Learning from Experience – Intra Operative, Chapters 31 and 32

INTRA-OPERATIVE

Chapter 33

TURP syndrome or Myocardial Infarction

Dr. Vasanthi Vidyasagaran*

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

A 68-year-old man was posted for a TURP. He had no significant past medical or surgical history, and all his routine preoperative investigations were within normal limits. He was taken up for surgery under spinal anaesthesia with 2.5 ml of 0.5% Bupivacaine. There was a drop-in blood pressure to 88/50mm Hg which was controlled with couple of doses of 3 mg Ephedrine. The procedure was completed in 2 hours which involved a resection time of 1 and a half hours.

A total of 900 ml NS I.V. was given. Towards the end of the procedure ST depressions and T wave inversions were noticed on his ECG. Patient started to complain of difficulty in breathing and saturation dropped to 92%. The heart rate increased to 120/min from a baseline of 75. On auscultation, bilateral basal crepitations were heard.

He was immediately oxygenated with 100% oxygen, and injection Frusemide 40 mg IV was given. His breathlessness worsened and he developed frank pulmonary oedema. Patient was intubated using Thiopentone 150 mg and Succinylcholine 75 mg, IPPV was initiated. The ECG changes did not seem to revert. A cardiologist opinion was called for and blood was sent to evaluate serum electrolytes and cardiac enzymes. He was shifted to the ICU for elective post-operative ventilation. The pulmonary oedema subsided after 24 hours of ventilation and supportive management.

Investigations showed elevated cardiac enzymes, clear signs of pulmonary oedema on chest x-ray, and normal serum electrolytes.

Discussion

This was an emergency clinical situation resembling TURP syndrome. Complete examination and having differential diagnosis in mind, helped make the correct diagnosis. Acute MI was suspected and diagnosed because of the ECG changes. Prolonged procedure, patient age and susceptibility, use of Ephedrine intraoperatively, could have been added risk factors precipitating the coronary spasm and an acute cardiac event. Hence it was confirmed that the pulmonary oedema in this case was a result of MI. The management of the patient was towards providing ventilator support and maintaining haemodynamic stability.

TURP syndrome associated with fluid overload and hyponatremia may present first with neurological symptoms associated with disorientation, drowsiness, apprehension, nausea and visual disturbances. ECG changes include T wave inversion, prolonged QRS interval, arrhythmias, hypertension/hypotension, and bradycardia leading to cardiovascular collapse in extreme situations.

In perioperative myocardial infarction, cardiovascular symptoms occur predominantly with ECG changes showing ST depression/elevation, arrhythmias and sometimes associated neurological symptoms such as altered sensorium.

Withholding antiplatelet before surgery in cardiac patients may also increase the chances of an acute MI. The volume overload state of TURP syndrome may lead to cardiac decompensation and LV failure causing both conditions to coexist. The test to effectively diagnose immediately is a stat sodium sample. TURP syndrome is always associated with hyponatremia. Once supportive management is provided, it is important to distinguish between TURP syndrome and perioperative MI as the continued course of treatment varies. MI requires a close follow up and a thorough cardiac evaluation.

Perioperative cardiac event in TURP:

BPH itself can be associated with cardiovascular disease, without any pre-diagnosed hypertension or ischemia. Risks of cardiac event post TURP or open prostatectomy are multiple, with age related pathophysiology as one of important factors.

Predisposing patient factors: Pre-existing anaemia, age >60 years being an independent risk factor, surgical stress factors, comorbidities, polypharmacy

Surgical factors: Prolonged procedure, large surface area operated upon.

Anaesthesia and drug related factors: Choice of anaesthesia, and hemodynamic instability.

Indicators for MI are not very clear. Troponin T may not be raised in first 48 hours, brain natriuretic peptide may be elevated. ECG changes may not be classical either. It is important to remember avoiding anticoagulants/Streptokinase during management of myocardial infarction post TURP. Surgical site bleeding and impending coagulopathy are serious risks.

References

De Lucia C., et al. Risk of acute myocardial infarction after transurethral resection of prostate in elderly. BMC surg 2013:S35.

Steven A, et al. Update on the American Urological Association Guidelines for the Treatment of Benign Prostatic Hyperplasia. Urol. 2006;8(Suppl 4):S10-S17.

Wei J, et al. Urologic diseases in America project: benign prostatic hyperplasia. J Urol. 2005;173:1256.

Biester K, et al. Systematic review of surgical treatments for benign prostatic hyperplasia and presentation of an approach to investigate therapeutic equivalence (non-inferiority). BJU Int. 2012;109:722-730.

