Gastroenterology

Constantinos A Parisinos

Outline

Station 4.2: Spontaneous bacterial peritonitis

Station 4.3: Paracetamol overdose, (written by Shiying Hey)

Station 4.1: Severe ulcerative colitis

You are the junior doctor covering the medical assessment unit overnight. You are to see a 27-year-old man (John Smith 12/08/87) who has been admitted with a 48-hour history of bloody diarrhoea (>10 stools a day). You are told he has a previous diagnosis of ulcerative colitis (UC), normally well controlled with no regular medications.

Patient Details

Name:	John Smith
DOB:	12/08/87
Hospital Number:	1208970076
Weight:	72 kg
Height:	1.7 m
Consultant:	Dr Cox
Hospital/Ward:	WGH Ward 3
Current Medications:	Sulfasalazine 500 mg QDS oral
Allergies:	Penicillin (rash)
Admission date:	12/11/14

Initial differential diagnosis

Flare up of UC

Infective colitis (bacterial, viral, e.g. CMV)

Ischaemic colitis

Angiodysplasia, bleeding vessel

Complications of severe ulcerative colitis

Toxic megacolon

Perforation

Sepsis

Management of severe ulcerative colitis

Resuscitate using an ABCDE approach

Fluids

Corticosteroids

Early specialist input including consideration of need for surgery

Initial Assessment

Airway

Assess patency of the airway. The patient may have also been vomiting, and is at risk of aspirating. A quick way to assess the airway is to see whether the patient can speak back to you

‘The patient is speaking back to you in full sentences. He denies any episodes of vomiting.’

You are satisfied that the airway is patent.

Breathing

Assess the respiratory rate and oxygen saturations. A dehydrated, shocked patient may have an increased respiratory rate while trying to compensate for a presumed metabolic acidosis

Perform a respiratory exam, looking for evidence of aspiration

‘The patient is visibly tachypnoeic, with a respiratory rate of 24/min. On examination, his chest is clear, with vesicular breath sounds and good air entry bilaterally. Saturations are 98% on air, so supplementary oxygen is not required.’

You are satisfied that there is no evidence of an aspiration pneumonia. However, you will still order a CXR (to rule out perforation), as well as performing an ABG, which has already been sent for processing. Saturations are 98% on air.

Acute severe colitis is best defined by the Truelove and Witts’ criteria

Circulation

Perform a cardiovascular exam. Cool peripheries, delayed capillary refill time, tachycardia, a weak central pulse, dry mucous membranes, non-visible JVP are all signs of hypovolaemia

Assess fluid balance by measuring pulse (rate, rhythm and character), blood pressure, capillary refill time, JVP and urine output (if being recorded). This patient is likely to be hypovolaemic given his history of diarrhoea. Tachycardia in a young patient is of concern despite a normal blood pressure, due to their ability to still maintain a normal blood pressure in the initial stages of shock

‘On examination the patient is tachycardic, with a raised CRT. He is cool peripherally, and has a weak brachial pulse. JVP is not visible, and his mucous membranes are dry. Heart rate is 108 bpm, blood pressure 108/76 mmHg. He denies any chest pain, and on ausculation, heart sounds are normal with no added sounds.’

Following this assessment, you establish intravenous access and send off urgent bloods. You also perform an ECG. You start a urine chart, measuring hourly urine output.

Prescribe (see Figs 4.1–4.3)

Fluid bolus, e.g. 0.9% SODIUM CHLORIDE 500 mL (over 15 min)

Figure 4.1

Figure 4.2

Figure 4.3

Disability

Assess the patient’s conscious level, either using AVPU (is the patient Alert? If not, do they respond to Verbal or Painful stimuli? Or are they Unresponsive?) or Glasgow coma score (GCS)

Check glucose levels

‘Glucose level is 5.8 mmol/L and he is alert although visibly tired.’

Exposure

Expose the patient, and look for further evidence of bloody diarrhoea. Examine the abdomen for any tenderness or masses. Listen for bowel sounds. Look at the calves and examine for tenderness (ulcerative colitis, alongside hypovolaemia are risk factors for a DVT)

‘There is no obvious bleeding and no calf tenderness. Abdomen is soft but generally tender, with hyperactive bowel sounds on auscultation. There is no organomegaly or signs of peritonism. Temperature is 37.9°C.’

