Patients in an intensive care unit (ICU) are commonly subject to episodes of hypotension, or low blood pressure, leading to a dangerous reduction in blood supply to the brain and other crucial organs. Doctors treating such patients must manage persistent hypotension, often through the administration of vasopressors, which contract blood vessels to increase arterial blood pressure [1]. According to Surviving Sepsis guidelines [2], the patient’s mean arterial pressure (MAP) must not go below 65 mmHg to prevent sepsis and keep the central nervous system auto-regulated. Studies have shown that septic ICU patients with a MAP ≤ 65mmHg were at high risk for mortality, acute kidney injury (AKI), and myocardial injury [3,4].
Vasopressor infusion is used to treat severe patient hypotension, with the assumption that vasoconstriction will improve the patient’s organ perfusion and combat hypotension. Examples of commonly-used vasopressors include norepinephrine, epinephrine, vasopressin, phenylephrine, dopamine [5]. In the ICU, patients receive an ongoing titration of vasopressor, with the need for constant adjustments to ensure MAP targets. However, too much vasoconstriction can lead to excess cardiac demand, cardiac ectopy, and poor tissue perfusion [6].
A study from 2012 [7] indicates that catecholamine vasopressor therapy may contribute to adverse cardiac events, ranging from prolonged elevated heart rate to acute cardiac arrest or death. One study found that patients experienced ischemic skin lesions as a result of a continuous infusion of arginine-vasopressin (AVP) [8]. Furthermore, a retrospective correlational design study from 2015 [9] indicates that the administration of vasopressin concomitantly with a first-line agent such as norepinephrine is significantly associated with the development of pressure ulcers. This study also suggests that, because necessary vasopressor use cannot simply be halted just to avoid the development of pressure ulcers, these complications may be unavoidable.
Another area of potential adverse effects from vasopressor use lies not in the physical ramifications of vasopressors on patient health, but in the procedures used by doctors and nurses to administer vasopressors. For one, there is no clear optimal approach to titrating vasopressor therapy, other than the need to constantly adjust for each patient. However, an observational study from 2017 [6] reveals that clinicians administering vasopressor therapy may be more influenced by local practice patterns as opposed to tailoring therapy based on individual patient characteristics, such as chronic hypotension. In this case, nurses and physicians avoided under-dosing vasopressors by maintaining a patient-level average MAP of 75 mmHg, 10 mmHg above stated practices. The study suggests that reducing unnecessary exposure to vasopressor therapy may be key to averting certain adverse cardiac events, as explained earlier.
In addition, a 2014 study [10] found that ICU patients frequently experience episodes of hypotension lasting longer than 15 minutes while receiving vasopressor infusions, indicating that even current rates of compliance with MAP goals are suboptimal. The study suggests that formulating methods by which clinicians can predict when dose changes are necessary for a patient before hypotension develops may be critical. Ultimately, while vasopressor therapy is used to treat hypotension in ICU patients, a closer examination of vasopressor use both in its physical impact and the way it is administered is important to consider.
References
[1] Yapps, Bryce, Sungtae Shin, Ramin Bighamian, Jill Thorsen, Colleen Arsenault, Sadeq A. Quraishi, Jin-Oh Hahn, and Andrew T. Reisner. “Hypotension in ICU patients receiving vasopressor therapy.” Scientific Reports 7, no. 1 (2017): 1-10.
[2] Dellinger, R. Phillip, Mitchel M. Levy, Andrew Rhodes, Djillali Annane, Herwig Gerlach, Steven M. Opal, Jonathan E. Sevransky et al. “Surviving Sepsis Campaign Guidelines Committee including the Pediatric Subgroup Surviving sepsis campaign: international guidelines for management of severe sepsis and septic shock: 2012.” Crit Care Med 41, no. 2 (2013): 580-637.
[3] Maheshwari, Kamal, Brian H. Nathanson, Sibyl H. Munson, Victor Khangulov, Mitali Stevens, Hussain Badani, Ashish K. Khanna, and Daniel I. Sessler. “The relationship between ICU hypotension and in-hospital mortality and morbidity in septic patients.” Intensive care medicine 44, no. 6 (2018): 857-867.
[4] Legrand, Matthieu, Claire Dupuis, Christelle Simon, Etienne Gayat, Joaquim Mateo, Anne-Claire Lukaszewicz, and Didier Payen. “Association between systemic hemodynamics and septic acute kidney injury in critically ill patients: a retrospective observational study.” Critical Care 17, no. 6 (2013): R278.
[5] Van Valkinburgh, Danny, and Muhammad F. Hashmi. “Inotropes and vasopressors.” (2019).
[6] Lamontagne, Francois, Deborah J. Cook, Maureen O. Meade, Andrew Seely, Andrew G. Day, Emmanuel Charbonney, Karim Serri et al. “Vasopressor use for severe hypotension—a multicentre prospective observational study.” PloS one 12, no. 1 (2017): e0167840.
[7] Schmittinger, Christian A., Christian Torgersen, Günter Luckner, Daniel CH Schröder, Ingo Lorenz, and Martin W. Dünser. “Adverse cardiac events during catecholamine vasopressor therapy: a prospective observational study.” Intensive care medicine 38, no. 6 (2012): 950-958.
[8] Dünser, Martin W., Andreas J. Mayr, Andreas Tür, Werner Pajk, Friesenecker Barbara, Hans Knotzer, Hanno Ulmer, and Walter R. Hasibeder. “Ischemic skin lesions as a complication of continuous vasopressin infusion in catecholamine-resistant vasodilatory shock: incidence and risk factors.” Critical care medicine 31, no. 5 (2003): 1394-1398.
[9] Cox, Jill, and Sharon Roche. “Vasopressors and development of pressure ulcers in adult critical care patients.” American Journal of Critical Care 24, no. 6 (2015): 501-510.
[10] Bighamian, Ramin, Cal Rubbo, Jill E. Thorsen, Jin-Oh Hahn, and Andrew T. Reisner. “Is there opportunity for automated decision-support and closed-loop control in ICU patients receiving vasopressor infusion?.” In 2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, pp. 1949-1952. IEEE, 2014.
