title: May Renal Resistive Index be an early predictive tool of postoperative complications in major surgery? Preliminary results.
abstract: BACKGROUND
  Patients who undergo high-risk surgery represent a large amount of post-operative ICU-admissions. These patients are at high risk of experiencing postoperative complications. Renal Resistive Index was found to be related with renal dysfunction, hypertension, and posttraumatic hemorrhagic shock, probably due to vasoconstriction. We explored whether Renal Resistive Index (RRI), measured after awakening from general anesthesia, could have any relationship with postoperative complications.
  
  
  METHODS
  In our observational, stratified dual-center trial, we enrolled patients who underwent general anesthesia for high-risk major surgery. After awakening in recovery room (or during awakening period in subjects submitted to cardiac surgery) we measured RRI by echo-color-Doppler method. Primary endpoint was the association of altered RRI (>0.70) and outcome during the first postoperative week.
  
  
  RESULTS
  205 patients were enrolled: 60 (29.3%) showed RRI > 0.70. The total rate of adverse event was 27 (18.6%) in RRI ≤ 0.7 group and 19 (31.7%) in RRI > 0.7 group (P = 0.042). Significant correlation between RRI > 0.70 and complications resulted in pneumonia (P = 0.016), septic shock (P = 0.003), and acute renal failure (P = 0.001) subgroups. Patients with RRI > 0.7 showed longer ICU stay (P = 0.001) and lasting of mechanical ventilation (P = 0.004). These results were confirmed in cardiothoracic surgery subgroup. RRI > 0.7 duplicates triplicates the risk of complications, both in general (OR 2.03 93 95% CI 1.02-4.02, P = 0.044) and in cardiothoracic (OR 2.62 95% CI 1.11-6.16, P = 0.027) population. Furthermore, we found RRI > 0.70 was associated with a triplicate risk of postoperative septic shock (OR 3.04, CI 95% 1.5-7.01; P = 0.002).
authors: Department of Anesthesia and Intensive Care Unit, Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano (Milano), Italy.
authors: Enrico
authors: 0000-0001-6649-1752
authors: E
authors: Giustiniano
authors: Cardiac Surgery Anesthesia Unit, Sant'Ambrogio Clinical Institute, Milano, Italy.
authors: Massimo
authors: M
authors: Meco
authors: Biostatistic Unit, Humanitas Research Hospital, Rozzano (Milano), Italy.
authors: Emanuela
authors: 0000-0002-0254-3143
authors: E
authors: Morenghi
authors: Department of Anesthesia and Intensive Care Unit, Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano (Milano), Italy.
authors: Nadia
authors: N
authors: Ruggieri
authors: Cardiac Surgery Anesthesia Unit, Sant'Ambrogio Clinical Institute, Milano, Italy.
authors: Daniele
authors: D
authors: Cosseta
authors: Cardiac Surgery Anesthesia Unit, Sant'Ambrogio Clinical Institute, Milano, Italy.
authors: Silvia
authors: S
authors: Cirri
authors: Department of Anesthesia and Intensive Care Unit, Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano (Milano), Italy.
authors: Orazio
authors: 0000-0003-0307-3136
authors: O
authors: Difrancesco
authors: Department of Anesthesia and Intensive Care Unit, Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano (Milano), Italy.
authors: Paola Cosma
authors: PC
authors: Zito
authors: Department of Anesthesia and Intensive Care Unit, Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano (Milano), Italy.
authors: Yari
authors: Y
authors: Gollo
authors: Department of Anesthesia and Intensive Care Unit, Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano (Milano), Italy.
authors: Ferdinando
authors: F
authors: Raimondi
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058186:Acute Kidney Injury / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D007668:Kidney / Q000000981:diagnostic imaging / Q000503:physiopathology; D011014:Pneumonia / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology; D012307:Risk Factors; D012772:Shock, Septic / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D018616:Ultrasonography, Doppler, Duplex