Armand Mekontso-Dessap

Combination of venoarterial PCO2 difference with arteriovenous O2 content difference to detect anaerobic metabolism in patients.

Abstract.Objective: Under conditions of tissue hypoxia total CO2 production (VCO2) should be less reduced than O2 consumption (VO2) since an anaerobic CO2 production should occur. Thus the VCO2/VO2 ratio, and hence the venoarterial CO2 tension difference/arteriovenous O2 content difference ratio (ΔPCO2/C(a-v)O2), should increase. We tested the value of the ΔPCO2/C(a-v)O2 ratio in detecting the presence of global anaerobic metabolism as defined by an increase in arterial lactate level above 2xa0mmol/l (Lac+). Design and setting: Retrospective study over a 17-month period in medical intensive care unit of a university hospital. Patients: We obtained 148 sets of measurements in 89 critically ill patients monitored by a pulmonary artery catheter. Results: The ΔPCO2/C(a-v)O2 ratio was higher in those with increased (n=73) than in the normolactatemic group (2.0±0.9 vs. 1.1±0.6, p<0.0001). Among all the O2- and CO2-derived parameters the ΔPCO2/C(a-v)O2 ratio had the highest correlation with the arterial lactate level (r=0.57). Moreover, for a threshold value of 1.4 the ΔPCO2/C(a-v)O2 ratio predicted significantly better than the other parameters (receiver operating characteristic curves) the presence of hyperlactatemia (positive and negative predictive values of 86% and 80%, respectively). The overall survival estimate at 1xa0month was greater when the ΔPCO2/C(a-v)O2 ratio was less than 1.4 on the first set of measurements (38±10% vs. 20±8%, p<0.01). Conclusion: The ΔPCO2/C(a-v)O2 ratio seems a reliable marker of global anaerobic metabolism. Its calculation would be helpful for a better interpretation of pulmonary artery catheter data.

B-type natriuretic peptide and weaning from mechanical ventilation

ObjectiveCardiac function and volume status could play axa0critical role in the setting of weaning failure. B-type natriuretic peptide (BNP) is axa0powerful marker of cardiac dysfunction. We assessed the value of BNP during the weaning process.Design, setting and patientsOne hundred and two consecutive patients considered ready to undergo axa01-h weaning trial (T-piece or low-pressure support level) were prospectively included in axa0medical intensive care unit of axa0university hospital. Weaning was considered successful if the patient passed the trial and sustained spontaneous breathing for more than 48u202fh after extubation.InterventionsPlasma BNP was measured just before the trial in all patients, and at the end of the trial in the first 60xa0patients.ResultsOverall, 42xa0patients (41.2%) failed the weaning process (37xa0patients failed the trial and 5 failed extubation). Logistic regression analysis identified high BNP level before the trial and the product of airway pressure and breathing frequency during ventilation as independent risk factors for weaning failure. BNP values were not different at the end of the trial. In nine of the patients in whom the weaning process failed, it succeeded on axa0later occasion after diuretic therapy. Their BNP level before weaning decreased between the two attempts (517 vs 226u202fpg/ml, pu202f=u202f0.01). In survivors, BNP level was significantly correlated to weaning duration (rhou202f=u202f0.52, pu202f<u202f0.01).ConclusionsBaseline plasma BNP level before the first weaning attempt is higher in patients with subsequent weaning failure and correlates to weaning duration.

Delayed hemolytic transfusion reaction in adult sickle-cell disease: presentations, outcomes, and treatments of 99 referral center episodes.

Delayed hemolytic transfusion reaction (DHTR) is one of the most feared complications of sickle‐cell disease (SCD). We retrospectively analyzed the clinical and biological features, treatments and outcomes of 99 DHTRs occurring in 69 referral center patients over 12 years. The first clinical signs appeared a median of 9.4 [IQR, 3–22] days after the triggering transfusion (TT). The most frequent DHTR‐related clinical manifestation was dark urine/hemoglobinuria (94%). Most patients (89%) had a painful vaso‐occlusive crisis and 50% developed a secondary acute chest syndrome (ACS). The median [IQR] hemoglobin‐concentration nadir was 5.5 [4.5–6.3] g/dL and LDH peak was 1335 [798–2086] IU/L. Overall mortality was 6%. None of the patients had been receiving chronic transfusions. Among these DHTRs, 61% were developed in previously immunized patients, 28% in patients with prior DHTR. Among Abs detected after the TT in 62% of the episodes, half are classically considered potentially harmful. No association could be established between clinical severity and immunohematological profile and/or the type and specificity of Abs detected after the TT. Management consisted of supportive care alone (53%) or with adjunctive measures (47%), including recombinant erythropoietin and sometimes rituximab and/or immunosuppressants. Additional transfusions were either ineffective or worsened hemolysis. In some cases, severe intravascular hemolysis can be likely responsible for the vascular reaction and high rates of ACS, pulmonary hypertension and (multi)organ failure. In conclusion, clinicians and patients must recognize early DHTR signs to avoid additional transfusions. For patients with a history of RBC immunization or DHTR, transfusion indications should be restricted. Am. J. Hematol. 91:989–994, 2016.

