Reliability of Passive Leg Raising, Stroke Volume Variation and Pulse Pressure Variation to Predict Fluid Responsiveness During Weaning From Mechanical Ventilation After Cardiac Surgery: A Prospective, Observational Study

Abstract

Objective: During assisted ventilation and spontaneous breathing, functional haemodynamic parameters, including stroke volume variation (SVV) and pulse pressure variation (PPV), are of limited value to predict fluid responsiveness, and the passive leg raising (PLR) manoeuvre has been advocated as a surrogate method. We aimed to study the predictive value of SVV, PPV and PLR for fluid responsiveness during weaning from mechanical ventilation after cardiac surgery. Methods: Haemodynamic variables and fluid responsiveness were assessed in 34 patients. Upon arrival at the intensive care unit, measurements were performed during continuous mandatory ventilation (CMV) and spontaneous breathing with pressure support (PSV) and after extubation (SPONT). The prediction of a positive fluid responsiveness (defined as stroke volume increase >15% after fluid administration) was tested by calculating the specific receiver operating characteristic (ROC) curves. Results: A significant increase in stroke volumes was observed during CMV, PSV and SPONT after fluid administration. There were 19 fluid responders (55.9%) during CMV, with 22 (64.7%) and 13 (40.6%) during PSV and SPONT, respectively. The predictive value for a positive fluid responsiveness (area under the ROC curve) for SVV was 0.88, 0.70 and 0.56; was 0.83, 0.69 and 0.48 for PPV; was 0.72, 0.74 and 0.70 for PLR during CMV, PSV and SPONT, respectively. Conclusion: During mechanical ventilation, adequate prediction of fluid responsiveness using SVV and PPV was observed. However, during spontaneous breathing, the reliability of SVV and PPV was poor. In this period, PLR as a surrogate was able to predict fluid responsiveness better than SVV or PPV but was less reliable than previously reported. Keywords: Stroke volume variation, pulse pressure variation, passive leg raising, functional haemodynamic parameter, pulse contour analysis Amaç: Yardımlı ventilasyon ve spontan solunum sırasında, Atım Hacmi Varyasyonu (SVV) ve Nabız Basıncı Varyasyonunun (PPV) dâhil olmak üzere fonksiyonel hemodinamik parametreler, sıvı duyarlılığını tahmin etmek için sınırlı değerdedir ve pasif bacak kaldırma (PLR) manevrası alternatif bir yöntem olarak savunulmuştur. Kalp cerrahisi sonrası mekanik ventilasyondan weaning sırasındaki sıvı yanıtı için SVV, PPV ve PLR'nin prediktif değerini araştırmayı amaçladık. Yöntemler: Hemodinamik değişkenler ve sıvı yanıtı 34 hastada değerlendirildi. Yoğun bakım ünitesine varışta, sürekli zorunlu ventilasyon (CMV) ve basınç desteği (PSV) ile spontan solunum esnasında ve ekstübasyon sonrası (SPONT) ölçümler yapıldı. Pozitif sıvı cevabı (sıvı uygulamasından sonra atım hacmi artışı >%15 olarak tanımlanır), belirli alıcı işlem karakteristik eğrileri-nin (ROC) hesaplanmasıyla test edildi. Bulgular: Sıvı uygulamasından sonra CMV, PSV ve SPONT esnasında, atım hacimlerinde belirgin bir artış gözlendi. CMV esnasında, 19 sıvı yanıtı (%55,9) ve PSV ve SPONT esnasında sırasıy-la 22 (%64,7) ve 13 (%40,6) sıvı yanıtı vardı. Pozitif sıvı cevabı (ROC eğrisinin altındaki alan) i...

Accuracy of pulse pressure variations for fluid responsiveness prediction in mechanically ventilated patients with biphasic positive airway pressure mode

“…However, patient's bedside conditions of measurement of these dynamic indices at ICU remain a still moot issue. Experimental studies have shown conflicting results regarding the accuracy of PPV to individually predict the response to volume expansion in patients mechanically ventilated under PC versus VC modes [1][2][3][4]. Moreover, most of the validation studies of PPV as fluid responsiveness predictor in critically ill patients have exclusively included patients who were ventilated with VC mode, generally with a tidal volume > 8 ml kg −1 of ideal body weight (IBW).…”

“…Nevertheless, the expected effect of spontaneous breathing on variations in left ventricular SV may be inverted to the effect of mechanical ventilation (MV), due to inverted cardiopulmonary interactions. Moreover, respiratory changes in intra-thoracic pressure during pressure control mode might be insufficient to modify loading conditions of ventricles [3,13]. Therefore, the ability of PPV to predict fluid responsiveness in septic patients mechanically ventilated with pressure-controlled mode is still under debate [11].…”

Estudo clínico prospectivo sobre preditores de fluido responsividade em pacientes no pós-operatório de cirurgia cardíaca

“…Duas metanálises recentes demonstraram alta acurácia do teste em predizer o aumento do índice cardíaco (IC) na terapia intensiva 20,21 . Entretanto, os resultados dos poucos estudos realizados no pós-operatório de cirurgia cardíaca demostraram acurácia do teste inferior [22][23][24] e, portanto ainda faltam evidências nesta população.…”

“…Diversos estudos realizados em cirurgia cardíaca, demostram a inabilidade da PVC com preditor da resposta ao fluido 22,69 , reportando AUC ROC entre 0,58 15 , 0,58 70 , 0,34 intraoperatório antes da cirurgia 71 A pressão positiva da ventilação mecânica provoca uma diminuição cíclica do volume sistólico do ventrículo direito por dois mecanismos:…”