Objectives Discuss –basic blood tests –ABGs Use some case examples and practice some sample questions Questions
Why do blood tests? Haematinics Nutritional status Exposure to toxic substances Markers of infection Hydration status Renal function Baseline before treatment Etc…
What blood tests are available to us? Full blood count –Red cells, white cells, platelets Urea and electrolytes –Sodium, potassium, urea, creatinine Liver function tests –Bilirubin, total protein, albumin, ALP,ALT,GGT Inflammatory markers –CRP, ESR Thyroid function tests –TSH, T4,T3
Others Troponin I Calcium/magnesium/phosphate Glucose Amylase Clotting/INR/APTT
Patterns in disease Infective process e.g. Strep Pneumonia –WCC - neutrophillia –CRP Anaemia –Macrocytic - High MCV –Microcytic - Low MCV –Normocytic - Normal MCV
Metabolic acidosis - pH , CO2 (N) HCO3 –With respiratory compensation, CO2 may be Metabolic alkalosis - pH , CO2 (N), HCO3 –With respiratory compensation, CO2 may be Respiratory acidosis - pH , CO2 HCO3 (N) –With metabolic compensation, HCO3 may be Respiratory alkalosis - pH , CO2 , HCO3 (N) –With metabolic compensation, HCO3 may be
Case studies A 60 year old man was admitted with an exacerbation of chronic obstructive pulmonary disease. His arterial blood gases on air showed: pH 7.29 7.35-7.45 PaCO2 8.5 kPa 4.7-6.0 Pao2 8.0 kPa10-13 HCO3 30.5 mmol/l. 22-30 What is the acid-base disturbance and what is the management?
Respiratory Acidosis –Type 2 failure Treatment is nebulisers/steroids/NIV
A 45 year old lady with previous peptic ulcer disease was admitted with persistent vomiting. She looked dehydrated. Her blood results were sodium 140 mmol/l 135-145 potassium 2.5 mmol/l 3.5-5.5 pH 7.5 7.35-7.45 Paco2 6.0 kPa4.7-6.0 Pao2 14 kPa 10-13.0 HCO3 40 mmol/l. 22-30 What is the acid-base disturbance and why? How would you treat this patient?
This patient had alkalosis due to a high standard bicarbonate-metabolic alkalosis. The PaCO2 was appropriately low in compensation. This was hypokalaemic hypochloraemic metabolic acidosis because of potassium and chloride loss from vomiting. Treatment was of the underlying cause (pyloric stenosis) and intravenous sodium chloride with potassium.
A 58 year old lady recently underwent a left hemicolectomy for cancer. 4 days later she complained of substernal abdominal pain,was nauseous and sweaty. Her gases showed: pH 7.1 7.35 - 7.45 PCO2 - 3.54.7 - 6.0 PO2 - 18.310 - 13.0 HCO3 - 1322 - 30 BE - -12-2 - +2 What would you do now? How would you manage this lady?
Practice questions 79 year old man started on diuretics for hypertension 2 weeks ago presents with a seizure. Bloods: –FBC, Ca2+ (N) –U+Es »Na 107 »K 3.1 »U 7.2 »Cr 122 Diagnosis? Hyponatraemia secondary to diuretic use
17 year old presents with confusion, dehydration, fever. T39.5, HR 120, BP 100/50. –Bloods –FBC: Hb 13.0, WCC 19.2, Plt 180 –U+Es: Na 147, K 5.1, U 26.2, Cr 208 –Gluc: 34.9 Diagnosis? Diabetic Ketoacidosis
47 year old lady presents with abdominal pain. Lost 3 stones over 6 months. On examination she has a palpable gallbladder. Bloods FBC - Hb 8.1, MCV 69, WCC 7.5 U+Es - Na 135, K 3.4, U 7.2, Cr 145 LFTs - Bili 190, ALP 360, ALT 55, GGT 450 Diagnosis? Obstructive Jaundice likely secondary to malignancy
28 year old Nigerian man presents to casualty jaundiced with vomiting, diarrhoea. History of flu like symptoms 2 weeks previously. –LFTs - bilirubin 43, ALP 96, ALT 1522, GGT 45. INR 1.2 Diagnosis? Hepatitis A most likely
61 year old arteriopath presents having recently been started on ACE inhibitors, with confusion and pruritis. –FBC normal –U+Es - Na 130, K 7.4, Ur 37, Cr 841 Diagnosis? Renal artery stenosis
35 year old presents with diarrhoea, sweating and palpitations. –FBC (N) –U+E (N) –TFTs: TSH 0.01, T4 250 Diagnosis? Hyperthyroidism- Graves disease