Tamas Szakmany

Hemodynamic and respiratory changes during lung recruitment and descending optimal positive end-expiratory pressure titration in patients with acute respiratory distress syndrome.

OBJECTIVESnTo investigate respiratory and hemodynamic changes during lung recruitment and descending optimal positive end-expiratory pressure (PEEP) titration.nnnDESIGNnProspective auto-control clinical trial.nnnSETTINGnAdult general intensive care unit in a university hospital.nnnPATIENTSnEighteen patients with acute respiratory distress syndrome.nnnINTERVENTIONSnFollowing baseline measurements (T0), PEEP was set at 26 cm H2O and lung recruitment was performed (40/40-maneuver). Then tidal volume was set at 4 mL/kg (T26R) and PEEP was lowered by 2 cm H2O in every 4 mins. Optimal PEEP was defined at 2 cm H2O above the PEEP where Pao2 dropped by > 10%. After setting the optimal PEEP, the 40/40-maneuver was repeated and tidal volume set at 6 mL/kg (T(end)).nnnMEASUREMENTS AND MAIN RESULTSnArterial blood gas analysis was done every 4 mins and hemodynamic measurements every 8 mins until T(end), then in 30 (T30) and 60 (T60) mins. The Pao2 increased from T0 to T(end) (203 +/- 108 vs. 322 +/- 101 mm Hg, p < .001), but the extravascular lung water (EVLW) did not change significantly. Cardiac index (CI) and the intrathoracic blood volume (ITBV) decreased from T0 to T26R (CI, 3.90 +/- 1.04 vs. 3.62 +/- 0.91 L/min/m2, p < .05; ITBVI, 832 +/- 205 vs. 795 +/- 188 m/m2, p < .05). There was a positive correlation between CI and ITBVI (r = .699, p < .01), a negative correlation between CI and central venous pressure (r = -.294, p < .01), and no correlation between CI and mean arterial pressure (MAP).nnnCONCLUSIONSnFollowing lung recruitment and descending optimal PEEP titration, the Pao2 improves significantly, without any change in the EVLW up to 1 hr. This suggests a decrease in atelectasis as a result of recruitment rather than a reduction of EVLW. There is a significant change in CI during the maneuver, but neither central venous pressure, heart rate, nor MAP can reflect these changes.

Microalbuminuria does not reflect increased systemic capillary permeability in septic shock

ObjectiveTo investigate the correlation between microalbuminuria and extravascular lung water in patients in septic shock who require mechanical ventilation for severe respiratory failure.Design and settingProspective, observational, clinical study in the 20-bed intensive care unit of a university hospital.Patients and participants25 consecutive patients in septic shock and also in severe respiratory failure requiring mechanical ventilation.InterventionsHemodynamic parameters and extravascular lung water were determined by single arterial thermodilution. Together with each hemodynamic measurement the PaO2/FIO2 ratio and urinary microalbumin to creatinine ratio (M:Cr) was measured. Serum C-reactive protein (CRP) and procalcitonin (PCT) levels were also determined daily.Measurements and resultsThe EVLW index was significantly higher than normal throughout the study. Microalbuminuria was in the normal range on entry and remained so for the rest of the study period. Serum PCT and CRP levels were significantly higher than normal at every assessment points. No significant correlation was found between M:Cr and either EVLW or PaO2/FIO2 .ConclusionsIn this study patients in septic shock with significantly elevated EVLW had normal urinary M:Cr, and there was no correlation between M:Cr and EWLV, and PaO2/FIO2. Therefore based on the current results routine measurements of microalbuminuria to determine endothelial permeability cannot be recommended in critically ill patients.

Effects of volumetric vs. pressure-guided fluid therapy on postoperative inflammatory response: a prospective, randomized clinical trial

ObjectiveTo compare intrathoracic blood volume (ITBV) guided fluid management and central venous pressure (CVP) guided therapy in ameliorating the progression of early systemic inflammatory response in patients undergoing major surgery.DesignProspective, randomized clinical trial.PatientsForty patients undergoing major abdominal surgery were randomized into CVP and ITBV groups.InterventionsIn the CVP group the target CVP was 8–12xa0mmHg while in the ITBV group the goal was to keep the ITBV between 850 and 950xa0ml/m2 during the operation.Measurements and resultsHemodynamic parameters were determined by single arterial thermodilution. Measurements were repeated every 30xa0min intraoperatively. Serum procalcitonin (PCT) and C-reactive protein (CRP) was monitored preoperatively, on ICU admission, and then daily for 3xa0days. Serum TNF-α levels were measured intraoperatively hourly and then daily for 3xa0days. There was no significant difference between the two groups regarding hemodynamic parameters at any assessment point. In the overall population changes in the stroke volume index showed a significant correlation with changes in CVP and ITBV. TNF-α levels remained in the normal range intraoperatively and during the three postoperative days in both groups. Preoperatively normal PCT and CRP levels increased significantly postoperatively, without significant differences between the groups.ConclusionsITBV guided fluid therapy did not alter the magnitude of inflammatory response as monitored by serum PCT, CRP, and TNF-α in the early postoperative period.