Initial Investigations

ABG: Important to assess patient acid–base status. Look out for evidence of a metabolic acidosis. A lactate of>2.5 suggests significant tissue hypoperfusion

CXR: To rule out possible aspiration. Ensure you look under the diaphragm for free air, a radiological sign of perforation

AXR: Urgent investigation to rule out the presence of toxic megacolon, which is a surgical emergency. Consider a need for daily AXR especially if there are signs of colonic distension and/or there is significant deterioration in clinical condition/blood parameters

ECG: Diarrhoea and vomiting may lead to dangerous electrolyte imbalances, which may in turn predispose the individual to potentially fatal arrhythmias

Bloods: Full blood count, clotting, urea and electrolytes, liver function tests, serum albumin, glucose, CRP, ESR, blood cultures, group and save. Look for evidence of infection, assess renal function and possible electrolyte abnormalities. Ensure blood cultures are taken. Group and save is vital as the patient may require early surgical intervention. Daily bloods are required in severe ulcerative colitis

Stool samples: Stool culture and C. difficile assay on at least three stool samples to detect 90% of cases. Cytomegalovirus (CMV) should be considered in severe or refractory colitis. Results should not delay the administration of corticosteroid treatment

Flexible sigmoidoscopy: Flexible sigmoidoscopy and biopsy should be requested and available within 72 hours (ideally 24 hours) and a histological diagnosis within 5 days to confirm diagnosis and exclude CMV

Urine dipstick: To look for possible evidence of a UTI (with abdominal pain), and for evidence of bleeding elsewhere (in urine)

‘Blood tests: Hb 110 g/L, WCC 14×10⁹/L, CRP 120 mg/L, normal clotting, glucose, liver and renal function. ABG: PaO₂14 kPa, PaCO₂3.2 kPa, HCO₃19 mmol/L, lactate 2.7 mmol/L, pH 7.3 (metabolic acidosis, with partial respiratory compensation). AXR: distal faecal loading, featureless descending colon consistent with colitis, no evidence of toxic megacolon. Urine dip: positive for ketones (+).’

Table 4.1

Mr Smith’s blood results

Parameter	Value	Normal range (Units)
WCC	14×10⁹/L	4–11 (×10⁹/L)
Neutrophil	6×10⁹/L	2–7.5 (×10⁹/L)
Lymphocyte	3×10⁹/L	1.4–4 (×10⁹/L)
Platelet	220×10⁹/L	150–400 (×10⁹/L)
Haemoglobin	110 g/L	Men: 135–180 (g/L) Women: 115–160 (g/L)
CRP	120 mg/L	0–5 (mg/L)
Urea	6.4 mmol/L	2.5–6.7 (mmol/L)
Creatinine	90 μmol/L	79–118 (μmol/L)
eGFR	>60 mL/min	>60 (mL/min)
Sodium	138 mmol/L	135–146 (mmol/L)
Potassium	3.8 mmol/L	3.5–5.0 (mmol/L)
Lactate	2.7 mmol/L	0.6–2.4 (mmol/L)
Bilirubin	8 μmol/L	<17 (μmol/L)
ALT	20 IU/L	<40 (IU/L)
ALP	55 IU/L	39–117 (IU/L)
Albumin	40 g/L	35–50 (g/L)
Glucose	5 mmol/L	4.5–5.6 (mmol/L) (fasting)
PT	12 seconds	11.5–13.5 seconds
APTT	30 seconds	26–37 seconds
pH	7.3	7.35–7.45
PaO₂	14 kPa	10.6–13.3 (kPa) on air
PaCO₂	3.2 kPa	4.8–6.1 (kPa)
HCO₃	19 mmol/L	22–26 (mmol/L)

Initial Management [1]

Withdraw agents that may precipitate colonic dilatation: Anticholinergic, anti-diarrhoeal agents, NSAIDs, opioid drugs, risk precipitating colonic dilatation

IV fluids: Intravenous fluid and electrolyte replacement to correct and prevent dehydration or electrolyte imbalance, consider blood transfusion to maintain Hb>100 g/L

Isolation: Keep patient isolated until clear that the diarrhoea is non infective in nature.

Prescribe (see Figs 4.1–4.3)

Further fluids (depending on response), e.g. 0.9% SODIUM CHLORIDE 500 mL (over 15 min)

Reassessment

‘Following IV fluid resuscitation, the patient is maintaining his airway and talking comfortably in full sentences. He is apyrexial, his respiratory rate is 18/min, heart rate 95 bpm and blood pressure 130/74 mmHg. The patient looks more comfortable and settled.’

