Manu Mathew Lal¹, Deepali Rajpal^2*, Manhar Shah³, Utkarsh Khandelwal⁴

¹Senior Resident, ²Professor, ³Professor & HOD, Department of Emergency Medicine, Dr D Y Patil Medical College and Research Institute; Navi Mumbai, INDIA.
⁴Senior Resident, All India Institute of Medical Sciences, Delhi, INDIA.

Email: dypemergencymedicine6@gmail.com  

OBSERVATIONS AND RESULTS
                                                                                          Table 1:

The average pulse of patients who presented with hypotension was 108.4 ; and the standard deviation was 8.5

Table 2:

The average pulse of patients with hypotension after 1 liter of isotonic fluid was 101.4 ; and the standard deviation was 7.8

Table 3:

The average spo2 of patients who presented with hypotension was 94.18 ; and the standard deviation was 3.5

Table 4: Comparison of systolic BP

The average systolic bp of patients who presented with hypotension was 81.6 ; and the standard deviation was 16.8

The average systolic bp of patients with hypotension after 1 liter of isotonic fluid was 92.4 ; and the standard deviation was 25.7.

Table 5: comparison of diastolic BP

The average diastolic bp of patients who presented with hypotension was 55.2 ; and the standard deviation was 8.1

The average systolic bp of patients with hypotension after 1 liter of isotonic fluid was 72.1 ; and the standard deviation was 11.8

Table 6: Comparison of expiratory diameter

The average diameter of ivc of patients who presented with hypotension, during expiratory phase was 1.74; and the standard deviation was 0.35. The average diameter of ivc of patients with hypotension after 1 liter of isotonic fluid during expiratory phase was 1.88; and the standard deviation was 0.44

Table 7: Comparison of inspiratory diameter

The average diameter of ivc of patients who presented with hypotension, during inspiratory phase was 0.54; and the standard deviation was 0.27. The average diameter of ivc of patients with hypotension after 1 liter of isotonic fluid during inspiratory phase was 1.07; and the standard deviation was 0.57

Table 8: Comparison of collapsability index

The average collapsability index of ivc of patients who presented with hypotension was 69.33; and the standard deviation was 14.9The average collapsability index of ivc of patients with hypotension after 1 liter of isotonic fluid was 45.9; and the standard deviation was 21.2.

DISCUSSION

The primary utility of bedside ultrasound of the ivc is to aid in assessment of the intravascular volume status of the patient. This may be of particular utility in cases of undifferentiated hypotension or other scenarios of abnormal volume states, such as sepsis, dehydration, hemorrhage, or heart failure. Point-of-care ultrasound has been increasingly used in evaluating hypotensive patients including the measurement of inferior vena cava (ivc) diameter. Combining the collapsibility and diameter size will increase the value of ivc measurement. This approach has been very useful in the resuscitation of hypotensive patients, monitoring their fluid demands, and predicting recurrence of shock. Pitfalls in measuring ivc diameter include increased intra-thoracic pressure by mechanical ventilation or increased right atrial pressure by pulmonary embolism or heart failure. The ivc diameter is not useful in cases of increased intra-abdominal pressure (abdominal compartment syndrome) or direct pressure on the ivc.

There are various methods to measure the fluid responsiveness which includes both

• Invasive methods
• Non-invasive methods

Poc-us is a non-invasive method of ivc measurement for the fluid responsiveness in hypotensive patients. The ivc is a thin-walled compliant vessel that adjusts to the body's volume status by changing its diameter depending on the total body fluid volume. The vessel contracts and expands with each respiration. Negative pressure created by the inspiration of the patient increases venous return to the heart, briefly collapsing the ivc. Exhalation decreases venous return and the ivc returns to its baseline diameter.in states of low intravascular volume, the percentage collapse of the vessel will be proportionally higher than in intravascular volume overload states. This is quantified by the calculation of the caval index: ivc expiratory diameter - ivc inspiratory diameter, divided by ivc expiratory diameter × 100 = caval index (%).the caval index is written as a percentage, where a number close to 100% is indicative of almost complete collapse (and therefore volume depletion), while a number close to 0% suggest minimal collapse (i.e., likely volume overload).the diameter of the ivc for calculation of the caval index should be measured 2 cm from where it enters the right atrium an alternative way to visualize respiratory variation is to use m-mode, with the beam overlying the ivc 2 cm from the right atrium. The inspiratory and expiratory diameter can then be measured on the m-mode image, at the smallest and largest locations, respectively

