Carbonic anhydrase inhibitors in patients with respiratory failure and metabolic alkalosis: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Metabolic alkalosis is common in patients with respiratory failure and may delay weaning in mechanically ventilated patients. Carbonic anhydrase inhibitors block renal bicarbonate reabsorption, and thus reverse metabolic alkalosis. The objective of this systematic review is to assess the benefits and harms of carbonic anhydrase inhibitor therapy in patients with respiratory failure and metabolic alkalosis. METHODS: We searched the following electronic sources from inception to August 2017: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and SCOPUS. Randomized clinical trials were included if they assessed at least one of the following outcomes: mortality, duration of hospital stay, duration of mechanical ventilation, adverse events, and blood gas parameters. Teams of two review authors worked in an independent and duplicate manner to select eligible trials, extract data, and assess risk of bias of the included trials. We used meta-analysis to synthesize statistical data and then assessed the certainty of evidence using the GRADE methodology. RESULTS: Six eligible studies were identified with a total of 564 participants. The synthesized data did not exclude a reduction or an increase in mortality (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.57 to 1.56) or in duration of hospital stay (mean difference (MD) 0.42 days, 95% CI -4.82 to 5.66) with the use of carbonic anhydrase inhibitors. Carbonic anhydrase inhibitor therapy resulted in a decrease in the duration of mechanical ventilation of 27 h (95% CI -50 to -4). Also, it resulted in an increase in PaO2 (MD 11.37 mmHg, 95% CI 4.18 to 18.56) and a decrease in PaCO2 (MD -4.98 mmHg, 95% CI -9.66, -0.3), serum bicarbonate (MD -5.03 meq/L, 95% CI -6.52 to -3.54), and pH (MD -0.04, 95% CI -0.07 to -0.01). There was an increased risk of adverse events in the carbonic anhydrase inhibitor group (RR 1.71, 95% CI 0.98 to 2.99). Certainty of evidence was judged to be low for most outcomes. CONCLUSION: In patients with respiratory failure and metabolic alkalosis, carbonic anhydrase inhibitor therapy may have favorable effects on blood gas parameters. In mechanically ventilated patients, carbonic anhydrase inhibitor therapy may decrease the duration of mechanical ventilation. A major limitation of this finding was that only two trials assessed this clinically important outcome.

Nondepolarizing muscle relaxant improves direct laryngoscopy view with no effect on face mask ventilation / Relaxantes musculares não despolarizantes melhoram a visibilidade em laringoscopia direta sem efeito sobre a ventilação via máscara facial

Abstract Background: Difficult or impossible face mask ventilation complicated with difficult tracheal intubation during anesthesia induction occurs in 0.4% of adult anesthesia cases, possibly leading to life-threatening complications. Because of such catastrophes, muscle relaxants have been recommended to be administered after confirming adequate face mask ventilation without a solid scientific validation of this principal. Methods: In this observational study, the ease of ventilation and the scores of direct laryngoscopy views before and after administration of cisatracurium were assessed in ninety young healthy adults, without anesthetic risks and without foreseen difficult intubation and who were scheduled for general elective surgeries. Results: Before muscle relaxation, 43 patients (48%) were Cormack Grade I, while the remaining 47 patients (52%) were either Cormack Grade II (28 patients, 31%) or Cormack Grade II (19 patients, 21%). Following muscle relaxation with cisatracurium, the number of patients with Cormack Grade I significantly increased from 43 patients (48%) to 65 patients (72%) (p = 0.0013). Only 1 patient out of 19 patients (5%) improved his Cormack grade from Grade III to Grade I while 16 out 19 patients (84%) improved their Cormack grade from Grade III to Grade II after the use of cisatracurium. The quality of face mask ventilation did not differ with and without muscle relaxants in all patients. Conclusion: The use of cisatracurium in healthy young adults undergoing general elective surgeries with no anticipated difficult endotracheal intubation had no effect on the quality of face mask ventilation despite resulting in a quantifiable improvement in the laryngeal view.

