Influence of body mass index on outcome of the mechanically ventilated patients.

BACKGROUND: There are limited data on the impact of body mass index on outcomes in mechanically ventilated patients. METHODS: Secondary analysis of a cohort including 4698 patients mechanically ventilated. Patients were screened daily for management of mechanical ventilation, complications (acute respiratory distress syndrome, sepsis, ventilator associated pneumonia, barotrauma), organ failure (cardiovascular, respiratory, renal, hepatic, haematological) and mortality in the intensive care unit. To estimate the impact of body mass index on acute respiratory distress syndrome and mortality, the authors constructed models using generalised estimating equations (GEE). RESULTS: Patients were evaluated based on their body mass index: 184 patients (3.7%) were underweight, 1995 patients (40%) normal weight, 1781 patients (35.8%) overweight, 792 patients (15.9%) obese and 216 patients (4.3%) severely obese. Severely obese patients were more likely to receive low tidal volume based on actual body weight but high volumes based on predicted body weight. In obese patients, the authors observed a higher incidence of acute respiratory distress syndrome and acute renal failure. After adjustment, the body mass index was significantly associated with the development of acute respiratory distress syndrome: compared with normal weight; OR 1.69 (95% CI 1.07 to 2.69) for obese and OR 2.38 (95% CI 1.15 to 4.89) for severely obese. There were no differences in outcomes (duration of mechanical ventilation, length of stay and mortality in intensive care unit and hospital) based on body mass index categories. CONCLUSIONS: In this cohort, obese patients were more likely to have significant complications but there were no associations with increased mortality.

Automatic oxygen administration and weaning in patients following mechanical ventilation.

PURPOSE: To evaluate efficacy of FreeO2 device in oxygen weaning of patients after being liberated from mechanical ventilation (MV). METHODS: Prospective crossover cohort study in patients admitted to ICU and after MV weaning. FreeO2 curves were recorded during constant flow and FreeO2 modes. Oxygenation parameters and O2 consumption were assessed. RESULTS: Fifty one records were obtained in 51 patients (median age, 62 years, 54.9% had COPD, admission for acute respiratory failure in 96%). NIV was used initially in 68.6%. For a median records duration of 2.04 h, the time spent within target SpO2 range was significantly higher with FreeO2 mode compared to constant O2 flow mode [86.92% (77.11-92.39) vs 43.17% (5.08-75.37); p < 0.001]. Time with hyperoxia was lower with FreeO2 mode: 8.68% (2.96-15.59) vs 38.28% (2.02-86.34). Times with hypoxaemia, and with severe desaturation, were similar. At the end of FreeO2 mode, O2 flow was lower than 1 l/min in 28 patients (54.9%), with a median of 0.99 l/min. CONCLUSIONS: For the purpose of oxygen weaning in patients recovering from MV, automatic O2 titration with FreeO2 was associated with a substantial reduction in O2 delivery and better oxygenation parameters in comparison with constant O2 flow.

[Multiple cranial nerve involvement: consider the diagnosis of cephalic tetanus. A case report and review of the literature]. / Atteinte multiple des nerfs crâniens : atteinte multiple des nerfs crâniens au cours du tétanos céphalique. À propos d'une observation et revue de la littérature.

INTRODUCTION: Cephalic tetanus is the most serious form of localized tetanus. It associates trismus with impairment of one or more cranial nerves. It was a rare condition, whose diagnosis can raise several problems. CASE REPORT: A 49-year-old-man presented multiple and unilateral cranial nerve involvement revealing cephalic tetanus. CONCLUSION: This case illustrates the importance of considering cephalic tetanus when patients present cranial nerve palsy associated with injury.

Cardiac dysfunction and pulmonary edema following scorpion envenomation.

Cardiac dysfunction with pulmonary edema following scorpion envenomation (SE) has been documented only in a few isolated case reports. We conducted a systematic hemodynamic study in five consecutive patients (mean age, 21.6 +/- 8 years) presenting with pulmonary edema occurring a few hours (9.6 +/- 5.2 hours) after SE. All patients had increased pulmonary capillary wedge pressure (mean, 25 +/- 1.8 mm Hg) while the systemic vascular resistance was elevated only in one. The stroke volume index was markedly depressed (21.7 +/- 3.6 ml/sq m) whereas cardiac index was normal or slightly decreased (2.5 +/- 0.4 L/min/sq m). Cerebral infarct and sudden cardiac arrest were the cause of death in two patients. In the three survivors, all the hemodynamic disturbances and respiratory abnormalities disappeared within a few days. We conclude that cardiac dysfunction was found in all five patients and this was reversible in the three surviving the acute episode.

