Outcomes Associated with a Screening and Treatment Pathway for Occult Hypoperfusion Following Cardiac Surgery

Ran Xu, Greg A. Laine, BeeBee Y. Hu, R. Thomas Solis, Arthur W. Bracey Jr., James M. Wilson, Amy R. Miclat, Susan Baimbridge, George J. Reul Jr.

Comprehensive Pharmacy Services, St Luke’s The Woodlands Hospital, The Woodlands, USA.
St Luke’s Episcopal Hospital, Houston, USA.
Texas Heart Institute, Houston, USA.

DOI: 10.4236/wjcs.2013.32007                

Abstract

Introduction: Routinely monitored parameters such as blood pressure (BP) and heart rate may not reliably detect per- fusion abnormalities. However, central venous oxygen saturation (ScvO₂) and lactate levels can detect occult hypoper- fusion (OH) and identify patients at risk for complications. The study objective was to assess the impact of an OH treatment pathway on morbidity and length of stay (LOS) post coronary bypass and valve surgery. Methods: This is a prospective cohort observational study following the implementation of a treatment pathway for OH, defined by ScvO₂ < 70% and lactate ≥ 2 mMol/L with systolic BP ≥ 90 mmHg. Initial treatment included volume resuscitation and/or blood transfusion, followed by additional interventions when ScvO₂ remained < 70%. Repeat lactate was obtained 18 hours postoperatively. Primary outcomes were intensive care unit (ICU)/hospital LOS and complications. Results: Comparing 53 patients managed by the OH pathway against 21 historical controls, median ICU LOS was 40.4 vs. 49.2 hours (p = 0.122), median hospital LOS 9.2 vs. 11.0 days (p = 0.0093), ICU readmission rate 7.5% vs. 28.6% (p = 0.026), and complication rate 26.4% vs. 47.6% (p = 0.101). Repeat lactate was checked 18 hours postoperatively in 47 of the 53 patients. Comparing 33 patients with repeat lactate at goal (< 2 mMoL/L) with 14 patients not at goal, median ICU LOS was 35.3 vs. 68.4 hours (p = 0.061), median hospital LOS 8.9 vs. 11.2 days (p = 0.058), median length of mechanical ventilation (LOMV) 13.3 vs. 28.4 hours (p = 0.0038), and complication rate 15.2% vs. 50.0% (p = 0.025). Conclusions: An OH screening and treatment pathway following cardiovascular surgery was associated with signifi- cantly shorter hospital LOS and lower ICU readmission rate. Among the OH pathway patients, achieving lactate goal 18 hours postoperatively was associated with significantly shorter LOMV and lower complication rate.

Keywords

Occult Hypoperfusion; Cardiovascular Surgery; Lactate; Central Venous Oxygen Saturation; Outcomes

