J . M . Cardenas et al .: J Extra Corpor Technol 2023 , 55 , 206 – 208 207
Figure 1 . Maximum daily End Organ Perfusion pressure over time . HD : Hospital Day .
Description
A 12-year-old , 63 kg , previously healthy female , presented to the emergency room for a two-day history of abdominal pain and emesis . Upon evaluation , she was found hypotensive ( 70 / 30 mm / Hg ), tachycardic ( sinus , HR 130 BPM ), and hypoxemic ( SpO2 85 %). Initial ancillary studies were significant for acute kidney injury ( serum creatinine 1.6 mg / dL , and BUN 40 mg / dL ). Echocardiography confirmed normal anatomy and function , and a chest roentgenogram was significant for basal pulmonary infiltrates . The patient received three liters of isotonic fluid resuscitation , was placed on high-flow oxygen , and was admitted to the pediatric intensive care unit with suspected septic shock .
Following admission , the patient developed anuric renal failure and acute respiratory distress syndrome associated with hemodynamics decompensation ( peak lactic acid 10.6 mmol / L ). There was no significant improvement following invasive mechanical ventilation , high doses of epinephrine , norepinephrine , and vasopressin infusions ( maximum vasoactiveinotropic score 180 ), broad-spectrum antibiotics , aggressive fluid resuscitation , stress dose steroids , and methylene blue . On Hospital Day ( HD ) # 2 , further investigation revealed the patient had intentionally ingested amlodipine 300 mg four days prior . Subsequently , high-dose intravenous insulin , lipid emulsion , and intravenous calcium were started with minimal improvement .
On HD # 3 , due to worsening multi-organ failure , the patient was centrally cannulated in the operating room for veno-arterial ( VA ) ECMO due to the high cardiac output state and anticipated limitations in the flow of peripheral ECMO cannulation . A 22-French elongated one-piece arterial aortic cannula ( Medtronic ) was placed in the ascending aorta and a 36 / 46- French three-stage cannula ( Edwards Lifesciences ) was into the right atrial appendage placed by cardiovascular surgery . Shortly after reaching ECMO flows of 7.0 L / min ( 111 mL / kg / min , Cardiac Index 4 L / min / m 2 ), the vasoactive drug requirement was significantly decreased , and urine output improved immediately . Anticoagulation was managed with bivalirudin
according to hospital protocol ( activated partial thrombin time goal 70-90 seconds ). Patient care continued in the pediatric cardiovascular intensive care unit . Figure 1 shows the dramatic drop in vasoactive inotropic score following cannulation and the improvement in organ perfusion pressure is shown in Figure 2 .
By HD # 6 , the vasoactive and mechanical support requirement was minimal . The patient tolerated an ECMO clamp trial well and decannulated with chest closure . She was extubated and weaned off vasoactive on HD # 7 and discharged home on HD # 21 with no significant disability . Currently , she continues to recover as an outpatient .
Comment
This case report highlights the utility of central ECMO cannulation in the setting of vasodilatory shock related to dihydropyridine CCB intoxication when conventional medical therapy fails to maintain adequate organ perfusion . To our knowledge , this is the first report of dihydropyridine CCB intoxication managed with central ECMO cannulation prior to circulatory collapse that survived to discharge with a good neurological outcome [ 3 , 4 ].
Severe amlodipine overdose induces a significant vasodilatory shock due to blockage of L-type calcium channels in the peripheral vasculature with reflex tachycardia- albeit bradycardia and heart block can be present due to loss of receptor selectivity . The management is mainly focused on reestablishing adequate organ perfusion until the drug is metabolized to non-toxic metabolites [ 3 ].
The rationale of central cannulation in vasodilatory shock resides in that organ perfusion pressure is driven by the mean arterial pressure ( MAP ) minus central venous pressure ( CVP ). MAP is driven by cardiac output ( CO ) and systemic vascular resistance ( SVR ). If vasoactive drugs are insufficient to increase the SVR enough to support adequate MAP , further increases in the CO might compensate for low SVR . Therefore , higher CO is required above what conventional ECMO flows provide , and