Prognostic value of serum cholinesterase in organophosphate poisoning.

OBJECTIVE: To determine whether serum cholinesterase level has a prognostic value in human acute organophosphorus poisoning. DESIGN: Cohort (prospective) prognosis study. SETTING: Medical ICU at University Hospital. PATIENTS: Thirty consecutive patients admitted to the ICU for acute organophosphate poisoning. MEASUREMENTS: Serum cholinesterase level was measured in all patients at the time of hospital admission. Severity of intoxication was assessed by the total dose of atropine required to relieve poisoning manifestations, the Simplified Acute Physiology Score, the need for assisted ventilation, and by a specific grading system previously validated that identified two groups of patients: group 1 (low severity, n = 18) and group 2 (high severity, n = 12). RESULTS: Serum cholinesterase level did not correlate with the total dose of atropine or with the Simplified Acute Physiology Score. Mean serum cholinesterase level was not significantly different between group 1 and group 2 patients (448 +/- 409 U/L in group 1 compared with 611 +/- 575 U/L in group 2 (p = NS); it was also not significantly different between patients with and without mechanical ventilation support (567 +/- 571 vs 470 +/- 409, respectively). CONCLUSION: Serum cholinesterase levels have no prognostic value in acute organophosphate poisoning. Thus, a grading system to identify high-risk patients based on this measurement is most likely unreliable.

Right ventricular dysfunction following severe scorpion envenomation.

OBJECTIVE: Evaluation of right ventricular (RV) performance in patients presenting with pulmonary edema following scorpion envenomation. DESIGN: Cohort study. SETTING: Medical intensive care unit of a teaching hospital. PATIENTS: Eight consecutive adult patients stung by yellow scorpion Androctonus australis and presenting with pulmonary edema at hospital admission. INTERVENTIONS: In all patients, standard hemodynamic parameters and RV volumes were measured using a pulmonary artery catheter equipped with a rapid responding thermistor enabling measurement of RV ejection fraction (RVEF). MEASUREMENTS: Hemodynamic evaluation was performed at the time of hospital admission prior to any therapeutic intervention and just before the removal of the pulmonary catheter (2.3 +/- 0.5 days after admission) in the surviving patients (n = 7). RESULTS: All patients had a decreased RVEF (24 +/- 7%) and cardiac index (2.44 +/- 0.5 L/min/m2) and increased pulmonary artery occlusion pressure (23 +/- 6 mm Hg). Right ventricular end-systolic pressure/volume ratio was decreased (.56 +/- .19 mm Hg/mL/m2), suggesting an altered RV contractility. Follow-up evaluation performed in survivors, without any inotropic support, showed hemodynamic changes reflecting a trend toward full recovery. Right ventricular ejection fraction and cardiac index improved markedly (from 24 +/- 7% to 39 +/- 10% and from 2.44 +/- 0.5 to 4 +/- .3 L/min/m2, respectively). Pulmonary artery occlusion pressure, peak systolic pulmonary artery pressure, and mean pulmonary artery pressure decreased significantly from baseline values (12 +/- 3 mm Hg, 29 +/- 5 mm Hg, and 20 +/- 4 mm Hg, respectively). Right ventricular end systolic pressure/volume ratio remained almost constant, suggesting that afterload enhancement accounted predominantly for RVEF improvement. CONCLUSION: These data show that RV function impairment is associated with left ventricular dysfunction, suggesting similarities between left ventricular and RV alterations following severe scorpion envenomation providing further arguments to the hypothesis of scorpionic myocarditis.

Dobutamine in severe scorpion envenomation: effects on standard hemodynamics, right ventricular performance, and tissue oxygenation.