Definitive Management

IV corticosteroids: Either hydrocortisone 100 mg four times a day or methylprednisolone 60 mg/day. IV corticosteroids are generally given for up to 5 days. Consider giving a proton pump inhibitor for gastric protection.

IV antibiotics: Only if infection is considered, or immediately prior to surgery

Subcutaneous LMWH: To reduce the risk of thromboembolism

Bone protection: Current guidelines recommend the use of calcium and vitamin D (e.g Adcal D3 1 tablet BD or Calcichew D3 Forte 1 tablet BD) during chronic corticosteroid use

Stool chart: To record number and character of bowel movements, including the presence or absence of blood and liquid versus solid stool

Toxic megacolon: If there is evidence of toxic megacolon (diameter>5.5 cm, or caecum>9 cm), organize an urgent surgical review

Surgical input: A stool frequency of>8/day or CRP>45 mg/L at 3 days appears to predict the need for surgery in 85% of cases. Surgical review and input from specialist colorectal nurse or stoma therapist is appropriate at this stage

Early specialist input: Patients admitted with known or suspected IBD should be discussed with (and normally transferred to the care of) a consultant gastroenterologist or colorectal surgeon within 24 hours of admission. Joint surgical and medical management is appropriate.

Disease modifying agents: Consider use of disease modifying agents such as infliximab or cyclosporin in severe cases that fail to respond to treatment with systemic corticosteroids

Prescribe (see Figs 4.1–4.3)

Corticosteroids, e.g. HYDROCORTISONE 100 mg IV STAT then 100 mg IV QDS

Thromboprophylaxis, e.g. DALTEPARIN 5000 units SC OD

Bone protection, e.g. ADCAL D3 1 tablet ORAL BD

Patient’s regular aminosalicylate prescription, SULFASALAZINE 500 mg ORAL QDS

Handing over the Patient

‘This is a 27-year-old patient, presenting with a severe exacerbation of ulcerative colitis.

He presented with a 2-day history of bloody diarrhoea on a background of a known diagnosis of ulcerative colitis, normally well controlled with aminosalicylate treatment.

On initial assessment, the patient was significantly dehydrated, with a HR 108 bpm, and BP 108/76 mmHg. The abdomen was soft with generalized tenderness but no peritonism. An abdominal film shows no evidence of toxic megacolon. Routine bloods demonstrate raised inflammatory markers, and a slight reduced Hb at 110 g/L, probably partly related to chronic disease, and partly due to acute bleeding.

The patient showed good response to IV fluid resuscitation. The current plan is commencing maintenance IV fluids, IV corticosteroid treatment, daily blood tests, four stool samples to exclude infective colitis, and urgent referral to gastroenterology.’

We had a patient with a background of UC who had been complaining of right iliac fossa pain and constipation for 3 weeks. He was given a dose of antibiotics for presumed infective colitis. During his third presentation to casualty in 7 days, a CT abdomen demonstrated acute appendicitis, and the patient was taken to theatre on the same day. Patients with inflammatory bowel disease may also develop other causes for abdominal pain, and lateral thinking is essential when reviewing such patients.

Station 4.2: Spontaneous bacterial peritonitis

You are the junior doctor covering the medical assessment unit. You are called to see a 72-year-old gentleman (Andrew Reddy 12/08/42) with known alcoholic liver cirrhosis, who presents with mild abdominal pain and confusion. You recognize him immediately as you also work on the gastroenterology ward, where this patient attends every few weeks for therapeutic paracentesis.

Patient Details

Name:	Andrew Reddy
DOB:	12/08/42
Hospital Number:	1208420060
Weight:	70 kg
Height:	1.76 m
Consultant:	Dr Bing
Hospital/Ward:	WGH Ward 4
Current Medications:	Thiamine 100 mg oral TDS (for malnutrition), furosemide 40 mg oral OD and spironolactone 100 mg oral OD (for ascites)
Allergies:	No known drug allergies
Admission date:	12/11/14

Initial differential diagnosis

Infection (SBP, lower respiratory tract infection, UTI)

Constipation

Hepatocellular carcinoma

Wernicke’s encephalopathy

Alcohol intoxication

Alcoholic hepatitis

Upper gastrointestinal bleed

Complications of chronic liver disease

Portal hypertension:

Ascites

Hypersplenism

Varices

Synthetic dysfunction:

Hypoalbuminaemia

Coagulopathy

Hepatopulmonary syndrome

Hepatorenal syndrome

Encephalopathy

Hepatocellular carcinoma

Management of chronic liver disease

Resuscitate using an ABCDE approach

Diagnostic paracentesis

Albumin infusion

IV antibiotics

A diagnostic paracentesis should be performed in all cirrhotic patients with ascites, in those who have signs and symptoms of peritoneal infection, including the development of encephalopathy, renal impairment, or peripheral leucocytosis without a precipitating factor.

Initial assessment

Airway

Assess patency of the airway

‘The patient is drowsy, however, speaks in full sentences, and rousable.’

Secure the airway if necessary. Encephalopathic patients are often drowsy, confused, and risk of aspiration is very high. You are satisfied that the airway is safe and proceed to assess breathing.

Breathing

Assess the respiratory rate, and oxygen saturations

Give supplementary oxygen to maintain oxygen saturations>94%

Perform a respiratory exam, listening for basal crepitations which may suggest a lower respiratory tract infection. This patient is at risk of community-acquired pneumonia, hospital-acquired pneumonia (recurrent admissions) and aspiration pneumonia

Request a CXR

‘Saturations are 92% on 1 L with a respiratory rate of 22/min. Percussion reveals dull bases, and on auscultation, there is reduced air entry bilaterally. Portable CXR confirms small bilateral pleural effusions.’

Bilateral pleural effusions may be secondary to hypoalbuminaemia or congestive heart failure. No obvious consolidation is visible. You administer 2 L of oxygen to maintain saturations>94% and proceed to assess circulation.

Circulation

Assess haemodynamic stability by feeling the pulse, measuring capillary refill, looking at the JVP, auscultating the lung bases, while noting the blood pressure and urine output

Perform a full cardiovascular exam

Obtain IV access and take bloods

Perform ABG if unwell, to assess both oxygenation and his metabolic status

Perform an ECG and place on telemetry

‘The patient is slightly tachycardic (95 bpm), with a normal blood pressure (120/60 mmHg). ECG shows sinus tachycardia. His JVP is not visible, however, on examination he has obvious abdominal distension and bilateral pitting oedema to the knees.’

This patient appears to be fluid overloaded but mildly intravascularly depleted. You prescribe intravenous fluids (human albumin solution or gelofusine) and go on to assess disability.

Prescribe (see Figs 4.4–4.6)

OXYGEN, e.g. 2 L/min via NASAL CANNULAE

Fluids, e.g. HUMAN ALBUMIN SOLUTION 20% 500 mL IV 83 mL/h

Figure 4.4

Figure 4.5

Figure 4.6

Disability

Assess the patient’s conscious level, either using AVPU (is the patient Alert? If not, do they respond to Verbal or Painful stimuli? Or are they Unresponsive?) or GCS. Check glucose

‘The patient is rousable on voice. Blood sugar is 5.8 mmol/L.’

Exposure

Expose the patient, and perform a full examination focusing on signs of chronic liver disease (spider naevi, Dupuytren’s contracture, loss of secondary hair, gynaecomastia) and any obvious precipitating factors of decompensated disease (haemorrhage, sepsis). Assess for evidence of decompensated liver disease (ascites, jaundice, encephalopathy, hepatic flap). Look for evidence of an upper GI/variceal bleed (digital rectal examination). Examine abdomen looking for obvious ascites (shifting dullness) or signs suggestive of peritonism (tender, rigid abdomen, guarding)

‘There are>10 spider naevi in the SVC distribution, with loss of secondary hair and gynaecomastia. The patient is jaundiced. The patient is holding his abdomen in some distress, but there are no signs of peritonism. Abdominal distension with positive shifting dullness is in keeping with ascites.’

You kindly request the nurse to prepare a trolley for an urgent ascitic tap to rule out spontaneous bacterial peritonitis (SBP) while you attempt to find an ultrasound machine.

