POST-OPERATIVE – Chapter 3

Cardiac Event/Thyroid Storm in a Young Patient Following Total Thyroidectomy

Dr. Vasanthi Vidyasagaran*

Department of Anaesthesiology, Kauvery Hospital, Chennai, Tamilnadu, India

*Correspondence: Vasanthi.vidyasagaran@gmail.com

A 19-year-old girl with thyroid swelling, diagnosed with hyperthyroidism, on anti-thyroid drugs, Carbimazole and Propranalol, was booked for total thyroidectomy. At preoperative assessment, she had no other comorbidities, asymptomatic on drugs, no palpitations or visual symptoms. She did not have any difficulty in breathing and had no change in voice. On examination, she had a thyroid swelling without any retrosternal extension. No ophthalmic signs. Good range of neck movement was present. No airway difficulty was anticipated. Chest was clear with no added sounds.

Investigations showed euthyroid state, no anaemia, and normal coagulation status. CXR revealed normal position of trachea, no tracheal narrowing, and lung fields clear. Patient underwent uneventful anaesthesia and surgery. Trachea was extubated after confirming good respiratory effort, and normal bilateral vocal cord movement. Soon after extubation, as the patient was getting ready to be shifted to recovery, a sudden increase in heart rate was noticed.

Patient was quickly moved back onto the theatre table and ECG monitors applied. Heart rate went up to 170/min. She was given 100% Oxygen, IV Midazolam 2 mg, and IV Fentanyl 50 mcg. But the rate did not come down. IV beta-blocker Metoprolol 2 mg boluses were administered, up to 6 mgs. Rate slowed down to 140/min, but she soon developed difficulty in breathing and chest pain.

At this point the diagnosis was thyroid storm. Blood sample was sent for electrolytes, serum calcium levels, thyroxine, and parathormone levels. 12 lead ECG showed global ST segment elevation and T wave inversion. Patient was shifted to intensive care unit, on 100% oxygen, maintaining own airway.

Investigations showed near normal calcium – 9 mg%; PTH levels were normal. T3 levels were raised. Hence hyperthyroid state (post thyroidectomy) was diagnosed. Hypocalcaemia and hypoparathyroidism were ruled out. At this juncture, symptomatic management to prevent further cardiac injury was commenced. Rate control with beta-blocker was done with cardiologist advice. IV Frusemide was administered, with close watch on blood pressure. Anti-thyroid drugs were administered via nasogastric tube. Blood pressure maintained at 100/60.

ECG changes persisted at 24 hours, and serum Troponin I level done at 24 hours was high. This confirmed a diagnosis of an acute cardiac event.

Discussion

  1. This was a challenging clinical scenario of Thyroid storm precipitating a cardiac event. Systematic approach to the case and management saved the patient from long term complications. She was discharged after a week without any further untoward event.
  2. It is postulated that sudden gush of thyroid hormone into circulation during surgical manipulation or post-surgery triggers a load of catecholamines which cause coronary vasospasm and potentiates cardiac event. In this scenario, preoperatively patient was euthyroid and optimized, but still surgery acted as a key stress factor causing thyroid storm. (Other factors include infection, emotional stress, hypoglycaemia, trauma, parturition, and tooth extraction).
  3. In a typical thyroid storm situation, patient presents with catabolic state, hyperthermia, sweating, dehydration, and hyperglycaemic stress response, requiring liberal fluid therapy, rehydration and temperature control.
  4. However, ours was an atypical case with ECG changes and cardiac failure, requiring restricted intravenous fluid therapy. Steroids may be considered to reduce stress response.
  5. Key point that was learnt from this case was accurate diagnosis may not be possible at situation zero . But arriving at a potential diagnosis, identifying the clinical features, and initiating treatment without any delay, will pave way for a positive outcome

Reference

  1. Aulet RM, Wein RO, Siegel RD. Surgical management of an atypical presentation of a thyroid storm. Int J Endocrinol Metab. 2014 Apr. 12(2):e13539.
  2. Peter F Czako et al. Thyrotoxic Storm Following Thyroidectomy Treatment & Management; http://emedicine.medscape.com/article/850924-overview#showall

POST-OPERATIVE – Chapter 4

 

Chemotherapy Induced Cardiomyopathy

A 29-year-old woman, 34 weeks pregnant was booked for an emergency LSCS for early foetal distress. She was previously diagnosed with carcinoma breast stage 2, operated and on chemotherapy. She had developed breast lesion during the second trimester. Ultrasound of foetus had been showing normal growth for the gestational age. There was no history suggestive of preeclampsia or gestational diabetes.

During chemotherapy, she had been hospitalised and recorded no complications such as very low blood counts or sepsis. However, she had been very tired, known complication in chemotherapy and accepted, with limited exertion capacity, and she remained within her home. Currently she had been admitted with decreased foetal movements and CTG showing signs of distress and hence taken up for emergency delivery of foetus.

As this was an emergency situation, blood sample was sent for urgent haemogram, clotting and renal profile, and the patient was quickly wheeled into theatre. Blood results showed Hb=10 g/dl and normal platelet count. Clotting profile was normal. Hence it was decided to perform the surgery under spinal anaesthesia.

