A Two Parameters for the Evaluation of Hypovolemia in Patients with Septic Shock: Inferior Vena Cava Collapsibility Index (IVCCI), Delta Cardiac Output

Abstract

BackgroundThe aim of this study was to determine the correlation between inferior vena cava collapsibility index and changes in cardiac output measured during passive leg raising test in patients with spontaneous breathing and septic shock.Material/MethodsFifty-six patients were included in the study. All of these 56 patients were diagnosed with septic shock and had spontaneous breathing under continuous positive airway pressure. Patients exclusions included: patients with cardiac pathology, not septic shock, pregnant, spontaneous breathing, increased intra-abdominal pressure, inferior vena cava could not be visualized, arrhythmia and pulmonary hypertension.Exclusion criteria for the study were as follows: 1) left ventricular systolic dysfunction, 2) cardiomyopathy, 3) medium severe heart valve disease, 4) patients with arrhythmia; 5) pulmonary hypertension, 6) patients without spontaneous breathing (for inferior vena cava collapsibility index, it is not evaluated), 7) patients with >60 mmHg CO2 in arterial blood gas; 8) pregnant patients; 9) patients with neurogenic shock, cerebrovascular incident or traumatic brain injury, 10) patients whose inferior vena cava and parasternal long axis cannot be visualized, and 11) patients with increased intra-abdominal pressure.Patients were placed in neutral supine position, and the inferior vena cava collapsibility index and cardiac output 1 were recorded. In passive leg raising test, after which the cardiac output 2 is recorded in terms of L/min. The percentage increase between the 2 cardiac outputs was calculated and recorded.ResultsA moderately positive correlation was also observed between the inferior vena cava collapsibility index and delta cardiac output (r=0.459; r2=0.21), which was statistically significant (P<0.001). The cutoff value for the delta cardiac output was 29.5.ConclusionsIn conclusion, we found that the inferior vena cava collapsibility index, which is one of the dynamic parameters used in the diagnosis of hypovolemia in patients with septic shock, is correlated with delta cardiac output after leg raising test. We believe that, based on a clinician’s experience, looking at 1 of these 2 parameters is sufficient for the identification of hypovolemia in patients diagnosed with septic shock.

Association of inferior vena cava diameter in the emergency room and early mortality in septic patients

“…There are several studies that associate IVC with fluid responsiveness and volemia in septic patients 8,9 . Protocols assessing the use of POCUS to diagnose volemic state in septic shock patients have showed encouraging results 13 .…”

“…Point-of-care-ultrasound (POCUS) helps clinicians identify critical diagnoses enabling decisive interventions in a timely fashion 7 . Inferior Vena Cava (IVC) visualized through POCUS at the bedside is a rapid way to approximate the volemic state in septic patients and guide fluid management, although with limitations 8,9 . The use of ultrasound in emergency medicine has grown in the past years, demonstrating an added value to the bedside clinical exam 10 .…”

Echocardiographic Examination of the Effects of Midazolam on Volume Change in Patients Who are Hospitalized in Intensive Care, Who Have Spontaneous Breathing

“…17 Bir çalışma da ise CI ve SV'nin sıvı yanıtlılığı ile yüksek derecede korelasyonu olduğu gösterilmiştir. 21,22 Başka bir grup yazarın yaptığı çalışmada ise 500 mL (130/0,4)-%6 hidroksietil nişaşta infüzyonu öncesi ve 15 dk sonrası transtorasik EKO (TTE) ile VCI-CI ölçmüşler, daha sonra VTI ölçmüşler ve VTI'nın sıvı verilmesi sonrası %15'lik artışı sıvı yanıtı var olarak kabul edilmiştir. Aynı çalışmada, VCI-CI'nın ise >%40 olduğu zaman hastanın hipovolemik olduğu düşünülmüştür.…”

“…Midazolam sedasyonunun hastaların rölatif hipovolemisini artırdığını düşündük. [16][17][18][19][20][21][22][23]27 Biz, çalışmamızda, iki kez PBKT i uyguladık, birincisi midazolam uygulanması yapılmadan önceydi; supin pozisyon ve PBKT sonrası iki kez SAB, CI, CO, VTI ölçümü yaptık. Midazolam…”

“…[17][18][19][20][21] PBKT yapmadan da VCI-CI, delta velocite peak (Delta Vpeak) ve kardiyak out-put (CO) artış yüzdesi ile de hipovolemi tanısı konabilir. 13,22,23 Sedatif ilaçlar, yoğun bakım ünitelerinde yatan hastalarda sık kullanılan ilaçlardır. Fakat sedatif ilaçlar venöz kapasitansı artırarak rölatif hipovolemiye zemin hazırlar ve bunun sonucu olarak azalmış kan volümü, CO, dokularda oksijen ihtiyacını karşılayamama durumu ve potansiyel olarak hipoksi ortamı oluşturabilir.…”