Resumo Justificativa: A ventilação difícil ou impossível via máscara facial complicada pela intubação traqueal difícil durante a indução da anestesia ocorre em 0,4% dos casos de anestesia em adultos, possivelmente leva a complicações fatais. Devido a tais catástrofes, recomendou-se que a administração de relaxantes musculares seja feita após a confirmação de ventilação adequada via máscara facial, sem uma validação científica sólida dessa conduta. Métodos: Neste estudo observacional, a facilidade de ventilação e os escores de visibilidade em laringoscopia direta antes e após a administração de cisatracúrio foram avaliados em 90 adultos jovens e saudáveis, sem riscos anestésicos e sem intubação difícil prevista, agendados para cirurgias eletivas gerais. Resultados: Antes do relaxamento muscular, 43 pacientes (48%) eram Cormack Grau I, enquanto os 47 (52%) restantes eram ou Cormack Grau II (28, 31%) ou Cormack Grade III (19, 21%). Após o relaxamento muscular com cisatracúrio, o número de pacientes com Cormack Grau I aumentou significativamente de 43 (48%) para 65 (72%) (p = 0,0013). Apenas um paciente (5%) dos 19 melhorou sua classificação de Cormack do Grau III para o Grau I, enquanto 16 dos 19 (84%) melhoraram suas classificações de Cormack do Grau III para o grau II após o uso de cisatracúrio. A qualidade da ventilação via máscara facial não diferiu com ou sem relaxantes musculares em todos os pacientes. Conclusão: O uso de cisatracúrio em adultos jovens saudáveis submetidos a cirurgias eletivas gerais sem intubação traqueal difícil prevista não teve efeito sobre a qualidade da ventilação via máscara facial, mesmo resultando em melhora quantificável da visibilidade da laringe.

[Nondepolarizing muscle relaxant improves direct laryngoscopy view with no effect on face mask ventilation]. / Relaxantes musculares não despolarizantes melhoram a visibilidade em laringoscopia direta sem efeito sobre a ventilação via máscara facial.

BACKGROUND: Difficult or impossible face mask ventilation complicated with difficult tracheal intubation during anesthesia induction occurs in 0.4% of adult anesthesia cases, possibly leading to life-threatening complications. Because of such catastrophes, muscle relaxants have been recommended to be administered after confirming adequate face mask ventilation without a solid scientific validation of this principal. METHODS: In this observational study, the ease of ventilation and the scores of direct laryngoscopy views before and after administration of cisatracurium were assessed in ninety young healthy adults, without anesthetic risks and without foreseen difficult intubation and who were scheduled for general elective surgeries. RESULTS: Before muscle relaxation, 43 patients (48%) were Cormack Grade I, while the remaining 47 patients (52%) were either Cormack Grade II (28 patients, 31%) or Cormack Grade II (19 patients, 21%). Following muscle relaxation with cisatracurium, the number of patients with Cormack Grade I significantly increased from 43 patients (48%) to 65 patients (72%) (p=0.0013). Only 1 patient out of 19 patients (5%) improved his Cormack grade from Grade III to Grade I while 16 out 19 patients (84%) improved their Cormack grade from Grade III to Grade II after the use of cisatracurium. The quality of face mask ventilation did not differ with and without muscle relaxants in all patients. CONCLUSION: The use of cisatracurium in healthy young adults undergoing general elective surgeries with no anticipated difficult endotracheal intubation had no effect on the quality of face mask ventilation despite resulting in a quantifiable improvement in the laryngeal view.

Use of noninvasive positive pressure ventilation in emergency departments of public and private hospitals in Lebanon.

Noninvasive positive pressure ventilation is increasingly being used in emergency departments across Europe and North America. To our knowledge, no similar data are available from other countries. The aim of this study is to describe the current use of noninvasive positive pressure ventilation in the emergency departments of Lebanese hospitals. A structured and validated questionnaire was sent to all emergency departments in Lebanon. In Lebanon, 48.4% of emergency departments use noninvasive positive pressure ventilation. It is mostly used for patients with chronic obstructive pulmonary diseases and cardiogenic pulmonary edema. Bilevel and continuous positive airway pressures are the two most widely used modalities for noninvasive positive pressure ventilation. Face mask is the most used patient interface. The use of uniform protocols and training is lacking. Noninvasive positive pressure ventilation in Lebanese emergency departments is underused, with significant potential for improvements in its current practice.

Use of recombinant activated factor VII for intractable bleeding in patients without hemophilia: A developing country tertiary care center's experience.

