Give me post op compliments of a patient who has gone through CABG traditional way
I'll look up post-operative complications of traditional (open) CABG from the medical library.
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Now let me search the library and web in parallel for CABG post-op complications.
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postoperative complications traditional open CABG coronary artery bypass graft
Excellent - found the dedicated CABG complications section in Sabiston. Let me read it fully.
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I can see the table reference. Let me read the actual CABG complications section and the table earlier in the block.
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There's a main section at line 2937. Let me read both that and the Table 111.6 section.
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I have very rich data from the Sabiston table. Let me read more of it and also get the dedicated complications text section.
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I have enough content from the Sabiston table and paragraphs to give a thorough answer. Here is the complete, structured breakdown:
Post-Operative Complications of Traditional (Open) CABG
Traditional CABG uses cardiopulmonary bypass (CPB) with median sternotomy and aortic cross-clamping. This approach carries a wide spectrum of complications spanning multiple organ systems.
1. Cardiovascular Complications
| Complication | Key Details |
|---|---|
| Myocardial Stunning | Post-ischemic contractile dysfunction occurring in 10-70% of patients; associated with up to 17% mortality in some series. Caused by global ischemia during cardioplegia and fluid overload from acute myocardial protection. Prevention: adequate and frequent cardioplegia administration, minimizing CPB time. |
| Graft Failure / Occlusion | Decreased graft flow on imaging, wall motion abnormalities on echo, or new pericardial effusion. Risk factors: poor graft/target artery quality, small diameter, and technical issues. Arterial grafts (especially LITA) have better long-term patency than vein grafts. |
| Graft Spasm | Can cause acute ischemia, especially with vein grafts. Managed with calcium channel blockers and nitrates. |
| Post-op Atrial Fibrillation (AF) | Most common post-CABG arrhythmia. New-onset AF is associated with a 4-fold increased risk of stroke. Oral beta-blockers are strongly recommended (COR 1) post-CABG to reduce AF incidence. |
| Other Arrhythmias | SVTs, VT, heart block - triggered by surgical trauma, electrolyte imbalance, ischemia, or conduction system injury. |
| Bleeding / Tamponade | Anticoagulation use, surgical technique, and coagulopathies are key risk factors. Cardiac tamponade presents as rapid cardiovascular compromise and requires urgent surgical re-exploration. |
| Perioperative MI | Graft failure, embolism, or incomplete revascularization can precipitate MI in the immediate post-op period. |
| Air Embolism | Rapid cardiovascular compromise from improper de-airing during cannulation. Managed by stopping pump, Trendelenburg position, 100% O2 ventilation. |
| Low Cardiac Output Syndrome | From impaired LV function, residual ischemia, or poor myocardial protection. |
2. Pulmonary Complications (Most Common Organ Injured)
| Complication | Key Details |
|---|---|
| Atelectasis | Most common pulmonary complication; results from general anesthesia, pleural effusions, and diaphragm dysfunction. |
| Pleural Effusion | Common after CABG; left-sided more common when LITA harvested. |
| Prolonged Mechanical Ventilation | Difficulty liberating from ventilator - especially in patients with pre-existing COPD, advanced age, and prolonged CPB time (>=120 min - nearly 100% of patients develop some degree of pulmonary injury). |
| Pneumonia / Hospital-acquired Infection | Increased risk with prolonged intubation and ICU stay. |
| ARDS / Acute Lung Injury | Systemic inflammatory response from CPB can precipitate ARDS. Genetic variants further modulate risk. |
| Phrenic Nerve Injury | From cold cardioplegia or ice slush causing hemidiaphragm paralysis. |
3. Neurological Complications
| Complication | Key Details |
|---|---|