OBJECTIVES: To document the effects of dobutamine on standard hemodynamics and right ventricular (RV) performance in patients exhibiting pulmonary edema following severe scorpion envenomation, and to characterize the tissue oxygenation profile in patients sustaining scorpion envenomation-related shock. DESIGN: Prospective cohort study. SETTING: An ICU in a university hospital. PATIENTS: Nineteen consecutive patients were admitted to the ICU for severe scorpion envenomation; all 19 patients exhibited hemodynamic pulmonary edema, and 10 patients had peripheral shock. INTERVENTIONS: All patients underwent a hemodynamic study with a Swan-Ganz catheter. In 8 of 19 patients, the thermodilution catheter was equipped with a fast-response thermistor. MEASUREMENTS AND RESULTS: Standard hemodynamic parameters were recorded on admission and following the infusion of dobutamine in all patients at a dosage, from 7 to 20 microg/kg/min, intended to achieve the best hemodynamic and tissue oxygenation compromise. RV ejection fraction (RVEF) and RV volumes were simultaneously recorded in 8 patients, and tissue oxygenation parameters were assessed in the 10 patients with peripheral shock. The clinical signs of tissue hypoperfusion improved, and optimal hemodynamic parameters were achieved at a mean +/- SD dobutamine dosage of 17 +/- 7 microg/kg/min. Dobutamine infusion evoked statistically significant increases in cardiac index, from 2.3 +/- 0.6 to 3.6 +/- 0.7 L/min/m2; stroke volume index, from 18 +/- 5 to 31 +/- 10 mL/m2; and systemic arterial pressure, from 64 +/- 12 to 78 +/- 14 mm Hg. Pulmonary artery occlusion pressure (PAOP) and venous admixture decreased significantly: from 23 +/- 4 to 15 +/- 6 mm Hg and from 29 +/- 7% to 20 +/- 5%, respectively. With respect to RV function, dobutamine infusion significantly increased the RVEF, from 24 +/- 7% to 42 +/- 9%, without significantly changing the RV end-diastolic volume index, reflecting an enhanced RV contractility. In patients with peripheral circulatory failure, the baseline tissue oxygenation profile was consistent with cardiogenic shock, showing increased oxygen extraction as a consequence of a striking depression in oxygen delivery (DO2). After dobutamine infusion, DO2 improved significantly, from 386 +/- 104 to 676 +/- 156 mL/min/m2, with a significant decrease in oxygen extraction, from 34 +/- 8% to 24 +/- 6%. CONCLUSIONS: In severe scorpion envenomation, dobutamine infusion improves impaired heart function. The effects involve both left ventricular and RV dysfunction. Impaired tissue oxygenation is also improved.

Short-term treatment of severe hypertension of pregnancy: prospective comparison of nicardipine and labetalol.

OBJECTIVES: To assess the efficacy and safety of nicardipine in comparison to labetalol in the initial management of severe hypertension in pregnancy. DESIGN. Randomized prospective study. SETTING: The obstetric ward of the teaching hospital of Monastir Tunisia. PATIENTS: Sixty consecutive pregnant women admitted beyond the 24th week of pregnancy with severe hypertension. INTERVENTION: Patients were randomly assigned to receive intravenously for 1 h either labetalol ( n=30) or nicardipine ( n=30). Treatment was titrated to achieve a 20% lowering of blood pressure (BP). MEASUREMENTS: Maternal BP and heart rate were measured at inclusion and repeatedly during the first hour following the drugs administration. Fetal heart rate was recorded throughout the study period. The main outcome endpoints were the success rate and the length of time needed to achieve the therapeutic goal. The rate of maternal and fetal adverse events and dose adjustments were also analyzed. RESULTS: Labetalol and nicardipine achieved the 20% lowering in BP in the same proportion (63% and 70% success rates, respectively). Overall nicardipine caused a significantly greater decrease in systolic and diastolic BP. No patient had any episode of hypotension. The length of time to achieve the BP goal was also similar (12 vs. 11 min, respectively). Both drugs were well tolerated except for a moderate tachycardia observed with the use of nicardipine. CONCLUSION: Nicardipine and labetalol are effective and safe in the initial treatment of severe hypertension of pregnancy.

A controlled trial of nebulized salbutamol and adrenaline in acute severe asthma.