Although the use of recombinant activated factor VII (rFVIIa) to control intractable bleeding in nonhemophiliac patients is expanding, several issues pertinent to its potential thrombotic complications and effect on patient mortality are still of concern. We herein describe our experience at a developing country tertiary care center over a period of 4 years. A total of 49 patients were identified of whom 28.6% belong to the pediatric age group. The most common bleeding settings were intracerebral hemorrhage, abdominal aortic surgery, general surgery, and disseminated intravascular coagulopathy. All patients achieved cessation or significant reduction in bleeding. Only 1 patient had a documented postuse thrombotic complication. Of the whole group, 12 patients (24.4%) eventually died with only 1 death having a possible association to rFVIIa use. There was a statistically significant reduction in the need for blood product transfusion after the use of rFVIIa. The use of rFVIIa was in accordance with the hospital's algorithm (identifying salvageable patients, preconditioning, blood product replacement, and dosing) in 30 (61.2%) patients. We conclude that rFVIIa should continue to be considered in nonhemophiliac patients failing to respond to conventional measures of bleeding control. However, this off-label use should be coupled with strict adherence to the treatment algorithms, which remains essential in developing countries with limited health care resources.

Critical care clinicians' knowledge of evidence-based guidelines for preventing ventilator-associated pneumonia.

BACKGROUND: Ventilator-associated pneumonia is the most common hospital-acquired infection among patients receiving mechanical ventilation in an intensive care unit. Different initiatives for the prevention of ventilator-associated pneumonia have been developed and recommended. OBJECTIVE: To evaluate knowledge of critical care providers (physicians, nurses, and respiratory therapists in the intensive care unit) about evidence-based guidelines for preventing ventilator-associated pneumonia. METHODS: Ten physicians, 41 nurses, and 18 respiratory therapists working in the intensive care unit of a major tertiary care university hospital center completed an anonymous questionnaire on 9 nonpharmacological guidelines for prevention of ventilator-associated pneumonia. RESULTS: The mean (SD) total scores of physicians, nurses, and respiratory therapists were 80.2% (11.4%), 78.1% (10.6%), and 80.5% (6%), respectively, with no significant differences between them. Furthermore, within each category of health care professionals, the scores of professionals with less than 5 years of intensive care experience did not differ significantly from the scores of professionals with more than 5 years of intensive care experience. CONCLUSIONS: A health care delivery model that includes physicians, nurses, and respiratory therapists in the intensive care unit can result in an adequate level of knowledge on evidence-based nonpharmacological guidelines for the prevention of ventilator-associated pneumonia.

Use of heparinized versus non-heparinized syringes for measurements of the pleural fluid pH.

BACKGROUND: Pleural fluid (PF) pH measurement is important for establishing a diagnosis and for guiding clinical management. The current standard practice is to collect PF samples for pH measurement in heparinized syringes at room temperature and to instantaneously process these samples. OBJECTIVE: The purpose of this study is to investigate the effect of collecting PF in heparinized versus non-heparinized syringes at room temperature on PF pH measurements when processed at various time intervals. METHODS: From 50 consecutive thoracenteses, 1 ml of PF was collected anaerobically in each of six 3-ml syringes. Only three syringes were coated with heparin. The samples were processed for PF pH measurements at time 0 (T(0)) and 1 h (T(1)) and 2 h (T(2)) after collection. All specimens were preserved at room temperature, until the measurements were carried out in duplicates by a calibrated blood gas analyzer. RESULTS: PF pH values were significantly lower with heparinized versus non-heparinized syringes at all time intervals (T(0): pH heparinized = 7.378 +/- 0.107 vs. pH non-heparinized = 7.390 +/- 0.108; T(1): pH heparinized = 7.378 +/- 0.115 vs. pH non-heparinized = 7.389 +/- 0.111; T(2): pH heparinized = 7.367 +/- 0.105 vs. pH non-heparinized = 7.389 +/- 0.121). In the heparinized syringes, there was a significant decrease in PF pH values at T(2) versus T(0) and T(1). There were no significant changes in PF pH values over time in the non-heparinized syringes. CONCLUSIONS: For serial PF pH measurements, the same type of syringes (either heparinized or non-heparinized) should be consistently used. With heparinized syringes, processing of PF pH measurements should be performed within 1 h after collection.