INTRA-OPERATIVE

Chapter 29

Procedural sedation – compromise leads to catastrophe

Dr. Vasanthi Vidyasagaran*

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

*Correspondence: Vasanthi.vidyasagaran@gmail.com

Dr. Vasanthy Vidyasagaran Muralidharan

Anaemia or Hydrocele
Anaemia or Hydrocele

Case 1:

A 25-year-old lady was posted for oesophagoscopy and dilatation of a stricture oesophagus following corrosive poisoning. Being a minor procedure, she came to the OP at 9 AM, as a day care procedure.

No investigations were done. While introducing the endoscope she became uncooperative and the gastroenterologist requested procedural sedation. Anaesthetist was called in at that time and a brief history was provided. The patient was starved overnight.

The anaesthetist failed to do a thorough pre-op evaluation, as the patient was on the table already and very apprehensive.

Glycopyrrolate 0.2 mg, Fentanyl 50 mic gm and Propofol 80 mg were given.

As the scope was introduced it was seen that the anatomy of the upper airway was entirely altered. Neither the epiglottis nor the cords were visible as the scope was manipulated through the oesophageal opening.

A nasopharyngeal airway was quickly introduced and oxygen was administered through it. She maintained spontaneous ventilation throughout.

If she had desaturated, or the oesophagoscope caused a traumatic bleed it would have been disastrous.

It is common practice even in established hospitals to underestimate the seriousness of procedural sedation. It is in fact more important as the airway is unprotected.

Standards of anaesthesia care must be the same regardless of length of procedure.

Anesthesiologists must be discouraged from administering sedation in ill-equipped areas as doing so amounts to negligence. Patient safety is the priority

Case 2:

A 55-year-old man was posted for endoscopic removal of a gastric polyp

It was scheduled as a daycare procedure. The patient was clinically evaluated and his airway was assessed to be normal. He was given 200 mg Propofol IV. The endoscope was introduced and the polyp was identified.

The polyp was removed with a snare and the base was cauterized to prevent bleeding.

As it was being brought out, there was resistance at the level of the cricoid and at that point, the patient had mild laryngeal spasms and started desaturating to 93%.

The gastroenterologist attempted again to remove the polyp but the spasm became worse as it was obstructing the airway. To avoid it migrating into the trachea, he was advised to quickly push it back into the oesophagus under vision. The patient was oxygenated and saturation improved. A third attempt was also unsuccessful. It was decided to let go off the polyp into the stomach.

Should we intubate such patients who are posted for removal of polyps/foreign bodies from the oesophagus in order to protect the airway?

Case 3:

A 48-year-old man, with a known case of stable angina, was taken up for an angiogram. The cardiologist began the procedure as a routine under local anaesthesia, and mild sedation with midazolam 2 mg.

During the procedure, the patient had a sudden cardiac arrest due to the dislodgement of a plaque. Balloon angioplasty was immediately done but the patient had refractory VT and VF.

An emergency alert from the Cath lab and the anesthesiologist were summoned.

The patient was intubated and adequately resuscitated with CPR and 4 defibrillator shocks.

A temporary pacemaker, and an IABP was inserted. Heparin infusion was started he was shifted to the operation theatre and taken up for emergency bypass surgery

Case 4:

A three-year-old child, weighing 10 kg, was posted for an MRI of his spine. An IV line was started and he was sedated with a 10 mg injection of ketamine IM. Just as he was about to be pushed into the chamber, he stopped breathing. MRI-compatible monitors were not available. He was ventilated with 100% oxygen using AMBU bag. Spontaneous respiration was restored and the procedure was completed without any further complications.

Discussion

Administration of Procedural sedation is a fine skill. During colonoscopy under sedation, bowel stimulation provokes reflex nausea and vomiting. Long procedures under sedation, with no measure of the level of consciousness, are prone to slipping into deeper levels of sedation, compromising the airway.

High-risk patients for sedation include; Obese, Patients with a history of OSA, and medically compromised patients.

We may not be able to change the scenario of getting called into providing monitored anaesthesia care in the last moment. But what may be modifiable is ensuring theatre environment in areas outside the operation theatre. The personnel in these areas are not trained like theater paramedical staff and it is important to get adequate timely help from the theatre when there is a crisis. The theatre must be informed well in advance so that recruitment of man power will be feasible. If the anaesthetist and the theater personnel are engaged in taking care of a patient in the theater it will be impossible to offer help when there is a crisis in some other location. We as a specialist group must ensure safety standards in our area of practice.