| Stroke | Risk has decreased over past decades but remains significant, especially in elderly patients, those with aortic atherosclerosis, or those undergoing combined CABG + valve surgery. Aortic manipulation and embolism are main mechanisms. |
| Post-op Cognitive Dysfunction (POCD) | Memory and concentration deficits following CPB - attributed to microemboli, cerebral hypoperfusion, and inflammation. Can persist for weeks to months. |
| Post-op Delirium | Common in the ICU, especially in elderly patients; associated with longer ICU stay and worse outcomes. |
| Peripheral Neuropathy | Brachial plexus injury from sternal retraction; saphenous nerve injury from leg graft harvest sites. |
4. Renal Complications
| Complication | Key Details |
|---|---|
| Acute Kidney Injury (AKI) | Caused by hypoperfusion during CPB, hemolysis, nephrotoxic drugs, and atheroembolism. Patients with diabetes are at particularly high risk. |
| Need for Dialysis | Severe AKI requiring renal replacement therapy - associated with significantly increased mortality. |
5. Wound and Infectious Complications
| Complication | Key Details |
|---|---|
| Sternal Wound Infection / Mediastinitis | Deep sternal wound infection (DSWI) is a feared complication with ~1-3% incidence but high mortality. Risk factors: bilateral IMA use, obesity, diabetes, COPD, prolonged CPB. Requires surgical debridement and VAC therapy or flap closure. |
| Superficial Sternal Wound Infection | More common, managed with antibiotics and wound care. |
| Leg Wound Infection / Lymphedema | At saphenous vein harvest sites - especially in diabetic/obese patients. |
| Endocarditis | Rare but possible after intracardiac manipulation. |
| Sepsis | From any of the above infectious sources, compounded by immunosuppression from CPB. |
6. Gastrointestinal Complications
| Complication | Key Details |
|---|---|
| Ileus | Common post-operatively from narcotics, reduced gut perfusion, and prolonged immobility. |
| Mesenteric Ischemia | Rare but catastrophic - from hypoperfusion or embolism during CPB. |
| GI Bleeding | Stress ulcer formation, especially in patients on antiplatelet/anticoagulant therapy. |
| Cholecystitis / Pancreatitis | Rare; related to splanchnic hypoperfusion during CPB. |
7. Hematological Complications
| Complication | Key Details |
|---|---|
| Coagulopathy | CPB activates the coagulation cascade and consumes clotting factors; requires careful monitoring and protamine use. |
| Thrombocytopenia | From CPB circuit-related platelet activation and destruction. |
| Heparin-Induced Thrombocytopenia (HIT) | Important to recognize and switch to alternative anticoagulants. |
| Anemia | From hemodilution on CPB and perioperative blood loss; often requires transfusion. |
8. Metabolic / Endocrine Complications
| Complication | Key Details |
|---|---|
| Hyperglycemia | Stress response and steroid use cause significant hyperglycemia; tight glycemic control reduces infectious complications. Diabetic females undergoing CABG face particularly adverse outcomes. |
| Electrolyte Imbalances | Hypokalemia and hypomagnesemia are common and predispose to arrhythmias; require vigilant monitoring and replacement. |
9. Pericardial Complications
| Complication | Key Details |
|---|---|
| Pericarditis / Dressler Syndrome | Autoimmune pleuropericarditis occurring 2-10 weeks post-op; presents with fever, pleuritic chest pain, pericardial rub. Managed with NSAIDs and colchicine. |
| Pericardial Effusion | Can develop in the weeks following surgery; large effusions require drainage. |
High-Risk Patient Groups
Certain populations face significantly elevated complication rates after CABG:
- Females - higher rates of renal failure, neurological complications, and post-op MI
- Diabetics - higher risk of AKI, prolonged ICU stay, and sternal wound infection
- Elderly (>=70 years) - higher stroke risk and neurocognitive decline
- Obese patients - higher wound infection rates despite a paradoxical survival benefit ("obesity paradox")
- Patients with prior CABG - technical difficulty and higher perioperative risk
Sources: Sabiston Textbook of Surgery - The Biological Basis of Modern Surgical Practice (Table 111.6: Summary of Common Complications of CABG); Braunwald's Heart Disease, 15th Ed.; Miller's Anesthesia, 10th Ed.
