PERI-OPERATIVE Chapters 9 and 10 – Learning from Experience

Mesenteric Vein Thrombosis

Dr. Vasanthi Vidyasagaran*

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

A 10-year-old boy weighing 60 kg was admitted with persistent abdominal pain following a blunt injury abdomen, two days ago. Ultrasound abdomen revealed free fluid for which an emergency laparotomy was planned. On examination, the boy was febrile with temperature = 102Â°F, pulse rate = 140/min, peripheries were cold.

His haemoglobin was 10 gm/dl, white cell count was raised at 17000/cu mm, and platelet count was 70000. He was septic with bowel perforation. Arterial blood gases showed pH = 7.1, paO2 = 120 on oxygen 6 litres/min, paCO2 = 22 mm Hg, HCO3 = 15mmol, BE = -6.7.

Preoperative optimisation with intravenous fluid bolus – 700 ml crystalloid and 250 ml colloids were given. Broad spectrum antibiotic was commenced. He was taken up for laparotomy under ASA IIIE. He was diagnosed to be a case of perforated appendix with sepsis. Though he complained of pain following blunt injury, a clinical picture was more in favour of severe sepsis.

The anaesthesiologist who examined the child was not convinced about the exact diagnosis, as clinically the child was very sick. Hence high-risk consent was requested explaining the severity and outcome. Parents were counselled as they were in a state of denial to accept the seriousness of the situation and were under the impression that it was just acute appendicitis in spite of explaining the risks involved. It took a lot of effort and time before the patient could be wheeled into the theatre.

General anaesthesia was induced with Thiopentone 150 mg and intubated with Vecuronium 5 mg. Anaesthesia was maintained with Oxygen/Nitrous Oxide and Sevoflurane. Fentanyl 100 microgram and Hydrocortisone 100 mg were given. The pulse rate was high throughout surgery 140-150/min. BP was between 90/45 and 100/50 mm Hg.

The laparotomy revealed a gangrenous appendix which was removed. Abdominal lavage was done and drain fixed. The rest of the bowel looked oedematous, and mildly discoloured. Surgeons decided not to interfere at that point of time. Urine output was 40 ml during the procedure, which lasted approximately 2 hours. His heart rate was 150/min, Spo2 97% on fiO2 50%, BP 90/50 and peripheries cold. We were contemplating whether to ventilate him electively. Beta blockers were not given to reduce the heart rate due to the age of the patient. However, since the child was fully conscious, making good respiratory effort, and did not need vasopressor support, it was decided to extubate on table and shift to ICU for postoperative observation and care.

On the first post-operative day, his condition deteriorated. He was persistently hypotensive and required vasopressor support to maintain a BP of 90/60 mm Hg. His urine output also decreased. Chest was clear with no ventilation issues. Re-laparotomy was decided. Administering anaesthesia to this sick child was quite a challenge.

He was induced with Midazolam 2 mg, Fentanyl 200 microgram, Ketamine 25 mg, and intubated with Vecuronium 5mg. Laparotomy revealed mesenteric vein thrombosis with extensive small bowel infarction. Infarcted bowel was resected and ileostomy done. Four units of packed cells, two FFP, and two units of platelets were transfused. Anastomosis was not done due to high risk of leak in unhealthy bowel. Anticoagulation was commenced on table and continued postoperatively. The child had a long stay in intensive care. Re-laparotomy for end to end anastomosis was performed once his condition improved. He was discharged after nearly 2 months of hospital stay.

Discussion

Here we had an obese septic child whose severity of sickness was disproportionate to the diagnosis of acute appendicitis. Family needed to be informed of this.

Mesenteric vein thrombosis is a relatively uncommon cause of intestinal ischemia. It is difficult to quote exact statistics in Indian populations. The diagnosis of AMVT remains mysterious with the condition often being diagnosed at laparotomy with reported high mortality of over 34%.

Patients with less acute presentation are more stable during the course of their illness. The extent of thrombosis is probably less. Early anticoagulation improves survival rates. The most common factors are protein C and S deficiencies and myeloproliferative disorder. In septic patients with infarcted bowel, mesenteric vein thrombosis must be considered. Early diagnosis, anticoagulation and definitive treatment in the form of quick surgical decision, and intensive care, looking into all aspects of the condition is vital. Multiple laparotomies increase risk of morbidity and mortality.

Anaesthetic implications

We must consider mechanical ventilation to ensure respiratory and cardiac support and allow time for the body to recover from the insult of sepsis and infarction.
Vigilant ICU care with special attention to fluid electrolytes and urine output, nutrition, temperature, and prevention of further infection is necessary.
Anticoagulation must be initiated and appropriately monitored.

This child was posted as a case of acute appendicitis and if the anaesthesiologist was not vigilant in the preoperative evaluation and routine anaesthesia administered, she/he is bound to face catastrophic results. Hence it is important to quickly evaluate in the preoperative visit whatever be the nature of emergency, and explain the risk involved directly to the patient relatives and obtain their signature.

References

S. Kumar, et al. Mesenteric venous thrombosis. N Engl J Med. 2001;23:1683-168.

J. Zhang, et al. Acute mesenteric venous thrombosis: a better outcome achieved through improved imaging and a changed policy of clinical management. Eur J Endovasc. 2004;28:329-34.

