UBP 2.7 (Long Form): Urology – TURP Flashcards
Secondary Subject -- Recent Myocardial Infarction/Recent Cardiac Stent Placement/Perioperative Glucose Management in the Diabetic Patient/ Spinal Anesthesia/Bladder Perforation/ Pseudocholinesterase Deficiency/ Post-operative Vision Loss
Intra-operative Management:
What anesthetic technique would you recommend for this patient?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
Given this patient’s cardiac status and the specific risks of TURP, and assuming there are no contraindications (i.e. metastatic disease to the lumbar spine or patient refusal), I would recommend – neuraxial anesthesia for this procedure.
Neuraxial anesthesia (spinal or epidural with a T10 sensory level) would allow for an awake patient, which may facilitate the early detection of –
- intraoperative myocardial ischemia
- (chest pain/pressure),
- TURP syndrome
- (confusion, restlessness, headache, dyspnea, arrhythmias, hypotension, and seizures), and
- bladder perforation
- (nausea, diaphoresis, sudden hypotension/hypertension, bradycardia, and abdominal or shoulder pain).
Neuraxial anesthesia may also be beneficial in –
- reducing blood loss (this finding is controversial, but may result from reduced intraoperative blood pressure),
- avoiding aspiration (possible autonomic neuropathy), and
- improving postoperative analgesia, which may be of particular importance to a patient with coronary artery disease who may not tolerate postoperative anemia, hypertension, and/or tachycardia.
If regional anesthesia were contraindicated, I would proceed with general anesthesia, recognizing that the incidence of perioperative MI, pulmonary embolism, cerebrovascular accident, cognitive impairment, renal failure, and death is similar when comparing regional and general anesthesia.
Although the detection of TURP syndrome (specifically hyponatremia) may prove more difficult under general anesthesia, careful monitoring of the patient’s serum sodium would decrease the risk of a delayed diagnosis.
- Clinical Note:*
- Although the preservation of the prostatic capsule with newer laser prostate ablation techniques has reduced the incidence of TURP syndrome, hyponatremia and volume overload, secondary to the absorption of large volumes of irrigation solution , may still occur.
Intra-operative Management:
What monitors would you place for this case?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
In addition to the ASA standard monitors, I would place a 5-lead EKG to monitor for myocardial ischemia.
If I were planning a general anesthetic, I would maybe place an arterial line to help maintain stable hemodynamics as well as provide access for frequent serum sodium blood draws.
Given this patient’s cardiac status, and depending on the method of prostate resection, I would consider placing a central venous line to monitor CVP and help identify volume overload.
Intra-operative Management:
Assume you are planning a subarachnoid block. Which local anesthetic would you use? What spinal level of anesthesia do you need for TURP?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
I would choose to use either hyperbaric bupivacaine or tetracaine due to their duration of action, which ranges from 90-120 minutes without added epinephrine.
My goal would be to achieve a T10 sensory level of anesthesia, which would provide adequate analgesia for the procedure while, at the same time, allowing monitoring for the signs and symptoms of bladder perforation.
The abdominal pain and/or diaphragmatic irritation (shoulder pain) often associated with bladder perforation would not be masked by a neuraxial anesthetic providing T10 sensory analgesia.
Intra-operative Management:
Which irrigation solutions are available for TURP?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
Some of the solutions available for use during TURP include –
glycine, sorbitol, mannitol, Cytal (sorbitol and mannitol), 2.5-4.0% glucose, urea, and balanced electrolyte solutions (i.e. Ringer lactate).
While there are many options, the ideal irrigation fluid would be – nonhemolytic, isotonic, electrically inert, nontoxic, transparent, inexpensive (important because of the large volume used), and undergo minimal metabolism and rapid excretion if absorbed.
Isotonic or near-isotonic solutions are desirable, because hypotonic solutions result in hemolysis.
Electrically inert solutions are preferred because balanced electrolyte solutions (i.e. LR) can interfere with electrocautery and disperse electrical current, placing the surgeon and patient at risk of burn injury.
Transparency is desirable to improve surgical visualization.
And, finally, nontoxic irrigates that are minimally metabolized and rapidly excreted are ideal due to the risk of toxicity with significant absorption.