Note: The user asked for "compliments" but this appears to be a typo for "complications," which is what has been addressed above. If you meant something else, please clarify.
Patient complain of coughs with constipation and nausea what could be the possible reasons and is it common after surgery
Post-CABG cough, constipation, and nausea are all common and have well-recognized causes. Cough often relates to ACE inhibitors, fluid retention, or pleural irritation; constipation and nausea are typically drug-related (opioids, anesthesia). Let me pull detailed textbook content on each.
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Good data. Let me now get more on ACE inhibitor cough and pleural effusion-related cough post-CABG, plus ileus after surgery.
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I now have solid textbook backing across all three symptoms. Here is the full clinical answer:
Post-CABG: Cough, Constipation & Nausea - Causes and Clinical Significance
Yes, all three symptoms are common after traditional open CABG. They each have multiple, overlapping causes rooted in surgery, anesthesia, and post-op medications.
1. COUGH
Post-CABG cough is very common and almost always has an identifiable cause.
A. ACE Inhibitor-Induced Cough (Most Common Drug Cause)
ACE inhibitors (ramipril, enalapril, lisinopril) are routinely started after CABG to reduce LV remodeling and mortality. They cause a dry, persistent, tickling cough in up to 20% of patients - mediated by accumulation of bradykinin in the airway mucosa.
- Onset: days to weeks after starting the drug
- Character: dry, irritating, non-productive
- Management: switch to an ARB (e.g., valsartan), which does not cause cough
"ACE inhibitors are not associated with the cough that may occur in up to 20% of persons receiving an ACE inhibitor" - Brenner and Rector's The Kidney
B. Pleural Effusion
After CABG, pleural effusions are extremely common (especially left-sided when the LITA is harvested). Fluid accumulates in the pleural space and irritates the lung, causing:
- Productive or dry cough
- Positional cough (worse lying flat)
- Associated breathlessness
- Requires drainage if large
C. Pulmonary Congestion / Left Heart Failure
Low cardiac output syndrome or fluid overload from CPB can lead to pulmonary edema with frothy cough, orthopnea, and crackles on auscultation.
D. Atelectasis and Secretion Retention
Post-sternotomy pain discourages deep breathing and effective coughing, leading to lobar collapse, mucus plugging, and productive cough. This is called "splinting" - the patient guards the sternal wound and cannot generate enough force to clear secretions effectively.
"Splinting may promote atelectasis and interfere with the patient's ability to cough and clear secretions" - Miller's Anesthesia, 10th Ed.
E. Amiodarone Pulmonary Toxicity
Amiodarone, frequently used to treat post-CABG AF, can cause subacute pulmonary toxicity presenting as cough, dyspnea, fever, and patchy infiltrates. Rare but important to recognize.
"Amiodarone-induced pulmonary toxicity usually presents as a subacute illness characterized by cough, dyspnea, fever, and patchy pulmonary infiltrates" - Fishman's Pulmonary Diseases and Disorders
F. Hospital-acquired Pneumonia
Prolonged intubation and ICU stay increase aspiration and infection risk, causing productive cough with fever and consolidation.
2. CONSTIPATION
Constipation is almost universal in the first days to weeks after CABG and is multifactorial.
A. Opioid Analgesia (Primary Cause)
Post-CABG pain is managed with opioids (morphine, fentanyl, oxycodone). Opioids act on mu-receptors throughout the GI tract causing:
- Decreased gastric motility and emptying
- Decreased pyloric tone
- Reduced intestinal peristalsis
- Constipation, ileus, and occasionally nausea/vomiting
"Common adverse side effects associated with opioid therapy include nausea, vomiting, constipation, urinary retention, delirium..." - Barash Clinical Anesthesia, 9th Ed.
