General surgery
Anatole V Wiik
Outline
Station 8.1: Venous thromboembolism (VTE) prophylaxis
Station 8.2: Acute pancreatitis
Station 8.3: Intestinal obstruction
Station 8.4: Diabetes in the surgical patient
Station 8.1: Venous thromboembolism (VTE) prophylaxis
You are the surgical junior doctor. A 23-year-old woman (Nicole Smith 05/03/91) is brought to the emergency department with periumbilical pain that has radiated to the right iliac fossa. She also has fever. She is on the oral contraceptive pill and previously her mother had a DVT. Your registrar has reviewed the patient and has decided that this patient requires an appendicectomy tomorrow. She has normal renal function, raised CRP and raised white cell count. The registrar wants you to start regular pain killers (paracetamol and codeine), IV fluids, and IV antibiotics (cefuroxime and metronidazole). Please also perform a VTE prophylaxis assessment and prescribe the appropriate treatment.
Thromboprophylaxis
All patients admitted to hospital require a VTE prophylaxis assessment.
Assessment of venous thrombosis risk factors
Surgical patients are at increased risk of VTE (venous thromboembolism) if they have one or more of the following risk factors [1]:
1. Age>60
2. Dehydration
7. Varicose veins with phlebitis
8. Oestrogen therapy (HRT/OCP)
9. Active cancer or chemotherapy
10. Reduced mobility
11. Personal or family history of DVT
12. Significant medical co-morbidities
13. Surgical procedures taking longer than 90 minutes in theatre
14. Acute admission with infection/inflammation/intra-abdominal condition.
General measures to reduce VTE risk
2. Encourage early mobilization
3. Aspirin or clopidogrel is not adequate VTE prophylaxis
4. Consider caval filter if prophylaxis is contraindicated (CI)
VTE prophalaxis (pharmacological or mechanical) does not need to be routinely offered to all surgical patients. For example, it is not indicated in a patient undergoing a surgical procedure with local anaesthesia by local infiltration with no limitation of mobility.
However, most surgical patients at increased risk of VTE (by the above criteria) should receive mechanical VTE prophylaxis as well as pharmacological (unless contraindicated).
Mechanical thromboprophYlaxis
Prescribing mechanical thromboprophylaxis
There are several types of mechanical VTE prophylaxis available. Graduated compression stockings, e.g. TED stockings, are the most common. Other possible options used less commonly are intermittent pneumatic compression (thigh or knee), and foot impulse devices.
Pharmacological thromboprophalaxis
Risk of bleeding on VTE prophylaxis
Potential contraindications to pharmacological VTE prophylaxis:
3. Significant procedure-related bleeding risk
4. Acute stroke: haemorrhagic or large infarct
5. Untreated inherited or acquired bleeding disorders (e.g. haemophilia, Von Willebrand disease)
7. Platelets<75×109/L or abnormal clotting screen
8. BP>230 mmHg systolic or>120 mmHg diastolic
9. Lumbar puncture/epidural/spinal anaesthesia in previous 4 hours or within next 12 hours
Offer to patient and/or families information on:
1. Risks and possible consequence of VTE
2. Importance of VTE prophylaxis and its possible side effects
3. The correct use of VTE prophylaxis
In those whom thromboprophylaxis is felt not indicated, this should be reassessed on a daily basis while in hospital.
Prescribing pharmacological thromboprophylaxis
The option depends on renal function.
If normal renal function, prescribe subcutaneous LMWH/factor Xa inhibitor (e.g. enoxaparin, or dalteparin, or fondaparinux).
Several possible variants occur in reduced renal function, so consult your local hospital formulary. Both the definition of reduced renal function, and the management will vary from trust to trust.
Nicole’s Risk Factors and Bleeding Risk
1. Nicole is a surgical patient
2. She is an acute admission with an inflammatory/infective/intra-abdominal condition
3. She currently is using the OCP, which promotes a prothrombotic state
4. She has a family history of DVTs, which gives her a theoretical risk of thrombosis
5. She potentially could be a critical care admission if she becomes septic
Nicole has no bleeding risk factors. Therefore, in addition to mechanical VTE prophylaxis, heparin prophylaxis is required as her VTE risk is high.
Prescribe (see Figs 8.1 and 8.2) 
Figure 8.1
Figure 8.2
Note that the patient will need to be fasted preoperatively. Policy for this will vary between units. Once a time for surgery is settled, the patient, for instance, would not be allowed water or oral medications for 4 hours preoperatively. Therefore, oral medications would not be allowed in this time window.
Station 8.2: Acute pancreatitis
You are the surgical junior doctor in the emergency department. A 42-year-old obese female with a background of gallstones presents with severe epigastric pain radiating to the back. She has vomited on multiple occasions and feels that she is becoming more breathless. Please assess her and commence appropriate management.