OBJECTIVE: To compare efficacy and safety of nebulisation of adrenaline (2 mg over 10 min) and salbutamol (5 mg over 10 min) in acute severe asthma. DESIGN: Prospective randomized and double blind study. SETTING: Intensive care unit of a University teaching hospital. PATIENTS AND PARTICIPANTS: 22 asthmatic patients presenting to the emergency room with acute severe asthma. INTERVENTIONS: Patients were randomly assigned to receive either adrenaline (n = 11) or salbutamol (n = 11) via a nebulizer. Additional treatment comprised hydrocortisone hemisuccinate (100 mg) and supplemental oxygen (71/min). The efficacy and safety of both drugs were evaluated at 20 and 40 min. RESULTS: A statistically significant increase in the Peak Expiratory Flow (PEF) was achieved at the 20th min in both groups (from 85 +/- 38 l/min to 120 +/- 45 l/min; p < 0.001; and from 107 +/- 28 l/min to 145 +/- 19 l/min; p < 0.001; in adrenaline group and salbutamol group respectively). With both drugs, PEF further increased at 40 min to a level that was statistically significant when compared to the 20 min evaluation. The magnitude of the absolute variation in PEF was similar with both drugs. Both drugs induced a significant decrease in heart rate, respiratory frequency and PaCO2 while the increase of PaO2/FIO2 ratio was not significant. The decrease of respiratory frequency at 40 min was more important with salbutamol (p = 0.03). No side effects were recorded in both groups. CONCLUSION: After a single dose, nebulized adrenaline (2 mg) proved as effective and safe as salbutamol (5 mg) in acute severe asthma.

Hellp syndrome: incidence and maternal-fetal outcome--a prospective study.

OBJECTIVE: To determine the incidence of Hellp syndrome (HS) and the maternal fetal outcome associated with its occurrence. DESIGN: A prospective study during a 6-month period. SETTING: The department of obstetrics and gynecology and the Intensive Care Unit of a 700 bed teaching hospital. PATIENTS: Sixty-two consecutive preeclamptic and eclamptic women. MEASUREMENTS AND RESULTS: All patients were systematically investigated for the biological markers of HS. The effects of the occurrence of HS on maternal and fetal prognosis were evaluated by comparing for prognosis indicators usually assessed in gravidic hypertension, pre-eclamptic and eclamptic woman who exhibited HS (HS+ subgroup) with HS free patients (HS- subgroup). HS was found in 12 out of the 62 pre-eclamptic and eclamptic women (19.3%). Its occurrence was associated with higher maternal mortality (16.7% vs 0%; p = 0.03), a greater incidence of eclamptic crisis (50% vs 20%; p = 0.03), severe hypertension (33% vs 8%; p = 0.03) and episodes of acute renal failure (66% vs 30%; p = 0.02). Mean proteinuria was also higher in HS+ patients (4.6 +/- 3.3 vs 2.2 +/- 2.5 g/day; p = 0.001). However, fetal outcome was not significantly altered. CONCLUSION: Pre-eclampsia and eclampsia may be more severe in the presence of HS with a worsening of maternal prognosis while fetal outcome seems not altered.

Assessment of left ventricular function in severe scorpion envenomation: combined hemodynamic and echo-Doppler study.

OBJECTIVE: To assess left ventricular function in patients presenting with pulmonary edema following scorpion envenomation. DESIGN: Cohort study. SETTING: Medical intensive care unit of a teaching hospital. PATIENTS: Nine consecutive adult patients stung by Androctonus australis and presenting with pulmonary edema entered the study. Fourteen normal volunteers comprised the control group. INTERVENTIONS: Upon admission, all patients had right heart catheterization and, within the first 8 h, a Doppler echocardiographic study. Results of Doppler echocardiographic studies were compared to those of controls. MEASUREMENTS AND RESULTS: Usual hemodynamic information (heart and vascular pressures, derived data and tissue oxygenation parameters), left ventricular dimensions and indicators of systolic function, and Doppler-derived parameters of left ventricular filling and diastolic function were obtained upon admission. Serial echocardiographic measurements were repeated daily until full clinical recovery (eight patients) or death (one patient). All patients had a hemodynamic profile of acute congestive heart failure (mean PAOP = 24 +/- 2 mmHg; mean SVI = 22 +/- 7 ml/m2; mean CI = 2.5 +/- 0.5 l/min/m2). However, SVR were not increased (mean = 22 +/- 3 U/m2). Left ventricle was hypokinetic in all patients with transient mitral regurgitation present in five patients. Left ventricular systolic function was markedly depressed (FS = 12 +/- 6%; EF = 26 +/- 12%). An associated diastolic dysfunction is suggested by Doppler records of mitral inflow. Left ventricular systolic function evolved toward normalization within 6 +/- 2 days preceded by full clinical recovery. CONCLUSIONS: These data suggest that pulmonary edema in scorpion envenomation is of hemodynamic origin and is related to a severe and prominent impairment of left ventricular systolic function.

