Intermittent recruitment with high-frequency oscillation/tracheal gas insufflation in acute respiratory distress syndrome.

In acute respiratory distress syndrome (ARDS), recruitment sessions of high-frequency oscillation (HFO) and tracheal gas insufflation (TGI) with short-lasting recruitment manoeuvres (RMs) may improve oxygenation and enable reduction of subsequent conventional mechanical ventilation (CMV) pressures. We determined the effect of adding HFO-TGI sessions to lung-protective CMV on early/severe ARDS outcome. We conducted a prospective clinical trial, subdivided into a first single-centre period and a second two-centre period. We enrolled 125 (first period, n = 54) patients with arterial oxygen tension (P(a,O(2)))/inspiratory oxygen fraction (F(I,O(2))) of <150 mmHg for >12 consecutive hours at an end-expiratory pressure of ≥ 8 cmH(2)O. Patients were randomly assigned to an HFO-TGI group (receiving HFO-TGI sessions with RMs, interspersed with lung-protective CMV; n = 61) or CMV group (receiving lung-protective CMV and RMs; n = 64). The primary outcome was survival to hospital discharge. Pre-enrolment ventilation duration was variable. During days 1-10 post-randomisation, P(a,O(2))/F(I,O(2))), oxygenation index, plateau pressure and respiratory compliance were improved in the HFO-TGI group versus the CMV group (p < 0.001 for group × time). Within days 1-60, the HFO-TGI group had more ventilator-free days versus the CMV group (median (interquartile range) 31.0 (0.0-42.0) versus 0.0 (0.0-23.0) days; p < 0.001), and more days without respiratory, circulatory, renal, coagulation and liver failure (p ≤ 0.003). Survival to hospital discharge was higher in the HFO-TGI group versus the CMV group (38 (62.3%) out of 61 versus 23 (35.9%) out of 64 subjects; p = 0.004). Intermittent recruitment with HFO-TGI and RMs may improve survival in early/severe ARDS.

Current pharmacological advances in the treatment of cardiac arrest.

Cardiac arrest is defined as the sudden cessation of spontaneous ventilation and circulation. Within 15 seconds of cardiac arrest, the patient loses consciousness, electroencephalogram becomes flat after 30 seconds, pupils dilate fully after 60 seconds, and cerebral damage takes place within 90-300 seconds. It is essential to act immediately as irreversible damage can occur in a short time. Cardiopulmonary resuscitation (CPR) is an attempt to restore spontaneous circulation through a broad range of interventions which are early defibrillation, high-quality and uninterrupted chest compressions, advanced airway interventions, and pharmacological interventions. Drugs should be considered only after initial shocks have been delivered (when indicated) and chest compressions and ventilation have been started. During cardiopulmonary resuscitation, no specific drug therapy has been shown to improve survival to hospital discharge after cardiac arrest, and only few drugs have a proven benefit for short-term survival. This paper reviews current pharmacological treatment of cardiac arrest. There are three groups of drugs relevant to the management of cardiac arrest: vasopressors, antiarrhythmics, and other drugs such as sodium bicarbonate, calcium, magnesium, atropine, fibrinolytic drugs, and corticosteroids.

Static pressure-volume curves and body posture in severe chronic bronchitis.

Based on prior data, the current authors hypothesised that beneficial pronation effects on gas exchange and respiratory mechanics might be maximised in severely hyperinflated chronic bronchitis patients. The current authors also sought to elucidate underlying mechanisms and to determine whether pronation effects are reflected by postural changes in inspiratory pressure-volume (P-V) curve characteristics. A total of 16 mechanically ventilated patients (for 16-36 h) with chronic bronchitis exacerbation were studied in pre-prone semirecumbent (SREC), prone and post-prone SREC postures. Static respiratory system intrinsic positive end-expiratory pressure (PEEPi,rs) was >12 cmH2O. Haemodynamics, partitioned respiratory mechanics, gas exchange, and lung volumes were determined at zero external positive end-expiratory pressure. P-V curves were constructed from functional residual capacity. End-expiratory lung volume exceeded opening volume. Prone position versus pre-prone SREC resulted in 20% reduced pressure at the lower inflection point (LIP) and 17% increased volume at the upper inflection point of the lung P-V curve, improved lung mechanics and volumes, oxygenation, and carbon dioxide arterial tension (Pa,CO2). In multiple linear regression, postural decreases in PEEPi,rs and additional lung resistance independently predicted postural decreases in lung LIP pressure and Pa,CO2), respectively. In conclusion, in severely hyperinflated patients, pronation reduces lung lower inflection point pressure and increases lung upper inflection point volume. Pronation effects on ventilation homogeneity and carbon dioxide arterial tension are maximised, implying that pronation can be useful during early controlled ventilation.

Prone position reduces lung stress and strain in severe acute respiratory distress syndrome.

