Myocardial infarction associated with the administration of intravenous ephedrine and metaraminol for spinal‐induced hypotension

Abstract

SummaryA 31-year-old female with no risk factors for cardiac disease suffered a peri-operative myocardial infarction during an elective gynaecological procedure under spinal anaesthesia. The timing and nature of cardiac symptoms suggest that the myocardial infarction was caused by coronary artery vasospasm secondary to ephedrine and ⁄ or metaraminol, which were administered to treat spinalinduced hypotension. We review the recent literature and case reports on myocardial infarction attributed to sympathomimetic drugs, and recommend the use of sublingual or intravenous nitrates when signs or symptoms of coronary arterial vasospasm become evident during their use. Spinal anaesthesia is associated with cardiovascular complications, most notably hypotension and bradycardia [1], which often necessitate the use of sympathomimetic drugs such as ephedrine and metaraminol. These agents can cause coronary artery vasospasm, which is thought to be due to their action on alpha-adrenergic receptors on large epicardial arteries [2]. There have been several case reports of myocardial injury as a result of such vasospasm [3][4][5][6]. We describe a case of myocardial infarction in a fit, healthy woman, the signs and symptoms of which were closely temporally related to the administration of ephedrine and metaraminol for spinal-induced hypotension. Case reportA 31-year-old female with a history of stress incontinence was scheduled for an elective tension-free vaginal tape (TVT) procedure under spinal anaesthesia. She had previously received epidural analgesia, with no complications, for two normal vaginal deliveries. She had no history of cardiovascular disease and no risk factors. There was no history of illicit drug use. She was fit and healthy and regularly cycled 20 miles.Prior to insertion of the spinal anaesthetic, she was given 1 l of Hartmann's solution intravenously. She was very anxious about the procedure and so was given intravenous midazolam 2 mg in 1-mg increments. Blood pressure was recorded as 120 ⁄ 72 mmHg and heart rate 74 beats.min )1 . Spinal anaesthesia was induced with 2.7 ml hyperbaric bupivacaine 0.5%. Ten minutes after induction of anaesthesia, her blood pressure fell to 105 ⁄ 65 mmHg and her heart rate to 60 beats.min. She complained of feeling faint and became pale. She was treated with intravenous ephedrine 5 mg, followed by intravenous metaraminol 1 mg. Her blood pressure rose to 180 ⁄ 120 mmHg and she developed a sinus tachycardia of 120 beats.min )1 with frequent ventricular ectopic beats. This was associated with chest tightness and anxiety. She was given a further 2 mg intravenous midazolam in 1-mg increments. After 5 min, her chest discomfort had resolved and the procedure was completed without further complication or significant blood loss. She was transferred to the recovery room.

Management of blood pressure during spinal anaesthesia

“…We would like to thank Professor Wildsmith for his interest in our case report [1]. We would, however, like to address several of the comments he makes.…”

“…In reporting a patient who suffered a myocardial infarction during spinal anaesthesia, Khavandi et al [1] recommend systemic nitrate therapy for coronary arterial spasm due to sympathomimetic drugs. In this they promote a 'reactive' approach to the patient's condition and its management, but their report raises a number of issues:…”

Perioperative Myocardial Infarction in Thoracic Surgery: Awareness, Diagnosis, Follow-up and Treatment

“…Literatüre bakıl-dığında az sayıda rejyonel veya lokal anestezi altında hasta bir rahatsızlık hissinden söz etmiştir (7,8) . Bulgular genellikle hipotansiyon, ritim sorunları gibi belirsizdir ve ST değişikliklerini ameliyat odası koşulların-da yorumlamak güçtür.…”

“…Bulgular genellikle hipotansiyon, ritim sorunları gibi belirsizdir ve ST değişikliklerini ameliyat odası koşulların-da yorumlamak güçtür. Yayınlarda adrenerjik ajanlara (efedrin, metaraminol, adrenalin) bağlı vazospazm ya da doğrudan cerrahi uyaranla oluştuğu gözlenmiştir (7)(8)(9) . Bir olguda ise göz cerrahisi sırasında hiçbir EKG değişikliği olmaksızın PMI oluşmuştur (9) .…”

Potential hazard when calibrating fuel cell oxygen analysers

“…Dural puncture with a 16-G Tuohy needle can result in severe post-dural puncture headache (PDPH) in up to 88% of cases [1,2]. The incidence of severe PDPH is significantly higher following ADP with a 16-G needle rather than a 17-or 18-G needle [1]. We reviewed our practice of using an 18-G Tuohy needle for siting obstetric epidurals over a 10-year period.…”