Malnutrition and Perioperative Nutritional Support in Retroperitoneal Sarcoma Patients: Results from a Prospective Study.

INTRODUCTION: Retroperitoneal soft tissue sarcomas (RPSs) are mesenchymal neoplasms. The prevalence of protein energetic malnutrition (PEM) and its impact in RPS patients who were candidates for surgery is unknown. MATERIALS AND METHODS: A prospective feasibility study enrolled 35 patients with primary RPS who were candidates for extended multivisceral resection. PEM was screened at enrollment. Preoperative high protein ß-hydroxy-ß-methyl butyrate oral nutritional support (ONS) was provided according to the degree of PEM. After surgery, nutritional support followed standard practice, targeting at least 1 g/kg/day protein and 20 kcal/kg/day caloric intake within the third postoperative day (POD). PEM was re-evaluated before surgery on POD 10, and at 4 and 12 months after surgery. Primary outcomes were the patient's compliance to preoperative ONS and the physician's compliance to postoperative nutritional targets. RESULTS: PEM was documented in 46% of patients at baseline; ONS met a 91% adherence (overall well tolerated). After ONS, PEM reduced to 38% (p = 0.45). The postoperative caloric target was reached on day 4.1 (standard error ± 2.7), with a protocol adherence rate of 52%. On POD 10, 91% of patients experienced PEM, the worsening of which was greater after resection of four or more organs (p = 0.06). At 4 and 12 months after surgery, almost all patients had fully recovered. A significant correlation between PEM at surgery and postoperative complications was found (p = 0.04). CONCLUSIONS: Relevant PEM prevalence in RPS is documented for the first time. PEM correlates with greater morbidity. In this setting, preoperative ONS was feasible and well-tolerated. Disease-related factors for PEM and the ideal perioperative caloric target in the context of extended multivisceral resection need to be further investigated. Nutritional support should be included in enhanced recovery after surgery programs for RPS. TRIAL REGISTRY: ClinicalTrials.gov identifier: NCT03877588.

Inflammation and primary graft dysfunction after lung transplantation: CT-PET findings.

BACKGROUND: The leading cause of early mortality after lung transplantation is Primary graft dysfunction (PGD). We assessed the lung inflammation, inflation status and inhomogeneities after lung transplantation. Our purpose was to investigate the possible differences between patients who did or did not develop PGD. METHODS: We designed a prospective observational study enrolling patients who underwent a CT-PET study within 1 week after lung transplantation. Twenty-four patients (10 after double- and 14 after single-lung) were enrolled. Respiratory and hemodynamic data were collected before, during and after lung transplantation. Each patient underwent computed tomography-positron emission tomography (CT-PET) scan early after surgery. Broncho-alveolar lavage (BAL) fluid collection was performed to analyze inflammatory mediators. RESULTS: The grafts showed a [18F]fluoro-2-deoxy-D-glucose ([18F]FDG) uptake rate of 26[18-33]*10-4 mLblood/mLtissue/min (reference values 11[7-15]*10-4). Three double- and six single-lung recipients developed PGD. The grafts of patients who developed PGD had similar [18F]FDG uptake than grafts of patients who did not (28[18-26]*10-4 versus 26[22-31]*10-4, P=0.79). Not-inflated tissue fraction was significantly higher (28[20-38]% versus 14[7-21]%, P=0.01) while well-inflated fraction was significantly lower (29[25-41]% versus 53[39-65]%, P<0.01). Inhomogeneity extent was higher in patients who developed PGD (23[18-26]% versus 14[10-20]%, P=0.01)The lung weight was 650[591-820]g versus 597[480-650]g (P=0.09)). BAL fluid analysis for inflammatory mediators did not detect a difference between the study groups. CONCLUSIONS: Compared to healthy lungs, all the grafts showed increased [18F]FDG uptake rate, but there were no differences between patients who developed PGD and patients who did not. Of note, the PGD patients showed a worse inflation status of lungs and a higher inhomogeneity extent.

Sodium bicarbonate treatment during transient or sustained lactic acidemia in normoxic and normotensive rats.

INTRODUCTION: Lactic acidosis is a frequent cause of poor outcome in the intensive care settings. We set up an experimental model of lactic acid infusion in normoxic and normotensive rats to investigate the systemic effects of lactic acidemia per se without the confounding factor of an underlying organic cause of acidosis. METHODOLOGY: Sprague Dawley rats underwent a primed endovenous infusion of L(+) lactic acid during general anesthesia. Normoxic and normotensive animals were then randomized to the following study groups (n = 8 per group): S) sustained infusion of lactic acid, S+B) sustained infusion+sodium bicarbonate, T) transient infusion, T+B transient infusion+sodium bicarbonate. Hemodynamic, respiratory and acid-base parameters were measured over time. Lactate pharmacokinetics and muscle phosphofructokinase enzyme's activity were also measured. PRINCIPAL FINDINGS: Following lactic acid infusion blood lactate rose (P<0.05), pH (P<0.05) and strong ion difference (P<0.05) drop. Some rats developed hemodynamic instability during the primed infusion of lactic acid. In the normoxic and normotensive animals bicarbonate treatment normalized pH during sustained infusion of lactic acid (from 7.22 ± 0.02 to 7.36 ± 0.04, P<0.05) while overshoot to alkalemic values when the infusion was transient (from 7.24 ± 0.01 to 7.53 ± 0.03, P<0.05). When acid load was interrupted bicarbonate infusion affected lactate wash-out kinetics (P<0.05) so that blood lactate was higher (2.9 ± 1 mmol/l vs. 1.0 ± 0.2, P<0.05, group T vs. T+B respectively). The activity of phosphofructokinase enzyme was correlated with blood pH (R2 = 0.475, P<0.05). CONCLUSIONS: pH decreased with acid infusion and rose with bicarbonate administration but the effects of bicarbonate infusion on pH differed under a persistent or transient acid load. Alkalization affected the rate of lactate disposal during the transient acid load.