The present authors hypothesised that in severe acute respiratory distress syndrome (ARDS), pronation may reduce ventilator-induced overall stress (i.e. transpulmonary pressure (P(L))) and strain of lung parenchyma (i.e. tidal volume (V(T))/end-expiratory lung volume (EELV) ratio), which constitute major ventilator-induced lung injury determinants. The authors sought to determine whether potential pronation benefits are maintained in post-prone semirecumbent (SR(PP)) posture under pressure-volume curve-dependent optimisation of positive end-expiratory pressure (PEEP). A total of 10 anesthetised/paralysed, mechanically ventilated (V(T) = 9.0+/-0.9 mL.kg(-1) predicted body weight; flow = 0.91+/-0.04 L.s(-1); PEEP = 9.4+/-1.3 cmH(2)O) patients with early/severe ARDS were studied in pre-prone semirecumbent (SR(BAS)), prone, and SR(PP) positions. Partitioned respiratory mechanics were determined during iso-flow (0.91 L.s(-1)) experiments (V(T) varied within 0.2-1.0 L), along with haemodynamics, gas exchange, and EELV. Compared with SR(BAS), pronation/SR(PP) resulted in reduced peak/plateau P(L) at V(T)s> or =0.6 L; static lung elastance and additional lung resistance decreased and chest wall elastance (in prone position) increased; EELV increased (23-33%); V(T)/EELV decreased (27-33%); arterial oxygen tension/inspiratory oxygen fraction and arterial carbon dioxide tension improved (21-43/10-14%, respectively), and shunt fraction/physiological dead space decreased (21-50/20-47%, respectively). In early/severe acute respiratory distress syndrome, pronation under positive end-expiratory pressure optimisation may reduce ventilator-induced lung injury risk. Pronation benefits may be maintained in post-prone semirecumbent position.

Colistin treatment in patients with ICU-acquired infections caused by multiresistant Gram-negative bacteria: the renaissance of an old antibiotic.

A retrospective case series study was performed in a 30-bed general intensive care unit (ICU) of a tertiary care hospital to assess the effectiveness and safety of colistin in 43 critically ill patients with ICU-acquired infections caused by multiresistant Gram-negative bacteria. Various ICU-acquired infections, mainly pneumonia and bacteraemia caused by multiresistant strains of Pseudomonas aeruginosa and/or Acinetobacter baumannii, were treated with colistin. Good clinical response (cure or improvement) was noted in 74.4% of patients. Deterioration of renal function occurred in 18.6% of patients during colistin therapy. Nephrotoxicity was elevated significantly in those patients with a history of renal failure (62.5%). All-cause mortality amounted to 27.9%. In this group of critically ill patients, an age of >50 years (OR, 5.4; 95% CI 1.3-24.9) and acute renal failure (OR, 8.2; 95% CI 2.9-23.8) were independent predictors of mortality. Colistin should be considered as a treatment option in critically ill patients with infection caused by multiresistant Gram-negative bacilli.

Prone position improves expiratory airway mechanics in severe chronic bronchitis.

Based on lung parenchyma-airways' interdependence, the present authors hypothesised that prone positioning may reduce airway resistance in severe chronic bronchitis. A total of 10 anaesthetised/mechanically ventilated patients were enrolled. Partitioned respiratory system (RS) mechanics during iso-flow experiments (flow = 0.91 L x s(-1), tidal volume (VT) varied within 0.2-1.2 L), haemodynamics, gas-exchange, expiratory airway resistance (Raw,exp), functional residual capacity (FRC), change in FRC (DeltaFRC), end-expiratory lung volume (EELV), expiratory airway resistance at EELV (Raw,exp,EELV), intrinsic positive end-expiratory pressure (PEEPi), and mean end-expiratory flow were determined in baseline semirecumbent (SRBAS), prone, and post-prone semirecumbent (SRPP) postures. Pronation versus SRBAS resulted in significantly reduced Raw,exp (at VT > or =0.8 L), Raw,exp,EELV (18.3+/-1.4 versus 31.6+/-2.6 cm H2O x L(-1) x s(-1)), inspiratory airway resistance (at VT > or =1.0 L), static lung elastance (at VT < or =0.6 L), "additional" RS/lung resistance (at a range of VTs), DeltaFRC (0.35+/-0.03 versus 0.47+/-0.03 L), EELV (4.92+/-0.49 versus 5.65+/-0.65 L), RS/lung PEEPi (6.7+/-1.1/5.4+/-0.6 versus 8.9+/-1.7/7.8+/-1.1 cm H2O), mean end-expiratory flow (63.9+/-4.2 versus 47.9+/-4.0 mL x s(-1)), and shunt fraction (0.16+/-0.03 versus 0.21+/-0.03); benefits were reversed in SRPP. In severe chronic bronchitis, prone positioning reduces airway resistance and dynamic hyperinflation.