References

[1]Jewett J, et al. Dexmedetomidine for procedural sedation in the emergency department. Eur J Emerg Med. 2010;17(1):60.

[2]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.

Chapter 30

Pulmonary embolism in a patient with fracture humerus

A 53-year-old man, a known smoker was posted for surgical correction of a 10-day-old fracture of his right humerus. He was diagnosed with COPD 5 years ago and was on chronic bronchodilator therapy.

On examination, he was found to be obese weighing 108 kg with a BMI of 35.3. All his investigations – routine blood, chest x-ray, ECG and ECHO, were within normal limits.

He was taken up for surgery under a supraclavicular nerve block with a catheter in-situ. The block was given by ultrasound-guided technique with 15 ml of 2% Lignocaine with Adrenaline, 15 ml 0.5% Bupivacaine and 5 ml of Soda Bicarbonate. After ensuring the adequacy of the block, the patient was placed in the lateral position and the surgery progressed.

Two hours into the procedure, the patient started complaining of pain. Also, the surgeons had planned to take a bone graft from the iliac crest. Hence it was decided to start general anaesthesia.

The patient was first repositioned to the supine position and general anaesthesia induced with 160 mg Propofol. Anticipating difficult intubation, 100 mg Succinylcholine was used to facilitate intubation. The tube was placed successfully only on the third attempt. The patient did not desaturate below 96% during that period.

Post intubation, pulse rate was 114 beats/min, BP 170/100 mm Hg, ETCO2 = 33, and SpO2 = 98%. For maintenance, a 40/60 mixture of Oxygen and Nitrous Oxide with Isoflurane1% was used. Muscle relaxant used was Atracurium, totalling 65 mg until completion of procedure. The patient was repositioned to lateral after bone harvesting from the iliac crest.

Towards the end, while the surgeons were beginning to suture the wound after a wash, there was resistance to manual ventilation, and the bag started becoming tight. X-ray chest on table was requested. The HR increased to 160 beats/min, and gradually the oxygen saturation began to fall, as well as EtCO2. Bilateral scattered rhonchi and crepitation were heard.

Injection Lasix 40 mg IV, Injection Deriphylline, and a dose of Dexamethasone 8 mg was given. On auscultation, air entry was heard, but with diminished intensity.100%oxygen was administered. There was unexpected rapid deterioration and patient went into asystolic cardiac arrest. Cardiopulmonary resuscitation was commenced and patient revived after two cycles of CPR, sinus rhythm maintained. He was transferred to the ICU for elective ventilation.

Despite continued supportive management, the patient expired after 48 hours. A post mortem examination revealed cause of death as pulmonary embolism. A deep vein thrombus in the brachiocephalic vein was identified as source of PE.

Discussion

(1) Differential diagnosis in this scenario:

(a)Hypoxia due to dislodgement of ETT during change of position.

(b) Tension Pneumothorax with initial supraclavicular block followed by general anaesthesia using IPPV with O2/ Nitrous oxide

(c) Fat embolism due to humerus nailing – very rare

(d) Thrombo-embolism – 10-day old fracture

First three possible reasons were ruled out; hence it was most likely thought to be a pulmonary thrombo-embolism from deep vein thrombosis in the upper limb.

(2) DVT and PE in ORIF humerus – Fracture treatment however aggressive involves immobilization. Immobilisation is a strong independent risk factor for further development of DVT and PE. It is to be noted that DVT prophylaxis and early mobilization are important for upper limb fractures as well.

(3) Upper-extremity DVT, although not as common as its lower-extremity counterpart, is a clinical entity with potentially devastating complications. Approximately 1-4% of all DVT cases involve the upper extremity, with 9-14% of these cases complicated by pulmonary embolism.

(4) Diagnosis with duplex ultrasonography and subsequent anticoagulation preoperatively are gold standards for identification and treatment. The majority of these cases are secondary to medical comorbidities such as malignancy, hypercoagulable states, and indwelling catheters. Although rare, upper-extremity DVT is reported in the literature.

(5) It is important to insist on a post-mortem to arrive at an undisputable diagnosis. This will avoid speculations and aid medicolegal investigations.

References

[1] Elman E, et al. The post-thrombotic syndrome after upper extremity deep venous thrombosis in adults: A systematic review. Thromb Res. 2006;117(6):609-14.

[2] Spence L, et al. Acute upper extremity deep venous thrombosis: safety and effectiveness of superior vena caval filters. Radiology. 1999;210(1):53-8.

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