Jean Francois Payen

Pain assessment is associated with decreased duration of mechanical ventilation in the intensive care unit: A post hoc analysis of the dolorea study

Background:Critically ill patients frequently experience pain, but assessment rates remain below 40% in mechanically ventilated patients. Whether pain assessment affects patient outcomes is largely unknown. Methods:As part of a prospective cohort study of mechanically ventilated patients who received analgesia on day 2 of their stay in the intensive care unit (ICU), the investigators performed propensity-adjusted score analysis to compare the duration of ventilator support and duration of ICU stay between 513 patients who were assessed for pain and 631 patients who were not assessed for pain. Results:Patients assessed for pain on day 2 were more likely to receive sedation level assessment, nonopioids, and dedicated analgesia during painful procedures than patients whose pain was not assessed. They also received fewer hypnotics and lower daily doses of midazolam. Patients with pain assessment had a shorter duration of mechanical ventilation (8 vs. 11 days; P < 0.01) and a reduced duration of stay in the ICU (13 vs. 18 days; P < 0.01). In propensity-adjusted score analysis, pain assessment was associated with increased odds of weaning from the ventilator (odds ratio, 1.40; 95% confidence interval, 1.00–1.98) and of discharge from the ICU (odds ratio, 1.43; 95% confidence interval, 1.02–2.00). Conclusions:Pain assessment in mechanically ventilated patients is independently associated with a reduction in the duration of ventilator support and of duration of ICU stay. This might be related to higher concomitant rates of sedation assessments and a restricted use of hypnotic drugs when pain is assessed.

Outcome after severe accidental hypothermia in the French Alps: A 10-year review

OBJECTIVE To describe the factors associated with outcome after accidental deep hypothermia. METHODS We conducted a retrospective cohort study on patients with accidental hypothermia (core temperature <28 °C) admitted to a Level I emergency room over a 10-year period. RESULTS Forty-eight patients were included with a median temperature of 26 °C (range, 16.3-28 °C) on admission. The etiology of hypothermia was exposure to a cold environment (n = 27), avalanche (n = 13) or immersion in cold water (n = 8). Mean age was 47 ± 22 years, and 58% were males. Thirty-two patients had a cardiac arrest (CA): 15 patients presented unwitnessed cardiac arrest (UCA) and 17 patients presented rescue collapse (RC). Extracorporeal life support (ECLS) was implemented in 21 patients with refractory cardiac arrest and in two patients with hemodynamic instability. Overall mortality was 50%. For cardiac arrest patients, only three out of 15 patients with UCA survived at day 28, whereas eight out of 17 patients with RC survived. The cerebral performance category score was 4 for all the survivors of UCA and 1 [range, 1-2] for survivors of RC. Patients with poor outcome presented more UCA, a lower pH, a higher serum potassium, creatinine, serum sodium or lactate level as well as more severe coagulation disorders. CONCLUSION Cardiac arrest related to rescue collapse was associated with favorable outcome. On-scene rescue collapse should prompt prolonged resuscitation and ECLS rewarming in all CA patients with deep hypothermia. Conversely, unwitnessed cardiac arrest was associated with unfavorable outcome and will likely not benefit from ECLS.

Detecting active pelvic arterial haemorrhage on admission following serious pelvic fracture in multiple trauma patients

BACKGROUND The early diagnosis of pelvic arterial haemorrhage is challenging for initiating treatment by transcatheter arterial embolization (TAE) in multiple trauma patients. We use an institutional algorithm focusing on haemodynamic status on admission and on a whole-body CT scan in stabilized patients to screen patients requiring TAE. This study aimed to assess the effectiveness of this approach. METHODS This retrospective cohort study included 106 multiple trauma patients admitted to the emergency room with serious pelvic fracture [pelvic abbreviated injury scale (AIS) score of 3 or more]. RESULTS Of the 106 patients, 27 (25%) underwent pelvic angiography leading to TAE for active arterial haemorrhage in 24. The TAE procedure was successful within 3h of arrival in 18 patients. In accordance with the algorithm, 10 patients were directly admitted to the angiography unit (n=8) and/or operating room (n=2) for uncontrolled haemorrhagic shock on admission. Of the remaining 96 stabilized patients, 20 had contrast media extravasation on pelvic CT scan that prompted pelvic angiography in 16 patients leading to TAE in 14. One patient underwent a pelvic angiography despite showing no contrast media extravasation on pelvic CT scan. All 17 stabilized patients who underwent pelvic angiography presented a more severely compromised haemodynamic status on admission, and they required more blood products during their initial management than the 79 patients who did not undergo pelvic angiography. The incidence of unstable pelvic fractures was however comparable between the two groups. Overall, haemodynamic instability and contrast media extravasation on the CT-scan identified 26 out of the 27 patients who required subsequent pelvic angiography leading to TAE in 24. CONCLUSIONS An algorithm focusing on haemodynamic status on arrival and on the whole-body CT scan in stabilized patients may be effective at triaging multiple trauma patients with serious pelvic fractures.