Intra-operative Management:
Can you use distilled water for irrigation?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
In the past, distilled water has been used for irrigation during TURP because it is electrically inert and completely transparent.
However, it is no longer used for this procedure because its hypotonicity places the patient at risk for intravascular hemolysis, hyponatremia, hemoglobinemia, shock, and renal failure.
On the other hand, it is still used for transurethral procedures where the risk of systemic absorption is minimal, such as cystoscopy.
Intra-operative Management:
The surgeon decides to use a glycine irrigation solution. Twenty minutes into the surgery the patient becomes agitated and his blood pressure increases to 190/100 mmHg.
What do you think is going on?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
There are several potential causes of this patient’s agitation and hemodynamic changes, including –
- inadequate spinal anesthesia,
- myocardial ischemia,
- bladder perforation,
- TURP syndrome,
- hypothermia,
- hypoxia,
- hypercarbia,
- septicemia, or
- a mixture of these complications.
In response, I would –
- ensure adequate ventilation with 100% oxygen;
- obtain a 12-lead EKG to look for signs of myocardial ischemia;
- ask the surgeont to stop operating and evaluate the patient for bladder perforation;
- ensure adequate analgesia; and
- check the patient’s temperature, hemoglobin, serum sodium, serum glucose, and arterial blood gases.
Intra-operative Management:
In addition to being agitated and hypertensive, the patient is now bradycardic, diaphoretic, nauseous, and complaining of pain in his abdomen and left shoulder.
What will you do?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
Although this clinical picture combined with abdominal pain is most consistent with – bladder perforation (left shoulder pain may represent referred pain from diaphragmatic irritation),
I would still need to rule out myocardial ischemia, which could present similarly or concurrently.
Therefore, I would obtain a 12-lead EKG to look for signs of myocardial ischemia, ensure adequate ventilation and oxygenation (100% oxygen, adequate hemoglobin), ensure adequate analgesia, and treat any hemodynamic instability.
At the same time, I would ask the surgeon to assess whether there has been decreased return of irrigation solution from the bladder (another sign of bladder perforation), discontinue or finish the procedure quickly, identify and assess any bladder perforation, and consider performing a suprapubic cystostomy (if bladder perforation is identified).
There is some evidence to suggest worse outcomes in patients with bladder perforation in whom suprapubic cystostomy was delayed more than 2 hours following bladder perforation.
Intra-operative Management:
The patient is uncooperative and trying to get off of the table. Would you convert to general anesthesia?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
Yes.
At this point, the patient is at risk of injuring himself or others in the operating room.
My goals would be to safely secure the airway, avoid hypoxia and/or hypercarbia, prevent aspiration, avoid worsening hypertension and/or hypotension, and quickly gain control of this uncooperative patient and potentially dangerous situation.
Therefore, assuming the patient had a reassuring airway, I would perform a rapid sequence induction with succinylcholine and cricoid pressure, carefully intubate the patient, and be prepared to treat any hemodynamic instability or signs of myocardial ischemia.
Ideally, the potential for a conversion to general anesthesia would have been discussed with the patient and his family when obtaining anesthetic consent.
Post-operative Management:
The case is completed under general anesthesia, and no additional muscle relaxants were administered following the succinylcholine.
Forty minutes following the discontinuation of anesthesia, the patient remains intubated and shows no signs of spontaneous respiration.
What might be the cause of this delayed emergence?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
His lack of respiratory effort forty minutes after the administration of succinylcholine is consistent with –
residual neuromuscular blockade secondary to pseudocholinesterase deficiency.
However, given this patient’s diabetes mellitus, CAD, HTN, COPD, and recent TURP with glycine irrigation solution, I would also consider the following causes and/or contributing factors:
- TURP syndrome
- (hyperglycinemia and hyperammonemia secondary to glycine metabolism can lead to CNS toxicity; hyponatremia secondary to volume overload can lead to cerebral edema);
- cerebral ischemia/hypoperfusion
- (secondary to cardiac arrhythmia, hypoxia, cerebral edema, hypotension, anemia, and/or an altered cerebral autoregulation curve with chronic HTN);
- hypoglycemia
- (increased risk with tight perioperative glucose control of an insulin dependent diabetic patient),
- hypothermia secondary to –
- autonomic neuropathy (increased susceptibility to hypothermia) and/or
- inadequate warming of irrigation solution or the operating room (decreases MAC and limits drug metabolism);
- hypoxia and/or hypercarbia secondary to
- the ventilation/perfusion mismatching that may occur with COPD, pulmonary edema, and/or aspiration;
- hypocarbia
- (secondary to overaggressive ventilation);
- medication error; and
- liver or kidney disease.