ß-adrenergic agonist infusion during extracorporeal lung perfusion: effects on glucose concentration in the perfusion fluid and on lung function.

BACKGROUND: We recently showed in a pig model of ex vivo lung perfusion (EVLP) that lung edema correlates with glucose consumption. We investigated whether salbutamol, a ß-adrenergic receptor agonist known to upregulate fluid transport in the lung, modulates glucose concentration in the perfusate during EVLP. METHODS: Lungs from domestic pigs underwent normothermic EVLP. At the end of controlled reperfusion, lungs were ventilated and perfused for 60 minutes, then randomized to salbutamol (ß-Agonist) infusion or placebo (Control) for 180 minutes. Functional parameters were assessed. RESULTS: In the ß-Agonist group, glucose concentration decreased over time more than corresponding Control values (analysis of variance [ANOVA], p = 0.05). Mean pulmonary artery pressure (mPAP) was 16 ± 1 mm Hg in the ß-Agonist group vs 21 ± 1 mm Hg in the Controls (ANOVA p < 0.05). Baseline mPAP was correlated with the drop of mPAP after the ß-agonist infusion (R(2) = 0.856, p < 0.05). Dynamic compliance dropped from 51 ± 10 to 31 ± 6 ml/cm H(2)O in the ß-Agonist group and from 60 ± 4 to 21 ± 3 ml/cm H(2)O in the Control group (ANOVA, p < 0.05 ß-agonist vs Control). The Δ partial pressure of oxygen/fraction of inspired oxygen was 418 ± 15 and 393 ± 12 mm Hg in the ß-Agonist and Control groups, respectively (t-test p = 0.106). CONCLUSIONS: Glucose concentration in the perfusate was affected by salbutamol. Salbutamol was associated with lower pulmonary pressures and better lung mechanics. These data suggest a possible role for salbutamol as a pharmacologic adjunct during EVLP before transplantation.

Management of mechanical ventilation during laparoscopic surgery.

Laparoscopy is widely used in the surgical treatment of a number of diseases. Its advantages are generally believed to lie on its minimal invasiveness, better cosmetic outcome and shorter length of hospital stay based on surgical expertise and state-of-the-art equipment. Thousands of laparoscopic surgical procedures performed safely prove that mechanical ventilation during anaesthesia for laparoscopy is well tolerated by a vast majority of patients. However, the effects of pneumoperitoneum are particularly relevant to patients with underlying lung disease as well as to the increasing number of patients with higher-than-normal body mass index. Moreover, many surgical procedures are significantly longer in duration when performed with laparoscopic techniques. Taken together, these factors impose special care for the management of mechanical ventilation during laparoscopic surgery. The purpose of the review is to summarise the consequences of pneumoperitoneum on the standard monitoring of mechanical ventilation during anaesthesia and to discuss the rationale of using a protective ventilation strategy during laparoscopic surgery. The consequences of chest wall derangement occurring during pneumoperitoneum on airway pressure and central venous pressure, together with the role of end-tidal-CO2 monitoring are emphasised. Ventilatory and non-ventilatory strategies to protect the lung are discussed.

Prevalence of endotoxemia after surgery and its association with ICU length of stay.

INTRODUCTION: The aim of this observational study was to investigate the prevalence of endotoxemia after surgery and its association with ICU length of stay. METHODS: 102 patients admitted to a university ICU after surgery were recruited. Within four hours of admission, functional data were collected and APACHE II severity score calculated. Arterial blood samples were taken and endotoxemia was measured by chemiluminescence (Endotoxin Activity (EA)). Patients were stratified according to their endotoxin levels (low, intermediate and high) and according to their surgical procedures. Differences between endotoxin levels were assessed by ANOVA, accepting P < 0.05 as significant. Data are expressed as mean +/- SD. RESULTS: EA levels were low in 68 (66%) patients, intermediate in 17 (17%) and high in 17 (17%). Age (61 +/- 17 years) and APACHE II score 8.3 +/- 3.7 (P = 0.542) were not significantly different in the three EA groups. Functional parameters on admission were similar between EA groups: white blood cells 11093 +/- 4605 cells/mm3 (P = 0.385), heart rate 76 +/- 16 bpm (P = 0.898), mean arterial pressure 88.8 +/- 13.6 mmHg (P = 0.576), lactate 1.18 +/- 0.77 mmol/L (P = 0.370), PaO2/FiO2 383 +/- 109 mmHg (P = 0.474). Patients with high levels of EA were characterized by longer length of stay in the ICU: 1.9 +/- 3.0 days in the low EA group, 1.8 +/- 1.4 days in intermediate and 5.2 +/- 7.8 days in high group (P = 0.038). CONCLUSIONS: 17% of our patients were characterized by high levels of endotoxemia as assessed by EA assay, despite their low level of complexity on admission. High levels of endotoxin were associated with a longer ICU length of stay.