Initial Investigations

Bloods: Full blood count, U&Es, liver function tests, clotting screen, C-reactive protein, lactate. Patients with alcoholic liver disease are almost invariably thrombocytopaenic, ensure, however, that the platelet count is stable and at least in double figures. Haemogloblin may be low due to anaemia of chronic disease. Liver failure and renal failure are both associated with a low sodium

ABG: Allows assessment of the patient’s metabolic state as well as ventilation/oxygenation. May find a metabolic acidosis secondary to sepsis

CXR: Look for evidence of a lower respiratory tract infection precipitating the patient’s decompensated liver disease. Evidence of an aspiration pneumonia secondary to encephalopathy may also exist. Look for air under the diaphragm, as ‘secondary peritonitis’ may be due to perforated bowel

ECG: Look for evidence of myocardial ischaemia or arrhythmias from electrolyte imbalances, or an acute bleed

Urine dipstick and culture: As part of septic screen

Diagnostic paracentesis: Mandatory in all patients with cirrhosis requiring hospital admission, as part of a general septic screen. It should further be performed in all cirrhotic patients with ascites who have signs and symptoms of peritoneal infection, including the development of encephalopathy, renal impairment, or peripheral leucocytosis without a precipitating factor. Ascitic fluid should be inoculated into blood culture bottles at the bedside. If the neutrophil count is>250 cells/mm³, then treat as spontaneous bacterial peritonitis (SBP)

‘Hb 104 g/L, WCC 16×10⁹/L, platelets 95×10⁹/L, bilirubin 60 µmol/L, ALT 140 IU/L, ALP 180 IU/L, Na 128 mmol/L, K 3.6 mmol/L, urea 6.4 mmol/L, creatinine 90 µmol/L, CRP 170 mg/L, lactate 2.7 mmol/L. Normal clotting. Blood gas shows a metabolic acidosis, with a pH 7.3, a bicarbonate of 19 mmol/L, and PaCO₂of 5 kPa. You are bleeped from the microbiology lab with the ascitic fluid results: neutrophil count>250 cells/mm³, RCC>20 cells/mm³.’

Table 4.2

Mr Reddy’s blood results

Parameter	Value	Normal range (Units)
Hb	104 g/L	Men: 135–180 (g/L) Women: 115–160 (g/L)
WCC	16×10⁹/L	4–11 (×10⁹/L)
Neutrophil	12×10⁹/L	2–7.5 (×10⁹/L)
Lymphocyte	2.7×10⁹/L	1.4–4 (×10⁹/L)
Platelet	95×10⁹/L	150–400 (×10⁹/L)
CRP	170 mg/L	0–5 (mg/L)
Urea	6.4 mmol/L	2.5–6.7 (mmol/L)
Creatinine	90 μmol/L	79–118 (μmol/L)
eGFR	>60 mL/min	>60 (mL/min)
Sodium	128 mmol/L	135–146 (mmol/L)
Potassium	3.6 mmol/L	3.5–5.0 (mmol/L)
Lactate	2.7 mmol/L	0.6–2.4 (mmol/L)
Bilirubin	60 μmol/L	<17 (μmol/l)
ALT	140 IU/L	<40 (IU/L)
ALP	180 IU/L	39–117 (IU/L)
PT	12 seconds	11.5–13.5 seconds
APTT	30 seconds	26–37 seconds
pH	7.3	7.35–7.45
PaO₂	13 kPa	10.6–13.3 (kPa) on air
PaCO₂	5 kPa	4.8–6.1 (kPa)
HCO₃	19 mmol/L	22–26 (mmol/L)

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Nov 18, 2017 | Posted by admin in PHARMACY | Comments Off

Airway

Breathing

Circulation

Disability

Exposure

Initial Management [1]

Airway

Breathing

Circulation

Disability

Exposure

Basicmedical Key

Fastest Basicmedical Insight Engine

Gastroenterology

Gastroenterology

Station 4.1: Severe ulcerative colitis

Initial Assessment

Initial Investigations

Reassessment

Definitive Management

Handing over the Patient

Station 4.2: Spontaneous bacterial peritonitis

Initial assessment

Initial Investigations

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Basicmedical Key

Fastest Basicmedical Insight Engine

Gastroenterology

Gastroenterology

Station 4.1: Severe ulcerative colitis

Initial Assessment

Airway

Breathing

Circulation

Disability

Exposure

Initial Investigations

Initial Management [1]

Reassessment

Definitive Management

Handing over the Patient

Station 4.2: Spontaneous bacterial peritonitis

Initial assessment

Airway

Breathing

Circulation

Disability

Exposure

Initial Investigations

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