"Opioids: Gastrointestinal - decreased motility, constipation, biliary colic" - Schwartz's Principles of Surgery, 11th Ed.
B. General Anesthesia and Reduced Gut Motility
General anesthesia suppresses autonomic GI function. Combined with CPB-related splanchnic hypoperfusion, the gut motility remains suppressed for days post-operatively.
C. Immobility and Reduced Oral Intake
Bed rest, restricted fluids, and reduced diet in the ICU further slow bowel transit.
D. Electrolyte Disturbances
Hypokalemia (common post-CPB) impairs smooth muscle function in the bowel wall, worsening constipation.
E. Reduced Fiber and Fluid Intake
Hospital diet restrictions and IV fluid management reduce the bulk and moisture that normally stimulate peristalsis.
Management: Routine stool softeners (docusate) and laxatives (senna, lactulose) should be prescribed prophylactically alongside opioids. Methylnaltrexone or naldemedine can be used for opioid-induced constipation specifically.
3. NAUSEA
Nausea is extremely common post-operatively and often clusters with constipation as part of opioid-induced bowel dysfunction.
A. Opioid-Induced Nausea
Opioids stimulate the chemoreceptor trigger zone (CTZ) in the medulla and reduce pyloric tone, causing nausea and vomiting.
"Decreased pyloric tone [from opioids leads to] nausea and vomiting" - Miller's Anesthesia, 10th Ed.
B. General Anesthesia / Post-Operative Nausea and Vomiting (PONV)
PONV affects 30-80% of surgical patients in the first 24-48 hours. Volatile anesthetics (sevoflurane, isoflurane) and nitrous oxide are the biggest triggers.
- Risk factors in CABG: female sex, non-smoking, history of motion sickness, prolonged procedure time
C. Digoxin Toxicity
Digoxin is sometimes used for rate control in post-CABG AF. Even at therapeutic levels, nausea, vomiting, and anorexia are classic early signs of digoxin toxicity - particularly if the patient has renal impairment (common post-CABG).
D. Hypokalemia and Electrolyte Disturbances
Low potassium (from diuretics, CPB hemodilution) causes generalized GI dysmotility with nausea and bloating.
E. Gastric Stasis / Ileus
CPB-related mesenteric hypoperfusion and opioid use together cause gastroparesis and ileus, with nausea, abdominal distension, and inability to tolerate oral feeds.
F. Amiodarone and Other Medications
Amiodarone, antibiotics, and other post-op drugs frequently list nausea as a side effect.
Summary Table
| Symptom | Most Common Cause | Other Important Causes |
|---|---|---|
| Cough | ACE inhibitor (up to 20%), pleural effusion | Atelectasis/splinting, pulmonary congestion, amiodarone toxicity, pneumonia |
| Constipation | Opioid analgesia | Anesthesia, immobility, hypokalemia, reduced intake |
| Nausea | Opioids / PONV | Digoxin toxicity, ileus, electrolytes, amiodarone, gastric stasis |
Is This Expected?
Yes - these symptoms together are the norm, not the exception. The combination of cough + constipation + nausea in a post-CABG patient almost always points to:
- ACE inhibitor started on discharge (cough)
- Opioid pain management (constipation + nausea)
The priority is to:
- Assess the cough - rule out pulmonary edema, effusion, or pneumonia first; if clear, switch ACE-I to ARB
- Treat constipation prophylactically with docusate/senna when opioids are prescribed
- Manage nausea with ondansetron or metoclopramide; check digoxin levels and potassium
- Encourage early mobilization - key to restoring GI function and clearing pulmonary secretions
Sources: Sabiston Textbook of Surgery; Miller's Anesthesia 10th Ed.; Barash Clinical Anesthesia 9th Ed.; Schwartz's Principles of Surgery 11th Ed.; Fishman's Pulmonary Diseases; Brenner and Rector's The Kidney
Patient complain of coughs with constipation and nausea what could be the possible reasons and is it common after surgery
This looks like a repeat of your previous question, which I just answered in detail above. Here's a quick recap of the key points:
Quick Recap - Post-CABG Cough, Constipation & Nausea
Yes, all three are common and expected after traditional open CABG.