Incidence, causes and prognosis of hypotension related to meprobamate poisoning

ObjectiveMeprobamate self-poisoning has been reported as potentially inducing hypotension. We examined the incidence and causes of hypotension induced by this poisoning and its prognosis.Design and settingRetrospective observational study conducted in a medical ICU between June 1997 and October 2003. Seventy-four patients admitted for meprobamate poisoning and needing mechanical ventilation were included. Demographic, clinical, and laboratory data were compared between patients with and without hypotension. All echocardiograms recorded in patients with hypotension were reviewed, and left ventricular (LV) and right ventricular (RV) functions were assessed.ResultsTwenty-nine (40%) patients exhibited hypotension without any significant difference in age, gender, cardiac history, or meprobamate concentration in blood when compared to patients without hypotension. Base excess was significantly lower in patients with hypotension. Echocardiography demonstrated a hypokinetic state, associating decreased LV ejection fraction (45±15%) and cardiac index (2±0.7xa0lxa0min−1xa0m−2), and increased inferior vena cava diameter. Most patients with hypotension received inotropic drugs by infusion, and were ventilated for significantly longer.ConclusionsMeprobamate self-poisoning induces hypotension, notably related to cardiac failure, in about 40% of cases. This has important therapeutic consequences, as frequent inotropic drug infusion. The mechanisms of cardiac toxicity remain largely unknown, and no predictive factor could be isolated.

Incidence and predictive score for delayed hemolytic transfusion reaction in adult patients with sickle cell disease

Delayed hemolytic transfusion reaction (DHTR) is a life‐threatening complication of transfusion in sickle cell disease (SCD). The frequency of DHTR is underestimated because its symptoms mimic those of vaso‐occlusive crisis and antibodies (Abs) are often not detectable. No predictive factors for identifying patients likely to develop DHTR have yet been defined. We conducted a prospective single‐center observational study over 30 months in adult sickle cell patients. We included 694 transfusion episodes (TEs) in 311 patients, divided into occasional TEs (OTEs: 360) and chronic transfusion program (CTEs: 334). During follow‐up, 15 cases of DHTR were recorded, exclusively after OTEs. DHTR incidence was 4.2% per OTE (95% CI [2.6; 6.9]) and 6.8% per patient during the 30 months of the study (95% CI [4.2; 11.3]). We studied 11 additional DHTR cases, to construct a predictive score for DHTR. The DHTR mortality is high, 3 (11.5%) of the 26 DHTR patients died. The variables retained in the multivariate model were history of DHTR, number of units previously transfused and immunization status before transfusion. The resulting DHTR‐predictive score had an area under the ROC curve of 0.850 [95% CI: 0.780‐0.930], a negative‐predictive value of 98.4% and a positive‐predictive value of 50%. We report in our study population, for the first time, the incidence of DHTR, and, its occurrence exclusively in occasionally transfused patients. We also describe a simple score for predicting DHTR in patients undergoing occasional transfusion, to facilitate the management of blood transfusion in SCD patients.

Red blood cells for transfusion in patients with sepsis: respective roles of unit age and exposure to recipient plasma

Red blood cell (RBC) storage in blood banks is not exempt from cellular injury. Alterations not observed on RBCs freshly isolated from units can rapidly appear in circulation. The transfusion of old blood units, even if this is a controversial issue, could therefore have adverse effects on the recipient. We wanted to determine the respective effects of storage duration and recipient plasma on RBCs for transfusion into patients with severe sepsis.

Insuffisance rénale aiguë au cours du syndrome de Stevens-Johnson et de la nécrolyse épidermique toxique : une étude rétrospective de 238 patients ☆

Introduction La mortalite des patients presentant un syndrome de Stevens-Johnson (SJS) ou une necrolyse epidermique toxique (NET) varie de 3xa0a 50xa0% pour les patients les plus severes. De nombreux facteurs pronostiques ont ete identifies, notamment un score clinicobiologique, le Scorten et la necessite d’une ventilation mecanique. La prevalence et le pronostic des patients necessitant une epuration extrarenale (EER) n’ont jamais ete etudies. Materiel et methodes Il s’agit d’une etude retrospective ayant inclus les patients admis dans les services de dermatologie et reanimation medicale de l’hopital Henri-Mondor de novembre 1997xa0a octobre 2014. Les caracteristiques cliniques, biologiques, les scores de gravite, l’evolution et la mortalite des patients ont ete recueillis. Les patients necessitant une EER pendant l’hospitalisation ont ete compares aux autres. L’imputabilite du medicament incrimine sur la necessite d’une EER a ete testee par regression logistique uni- et multivariee. Resultats Au total, 238xa0patients ont ete inclus dans l’etude, dont 22 (9,2xa0% [5,5–12,9]) ont necessite une EER pendant leur sejour. Par rapport aux autres, les patients ayant necessite une EER au cours du sejour avaient une presentation plus severe a l’admission avec un pourcentage de surface cutanee decollee plus eleve (45,4xa0vs. 11,6xa0%, p p p p xa0=xa00,005) et necessitaient plus souvent une admission directe en reanimation (63,6xa0vs. 11,5xa0%, p p p xa0=xa00,005). Discussion Cette etude met en evidence l’implication pronostique forte de l’insuffisance renale aigue au cours du SJS/NET, avec une presentation clinique initiale plus severe et une evolution vers le deces tres frequente en cas d’EER. L’insuffisance renale pourrait donc faire l’objet d’une attention particuliere a l’admission, en plus des facteurs pronostiques connus. L’allopurinol semble etre le seul medicament statistiquement associe a la necessite d’EER dans cette etude. Une etude prealable sur le DRESS avait mis en evidence l’association de ce medicament avec la survenue d’une insuffisance renale aigue, possiblement en lien avec les proprietes pharmacologiques propres au medicament. Conclusion Les patients presentant un SJS/NET et necessitant une EER au cours de l’hospitalisation ont une presentation initiale plus severe et une mortalite tres elevee. L’allopurinol semble etre associe a un sur-risque de necessite d’une EER au cours de l’hospitalisation.