J.H. Joh, et al. Mesenteric and portal vein thrombosis: treated with early initiation of anticoagulation. Eur J Endovasc. 2005;29:204-208.

S. Acosta, et al. Mesenteric venous thrombosis with transmural intestinal infarction: a population-based study. J Vasc Surg. 2005;41:59-63.

In an emergency situation, explain risk, document, and get relevant consent/ signature. Mutual trust among the team members is good, but cannot be blind especially in the modern era.

PERI-OPERATIVE

Chapter 10 Myocardial Ischaemia in the Peripartum Period

A 28-year-old primigravida was brought to the casualty with labour pains. She was being shifted for an emergency LSCS due to cephalo-pelvic disproportion and foetal distress. Her haemoglobin count was 8 g/dl. Last oral intake was 2 hours ago. Quick assessment was made and the patient was taken up under routine spinal anaesthesia.

Premedication with injection Ranitidine 50 mg and Metoclopramide 10 mg were given. Her PR was 95/min and blood pressure was 110/70 mm Hg. 1.8 ml of 0.5 % Bupivacaine was administered using a 25 G Quincke needle in the L3- L4 space. Level of block was T6 and surgery was allowed to proceed.

Oxygen was given via face mask at 5 litres/min. The blood pressure dropped to 86/46 mm Hg and patient started feeling nauseous. It was treated with injection Ephedrine 6 mg, followed by another bolus of 6 mg slowly. The baby was delivered uneventfully and an Oxytocin 20 units drip was on flow.

Persistent hypotension of 80/50 prompted another dose of Ephedrine 6 mg, totalling 30 mg to maintain her blood pressure. Additional intravenous fluids of 1 litre was administered. The patient complained of mild retrosternal discomfort. She was reassured and sedated with Midazolam 1 mg. The surgery was completed and she was shifted to the post-operative ward with blood pressure of 90/60, and heart rate of 110/min.

After 2 hours, she still complained of chest tightness and was restless. Oxygen was on flow and saturation was maintained at 97%, blood pressure around 100/60 mm Hg and pulse rate of 110/min. A bed side ECG revealed ST elevation from V1-V4 and flattening of T waves. The cardiologist was involved and cardiac enzyme levels were requested. Patient was given Morphine 5 mg for pain relief. Results showed raised Troponin I levels, suggesting a coronary event, though the team was aware that raised troponin level in post-operative period without any pre-op value to compare has limitations. The patient being very symptomatic and the persistent ECG changes prompted the physician to shift her to the coronary care unit. She improved clinically only after coronary vasodilators were administered. She was also given LMWH.

Discussion

Acute myocardial ischemia in a 28-year-old healthy woman undergoing caesarean section is not something we come across regularly, and is not anticipated. The pregnancy hormones have a protective effect on the coronaries and myocardium. This case highlights that myocardial ischemia may happen in stressful situations such as emergency surgery in patient of any age with no pre-existing cardiac illness, though there was no concrete evidence to prove a coronary event, this patient responded to treatment with coronary vaso dilators, and her ECG reverted to normal in two days.

Some patients may be predisposed to such events due to raised catecholamines in circulation. Ephedrine as a vasoconstricting agent, should be used judiciously as it induces coronary vasospasm. The combined effect of vasoconstriction along with the increased circulatory volume (pregnancy induced and intravenous fluids), and use of pitocin could have precipitated this acute event.

Administration of Oxytocin and Ephedrine may produce drug interaction and increase sympathetic effects. Vasoconstrictors ideally should not be administered prophylactically. If necessary, they may be used in smaller doses e.g. 3 mg bolus.

Phenylephrine is the preferred vasoconstrictor in obstetrics now, predominantly acting through alpha receptors. It can be used in patients with a reasonable baseline heart rate over 75/min, reflex bradycardia must be avoided. Once Phenylephrine has been given, we must watch for the bradycardia response before repeating the dose.

Coronary vasospasm and non-Q myocardial infarction in a healthy woman has been reported in the past. It is important to bear in mind what is said about vasopressors by Wahl et al – “administration too much too early may lead to vasoconstriction and arrhythmias; too little too late may end in asystole”.

Thrombolysis as a first line treatment is deferred due to increased risk of bleeding in immediate post- operative period. Heparin and anti-platelets are used with caution. Morphine is not administered routinely in the post-partum period. This patient received Morphine due to her cardiac event, and she was allowed to breast feed her baby only after two days. The mainstay of treatment lies in administering coronary vasodilating agents and providing excellent post-surgical pain relief, avoiding tachycardia and hypertension.

This case is presented here as myocardial ischaemia is a rare event in a young lady.

References

Wahl, F. R. Eberli, et al. Coronary artery spasm and non-Q-wave myocardial infarction following intravenous ephedrine in two healthy women under spinal anaesthesia. British J Anaesth. 2002;89(3):519-23.
Derreza H, et al. Acute myocardial infarction after use of pseudoephedrine for sinus congestion. J Am Board FamPract. 1997;10:436-8.
Pollard JB. Cardiac arrest during spinal anesthesia: common mechanisms and strategies for prevention. Anesth Analg. 2001;92:252-6.
Khavandi A, et al. Myocardial infarction associated with the administration of intravenous ephedrine and metaraminol for spinal-induced hypotension. Anaesthesia. 2009;64(5):563-6.

PERI-OPERATIVE Chapters 9 and 10 – Learning from Experience