Soon after the delivery of the baby and administration of 15 units Oxytocin through the intravenous drip, she began to complain of severe breathlessness. Oxygen saturations fluctuated between 90 and 94

% on oxygen 6 litres/min. Heart rate went up to 120/minute, but there was no drastic change in blood pressure which remained between 100/70 -90/60 mm Hg. Lungs were clear. The level of spinal anaesthesia was up to T8.

Although effect of Oxytocin could be implicated, the patient was more tachypnoeic and dyspnoeic than usual, airway being maintained, with no evidence of bronchospasm. Causes of sudden onset breathlessness were being ruled out one by one, anaesthetist was suspecting a pulmonary embolic event. Arterial blood sample was sent for analysis.

Since the cause of this restlessness and breathlessness could not be pinpointed, patient was sedated with 1 mg Midazolam and 50 mcg Fentanyl with no effect. By the time surgery was over, she had received one and a half litres of crystalloids. At that stage, examination of the chest revealed basal crepitations. Head up tilt and 40 mg Furosemide was given. After about 2 hours, she settled down and was feeling much better, heart rate came down to 90/min, Sao2 97%, with 3L oxygen on flow, via a face mask.

Arterial blood gas analysis results were normal. Postoperatively patient was shifted to high dependency unit. She had a chest x-ray, ECG and echocardiogram, which revealed dilated cardiomyopathy with an EF of 30%. Cardiologists diagnosed it as chemotherapy related cardiomyopathy, exaggerated due to the stress of pregnancy and delivery.

She was followed up by the cardiology team and medical oncology. Mother and baby did well.

Discussion

  1. This pregnant woman underwent emergency LSCS, and had complications due to cardiac toxicity caused by the chemotherapy drugs. Ideally the obstetric team in liaison with medical oncology and anaesthetic team would plan timing of delivery to avoid complications, stopping drugs 3-4 weeks prior to delivery. However, emergency situation ruled out this option.
  2. This patient had no reported complications from chemotherapy during hospital admission. Still, it is prudent to remember that, effects of the drugs may be seen at a later date too. If the diagnosis of cardiomyopathy was known earlier, precautions to be taken during anaesthetic management would include, avoiding drugs causing tachycardia, hypotension, restrict fluid therapy and may be opt for general or epidural instead of spinal.
  3. Malignancy complicates 0.02-0.10% of all pregnancies. Breast cancer is the most common cancer seen in pregnancy and postpartum period; incidence quoted being 1:3000 pregnancies. The treatment is planned depending on type and stage of cancer as well as the gestational age of the foetus at the time of diagnosis. It is worthwhile having an echocardiogram for such patients at an antenatal visit.
  4. The evidence we have so far shows that chemotherapy is safe if women are at least 14 weeks pregnant (in their second and third trimester). Children born after exposure to chemotherapy do not have any more problems than children not exposed to chemotherapy. Chemotherapy is usually a combination of 2 or 3 different drugs. These may include Doxorubicin (Adriamycin), Cyclophosphamide, Flourouracil, Epirubicin and Docetaxel. Usual management is to stop chemotherapy 3 to 4 weeks before delivery due the complications from systemic effects of these drugs such as increased risk of bleeding and infection.

Implications of chemotherapeutic agents in anaesthesia

Most of the chemotherapeutic agents have risk of pulmonary, cardiac, hepatic and nephrotoxicity reported

  1. Chemotherapy drugs tend to damage myocytes, cause dysrhythmias, cardiomyopathy and reduce cardiac reserves.
  2. cytotoxic antibiotics (bleomycin, mitomycin-C, and doxorubicin),
  3. Nitrosureas (lomustine),
  4. Alkylating agents (cyclophosphamide, ifosfamide, melphalan, chlorambucil),
  5. Anti-metabolites (methotrexate, azathioprine, cytarabine, fludarabine),
  6. Plant alkaloids (vincristine, vinblastine, etoposide),
  7. Bilogical response modifiers (GM-CSF, interleukin-2, interferon, BCG),
  8. Drugs like Cisplatin and anthracyclines (including epirubicin and doxorubicin) cause Torsades de Pointes

References

  1. H Muir et al. Malignancy and Pregnancy. Chapter 21.Page 371Obstetric anaesthesia and uncommon disorders edited by David R. Gambling, M. Joanne Douglas, Robert S. F. McKay
  2. Perry M Ewer M, Benjamin R. Cardiotoxicity of chemotherapeutic drugs. In: Perry M, editor. The Chemotherapy Source Book. London: Williams and Wilkins; 1996. p. 649- 59.
  3. Pinder MC, Duan Z, Goodwin JS, Hortobagyi GN, Giordano SH. Congestive heart failure in older women treated with adjuvant anthracycline chemotherapy for breast cancer. J Clin Oncol 2007; 25:3808-15.
  4. Simpson AB, Paul J, Graham J, Kaye SB. Fatal bleomycin pulmonary toxicity in the west of Scotland 1991-95: a review of patients with germ cell tumours. Br J Cancer 1998; 78:1061-6.
  5. Neil Allan, Catherine Siller, and Andrew Breen Anaesthetic implications of chemotherapy Contin Educ Anaesth Crit Care Pain (2012) 12 (2): 52-56.

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