Post-operative Management:
- The case is completed under general anesthesia, and no additional muscle relaxants were administered following the succinylcholine.*
- Forty minutes following the discontinuation of anesthesia, the patient remains intubated and shows no signs of spontaneous respiration.*
What would you do?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
I would:
- ensure adequate oxygenation and ventilation;
- assess residual neuromuscular blockade with a nerve stimulator;
- auscultate the chest (aspiration, pulmonary edema, or pneumothorax could lead to hypoxia, hypercarbia, and severe metabolic acidosis);
- check the ECG for signs of myocardial ischemia or arrhythmia;
- ensure adequate perfusion pressure and normothermia;
- review all administered medications;
- check for signs of narcosis, such as constricted pupils (miosis);
- check serum electrolytes, glucose, and ammonia levels;
- check an ABG and chest x-ray; and,
- if a diagnosis was not readily apparent, consider a CT scan of the head.
I would also consider administering naloxone, flumazenil, and/or physostigmine to reverse any residual anesthetic effects and rule out the most common cause of delayed emergence.
Post-operative Management:
You use a peripheral nerve stimulator and notice fade with train-of-four. What do you think?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
Fade with a train of four is consistent with residual nondepolarizing blockade or Phase II blockade from a depolarizing muscle relaxant (succinylcholine).
Phase II blockade can occur with excessive doses (7-10 mg/kg), prolonged infusions, or abnormal metabolism of succinylcholine.
In this case, a medication error may have resulted in the administration of a large dose of succinylcholine or a nondepolarizing relaxant, or the patient has undiagnosed atypical plasma cholinesterase.
The latter may be undiagnosed if he did not receive succinylcholine during his previous anesthetic.
Normally, 90-95% of a typical dose of succinylcholine is metabolized prior to reaching the neuromuscular junction.
With atypical pseudocholinesterase activity, a much larger dose of succinylcholine may reach the neuromuscular junction resulting in a Phase II block.
Post-operative Management:
The patient’s dibucaine number is 32. What does this mean?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
The dibucaine number represents the percentage that dibucaine inhibits the hydrolysis of benzoylcholine by pseudocholinesterase (in the absence of dibucaine, total hydrolysis of benzoylcholine would result with the addition of the patient’s serum).
There are two alleles associated with the production of pseudocholinesterase.
Dibucaine inhibits the pseudocholinesterase activity of patients who are homozygous normal (two normal alleles → N/N) by 80%, homozygous atypical (two atypical alleles → AA) by 20%, and heterozygous (one normal and one atypical allele → A/N) by 40-60%).
A dibucaine number of 32, therefore, is consistent with a patient with the extremely rare (1/2500-3000) homozygous atypical genotype for pseudocholinesterase.
This patient is likely to require continued mechanical ventilation with adequate sedation for 4-8 hours following succinylcholine administration.
Refer to Master Review Sheet for more info on this.
Post-operative Management:
The patient’s dibucaine number is 32.
What would you do?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
I would – ensure adequate sedation and mechanical ventilation until passive diffusion of succinylcholine away from the neuromuscular junction results in the full return of the patient’s strength, and until the patient meets all other extubation criteria.
Alternatively, I could attempt to reverse the neuromuscular blockade with an anticholinesterase, but this has not proven reliable.
While the transfusion of fresh frozen plasma, containing normal pseudocholinesterase, may serve to augment the patient’s endogenous pseudocholinesterase activity, this practice is NOT recommended due to the potential for transfusion related complications (infection, transfusion reaction, immune modulation).