Chapter 34

Ventilation in a Patient with Moderate Tracheal Stenosis

A young woman, 20 years of age, was posted for oesophageal dilation as day care. She had history of corrosive acid ingestion one month ago, for which she was given treatment at a primary health centre. Her only complaint was difficulty in swallowing. No investigations, other than Hb and urine analysis were done as she was thought to be otherwise fit and well, and not on any medication.

With the knowledge of brief history provided by the surgeon, procedure was started under sedation with Midazolam 1 mg and Fentanyl 50 microgram given by a junior doctor in the procedure room. Patient was not cooperative; hence plan was to convert to general anaesthesia, and the anaesthetist was only then called.

The anaesthetist quickly examined the patient and found her to be clinically normal. Since the procedure was short he decided to go ahead with general anaesthesia. The patient was adequately starved. The anaesthetist being a trainee, did not anticipate any difficulty.

General anaesthesia was induced with Thiopentone 200 mg and Suxamethonium 75 mg as muscle relaxant. On direct laryngoscopy vocal cords were visualized, a size 7.0 ETT was passed through vocal cords, but could not be navigated beyond 1cm below the cords. Hence smaller size tube of size 6.5 was attempted. Similar resistance was felt. A senior anaesthetist was then called.

Bag mask ventilation was possible in between intubation attempts, and there was no drop in saturation. Size 6.0 endotracheal tube was inserted and resistance was felt as before. However, on connecting the tube to circuit and manually ventilating, with tip of tracheal tube beyond the vocal cords and cuff inflated, it was possible to ventilate lungs. Anaesthesia was carefully administered with n2o, o2 and 1%sevoflurane.

It was decided to go ahead with oesophagoscopy, since the patient was already anaesthetised, and ventilation was possible, and the procedure was short. Endoscopist completed the dilation in less than 10 minutes. No other problems were encountered. She was not given any further relaxation. At the end of procedure, patient was spontaneously breathing and tube was taken out. Patient recovered well and did not have any respiratory distress. She was referred to ENT specialist for airway evaluation and further management of the tracheal stenosis.

Discussion

This case highlights the problems in providing anaesthesia outside the operating theatre. Prime concern here is that anaesthetist was informed at the last moment when the patient did not tolerate the procedure; hence the whole team was not prepared. Ideally with a significant history such as corrosive acid ingestion and difficulty in swallowing, the patient must be assessed for airway and respiratory problems prior to considering sedation or general anaesthesia. The whole situation would have been under control without any panic, if the procedure had been done in an operating theatre with backup plans.

Having been called in a dire situation, an innovative technique was used to tide over the crisis. An endotracheal tube of smaller size was used, but not forced into the narrow trachea with concern of bleeding, and loss of airway in an environment outside the operating theatre with limited back up. This however is not a technique which can be recommended, is risky and may not be applicable if there were other problems like difficulty in ventilation or vomiting. The whole team was prepared to post pone the procedure if a problem were to arise. But fortunately, since ventilation was possible and with an E N T back up the procedure could be carried out.

Using rigid bronchoscope to ensure airway access and allow for oxygenation is another option to consider while there is a dual problem of tracheal and oesophageal stenosis.

There are enough opportunities during anaesthesia for mishaps, even as we follow the correct recommendations and techniques to the best of our knowledge. Hence, just because we can get away once with the wrong technique it does not mean it is the norm.

This situation occurs often in our country, where there is compromise, mostly in providing good anaesthesia equipment and good monitors, quoting financial constraints and this attitude should be discouraged. Even in corporate hospitals and teaching hospitals, the administrators are not aware of the dangers involved in anaesthetising patients in ill-equipped environment, and even if they are aware, are not willing to spend on anaesthesia equipment since they are of the wrong impression that we not contribute to the income of the institution. Little do they realise if anaesthesia is not safe, the whole system will collapse. Classic example is procuring a laparoscope for 20 lakhs, but refusing an end tidal co2 monitor which will cost less than 2 lakhs.

References

Hohl CM, et al. Safety and clinical effectiveness of midazolam versus Propofol for procedural sedation in the emergency department: a systematic review. Acad Emerg Med. 2008:15(1);1-8.

Newstead B, et al. Propofol for adult procedural sedation in a UK emergency department: safety profile in 1008 cases. Br J Anaesth. 2013

Learning from Experience – Intra Operative, Chapters 31 and 32

INTRA-OPERATIVE

Chapter 33

TURP syndrome or Myocardial Infarction

Discussion

References

Chapter 34

Ventilation in a Patient with Moderate Tracheal Stenosis

Discussion

References

Journals