Prophylactic N-acetylcysteine decreases serum CRP but not PCT levels and microalbuminuria following major abdominal surgery. A prospective, randomised, double-blinded, placebo-controlled clinical trial

ObjectiveOur objective was to investigate whether short-term infusion of the oxygen free radical scavenger N-acetylcysteine (NAC) administered before and during extensive abdominal surgery could ameliorate the progression of early systemic inflammatory response.DesignProspective, randomised, double-blinded, placebo-controlled clinical trial.SettingTwenty-bed intensive care unit in a university hospital.PatientsFollowing written informed consent, 100 patients were randomised into NAC and placebo groups. Three patients from the NAC group and four from the placebo group withdrew before the final analysis.InterventionThe treatment group (n=47) received NAC (150xa0mg/kg–1 bolus followed by a continuous infusion of 12xa0mg/kg–1/h–1) and the placebo group (n=46) received the same volume of 5% dextrose during surgery.Measurements and resultsSerum procalcitonin (PCT), C-reactive protein (CRP) and microalbuminuria was monitored preoperatively, on admission to ICU, then daily during the first 3xa0postoperative days. For statistical analysis Mann Whitney and Chi-squared tests were used. Patients clinical course was similar in each group as monitored by the Multiple Organ Dysfunction Scores. There was no significant difference between the two groups regarding PCT and microalbuminuria at any assessment point. Significantly lower CRP levels were found in the NAC group on days 1 and 2 (t24: median: 84.5 interquartile range: [62–120] vs. 118 [86–137] mg/l; p=0.020; t48: 136 [103–232] vs. 195 [154–252] mg/l; p=0.013, NAC vs. placebo respectively).ConclusionIn this study, short-term NAC treatment decreased CRP levels, but failed to attenuate any other inflammatory response, as monitored by serum PCT and microalbuminuria. Overall, our results do not support the routine prophylactic use of NAC as a free radical scavenger in abdominal surgery.

Increased glomerular permeability and pulmonary dysfunction following major surgery: correlation of microalbuminuria and PaO2/FiO2 ratio

Background:u2002 The aim of our trial was to evaluate the ability of microalbuminuria as an indicator of outcome and to investigate its relationship with the postoperative respiratory dysfunction in the initial postoperative period in a high‐risk patient group.

Short-term effects of N-acetylcysteine and ischemic preconditioning in a canine model of hepatic ischemia-reperfusion injury

Aims: We evaluated the possibility that repeated ischemic preconditioning or N-acetylcysteine (NAC) could prevent ischemia-reperfusion injury as determined by indocyanine green plasma disappearance rate (ICG-PDR) or has favorable hemodynamic effects during reperfusion in an in vivo canine liver model. Methods: Under general anesthesia, 3 groups of mongrel dogs (n = 5 per group) were subjected to (1) 60-min hepatic ischemia, (2) same ischemia preceded by intravenous administration of 150 mg kg–1 NAC, and (3) three episodes of IPC (10-min ischemia followed by 10-min reperfusion) prior to same ischemia. Hepatic reperfusion was maintained for a further 180 min, with hemodynamic and hepatic function parameters monitored throughout. Results: Plasma disappearance rate of indocyanine green and serum levels of aspartate transferase and alanine transferase showed no significant differences between groups. Although liver injury was obvious, reflected by hemodynamic, blood gas, and liver function tests, NAC and IPC failed to prevent decay in hepatic function in this canine model. Conclusion: The results do not support the hypothesis that short-term use of NAC and IPC is beneficial in hepatic surgery.

Routine chest x-ray after percutaneous tracheostomy: nicety or necessity?[Abstract]

Routine chest x-ray (CXR) after uncomplicated percutaneous dilatational tracheostomy (PDT) has been shown to be ineffective in diagnosing complications. Based on the available evidence, in 2010 our unit has adopted the approach of omitting the routine CXR after PDT, unless it was clinically indicated. nWe performed an audit to ascertain that possible life threatening complications are not going unnoticed after PDT without routine CXRs. nRetrospective chart review of patients who underwent PDT in our 10-bedded Critical Care unit between 2010-2012. We have reviewed the operation notes to look for immediate complications, the nursing and medical notes for the next 72 hrs to look for early complications and when available, the CXRs taken in the 72 hours postoperative period to look for new and unexpected findings. n136 patients underwent PDT in the 3-year period. All tracheostomies were inserted by ICU or ENT specialist under bronchoscopy guidance. In ten patients the procedure was described as difficult. There were no major complications. In the postoperative period 8 patients had slight oozing from the wound, none of them required intervention. There were 78/136 CXRs taken for other clinical reasons available for review. Meantime difference between the PDT and the CXR was 27 ± 18 hrs. 59/78 of the CXRs were taken to confirm CVP or NG tube placement. None of the CXRs showed any unexpected findings related to PDT. nIn our experience, omitting the routine postoperative CXR after uncomplicated PDT with bronchoscopy guidance did not increase the rate of unnoticed clinical complications. Our study confirms that adopting these evidence based recommendations does not affect patient safety on the ICU and that routine CXR is not a necessity after PDT.