Changes in Brain Tissue Oxygenation After Treatment of Diffuse Traumatic Brain Injury by Erythropoietin

Objectives:To investigate the effects of recombinant human erythropoietin on brain oxygenation in a model of diffuse traumatic brain injury. Design:Adult male Wistar rats. Setting:Neurosciences and physiology laboratories. Interventions:Thirty minutes after diffuse traumatic brain injury (impact-acceleration model), rats were intravenously administered with either a saline solution or a recombinant human erythropoietin (5000 IU/kg). A third group received no traumatic brain injury insult (sham-operated). Measurements and Main Results:Three series of experiments were conducted 2 hours after traumatic brain injury to investigate: 1) the effect of recombinant human erythropoietin on brain edema using diffusion-weighted magnetic resonance imaging and measurements of apparent diffusion coefficient (n = 11 rats per group); local brain oxygen saturation, mean transit time, and blood volume fraction were subsequently measured using a multiparametric magnetic resonance–based approach to estimate brain oxygenation and brain perfusion in the neocortex and caudoputamen; 2) the effect of recombinant human erythropoietin on brain tissue PO2 in similar experiments (n = 5 rats per group); and 3) the cortical ultrastructural changes after treatment (n = 1 rat per group). Compared with the sham-operated group, traumatic brain injury saline rats showed a significant decrease in local brain oxygen saturation and in brain tissue PO2 alongside brain edema formation and microvascular lumen collapse at H2. Treatment with recombinant human erythropoietin reversed all of these traumatic brain injury–induced changes. Brain perfusion (mean transit time and blood volume fraction) was comparable between the three groups of animals. Conclusion:Our findings indicate that brain hypoxia can be related to microcirculatory derangements and cell edema without evidence of brain ischemia. These changes were reversed with post-traumatic administration of recombinant human erythropoietin, thus offering new perspectives in the use of this drug in brain injury.

Pupillometry to detect pain response during general anaesthesia following unilateral popliteal sciatic nerve block: a prospective, observational study.

CONTEXT Pupillary reflex dilation appears to be a reliable indicator of response to noxious stimulation even under general anaesthesia. The ability of pupillometry to detect the effects of extremity blocks during continuous infusion of opioids remains unknown. OBJECTIVE To explore the performance of pupillometry to detect differences in pupillary reflex dilation response to a standardised noxious stimulus applied to each leg following unilateral popliteal sciatic nerve block during continuous infusion of remifentanil. DESIGN Prospective, observational study. SETTING University hospital anaesthesia department, between June 2010 and December 2010. PATIENTS Twenty-four adult patients undergoing elective foot or ankle surgery under general anaesthesia who requested a peripheral nerve block. Unilateral popliteal sciatic nerve block with 0.75% ropivacaine and 1% lidocaine was performed awake. General anaesthesia was maintained with steady-state infusions of propofol and remifentanil. MAIN OUTCOME MEASURE Video-based pupillometer was used to determine pupillary reflex dilation during tetanic stimulation (60 m, 100 Hz) applied to the skin area innervated by the sciatic nerve for 5 s after the onset of general anaesthesia. RESULTS Sensory nerve block led to a blunted maximal pupillary reflex dilation response to noxious stimulation compared with the non-blocked leg: median (interquartile range) change from baseline 2% (1 to 4%) versus 17% (13 to 24%), respectively (P < 0.01). The differences in the response persisted throughout the 5-s stimulus and the recovery phase. CONCLUSION These results are a proof of concept. The effects of peripheral nerve block can be detected via the measurement of pupillary reflex dilation response to noxious stimulation of the skin in patients receiving remifentanil.