Intracoronary thrombolysis and intraaortic balloon counterpulsation for the emergency treatment of probable coronary embolism after repair of an acute ascending aortic dissection.

IMPLICATIONS: This report shows that if diffuse coronary thromboembolism is encountered during ascending aortic dissection-repair, the option of combining single-bolus, intracoronary thrombolysis with intraaortic balloon counterpulsation should be considered.

The disposition of the cervical spine and deformation of available cord space with conventional- and balloon laryngoscopy-guided laryngeal intubation: a comparative study.

UNLABELLED: Orotracheal intubation causes cervical spine (C-spine) extension and potential (hypothetical) space available for the cord (SAC)-deformation. In the present study, we determined and compared the changes induced by conventional- and balloon laryngoscopy-guided orolaryngeal intubation in the upper C-spine's osseous unit-orientation, segmental angulation, segmental SAC-sagittal surface areas (SSAs), segmental/total posterior SAC-aspect, and segmental SAC-width. Eight healthy volunteers were enrolled. A set of neutral head position (baseline)- and two sets of intubation-lateral C-spine radiographs were obtained. Relative to baseline, both intubation techniques induced significant changes in the occiput (OCC)-, third cervical vertebra (C3)-, C4-, and C5-orientation, the OCC-C1-segmental angulation, all the segmental SAC-SSAs, and the OCC-C1-, and C1-2-posterior SAC-aspect (P < 0.05 to < 0.001); conventional intubation caused additional significant changes in C2-orientation, total (OCC through C5)-posterior SAC-aspect, and OCC-C1-SAC-width (P < 0.05 to < 0.001). Relative to conventional intubation, balloon-assisted intubation caused less change in C3-orientation and C2-3-SAC-width (P < 0.05), and less reduction in OCC-C1-, C1-2-, and C4-5-SAC-SSAs (P < 0.05 to < 0.01). Orotracheal intubation should be cautiously performed in patients with space-occupying upper-C-spine-SAC lesions, even if there is no concomitant osseous/ligamentous pathology. In such cases, balloon laryngoscopy may be chosen over the conventional technique, because it causes less SAC deformation. IMPLICATIONS: This study shows that direct laryngoscopy-guided orotracheal intubation causes deformation of the upper cervical space available for the cord, even in the absence of cervical spine instability. These effects are attenuated with balloon laryngoscopy, and thus, its use is recommended in patients with space-occupying lesions within the spinal canal.

Balloon versus conventional laryngoscopy: a comparison of laryngoscopic findings and intubation difficulty.

We compared laryngeal aperture (LA) exposure and endotracheal intubation difficulty scale (IDS) scores between balloon-assisted and conventional laryngoscopy. Thirty-two anesthetized and paralyzed elective surgery patients underwent laryngoscopy with a standard number 4 and a modified number 4 curved blade carrying a 6F Fogarty catheter. The balloon laryngoscopy technique included modified blade tip insertion into the vallecula, Fogarty catheter balloon inflation with 2 mL of air, and blade elevation until LA exposure maximization. On maximal LA exposure with both blades, the LA views were videotaped with a camcorder aligned to blade light source and the exposed LA areas measured electronically. The IDS scores were determined on passing the tip of an endotracheal tube through the vocal cords. The patient head position, the angle of laryngoscope handle elevation, and the time available for airway instrumentation were standardized. The data from 27 patients were analyzed. The exposed LA areas were significantly larger with balloon laryngoscopy than conventional (median, interquartile range: 0.94, 0.65-1.80 cm(2) vs. 0.52, 0.39-1.46 cm(2) respectively) (P = 0.027), and the IDS scores lesser (median, interquartile range: 0, 0-1 vs. 1, 0-2 respectively) (P = 0.012). We concluded that balloon laryngoscopy facilitates elective airway management.

Balloon laryngoscopy reduces head extension and blade leverage in patients with potential cervical spine injury.

BACKGROUND: Head extension and excessive laryngoscope blade levering motion (LBLM) are undesirable during airway management of trauma patients. We hypothesized that laryngoscopy with a modified blade facilitating glottic exposure by balloon inflation would reduce head extension and LBLM. PATIENTS AND METHODS: Seventeen elective surgery patients were enrolled. Patients lay supine with their heads flat on a rigid board and had a rigid collar around their necks. Laryngoscopy was performed with the modified blade and a standard curved blade. Head extension and LBLM angles were determined upon maximal glottic exposure and compared used paired t-tests. Laryngoscopic view grade and oxygen saturation were also determined. RESULTS: Balloon laryngoscopy resulted in less head extension and LBLM (P <0.001). Laryngoscopic view was approximately identical with both blades, and oxygen saturation was always above 97%. CONCLUSIONS: Balloon laryngoscopy reduces head extension and LBLM under simulated cervical spine precautions.