Pierre Lavagne

Assessing pain in critically ill sedated patients by using a behavioral pain scale

Objective To establish the validity and reliability of a new behavioral pain scale (BPS) for critically ill sedated adult patients. Design Prospective evaluation. Setting Ten-bed trauma and surgical intensive care unit in a university teaching hospital. Patients Thirty mechanically ventilated patients who were receiving analgesia and sedation. Intervention Assessments with the BPS were completed consecutively at standardized times (morning, afternoon, night) by pairs of evaluators (nurse and nurse’s aide). They collected physiologic parameters and BPS results before and during care procedures: nonnociceptive (group 1, compression stockings application and central venous catheter dressing change), nociceptive (group 2, endotracheal suctioning and mobilization), and retested nociceptive (group 3). The BPS score was the sum of three items that had a range score of 1–4: facial expression, movements of upper limbs, and compliance with mechanical ventilation. Measurements and Main Results Two hundred and sixty nine assessments were completed, including 104, 134, and 31 measurements in groups 1, 2 and 3, respectively. There was no difference in Ramsay scale scores between the three groups (Ramsay 4–6). Nociceptive stimulations (group 2) resulted in significantly higher BPS values than nonnociceptive ones (group 1, 4.9 vs. 3.5, p < .01), whereas the two groups had comparable BPS values before stimulation (3.1 vs. 3.0). A trend was found in group 2 between the dosage of sedation/analgesia and BPS: the higher the dosage, the lower BPS values and BPS changes to nociceptive stimulation. Group 3 had BPS values similar to group 2 at rest (3.2 vs. 3.2) and during the procedure (4.4 vs. 4.5), with good interrater correlations (r2 = .71 and .50, respectively). Conclusions These results indicate that the expression of pain can be scored validly and reliably by using the BPS in sedated, mechanically ventilated patients. Further studies are warranted regarding the utility of the BPS in making clinical decisions about the use of analgesic drugs in the intensive care unit.

Equimolar doses of mannitol and hypertonic saline in the treatment of increased intracranial pressure.

Objective:To compare the effects of equimolar doses of 20% mannitol solution and of 7.45% hypertonic saline solution (HSS) in the treatment of patients with sustained elevated intracranial pressure (ICP). Design:Parallel, randomized, controlled trial. Setting:Two intensive care units in a university hospital. Patients:A total of 20 stable patients with a sustained ICP of >20 mm Hg secondary to traumatic brain injury (n = 17) or stroke (n = 3). Interventions:A single equimolar infusion (255 mOsm dose) of either 231 mL of 20% mannitol (mannitol group; n = 10 patients) or 100 mL of 7.45% hypertonic saline (HSS group; n = 10 patients) during 20 mins of administration. Measurements:ICP, arterial blood pressure, cerebral perfusion pressure, blood flow velocities of middle cerebral artery using continuous transcranial Doppler, brain tissue oxygen tension, serum sodium and osmolality, and urine output during a study period of 120 mins. Main Results:The two treatments equally and durably reduced ICP during the experiment. At 60 mins after the start of the infusion, ICP was reduced by 45% ± 19% of baseline values (mean ± sd) in the mannitol group vs. 35% ± 14% of baseline values in the HSS group. Cerebral perfusion pressure and diastolic and mean blood flow velocities were durably increased in the mannitol group, resulting in lower values of pulsatility index at the different times of the experiment (p < .01 vs. HSS). No major changes in brain tissue oxygen tension were found after each treatment. Mannitol caused a significantly greater increase in urine output (p < .05) than HSS, although there was no difference in the vascular filling requirement between the two treatments. HSS caused a significant elevation of serum sodium and chloride at 120 mins after the start of the infusion (p < .01). Conclusions:A single equimolar infusion of 20% mannitol is as effective as 7.45% HSS in decreasing ICP in patients with brain injury. Mannitol exerts additional effects on brain circulation through a possible improvement in blood rheology. Pretreatment factors, such as serum sodium, systemic hemodynamics, and brain hemodynamics, thus should be considered when choosing between mannitol and HSS for patients with increased ICP.

