Anne Veinstein

Sequential Application of Oxygen Therapy Via High-Flow Nasal Cannula and Noninvasive Ventilation in Acute Respiratory Failure: An Observational Pilot Study

BACKGROUND: The aim of this study was to evaluate the clinical efficacy of humidified oxygen via high-flow nasal cannula (HFNC) alternating with noninvasive ventilation (NIV) in acute hypoxemic respiratory failure (AHRF). METHODS: We performed a prospective observational study in a 12-bed ICU of a university hospital. All subjects with a PaO2/FIO2 of ≤ 300 mm Hg with standard mask oxygen and a breathing frequency of > 30 breaths/min or signs of respiratory distress were included and treated with HFNC first and then NIV. Ventilatory parameters, blood gases, and tolerance were recorded during 2 consecutive sessions of NIV and HFNC. Outcome was assessed after continuation of this noninvasive strategy. RESULTS: Twenty-eight subjects with AHRF were studied, including 23 (82%) with ARDS. Compared with standard oxygen therapy, PaO2 significantly increased from 83 (68–97) mm Hg to 108 (83–140) mm Hg using HFNC and to 125 (97–200) mm Hg using NIV (P < .01), whereas breathing frequency significantly decreased. HFNC was significantly better tolerated than NIV, with a lower score on the visual analog scale. The non-intubated subjects received HFNC for 75 (27–127) h and NIV for 23 (8–31) h. Intubation was required in 10 of 28 subjects (36%), including 8 of 23 subjects with ARDS (35%). After HFNC initiation, a breathing frequency of ≥ 30 breaths/min was an early factor associated with intubation. CONCLUSIONS: HFNC was better tolerated than NIV and allowed for significant improvement in oxygenation and tachypnea compared with standard oxygen therapy in subjects with AHRF, a large majority of whom had ARDS. Thus, HFNC may be used between NIV sessions to avoid marked impairment of oxygenation.

Lack of effect of extracorporeal membrane oxygenation on tigecycline pharmacokinetics

Prevalence of faecal carriage of Enterobacteriaceae with NDM-1 carbapenemase at military hospitals in Pakistan, and evaluation of two chromogenic media. Sir, Extremely limited data are available on the pharmacokinetics of antimicrobial agents during extracorporeal membrane oxygen-ation (ECMO). We report the case of a young adult patient who was admitted on day 1 to our intensive care unit for acute respiratory failure due to intra-alveolar haemorrhage. Ventilator-acquired pneumonia due to Staphylococcus epidermidis and Staphylococcus warneri developed, initially treated with intravenous vancomycin. Despite maximal ventilator settings, optimal respiratory function could not be obtained, so veno-venous ECMO was started on day 38. The system comprised a membrane oxygenator (Quadrox Bioline, Jostra-Maquet, Orleans, France) and a centrifugal pump (Biomedicus 560, Medtronic, Minneapolis, MN, USA). Yet on day 50, respiratory conditions worsened. A persistent S. epidermidis pulmonary infection was observed, with induction of vancomycin resistance requiring antibiotic change to tigecycline on day 55. The patients renal function remained stable during hospital stay (CL CR 95 mL/min), but despite therapy and complete bacteria eradication the patients condition continued to deteriorate until death occurred on day 61. Tigecycline concentrations were measured by liquid chromatography–tandem mass spectrometry in plasma and tracheal aspirate. was used to predict tigecycline concentrations using population mean parameter estimates from a previously published pharmacokinetic study in critical care patients. 2 The tigecycline dosing regimen and concentrations are presented in Table 1. Interestingly, concomitant tigecycline concentrations measured in plasma and aspirate were virtually identical. The potential effect of ECMO on tigecycline pharmacokinet-ics had never been investigated before. Tigecycline is characterized by a large volume of distribution with a population mean value of 398 L in critical care patients, 2 which is therefore unlikely to be noticeably increased simply by dilution into the system, but adsorption on the circuit membranes could not be excluded. 3,4 However, measured tigecycline plasma concentrations were virtually similar to the values predicted for a critically ill patient with CL CR ¼ 95 mL/min and body surface area ¼ 1.42 m 2 , 2 suggesting that ECMO has no effect on tige-cycline pharmacokinetics. Table 1. Plasma and tracheal aspirate concentrations of tigecycline administered intravenously at a dose of 50 mg twice daily simultaneously to ECMO Measured tigecycline concentrations Predicted tigecycline concentrations from Rubino et al. 2 Day 58, time since treatment initiation 3 days Plasma concentrations, mg/L (time since last dose) 0.50 (2.5 h) 0.31 Plasma concentrations, mg/L (time since last dose) …

Letter to the Editor: Protective Effect of Medication Bezoar After a Massive Beta-Blocker, Digoxin, and Amitriptyline Poisoning

CASE REPORT A 32-yr-old female working as a nurse in an emergency department was admitted to the ICU after massive ingestion of metoprolol, amitriptyline, and digoxin. She had a previous history of depression and had been hospitalized several times for acute poisoning. Her usual medications were amitriptyline and cymamemazine. Several weeks before ingestion she collected numerous tablets of metoprolol and digoxin stolen from the cardiologic ward. On the morning of her admission, she put 115 tablets of metoprolol (11150 mg), 50 tablets of amitriptyline, 75 mg (3750 mg), and 25 tablets of digoxin (2.25 mg) in a bowl and threw away the empty boxes. She ingested all the tablets at 11 a.m. Four hours later she felt no significant effect except vomiting, and called a friend. She was then referred to the emergency ward. Her clinical examination showed no neurological alteration. Her arterial blood pressure was 140/80 mmHg, her heart rate was 60 beats per min. EKG showed sinus rhythm, PR space of 22 msec, and QT space of 0.36 msec. Plasma laboratory tests were the following: glucose=6.2 mmol/L; sodium=132 mmol/ L; potassium=6.2 mmol/L; chloride=96 mmol/L; bicarbonate=25 mmol/L; creatinine=122 mmol/L; AST=195 UI/L; ALT=100 UI/L; alkaline phosphatases=97 UI/L; bilirubin= 6 mmol/L. Plasma digoxin level was 12.10 ng per mL. Plasma metoprolol chromatographic analysis performed the next day of admission was 30 mg per mL. Urine qualitative determination was positive only for tricyclic antidepressant. She had a gastric lavage and received activated charcoal administration, and she was admitted to the ICU for monitoring. She received 480 mg of digoxin antibodies. Six hours later she had no hemodynamic disorder, her heart rate was 45 per min. EKG showed sinus rhythm with normal QRS complex and QT space. The thoracic X-ray performed after gastric emptying showed bezoar (Fig. 1). During the first 2 days of hospitalization she received 50 g of activated charcoal every 4 h and 4 L of polyethylene glycol. Abdominal X-ray showed the progressive desintegration of the bezoar. Gastric fibroscopy was not performed. Four days after her admission, clinical examination showed no abnormality, and she was transferred to a psychiatric ward.