ABSTRACT
BACKGROUND: Microcirculation and macrohemodynamics are severely compromised during septic shock. However, the relationship between these two compartments needs to be further investigated. We hypothesized that early resuscitation restores left ventricular (LV) performance and microcirculatory function but fails to prevent metabolic disorders. We studied the effects of an early resuscitation protocol (ERP) on LV pressure/volume loops-derived parameters, sublingual microcirculation, and metabolic alterations during endotoxic shock. METHODS: Twenty-five pigs were randomized into three groups: LPS group: Escherichia coli lipopolysaccharide (LPS); ERP group: LPS + ERP based on volume expansion, dobutamine, and noradrenaline infusion; Sham group. LV pressure/volume-derived parameters, systemic hemodynamics, sublingual microcirculation, and metabolic profile were assessed at baseline and after completing the resuscitation protocol. RESULTS: LPS significantly decreased LV end-diastolic volume, myocardial contractility, stroke work, and cardiac index (CI). Early resuscitation preserved preload, and myocardial contractility, increased CI and heart rate (p < .05). LPS severely diminished sublingual microvascular flow index (MFI), perfused vascular density (PVD), and the proportion of perfused vessels (PPV), while increased the heterogeneity flow index (HFI) (p < .05). Despite MFI was relatively preserved, MVD, PVD, and HFI were significantly impaired after resuscitation (p < .05). The macro- and microcirculatory changes were associated with increased lactic acidosis and mixed venous O2 saturation when compared to baseline values (p < .05). The scatter plot between mean arterial pressure (MAP) and MFI showed a biphasic relationship, suggesting that the values were within the limits of microvascular autoregulation when MAP was above 71 ± 6 mm Hg (R (2) = 0.63). CONCLUSIONS: Early hemodynamic resuscitation was effective to restore macrohemodynamia and myocardial contractility. Despite MAP and MFI were relatively preserved, the persistent microvascular dysfunction could explain metabolic disorders. The relationship between micro- and systemic hemodynamia and their impact on cellular function and metabolism needs to be further studied during endotoxic shock.
ABSTRACT
OBJETIVO: el objetivo de este estudio fue comparar la capacidad de la evaluación clínica y de la laringoscopía indirecta (LI) para predecir dificultades en la intubación orotraqueal en pacientes coordinados para procedimientos endoscópicos de vía aérea superior. METODOLOGÍA: se realizó un estudio prospectivo de 76 pacientes coordinados para procedimientos endoscópicos de vía aérea superior, con anestesia general y que requerían intubación orotraqueal. La vía aérea se evaluó clínicamente mediante el test de Mallampati, medidas de las distancias mentohioidea, tiromentoneana y rama horizontal del maxilar inferior, características del cuello, dientes, lengua, apertura bucal, y por laringoscopía indirecta. Esta evaluación determinó un diagnóstico de sospecha de intubación dificultosa que se correlacionó con los hallazgos durante las maniobras de laringoscopía e intubación orotraqueal. Se determinó la sensibilidad, especificidad, valor predictivo positivo (VPP) y negativo (VPN) de los diferentes métodos de evaluación. RESULTADOS: la evaluación clínica tuvo una sensibilidad del 50% y una especificidad del 81%, con un VPP de 24% y VPN de 93%. La LI tuvo una sensibilidad del 38% y una especificidad de 79%, con un VPP de 18% y VPN de 92%. CONCLUSIONES: la evaluación clínica fue superior que la LI para predecir dificultades en la intubación orotraqueal, pero el valor predictivo de ambos métodos fue bajo.
OBJECTIVE: The objective of this study was to compare the predictive value of clinical evaluation and indirect laryngoscopy (LI) to detect difficult tracheal intubation, in patients coordinated for endoscopic procedures of upper airway. METHODS: We studied 76 patients coordinated for endoscopic procedures of upper airway under general anesthesia with tracheal intubation. The airway was clinically evaluated with Mallampati test, hyomental and thyromental distances, horizontal branch of lower jaw distance, neck characteristics, teeth, tongue, mouth opening, and with indirect laryngoscopy. This evaluation was used as a predictor of difficult airway, and was correlated to the findings during direct laryngoscopy and intubation. From this data sensitivity, specificity, positive (PPV) and negative predictive (NPV) value were calculated. RESULTS: clinical evaluation had 50% sensitivity and 81% specificity, with a PPV of 24% and a NPV of 93%. Indirect laryngoscopy had 38% sensitivity and 79% specificity, with a PPV of 18% and a NPV of 92%. CONCLUSIONS: Clinical evaluation was best predictor of difficult airway than indirect laryngoscopy, but predictive value of both methods was low.