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	G. Friedman, D. De Backer, M. Shahla, et al., “Oxygen Supply Dependency Can Characterize Septic Shock,” Intensive Care Medicine, Vol. 24, No. 2, 1998, pp. 118-123. doi:10.1007/s001340050531
[2]	T. A. Ryan, M. Y. Rady, C. A. Bashour, et al., “Predictors of Outcome in Cardiac Surgical Patients with Prolonged Intensive Care Stay,” Chest, Vol. 112, No. 4, 1997, pp. 1035-1042. doi:10.1378/chest.112.4.1035
[3]	W. C. Shoemaker, C. Wo, D. Thangathurai et al., “Hemodynamic Patterns of Survivors and Nonsurvivors during High Risk Elective Surgical Operations,” World Journal of Surgery, Vol. 23, No. 12, 1999, pp. 1264-1271. doi:10.1007/s002689900660
[4]	M. Y. Rady, E. P. Rivers and R. M. Nowak, “Resuscitation of the Critically Ill in the ED: Responses of Blood Pressure, Heart Rate, Shock Index, Central Venous Oxygen Saturation and Lactate,” American Journal of Emergency Medicine, Vol. 14, No. 2, 1996, pp. 218-225. doi:10.1016/S0735-6757(96)90136-9
[5]	K. Reinhart, T. Rudolph, D. L. Bredle, et al., “Comparison of Central Venous to Mixed Venous Oxygen Saturation during Changes in Oxygen Supply/Demand,” Chest, Vol. 95, No. 6, 1989, pp. 1216-1221. doi:10.1378/chest.95.6.1216
[6]	J. C. Berridge, “Influence of Cardiac Output on the Correlation between Mixed Venous and Central Venous Oxygen Saturation,” British Journal of Anaesthesia, Vol. 69, No. 4, 1992, pp. 409-410. doi:10.1093/bja/69.4.409
[7]	A. Meregalli, R. P. Oliveira and G. Friedman, “Occult Hypoperfusion Is Associated with Increased Mortality in Hemodynamically Stable, High-Risk Surgical Patients,” Critical Care, Vol. 8, 2004, pp. 60-65. doi:10.1186/cc2423
[8]	R. Pearse, D. Dawson, J. Fawcett, et al., “Changes in Central Venous Saturation after Major Surgery, and Association with Outcome,” Critical Care, Vol. 9, 2005, pp. 694-699. doi:10.1186/cc3888
[9]	J. Maillet, P. Le Besnerais, M. Cantoni, et al., “Frequency, Risk Factors, and Outcome of Hyperlactatemia after Cardiac Surgery,” Chest, Vol. 123, No. 5, 2003, pp. 1361-1366. doi:10.1378/chest.123.5.1361
[10]	J. W. Kern and W. C. Shoemaker, “Meta-Analysis of Hemodynamic Optimization in High-Risk Patients,” Critical Care Medicine, Vol. 30, No. 8, 2002, pp. 1686-1692. doi:10.1097/00003246-200208000-00002
[11]	E. Rivers, B. Nguyen, S. Havstad, et al., “Early Goal-Directed Therapy in the Treatment of Severe Sepsis and Septic Shock,” New England Journal of Medicine, Vol. 345, No. 19, 2001, pp. 1368-1377. doi:10.1056/NEJMoa010307
[12]	R. M. Otero, B. Nguyen, D. T. Huang, et al., “Early Goal-Directed Therapy in Severe Sepsis and Septic Shock Revisited,” Chest, Vol. 130, No. 5, 2006, pp. 1579-1595. doi:10.1378/chest.130.5.1579
[13]	P. Polonen, E. Roukonen, M. Hippelainen, et al., “A Prospective, Randomized Study of Goal-Oriented Hemodynamic Therapy in Cardiac Surgical Patients,” Anesthesia & Analgesia, Vol. 90, No. 5, 2000, pp. 1052-1059. doi:10.1097/00000539-200005000-00010
[14]	B. Y. Hu, G. A. Laine, S. Wang, et al., “Combined Central Venous Oxygen Saturation and Lactate as Markers of Occult Hypoperfusion and Outcome Following Cardiac Surgery,” Journal of Cardiothoracic and Vascular Anesthesia, Vol. 26, No. 1, 2012, pp. 52-57. doi:10.1053/j.jvca.2011.07.021
[15]	S. A. Nashef, F. Roques, P. Michel, E. Gauducheau, S. Lemeshow and R. Salamon, “EuroSCORE European System for Cardiac Operative Risk Evaluation (EuroSCORE),” European Journal Cardio-Thoracic Surgery, Vol. 16, No. 1, 1999, pp. 9-13. doi:10.1016/S1010-7940(99)00134-7
[16]	Collaborative Study Group on Perioperative ScvO2 Monitoring, “Multicentre Study on Periand Postoperative Central Venous Oxygen Saturation in High-Risk Surgical Patients,” Critical Care, Vol. 10, No. 6, 2006, p. R158.
[17]	M. Ranucci, G. Isgrò, C. Carlucci, et al., “Surgical and Clinical Outcome Research Group. Central Venous Oxygen Saturation and Blood Lactate Levels during Cardiopulmonary Bypass Are Associated with Outcome after Pediatric Cardiac Surgery,” Critical Care, Vol. 14, 2010, p. R149.
[18]	A. Donati, S. Loggi, J. C. Preiser, et al., “Goal-Directed Intraoperative Therapy Reduces Morbidity and Length of Hospital Stay in High-Risk Surgical Patients,” Chest, Vol. 132, No. 6, 2007, pp. 1817-1824. doi:10.1378/chest.07-0621
[19]	M. S. Goepfert, D. A. Reuter, D. Akyol, et al., “Goal-Directed Fluid Management Reduces Vasopressor and Catecholamine Use in Cardiac Surgery Patients,” Intensive Care Medicine, Vol. 33, No. 1, 2007, pp. 96-103. doi:10.1007/s00134-006-0404-2
[20]	S. M. Lobo, F. R. Lobo, C. A. Polachini, et al., “Prospective, Randomized Trial Comparing Fluids and Dobutamine Optimization of Oxygen Delivery in High-Risk Surgical Patients,” Critical Care, Vol. 10, 2006, p. R72. doi:10.1186/cc4913