Post-operative Management:
Three hours later, the nurse calls to inform you that the patient is awake and stable, but is complaining of difficulty seeing? What do you think?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
There are a number of potential causes of this patient’s visual disturbance following TURP, including:
- anterior or posterior ischemic optic neuropathy,
- glycine toxicity,
- cortical blindness,
- acute glaucoma,
- retinal ischemia (branch and central retinal artery occlusion), and
- hemorrhagic retinopathy (the latter may occur after a rough emergence from anesthesia or protracted vomiting results in a sudden rise in intraocular venous pressure).
Other causes of post-operative vision disturbances, such as –
- corneal abrasion,
- chemical injury from solutions used for skin preparation (Hibiclens),
- laser-induced injury, and
- residual effects of petroleum-based ophthalmic ointments,
- are not likely etiologies in this particular patient who remained awake during the TURP procedure.
Therefore, assuming significant vision dysfunction, I would –
- obtain an urgent ophthalmology consult and perform a physical exam to help narrow my differential.
Clinical Note:
-
The typical physical exam findings associated with various causes of post-operative vision loss (POVL) are as follows:
-
Corneal abrasion:
- eye pain that is exacerbated by blinking and ocular movement; the sensation of a foreign body in the eye; tearing; conjunctivitis; photophobia
-
Acute Glaucoma:
- associated with severe and diffuse periorbital pain; a dry and pale eye; dilated pupil
-
Glycine Toxicity:
- elevated serum glycine level above 17 mg/L; dilated/nonreactive pupil; normal intra-ocular pressure, fundus examination, and extra-ocular muscle movement
-
Cortical Blindness:
- unilateral or bilateral vision loss; absent optokinetic nystagmus (an inability to follow moving objects with the head stationary); absent response to visual threat; agnosia (unable to interpret sensory stimuli); normal pupillary response, eye motility, optic nerve, and retina
-
Hemorrhagic Retinopathy (“valsalva retinopathy”):
- vision spots (“floaters”); unilateral or bilateral vision dysfunction; blurred vision or vision loss; pre-retinal hemorrhages; retinal edema
-
Retinal Ischemia (branch and central retinal artery occlusion): normal optic disc, initially; pale edematous retina; painless vision loss; narrowing of retinal arterioles
- Central Retinal Artery Occlusion = cherry red macula; absent/impaired light reflex;
- Branch Retinal Artery Occlusion = normal/impaired light reflex
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Ischemic Optic Neuropathy: painless visual loss; afferent pupil defect (absent/impaired light reflex); visual field deficits or complete vision loss
- Anterior Ischemic Optic Neuropathy: optic disc edema and/or hemorrhage
- Posterior Ischemic Optic Neuropathy: the optic disc appears normal initially
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Corneal abrasion:
Post-operative Management:
The next morning the patient becomes hypotensive, tachycardic, and febrile. What do you think is going on?
- (A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and bare metal stent placement at that time.*
- PMHx: HTN, COPD, CAD/MI, Type II DM, Impotence, Hypothyroidism*
- Anesth. Hx: Minor knee surgery without anesthetic complications.*
- Meds: HCTZ, Lisinopril, Synthroid, Plavix (discontinued 6 days ago), NPH insulin, and Lantus.*
- Allergies: NKDA*
- PE: Vital Signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight 82 Kg*
- Airway: MP II, TMD > 6 cm, full cervical range of motion*
- Lungs: Clear*
- CV: RRR*
- Labs: Na+ 138 mEq/L, K+ 4.0 mEq/L, Hgb 13.8 gm/dL, PTT 42, INR 1.2*
- EKG: Normal sinus rhythm, LVH, non-specific ST changes*
- Thallium: Small apical scar, no reversible myocardial ischemia, LV function preserved)*
This clinical picture is consistent with postoperative sepsis,
a condition that may occur with the spread of various bacteria located in the prostate through open prostatic venous sinuses into the systemic circulation.
Consideration should also be given to the possibility that these physical findings may represent one process or several processes occurring independent of each other.
Therefore, it would be important to evaluate the patient for other conditions that may independently cause hypotension, tachycardia, and/or fever such as –
- hypovolemia,
- anemia,
- cardiac ischemia,
- cardiac failure,
- inadequate analgesia,
- pneumonia (possibly secondary to aspiration),
- atelectasis,
- drug reactions,
- pneumothorax,
- thrombosis, or
- pulmonary embolism.