Successful weaning from mechanical ventilation following balloon mitral commissurotomy.

Successful weaning from mechanical ventilation (MV) following percutaneous balloon mitral commissurotomy (BMC) is reported in a 59-year-old woman with severe symptomatic rheumatic mitral stenosis. The patient was admitted to the Intensive Care Unit for acute respiratory failure secondary to pulmonary edema requiring intubation and mechanical ventilation. After resolution of the acute phase, she became completely dependent on mechanical ventilatory support. In spite of the reinforcement of conventional therapy (diuretics, digitalis, vasodilators), weaning attempts were unsuccessful because of persisting elevated left atrial pressure. Percutaneous BMC was performed with favorable hemodynamic results, allowing the removal of external ventilatory support 24 h later and discharge from the Intensive Care Unit the same day.

Intensive care use in a developing country: a comparison between a Tunisian and a French unit.

OBJECTIVES: To compare the variations in intensive care (ICU) outcome in relation to variations in resources utilization and costs between a developed and a developing country with different medical and economical conditions. DESIGN AND SETTING: Prospective comparison between a 26-bed French ICU and an 8-bed Tunisian ICU, both in university hospitals. PATIENTS: Four hundred thirty and 534 consecutive admissions, respectively, in the French and Tunisian ICUs. MEASUREMENTS: We prospectively recorded demographic, physiologic, and treatment information for all patients, and collected data on the two ICU structures and facilities. Costs and ICU outcome were compared in the overall population, in three groups of severity indexes and among selected diagnostic groups. RESULTS: Tunisian patients were significantly younger, were in better health previously and were less severely ill at ICU admission (p < 0.01). French patients had a lower overall mortality rate (17.2 vs 22.5%; p < 0.01) and received more treatment (p < 0.01). In the low severity range, the outcome and costs were similar in the two countries. In the highest severity range, Tunisian and French patients had similar mortality rates, while the former received less therapy throughout their ICU stays (p < 0.05). Conversely, in the mid-range of severity, mortality was higher among Tunisian patients, and a difference in management was identified in COPD patients. CONCLUSION: Although the Tunisian ICU might appear more cost-effective than the French one in the highest severity group of patients, most of this difference appeared in relation to shorter lengths of ICU stay, and a poorer efficiency and cost-effectiveness was suggested in the mid-range severity group. Differences in economical constraints may partly explain differences in ICU performances. These results indicate where resource allocation could be directed to improve the efficiency of ICU care.

Development of an ELISA for the detection of scorpion venoms in sera of humans envenomed by Androctonus australis garzonii (Aag) and Buthus occitanus tunetanus (Bot): correlation with clinical severity of envenoming in Tunisia.

A sandwich ELISA was set up for measuring scorpion venom levels in sera of accidentally envenomed humans with the aim to establish a quantitative relationship between these levels, envenoming severity and clinical symptoms. This assay used equine polyclonal F(ab')2, specific to two North African scorpion (Androctonus australis garzonii: Aag and Buthus occitanus tunetanus: Bot) venoms. The test proved to be simple, reproducible, very sensitive (detection limit = 0.9 ng/ml) and linear between 0.5 and 15 ng/ml of venom concentrations. A large survey on scorpion sting envenomings was conducted from 1993 to 1996 in Tunisia to gather accurate epidemiological, clinical and biological data from victims as well as informations on the treatment that they had received. Victims were classified into three grades (GI, GII and GIII) of increasing severity according to clinical signs of envenoming. Blood samples were collected from victims and tested by ELISA for their content of Aag and Bot venoms. A strong correlation was found between clinical symptoms of envenoming and the level of scorpion venom antigens in serum (r = 0.980). Mean serum venom concentrations were: 2.65 +/- 0.81 ng/ml in GI envenoming, 9.79 +/- 4.08 ng/ml in GII and 21.7 +/- 6.51 ng/ml in GIII. The difference between each group was statistically significant (p < 0.01). This ELISA may prove to be helpful to establish a rationale approach of specific antivenom therapy.