CONCLUSION

Measuring ivc collapsabilty index using ultrasound is a good non invasive bedside tool which can be used in critically ill patients presenting in emergency; not only to determine shock but also as a guidance in resuscitating patients in the hands of a well trained emergency physician.

REFERENCES

1. Manual of diagnostic ultrasound, p.e.s. palmer.
2. Tintinalli's emergency medicine, a comprehensive study guide, 7th edition
3. Blaivas m, pawl r. Analysis of lawsuits filed against emergency physicians for point-of-care emergency ultrasound examination performance and interpretation over a 20-year period. Am j emerg med. 2012;5(2):338–341.
4. Hatfield a, bodenham a. Ultrasound: an emerging role in anaesthesia and intensive care. Br j anaesth.1999;83:789–800.
5. Blehar dj, dickman e, gaspari r. Identification of congestive heart failure via respiratory variation of inferior vena cava diameter. Am. J. Emerg. Med. 2009;27:71-5.
6. Feissel m, michard f, faller jp, et al. The respiratory variation in inferior vena cava diameter as a guide to fluid therapy. Intensive care med. 2004;30:1834-7.
7. Merritt cr. Ultrasound safety: what are the issues? Radiology. 1989;5(2):304–306. 
8. World health organization. Training in diagnostic ultrasound: essentials, principles and standards. Report of a who study group: technical report series no. 875. Geneva: who; 1998. 
9. Romolo joseph gaspari jcf, sierzenski pr. Emergency ultrasound: principles and practice. Maryland heights geneva: mosby; 2005.
10. Understanding anesthesia equipment textbook, jerry a. Dorsch - susan e.dorsch
11. Clinical anatomy textbook, richard s.snells
12. Textbook of human anatomy; b d chaurasia's; volume 1
13. Textbook of human anatomy; b d chaurasia's; volume 3
14. Anatomy for anaesthetists textbook, h. Ellis, s. Feldman, w. Harrop-griffiths
15. Perera p, mailhot t, riley d, mandavia d. The rush exam: rapid ultrasound in shock in the evaluation of the critically lll. Emerg med clin north am. 2010;28:29–56. 
16. Fields jm, lee pa, jenq ky, et al. The interrater reliability of inferior vena cava ultrasound by bedside clinician sonographers in emergency department patients. Acad. Emerg. Med. 2011;18:98-101.
17. Kircher bj, himelman rb, schiller nb. Noninvasive estimation of right atrial pressure from the inspiratory collapse of the inferior vena cava. Am j. Cardiol. 1990;66:493-6.
18. Randazzo mr, snoey er, levitt ma, et al. Accuracy of emergency physician assessment of left ventricular ejection fraction and central venous pressure using echocardiography. Acad. Emerg. Med.2003;10:973-7.
19.  marik pe. Iatrogenic salt water drowning and the hazards of a high central venous pressure. Ann intensive care. 2014;4:21. 
20. Wang ch, hsieh wh, chou hc, et al. Liberal versus restricted fluid resuscitation strategies in trauma patients: a systematic review and meta-analysis of randomized controlled trials and observational studies. Crit care med. 2014;42:954–61. 
21.  boyd jh, forbes j, nakada ta, walley kr, russell ja. Fluid resuscitation in septic shock: a positive fluid balance and elevated central venous pressure are associated with increased mortality. Crit care med. 2011;39:259–65. 
22. Legrand m, dupuis c, simon c, et al. Association between systemic hemodynamics and septic acute kidney injury in critically ill patients: a retrospective observational study. Crit care. 2013;17