Transcranial Doppler to Predict Neurologic Outcome after Mild to Moderate Traumatic Brain Injury

Background:To assess the performance of transcranial Doppler (TCD) in predicting neurologic worsening after mild to moderate traumatic brain injury. Methods:The authors conducted a prospective observational study across 17 sites. TCD was performed upon admission in 356 patients (Glasgow Coma Score [GCS], 9 to 15) with mild lesions on cerebral computed tomography scan. Normal TCD was defined as a pulsatility index of less than 1.25 and diastolic blood flow velocity higher than 25 cm/s in the two middle cerebral arteries. The primary endpoint was secondary neurologic deterioration on day 7. Results:Twenty patients (6%) developed secondary neurologic deterioration within the first posttraumatic week. TCD thresholds had 80% sensitivity (95% CI, 56 to 94%) and 79% specificity (95% CI, 74 to 83%) to predict neurologic worsening. The negative predictive values and positive predictive values of TCD were 98% (95% CI, 96 to 100%) and 18% (95% CI, 11to 28%), respectively. In patients with minor traumatic brain injury (GCS, 14 to 15), the sensitivity and specificity of TCD were 91% (95% CI, 59 to 100%) and 80% (95% CI, 75 to 85%), respectively. The area under the receiver operating characteristic curve of a multivariate predictive model including age and GCS was significantly improved with the adjunction of TCD. Patients with abnormal TCD on admission (n = 86 patients) showed a more altered score for the disability rating scale on day 28 compared to those with normal TCD (n = 257 patients). Conclusions:TCD measurements upon admission may provide additional information about neurologic outcome after mild to moderate traumatic brain injury. This technique could be useful for in-hospital triage in this context. (Anesthesiology 2016; 125:346-54)

Anaesthesiological support in a cardiac electrophysiology laboratory: A single-centre prospective observational study

BACKGROUND Implantation of cardiovascular implantable electronic devices (CIEDs) has greatly increased during the last decade and anaesthetic management of these patients remains an open question. OBJECTIVE This study describes anaesthetic management and risk factors associated with complications occurring during these procedures. DESIGN A single-centre prospective observational study. SETTING Grenoble University Hospital, France, from May 2010 to October 2010. PATIENTS All patients admitted to the cardiac electrophysiology laboratory were included. INTERVENTION None. MAIN OUTCOME MEASURES Clinical data, anaesthetic and medical characteristics as well as complications (respiratory or cardiovascular) and treatment were recorded by the anaesthetic nurse at the end of each procedure. RESULTS Two hundred and sixty-nine patients were included, 229 (85%) with an American Society of Anaesthesiologists (ASA) status of 3 or 4, 103 (38%) with a New York Heart Association (NYHA) functional class of 3 or 4 and 136 (51%) with a left ventricular ejection fraction of less than 40%. Two hundred and forty-seven (92%) of the patients underwent deep sedation and 12 (8%) general anaesthesia. Seventy-eight (29%) patients had at least one complication, among whom 21 (27%) had at least one considered as severe. Fifty (19%) of the patients had a respiratory complication and 46 (17%) a cardiovascular complication; the latter was more frequently severe (41 vs. 12%; P = 0.001). Lead extraction [odds ratio (OR) 13.7, 95% confidence interval (CI) 3.5 to 53.3; P < 0.001], NYHA status of 4 (OR 11.8, 95% CI 1.8 to 74.8; P < 0.001), implantable cardioverter-defibrillator (ICD) testing by T-wave shock (OR 3.9, 95% CI 1.53 to 10.2; P = 0.005) and length of procedure (OR 1.01, 95% CI 1.004 to 1.031; P = 0.013) were identified as independent risk factors for cardiovascular complications. CONCLUSION Patients requiring cardiovascular implantable electronic device (CIED) implantation were fragile with a high complication rate and a high rate of severe complications even with anaesthesiological support. These complications, as well as the need for deep sedation or general anaesthesia, clearly justify the involvement of a qualified anaesthesiologist.

Hepatitis E Virus Infection after Platelet Transfusion in an Immunocompetent Trauma Patient

Hepatitis E virus (HEV) infection causes acute liver disease, but severe infections are rare in immunocompetent patients. We describe a case of HEV infection in a previously healthy male trauma patient in France who received massive transfusions. Genotyping confirmed HEV in a transfused platelet pool and the donor.