[Thrombophlebitis of the ovarian vein. Apropos of 2 cases]. / La thrombophlébite de la veine ovarienne. A propos de 2 cas.

Thrombophlebitis of the ovarian vein is a rare post-partum complication. Its diagnosis is said to be difficult, but was greatly facilitated by the progress made in imaging. The authors report about two cases identified with computed tomography. Evolution was favorable in both cases with an anticoagulant and antibiotic treatment.

[Sleep apnea syndromes and Arnold-Chiari malformation]. / Syndrome d'apnées du sommeil et malformation d'Arnold-Chiari.

The Arnold-Chiari malformation (MAC), ectopic medulla of the cerebral hemispheres, may be the basis of respiratory problems provoked by compression of the respiratory centre. It is associated with numerous respiratory problems in children; there are however few publications related to the association of MAC and ventilatory problems in adults. It was recently suggested and subsequently shown that the syndrome of sleep apnoea (SAS) could occur in relation to MAC. We report a new observation documenting the association of MAC and SAS. The surgical cure of MAC enabling a remission of SAS suggests the existence in this case of a causal relation between the two pathologies. A search for such a malformation by imagery of the occipito-medullary crest should be a part of the work up in SAS when the cause remains undetermined.

[C-reactive protein in bacterial meningitis in adults]. / La protéine c-réactive dans les méningites bactériennes de l'adulte.

In order to assess the benefits of serial assays of C-reactive protein in the course of bacterial meningitis in adults, daily blood samples were taken for CRP measurement during 10 days in 21 consecutive patients (mean age: 24 +/- 8 years) hospitalized for bacterial meningitis principally due to Neisseria meningitidis (n = 15). The highest CRP level (178 +/- 38 mg/l) was present on admission, followed by a regular decrease occurring in uncomplicated meningitis until normal level was achieved on day 9. The CRP kinetics was not influenced by the type of causative micro-organism. This study shows that CRP kinetics in adults is similar to that reported in children. The benefit of CRP assays in optimizing the duration of antibiotic treatment of meningitis needs to be more carefully assessed.

[Pulmonary embolism and paradoxical embolism in a patient with chronic respiratory insufficiency treated with mechanical ventilation]. / Embolie pulmonaire et embolie paradoxale chez un insuffisant respiratoire chronique en ventilation mécanique.

The authors report a case of paradoxical embolism associated with pulmonary embolism in a male patient under mechanical ventilation for chronic respiratory failure. They review the present diagnostic criteria of paradoxical embolism and insist on the determinant contribution of contrast echocardiography to the diagnosis. They also discuss the factors which make this type of patient liable to reopening of the foramen ovale and to paradoxical embolism. The clinical and gasometric characteristics of pulmonary embolism occurring in patients under mechanical ventilation are detailed.

Impact of the humidification device on intubation rate during noninvasive ventilation with ICU ventilators: results of a multicenter randomized controlled trial.

PURPOSE: The use of heat and moisture exchangers (HME) during noninvasive ventilation (NIV) can increase the work of breathing, decrease alveolar ventilation, and deliver less humidity in comparison with heated humidifiers (HH). We tested the hypothesis that the use of HH during NIV with ICU ventilators for patients with acute respiratory failure would decrease the rate of intubation (primary endpoint) as compared with HME. METHODS: We conducted a multicenter randomized controlled study in 15 centers. After stratification by center and type of respiratory failure (hypoxemic or hypercapnic), eligible patients were randomized to receive NIV with HH or HME. RESULTS: Of the 247 patients included, 128 patients were allocated to the HME group and 119 to the HH group. Patients were comparable at baseline. The intubation rate was not significantly different: 29.7% in the HME group and 36.9% in the HH group (p = 0.28). PaCO2 did not significantly differ between the two arms, even in the subgroup of hypercapnic patients. No significant difference was observed for NIV duration, ICU and hospital LOS, or ICU mortality (HME 14.1 vs. HH 21.5%, p = 0.18). CONCLUSIONS: In this study, the short-term physiological benefits of HH in comparison with HME during NIV with ICU ventilators were not observed, and no difference in intubation rate was found. The physiologic effects may have been obscured by leaks or other important factors in the clinical settings. This study does not support the recent recommendation favoring the use of HH during NIV with ICU ventilators.