Initial Assessment
Airway
‘The airway is secure and patent, as she is responding to questions.’
Continue to monitor the airway, but no intervention currently required.
Breathing
‘RR 28/min, oxygen saturations are 92% pre-oxygen therapy. She is using her accessory muscles of respiration. She has reduced air entry and crackles are heard throughout both lung fields bilaterally with some wheeze. She is complaining that she cannot catch her breath.’
This lady is tachypnoeic and unable to maintain normal saturations. She requires high- flow oxygen on a non-rebreather mask, and optimization of pain control. Could consider NSAIDs or other opiates such as pethidine or tramadol, but trial morphine if pain is severe: a PCA may be required to control the pain.
Circulation
‘HR 115 bpm, BP 90/60 mmHg, and CRT 3 seconds peripherally. Her hands are moist and cool with a thready pulse. Her mucous membranes are dry. Her eyes appear sunken. Her heart sounds are normal with no murmurs.’
This lady is intravascularly depleted. She needs aggressive fluid resuscitation. Two large bore IV cannulae (14 or 16 G) should be inserted (while simultaneously taking bloods) and a fluid challenge should be given (e.g. over 15 minutes). A urinary catheter should be inserted to assess end-organ perfusion.
Disability
‘She has normal neurological function with a 15/15 GCS and her last blood sugar was 10 mmol/L.’
No action currently required.
Figure 8.3
Figure 8.4
Figure 8.5
Exposure
‘This lady does not have any ecchymosis in the flank (Grey–Turner’s sign) or periumbilical (Cullen’s sign) area. Her abdomen is soft, but extremely tender throughout, mainly around the epigastric region. There is voluntary guarding, but no abdominal distension, or percussion tenderness. Her bowel sounds are present and her temperature is 37.5°C.’
Initial Investigations
Table 8.1
Miss Smith’s blood results, and ABG result
| Parameter | Value | Normal range (Units) |
| WCC | 18×109/L | 4–11 (×109/L) |
| Neutrophil | 12×109/L | 2–7.5 (×109/L) |
| Lymphocyte | 4×109/L | 1.4–4 (×109/L) |
| Platelet | 300×109/L | 150–400 (×109/L) |
| Haemoglobin | 135 g/L | Men: 135–177 (g/L) Women: 115–155 (g/L) |
| PT | 12 seconds | 11.5–13.5 seconds |
| APTT | 30 seconds | 26–37 seconds |
| CRP | 250 mg/L | 0–5 (mg/L) |
| Urea | 16.5 mmol/L | 2.5–6.7 (mmol/L) |
| Creatinine | 175 μmol/L | 79–118 (μmol/L) |
| Sodium | 138 mmol/L | 135–146 (mmol/L) |
| Potassium | 4 mmol/L | 3.5–5.0 (mmol/L) |
| eGFR | 36 mL/min | >60 (mL/min) |
| Bilirubin | 50 μmol/L | <17 (μmol/L) |
| ALT | 45 IU/L | <40 (IU/L) |
| ALP | 200 IU/L | 39–117 (IU/L) |
| Amylase | 477 IU/L | 25–125 (IU/L) |
| LDH | 460 IU/L | 240–480 (IU/L) |
| Glucose | 5.6 mmol/L | 4.5–5.6 (mmol/L) (fasting) |
| Calcium (corrected) | 2.20 mmol/L | 2.20–2.67 (mmol/L) |
| Albumin | 40 g/L | 35–50 (g/L) |
| Lactate | 3 mmol/L | 0.6–2.4 (mmol/L) |
| pH | 7.32 | 7.35–7.45 |
| PaCO2 | 4 kPa | 4.8–6.1 (kPa) |
| HCO3 | 18 mmol/L | 22–26 (mmol/L) |
| PaO2 | 10 kPa | 10.6–13.3 (kPa) on air |
| BE | −4 mmol/L | ±2 (mmol/L) |
‘ABG shows a pH of 7.32, PaCO24 kPa, PaO210 kPa, HCO318 mmol/L, lactate 3 mmol/L and BE is−4 mmol/L. Hb 135 g/L, CRP 250 mg/L, WCC 18×109/L, amylase 477 IU/L, bilirubin 50 µmol/L, ALT 45 IU/L, ALP 200 IU/L, potassium 4 mmol/L, sodium 138 mmol/L, creatinine 175 µmol/L and urea 16.5 mmol/L (eGFR 36 mL/min). Initial Imrie score is 2 (WCC and urea). CXR shows mild bilateral pulmonary infiltrates, no free air under the diaphragm. USS shows multiple gallstones with a CBD diameter of 12 mm. The pancreas is markedly inflamed, but no obvious collections.’