Prehospital shock index and pulse pressure/heart rate ratio to predict massive transfusion after severe trauma: Retrospective analysis of a large regional trauma database

BACKGROUND Early and accurate detection of severe hemorrhage is critical for a timely trigger of massive transfusion (MT). Hemodynamic indices combining heart rate (HR) and either systolic (shock index [SI]) or pulse pressure (PP) (PP/HR ratio) have been shown to track blood loss during hemorrhage. The present study assessed the accuracy of prehospital SI and PP/HR ratio to predict subsequent MT, using the gray-zone approach. METHODS This was a retrospective analysis (January 1, 2009, to December 31, 2011) of a prospectively developed trauma registry (TRENAU), in which the triage scheme combines patient severity and hospital facilities. Thresholds for MT were defined as either classic (≥10 red blood cell units within the first 24 hours [MT1]) or critical (≥3 red blood cells within the first hour [MT2]). The receiver operating characteristic curves and gray zones were defined for SI and PP/HR ratio to predict MT1 and MT2 and faced with initial triage scheme. RESULTS The TRENAU registry included 3,689 trauma patients, of which 2,557 had complete chart recovery and 176 (6.9%) required MT. In the whole population, PP/HR ratio and SI moderately and similarly predicted MT1 (area under the receiver operating characteristic curve, 0.77 [95% confidence interval {CI}, 0.70–0.84] and 0.80 [95% CI, 0.74–0.87], respectively, p = 0.064) and MT2 (0.71 [95% CI, 0.67–0.76] and 0.72 [95% CI, 0.68–0.77], respectively, p = 0.48). The proportions of patients in the gray zone for PP/HR ratio and SI were 61% versus 40%, respectively, to predict MT1 (p < 0.001) and 62% versus 71%, respectively, to predict MT2 (p < 0.001). In the least severe patient, both indices had fair accuracy to predict MT1 (0.91 [95% CI, 0.82–1.00] vs. 0.87 [95% CI, 0.79–1.00]; p = 0.638), and PP/HR ratio outperformed SI to predict MT2 (0.72 [95% CI, 0.59–0.84] vs. 0.54 [95% CI, 0.33–0.74]; p < 0.015). CONCLUSIONS In an unselected trauma population, prehospital SI and PP/HR ratio were moderately accurate in predicting MT. In the seemingly least severe patients, an improvement of prehospital undertriage for MT may be gained by using the PP/HR ratio. LEVEL OF EVIDENCE Epidemiolgic study, level III.

Mannitol Improves Brain Tissue Oxygenation in a Model of Diffuse Traumatic Brain Injury.

Objectives:Based on evidence supporting a potential relation between posttraumatic brain hypoxia and microcirculatory derangements with cell edema, we investigated the effects of the antiedematous agent mannitol on brain tissue oxygenation in a model of diffuse traumatic brain injury. Design:Experimental study. Setting:Neurosciences and physiology laboratories. Subjects:Adult male Wistar rats. Interventions:Thirty minutes after diffuse traumatic brain injury (impact-acceleration model), rats were IV administered with either a saline solution (traumatic brain injury-saline group) or 20% mannitol (1 g/kg) (traumatic brain injury-mannitol group). Sham-saline and sham-mannitol groups received no insult. Measurements and Main Results:Two series of experiments were conducted 2 hours after traumatic brain injury (or equivalent) to investigate 1) the effect of mannitol on brain edema and oxygenation, using a multiparametric magnetic resonance–based approach (n = 10 rats per group) to measure the apparent diffusion coefficient, tissue oxygen saturation, mean transit time, and blood volume fraction in the cortex and caudoputamen; 2) the effect of mannitol on brain tissue PO2 and on venous oxygen saturation of the superior sagittal sinus (n = 5 rats per group); and 3) the cortical ultrastructural changes after treatment (n = 1 per group, taken from the first experiment). Compared with the sham-saline group, the traumatic brain injury-saline group had significantly lower tissue oxygen saturation, brain tissue PO2, and venous oxygen saturation of the superior sagittal sinus values concomitant with diffuse brain edema. These effects were associated with microcirculatory collapse due to astrocyte swelling. Treatment with mannitol after traumatic brain injury reversed all these effects. In the absence of traumatic brain injury, mannitol had no effect on brain oxygenation. Mean transit time and blood volume fraction were comparable between the four groups of rats. Conclusion:The development of posttraumatic brain edema can limit the oxygen utilization by brain tissue without evidence of brain ischemia. Our findings indicate that an antiedematous agent such as mannitol can improve brain tissue oxygenation, possibly by limiting astrocyte swelling and restoring capillary perfusion.