23. Kaafarani hm, velmahos gc. Damage control resuscitation in trauma. Scand j surg. 2014;103:81–8
24. Maitland k, george ec, evans ja, et al. Exploring mechanisms of excess mortality with early fluid resuscitation: insights from the feast trial. Bmc med. 2013;11:68. 
25. Marik pe, monnet x, teboul jl. Hemodynamic parameters to guide fluid therapy. Ann intensive care. 2011;1:1. 
26. Marik pe, cavallazzi r. Does the central venous pressure predict fluid responsiveness? An updated meta-analysis and a plea for some common sense. Crit care med. 2013;41:1774–81. 
27. Nagdev ad, merchant rc, tirado-gonzalez a, sisson ca, murphy mc. Emergency department bedside ultrasonographic measurement of the caval index for non-invasive determination of low central venous pressure. Ann emerg med. 2010;55:290–5. 
28. Barbier c, loubieres y, schmit c, et al. Respiratory changes in inferior vena cava diameter are helpful in predicting fluid responsiveness in ventilated septic patients. Intensive care med. 2004;30:1740–6. 
29. Muller l, bobbia x, toumi m, et al. Respiratory variations of inferior vena cava diameter to predict fluid responsiveness in spontaneously breathing patients with acute circulatory failure: need for a cautious use. Crit care. 2012;16: 
30. Blehar dj, resop d, chin b, dayno m, gaspari r. Inferior vena cava displacement during respirophasic ultrasound imaging. Crit ultrasound j. 2012;4:18.
31. Soubrier s, saulnier f, hubert h, et al. Can dynamic indicators help the prediction of fluid responsiveness in spontaneously breathing critically ill patients? Intensive care med. 2007;33:1117–24.
32.  feissel m, michard f, mangin i, ruyer o, faller jp, teboul jl. Respiratory changes in aortic blood velocity as anindicator of fluid responsiveness in ventilated patients with septic shock. Chest. 2001;119:867–73. 
33. Lamia b, ochagavia a, monnet x, chemla d, richard c, teboul jl. Echocardiographic prediction of volume responsiveness in critically ill patients with spontaneously breathing activity. Intensive care med. 2007;33:1125–32. 
34. Maizel j, airapetian n, lorne e, tribouilloy c, massy z, slama m. Diagnosis of central hypovolemia by using passive leg raising. Intensive care med. 2007;33:1133–8. 
35. Squara p, denjean d, estagnasie p, brusset a, dib jc, dubois c. Non-invasive cardiac output monitoring (nicom): a clinical validation. Intensive care med. 2007;33:1191–4. 
36. Dunham cm, chirichella tj, gruber bs, et al. In emergently ventilated trauma patients, low end-tidal co2 and low cardiac output are associated and correlate with hemodynamic instability, hemorrhage, abnormal pupils, and death. Bmc anesthesiol. 2013;13:20. 
37. Garcia x, simon p, guyette fx, et al. Noninvasive assessment of acute dyspnea in the ed. Chest. 2013;144:610–5. 
38.  lichtenstein d. Falls-protocol: lung ultrasound in hemodynamic assessment of shock. Heart lung vessel. 2013;5:142–7. 
39. Haydar sa, moore et, higgins gl 3rd, irish cb, owens wb, strout td. Effect of bedside ultrasonography on the certainty of physician clinical decision making for septic patients in the emergency department. Ann emerg med. 2012;60:346–58. 
40. Caltabeloti f, monsel a, arbelot c, et al. Early fluid loading in acute respiratory distress syndrome with septic shock deteriorates lung aeration without impairing arterial oxygenation: a lung ultrasound observational study. Crit care. 2014;18.