PTSD). OBJECTIVES: Factors associated with these symptoms need to be identified. METHODS: For patients admitted to 21 ICUs between March and November 2003, we studied the family member with the main potential decision-making role. MEASUREMENTS: Ninety days after ICU discharge or death, family members completed the Impact of Event Scale (which evaluates the severity of post-traumatic stress reactions), Hospital Anxiety and Depression Scale, and 36-item Short-Form General Health Survey during a telephone interview. Linear regression was used to identify factors associated with the risk of post-traumatic stress symptoms. MAIN RESULTS: Interviews were obtained for family members of 284 (62%) of the 459 eligible patients. Post-traumatic stress symptoms consistent with a moderate to major risk of PTSD were found in 94 (33.1%) family members. Higher rates were noted among family members who felt information was incomplete in the ICU (48.4%), who shared in decision making (47.8%), whose relative died in the ICU (50%), whose relative died after end-of-life decisions (60%), and who shared in end-of-life decisions (81.8%). Severe post-traumatic stress reaction was associated with increased rates of anxiety and depression and decreased quality of life. CONCLUSION: Post-traumatic stress reaction consistent with a high risk of PTSD is common in family members of ICU patients and is the rule among those who share in end-of-life decisions. Research is needed to investigate PTSD rates and to devise preventive and early-detection strategies.

Half the family members of intensive care unit patients do not want to share in the decision-making process: a study in 78 French intensive care units.

OBJECTIVE: To evaluate the opinions of intensive care unit staff and family members about family participation in decisions about patients in intensive care units in France, a country where the approach of physicians to patients and families has been described as paternalistic. DESIGN: Prospective multiple-center survey of intensive care unit staff and family members. SETTING: Seventy-eight intensive care units in university-affiliated hospitals in France. PATIENTS: We studied 357 consecutive patients hospitalized in the 78 intensive care units and included in the study starting on May 1, 2001, with five patients included per intensive care unit. INTERVENTIONS: We recorded opinions and experience about family participation in medical decision making. Comprehension, satisfaction, and Hospital Anxiety and Depression Scale scores were determined in family members. MEASUREMENTS AND MAIN RESULTS: Poor comprehension was noted in 35% of family members. Satisfaction was good but anxiety was noted in 73% and depression in 35% of family members. Among intensive care unit staff members, 91% of physicians and 83% of nonphysicians believed that participation in decision making should be offered to families; however, only 39% had actually involved family members in decisions. A desire to share in decision making was expressed by only 47% of family members. Only 15% of family members actually shared in decision making. Effectiveness of information influenced this desire. CONCLUSION: Intensive care unit staff should seek to determine how much autonomy families want. Staff members must strive to identify practical and psychological obstacles that may limit their ability to promote autonomy. Finally, they must develop interventions and attitudes capable of empowering families.