Anatole V Wiik
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.
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 :
10. Reduced mobility
General measures to reduce VTE risk
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).
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.
Contraindications to mechanical VTE prophylaxis
Risk of bleeding on VTE prophylaxis
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.
Action in reduced renal function: a standard dose of dalteparin can be prescribed, but antifactor Xa levels need to be monitored. The peak level is measured 4 hours post-dose, and trough level immediately pre-dose. This should be done every 4–5 days while on LMWH. Peaks>0.6 and troughs>0.3 anti-Xa units/mL indicate a need for dose reduction.
Nicole’s Risk Factors and Bleeding Risk
Nicole has no bleeding risk factors. Therefore, in addition to mechanical VTE prophylaxis, heparin prophylaxis is required as her VTE risk is high.
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.
Additional VTE prophylaxis examples: SEE PRESCRIBE BOXES IN MARGIN (drug charts not shown)
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.
‘The airway is secure and patent, as she is responding to questions.’
Continue to monitor the airway, but no intervention currently required.
‘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.
‘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.
‘She has normal neurological function with a 15/15 GCS and her last blood sugar was 10 mmol/L.’
No action currently required.
Examine the abdomen as this is the source of the pain. Does she have any bruising around the flanks or periumbilical region? Does she have any tenderness on palpation? Are there any signs of peritonism, such as rebound, guarding or percussion-induced pain? Assess for flank tenderness. Measure temperature
‘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.’
Arterial blood gas: A metabolic acidosis is characterized by a low pH and bicarbonate with an increasingly negative base excess and elevated lactate. She may be compensating her pH by hyperventilating; a low CO2 would confirm this
Baseline bloods: FBC, U&E, CRP, LFT, amylase, LDH, calcium, coagulation profile and blood sugar. A raised amylase, 3 times its upper limit, is highly sensitive for acute pancreatitis. Assess her LFTs, raised ALP and bilirubin may be due to a stone in her common bile duct, and this could be causing pancreatitis. A CRP is a good surrogate to assess inflammation, the greater the more aggressive the inflammatory process. A raised WCC count may indicate infection (sometimes upper abdominal pain can be caused by a lower lobe pneumonia, or abdominal sepsis) but may be raised purely due to pancreatitis. A dropping Hb may be a sign of retroperitoneal haemorrhage. Additional bloods listed are used for severity scoring
Imaging: A CXR is extremely important to assess any element of ARDS. Diffuse bilateral pulmonary infiltrates are indicative of severe pancreatitis and that respiratory support may be pending. No free air under the diaphragm reduces the likelihood of perforation. An ultrasound is important; this will determine the aetiology and severity of the pancreatitis, 40% of pancreatitis is due to gallstones. The presence of stones and a dilated CBD is a good indicator of its origin. A non-dilated CBD does not exclude gallstones as the cause of pancreatitis
|Parameter||Value||Normal range (Units)|
|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)|
|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.’
Initial Management 
Analgesia: Opioids early to prevent any splinting of diaphragm due to pain. Patients generally require a PCA to control the pain; the ITU team will help you with this, but you can start with a regular oral morphine preparation
Fluid support: Monitor intravascular fluid volume with serial creatinine and urine output. Patients with severe pancreatitis normally need>5 L within the first 24 hours due to third space loss (the space between tissues where fluid does not normally collect). May require central access for blood pressure monitoring and accurate fluid balance
Nutrition: Acute pancreatitis is a catabolic event and promotes nutritional deterioration. Early feeding plays an important role in accelerating recovery. Start with oral fluids and avoid fatty foods. NG/NJ feeds may be required if unable to tolerate oral feeds. TPN is used for specific indications such as a paralytic ileus
Gastric protection: A lot of patients will get started on proton pump inhibitors since they present with epigastric pain initially, which could be caused by a gastric ulcer. It would be reasonable to start one in this case. However, they are not indicated routinely in pancreatitis, particularly if it is mild
The patient should be placed nil by mouth given the severe pain and vomiting. Oral medications (plus fluid and diet) can be restarted as soon as the patient can tolerate them. This could be after as little as a day if the pancreatitis is mild, but may be several weeks.