Cough - Top Causes:
- ACE inhibitor (ramipril, enalapril) - dry tickling cough in up to 20% of patients
- Pleural effusion - especially left-sided after LITA harvest
- Atelectasis/splinting - pain prevents effective deep breathing and coughing
- Pulmonary congestion - fluid overload from CPB
- Amiodarone toxicity - if started for post-op AF
Constipation - Top Causes:
- Opioid analgesia (morphine, oxycodone) - primary culprit; slows entire GI tract
- Anesthesia and immobility - suppress gut motility for days
- Hypokalemia - impairs smooth muscle contraction
- Reduced oral intake in ICU
Nausea - Top Causes:
- Opioids - stimulate the chemoreceptor trigger zone + reduce pyloric tone
- PONV (post-operative nausea and vomiting) - affects 30-80% of surgical patients
- Digoxin toxicity - if used for AF rate control, especially with renal impairment
- Gastric stasis/ileus - from CPB hypoperfusion + opioids
The full detailed answer with textbook citations, management strategies, and a summary table is in my response just above this one. Let me know if you'd like to focus on any specific aspect or management plan for this patient.
What is LITA
LITA - Left Internal Thoracic Artery
LITA stands for the Left Internal Thoracic Artery (also called the Left Internal Mammary Artery / LIMA). It is the most commonly used and most important conduit (graft vessel) in CABG surgery.
Where It Comes From
- It is a branch of the left subclavian artery
- Runs down the inner surface of the chest wall, just behind the sternum (breastbone), on the left side
- During CABG, the surgeon harvests (detaches) it from the chest wall and reroutes it to bypass a blocked coronary artery
Why LITA Is Preferred Over Vein Grafts
| Feature | LITA (Arterial Graft) | Saphenous Vein Graft |
|---|---|---|
| 10-year patency | ~90-95% | ~50-60% |
| Atherosclerosis resistance | High | Lower |
| Long-term survival benefit | Yes (proven) | Less so |
| Spasm risk | Higher early on | Lower |
The LITA is almost always grafted to the Left Anterior Descending (LAD) artery - the most important coronary artery. This LITA-to-LAD graft is considered the gold standard of CABG and is the single biggest determinant of long-term survival after the procedure.
LITA vs. RITA vs. LIMA
| Term | Meaning |
|---|---|
| LITA | Left Internal Thoracic Artery |
| RITA | Right Internal Thoracic Artery |
| LIMA | Left Internal Mammary Artery - same vessel as LITA, just an older name |
| RIMA | Right Internal Mammary Artery - same as RITA |
LITA and LIMA refer to the exact same vessel. The term "mammary" is older; "thoracic" is more anatomically precise and preferred in modern terminology.
Relevance to the Earlier Discussion
When the LITA is harvested during CABG, the left pleural space is often entered, which is why left-sided pleural effusions are so common after CABG - fluid accumulates where the artery was dissected from the chest wall, causing the cough we discussed earlier.
Which vein from lower limb is taken for CABG
The Great Saphenous Vein (GSV)
The Great Saphenous Vein (also called the Long Saphenous Vein) is the vein harvested from the lower limb for CABG.