Œdème cérébral par lésion de la barrière hématoencéphalique : mécanismes et diagnostic

Resume L’œdeme cerebral par lesion de la barriere hematoencephalique (BHE) ou œdeme vasogenique, est present dans la plupart des œdemes cerebraux. Selon la loi de Starling, le passage transmembranaire d’eau, d’ions et de proteines dans le secteur interstitiel peut s’effectuer en raison d’un gradient excessif de pression hydrostatique (origine mecanique) et/ou d’une augmentation de la permeabilite membranaire (origine chimique). Les deux mecanismes coexistent la plupart du temps. Le role d’une elevation du gradient de pression hydrostatique avec perte de l’autoregulation cerebrale a ete evoque dans la reperfusion d’une zone ischemique, le traumatisme crânien, le mal aigu des montagnes et l’eclampsie. La permeabilite de la BHE peut etre augmentee sous l’effet d’une reaction inflammatoire et/ou d’une atteinte de l’integrite membranaire. La reaction inflammatoire est mediee par de nombreux facteurs chimiques liberes par l’endothelium vasculaire (bradykinine) et par une reponse cellulaire secondaire (infiltrat leucocytaire et macrophagique). Ceci s’observe au cours du traumatisme crânien, de l’ischemie et des processus infectieux. Une atteinte de l’integrite physique de la BHE est aussi possible, soit de maniere transitoire (ouverture de la BHE), par exemple apres hyperosmolarite induite, soit de maniere permanente apres degradation enzymatique (metalloproteinases) ou par proliferation de neovaisseaux ayant une BHE absente ou partiellement rompue, sous l’influence du facteur de croissance endothelial (VEGF). C’est le cas des tumeurs et des lesions tissulaires postischemiques. La technique de choix pour le diagnostic d’œdeme vasogenique chez l’homme repose sur la mesure du coefficient de diffusion de l’eau par IRM, qui donne une information localisee et rapide sur la nature exacte de l’œdeme, vasogenique ou cellulaire.

Long-term results following emergency stent graft repair for traumatic rupture of the aortic isthmus†

Objectives Endovascular repair of traumatic injury of the aortic isthmus is a safe technique that has shown good short-term results. However, the future of these stent grafts remains unexamined, especially in relation to young patients. Methods Between January 2000 and December 2014, 60 patients were treated with endovascular aortic stent graft for injury of the aortic isthmus. Follow-up was done by computed tomography scans with intravenous contrast or magnetic resonance imaging associated with a chest X-ray in order to control the stent graft. Results In total, 48 men (80%) were included; the average age was 43 ± 17 years [17; 79]. The median time between the accident and endovascular repair was 6 h. Endovascular repair was successful in all cases with no cerebrovascular or paraplegia after treatment. Seventeen patients (27.3%) received a total coverage of the left subclavian artery; one of them received a subclavian carotid bypass. Mean follow-up was 5 years with a maximum of 14 years. There was no repeat surgery related to the aorta during follow-up. No stent graft failure, neurological or ischaemic event related to the stent graft was noted. One patient had a type 1 endoleak without any reintervention. The survival rate was 86.5% in 1 year, 81.6% in 5 years and 75.3% in 10 years. Conclusions Treatment of injuries of the aortic isthmus with stent graft seems to be a safe long-term technique; we did not notice any event related to the stent graft during the follow-up.

Le diverticule aortique: un diagnostic différentiel des lésions traumatiques de l'aorte thoracique

We report the case of a 31-year-old patient with a chest trauma after a mountaineering accident. Contrast enhanced spiral computed tomography of the thorax showed a lesion of the aortic isthmus, suspected of being an aortic disruption. As the diagnosis of aortic rupture could not be formally established with computed tomography, a transoesophageal echocardiography and an aortic angiography were performed which showed a ductus diverticulum, representing one of the differential diagnoses of traumatic aortic disruption. A knowledge of this entity and its diagnostic criteria may avoid an unnecessary thoracotomy.