Challenges in Managing a Patient with Refractory Shock due to Telmisartan Overdose

CASE DESCRIPTION

A 31-year-old woman, with no prior illnesses, was assessed in the emergency room (ER) following revelation to her partner about a total oral consumption quantity of telmisartan 400 mg and paracetamol 5 gm about 10 hours prior to her presentation. An hour prior to her ER presentation, a primary care physician undertook a gastric lavage and rushed her to our tertiary care center.

She was lethargic but conscious and coherent during the initial examination. She confirmed the dosages of medications consumed as well. The cardiovascular examination noted warm peripheries and a heart rate of 82/minute but with a blood pressure (BP) of 60/30 prompting emergent fluid resuscitation. Following 1500 mL of crystalloid fluid resuscitation during the initial hour, she remained hypotensive necessitating initiation of noradrenaline of 0.1 mcg/kg/minute. Due to significant hemodynamic instability, she was initiated on supplemental oxygen despite her room air SpO2 is 95%. Blood gas analysis at admission to ER showed significantly raised lactate with moderate to severe metabolic acidosis (BE: -15.3).

She was transferred to the intensive care unit (ICU) as she required continuous infusion of vasoactive medication to improve perfusion pressure. She required a noradrenaline dose of 0.5 mcg/kg/min to maintain a BP of 70/40 mm of Hg (heart rate of 120 per minute) at the initial assessment in ICU. During the hour elapsed from the time of arrival to ER and admission to ICU, she started to become restless with continued worsening in the hemodynamic state.

She underwent a point of care ultrasound to assess the shock state and it noted a hyperdynamic left ventricular ejection fraction (LVEF). Preload assessment noted an IVC collapsibility index of 60%. Noting the above she received further crystalloid fluid bolus along with escalating doses of noradrenaline. Over the next 2 hours, despite the fluid resuscitation, she required initiation of adjunct vasopressin infusion of 0.04 units/min and adrenaline infusion of 0.1 mcg/kg/min for refractory hypotension (Fig. 1).

Due to progressively worsening circulatory collapse and increasing restlessness, she required immediate initiation of mandatory mode mechanical ventilation along with deep sedation. Monitoring of acid-base state noted a worsening metabolic acidosis in conjunction with serum lactate levels making a decision to start continuous renal replacement therapy imminent (Fig. 2).

Despite the multiorgan support, she continued to have poor perfusion pressure during the initial 4 hours of ICU stay requiring the addition of not so commonly used phenylephrine infusion as a fourth vasoactive medication.

Though the assessment noted a vasoplegic state, as the circulatory collapse was secondary to anti-hypertensive agents, other rescue therapies were initiated following the risk-benefit assessment. She received a high dose insulin-dextrose infusion (insulin of 0.5U/kg/hr. and 50% dextrose at 50 mL/hr.) Insulin-dextrose infusion was titrated to a goal of >70 mm Hg. She also received intravenous formulations of ascorbic acid 1.5 gm every 6 hours and thiamine 200 mg every 12 hours as part of rescue therapies. N-acetyl cysteine (as per Prescott regimen) was added to other therapies for intake of subtoxic dose paracetamol. Her liver function test and coagulation profile pattern showed only minor changes consistent with circulatory shock.

As circulatory collapse was imminent a referral to the cardiac team for mechanical circulatory support was made and a decision against the use of an extracorporeal membrane oxygenator was made due to the severe vasodilatory nature of the shock. At this juncture, a decision to use methylene blue at a dose of 2 mg/kg given over 1 hour was made in desperation.

Following the above interventions within the first 12 hours of her ICU stay, she managed to maintain a mean arterial pressure of 55–60 mm Hg initially and consistently above 65 mm Hg over the next 48–72 hours. On day 3 of the ICU stay, she was off vasopressor support and was able to tolerate spontaneous breathing trials (SBT). She was also noted to start making urine (1 mL/kg/hr). Noting above and on passing SBT, she was liberated from mechanical ventilation and on day 5 transitioned to ward level care. Following physical and psychological evaluation, she was discharged home 7 days following her index admission with no residual organ dysfunction.