Where It Is
- It is the longest vein in the body
- Runs along the medial (inner) side of the leg, from the foot all the way up to the groin
- Starts at the medial aspect of the dorsum of the foot
- Travels up the medial side of the calf and thigh
- Drains into the femoral vein at the saphenofemoral junction in the groin
Why It Is Used
| Feature | Detail |
|---|---|
| Length | Long enough to create multiple bypass grafts in one surgery |
| Diameter | ~3-5 mm - closely matches coronary artery size |
| Accessibility | Superficial and easy to harvest |
| Expendable | Leg venous drainage continues fine through deep veins after removal |
How It Is Harvested
Two techniques are used:
| Method | Description | Advantage |
|---|---|---|
| Open harvesting | One long continuous incision along the medial leg | Faster, direct visualization |
| Endoscopic vein harvesting (EVH) | Small keyhole incisions with a camera | Less wound complications, better cosmesis, faster healing |
Limitations of the GSV Compared to LITA
| GSV | LITA | |
|---|---|---|
| 10-year patency | ~50-60% | ~90-95% |
| Atherosclerosis | Prone to developing it over time | Resistant |
| Graft failure | Higher long-term failure rate | Much lower |
| Reason for failure | Intimal hyperplasia and atherosclerosis in the vein wall | - |
Because of the lower long-term patency, the GSV is used for grafting vessels other than the LAD (e.g., the right coronary artery, circumflex artery), while the LITA is reserved for the critical LAD graft.
Leg Wound Complications After GSV Harvest
As mentioned in the earlier CABG complications discussion, the harvest site can cause:
- Wound infection - especially in diabetic and obese patients
- Lymphedema - disruption of lymphatics alongside the vein
- Leg swelling and pain at the harvest site
- Wound dehiscence - particularly with open harvesting technique
- Saphenous nerve injury - the nerve runs alongside the vein, causing medial leg numbness or paresthesia
Endoscopic harvesting significantly reduces these wound complications compared to the traditional open technique.
Can the Short Saphenous Vein Be Used?
The Small (Short) Saphenous Vein runs along the back of the calf and is occasionally used if the GSV is unavailable (e.g., previous varicose vein surgery, poor quality), but it is shorter and less ideal.
So in post op he is feeling nauseaous, can ondensetron be given and in what dosage and if not what can be given
Yes, ondansetron can be used post-CABG but with an important caution - it prolongs the QT interval, which matters in cardiac patients. Let me pull the exact dosing and alternatives from the textbooks.
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Good data found. Let me now get the exact ondansetron dosing and the full antiemetic options table from Harrison's.
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I have everything needed for a thorough, clinically accurate answer.
Ondansetron Post-CABG: Can It Be Given? Dose? Alternatives?
Can Ondansetron Be Given Post-CABG?
Yes - but with caution and an important cardiac warning.
Ondansetron is a 5-HT3 (serotonin) receptor antagonist and is the most effective first-line antiemetic for post-operative nausea and vomiting (PONV). It works at the chemoreceptor trigger zone and GI tract to block the nausea signal.
However, in a post-CABG patient, there is one critical concern:
⚠️ QT Prolongation Risk
Ondansetron prolongs the QT interval on ECG. This is significant in post-CABG patients because:
- Post-cardiac surgery patients are already at risk for arrhythmias (AF, VT)
- Many post-CABG drugs also prolong QT - amiodarone, some antibiotics (fluoroquinolones, azithromycin)
- Electrolyte disturbances common post-CABG (hypokalemia, hypomagnesemia) further prolong QT
- Combined QT prolongation can trigger Torsades de Pointes - a life-threatening polymorphic ventricular tachycardia
"In the case of torsades de pointes, underlying QT prolongation on the ECG may be intrinsic or drug related. The most commonly administered QT-prolonging drugs include ondansetron..." - Miller's Anesthesia, 10th Ed.
"FDA issued a safety advisory for ondansetron due to concern for QT prolongation. There are pediatric case reports of cardiac death possibly associated with ondansetron." - Tintinalli's Emergency Medicine
When Ondansetron IS Safe to Use Post-CABG
It can be used if:
- QTc interval is < 450 ms (men) / < 470 ms (women) on ECG
- Potassium and magnesium are within normal range
- Not combined with other QT-prolonging drugs (amiodarone - check carefully)
- Used at the lowest effective dose
Dosing of Ondansetron
| Route | Dose | Frequency |
|---|---|---|
| IV (preferred post-op) | 4 mg slow IV over 2-5 minutes | Every 4-6 hours as needed |
| Oral | 4-8 mg | Every 8 hours |
| Max single IV dose | 4 mg (the FDA reduced max IV dose from 32 mg to 32 mg single dose due to QT concerns; in PONV, 4 mg IV is the standard) |
Key point: For PONV, 4 mg IV is the standard effective dose. Higher doses do NOT give better PONV control but do increase QT risk.
Before giving: Check a 12-lead ECG, check K+ and Mg2+ levels, review other medications.
Alternatives If Ondansetron Is Contraindicated
If QTc is prolonged, amiodarone is on board, or electrolytes are severely deranged, use these alternatives:
1. Metoclopramide (Reglan)
- Mechanism: Dopamine (D2) antagonist + prokinetic - speeds gastric emptying
- Dose: 10 mg IV/IM/oral every 6-8 hours
- Advantage: Also helps gastric stasis and ileus - addresses two problems at once in post-CABG
- Caution: Can cause extrapyramidal side effects (restlessness, dystonia) especially in elderly patients; avoid in Parkinson's disease
2. Dexamethasone
- Mechanism: Unknown but highly effective antiemetic
- Dose: 4-8 mg IV once
- Advantage: Single dose, long-lasting (up to 24 hours), no QT effect
- Caution: Causes hyperglycemia - a significant concern in post-CABG diabetic patients; monitor blood glucose closely
- Often used in combination with ondansetron for better effect
3. Promethazine (Phenergan)
- Mechanism: H1 antihistamine + anticholinergic + antidopaminergic
- Dose: 12.5-25 mg IV/IM every 4-6 hours
- Caution: Causes sedation; IV use requires slow infusion (risk of tissue necrosis with extravasation); may cause respiratory depression
4. Prochlorperazine
- Mechanism: D2 antagonist (phenothiazine class)
- Dose: 5-10 mg IV/IM every 6 hours
- Use: Good for opioid-induced and post-op nausea
5. Haloperidol (low dose)
- Mechanism: D2 antagonist
- Dose: 0.5-2 mg IV
- Use: Effective, also addresses post-op delirium if present
- Note: Also has mild QT effect - check ECG
6. Domperidone (where available)
- Mechanism: Peripheral D2 antagonist + prokinetic
- Dose: 10 mg oral three times daily
- Advantage: Does not cross blood-brain barrier, fewer CNS side effects
- Note: Not available in the USA; used in UK, India, Europe
Practical Post-CABG Antiemetic Algorithm
Post-CABG nausea
|
Check ECG (QTc) + K+ + Mg2+
|
QTc normal + electrolytes OK?
YES NO
| |
Ondansetron 4mg IV Correct electrolytes first
(first line) Then use Metoclopramide 10mg IV
OR Dexamethasone 4mg IV
(avoid ondansetron if QTc >470ms)
|
Nausea persists?
|
Add Dexamethasone 4mg IV (combination)
OR switch to Metoclopramide
Summary
| Drug | Dose | Best For | Key Caution |
|---|---|---|---|
| Ondansetron | 4 mg IV slow push | First-line PONV | QT prolongation - check ECG first |
| Metoclopramide | 10 mg IV q6-8h | Opioid nausea + gastric stasis | Extrapyramidal effects |
| Dexamethasone | 4-8 mg IV once | Add-on, long duration | Hyperglycemia in diabetics |
| Promethazine | 12.5-25 mg IV/IM | Rescue antiemetic | Sedation, respiratory depression |
| Prochlorperazine | 5-10 mg IV/IM | Opioid-induced nausea | Extrapyramidal effects |
| Haloperidol | 0.5-2 mg IV | Nausea + delirium | Mild QT effect |
Sources: Miller's Anesthesia 10th Ed.; Tintinalli's Emergency Medicine; Harrison's Principles of Internal Medicine 22nd Ed.; Sleisenger & Fordtran's GI and Liver Disease
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