Laboratory in emergency settings POCT testing. Zsolt Baranyai MD

Transcription

1 Laboratory in emergency settings POCT testing Zsolt Baranyai D

2 Acute abdominal catastrophe The definition of acute abdomen describes imminent and potentially life-threatening abdominal diseases, that require prompt intervention As time is short, concentrate only on most urgent examinations Emergency surgery is required most often due to abscess formation and sepsis (40-50%), ileus (10-30%), intestinal perforation (10-15%) The mortality rate is highest in perforations (20-25%).

3 Acute abdominal catastrophelaboratory examinations 1. Consider in the blood count only the increasing or the already elevated WBC, especially, if you see left shift Low levels suggest viral infection (e.g. mesenterial lymphadenitis, gastroenteritis) 2. Hemoglobin and hematocrite are especially useful, if bleeding is suspected 3. In all cases CRP (C-reactive protein) has to be done: already at the beginning of bacterial infections it increases rapidly 4. Further important tests Serum electrolytes, creatinine, BUN (blood urea nitrogen) (hypovolemia, vomiting, diarrhoea), ABG (arterial blood gas analysis (hypoxia, shock, peritonitis, metabolic acidosis), serum amylase and lipase (pancreatitis), serum lactate (sepsis, pancreatitis, bowel infarction), liver enzymes, coagulation tests, urinalysis (kidney or ureter stone, inflammation) (protein, bilirubin, glucose or ketones).

4 Differential diagnosis

5 Secondary bacterial peritonitis ost common causes: perforation of abdominal hollow organs (stomach, bowels, gall bladder), bowel infarction, infections in the small pelvis, and suture insufficiency 1. Chemical irritation Sterile bile, rupture of the urinary bladder Gastric, duodenal perforation 6-12 hours Bacterial peritonitis gastric perforation 2. ixed bacterial flora Distal section of the small intestines - 30% aerobic, 10% anaerobic Appendix, colon, rectum - anaerobic (Gram negative) Severity influenced by: number and type of bacteria, general health status, immune status, duration of the infection

6 Secondary bacterial peritonitis Arterial blood gas analysis, coagulation tests (coagulopathia) Kidney and liver function tests elevated WBC increased CRP thrombocytopenia hyper-, then hypoglycemia procalcitonine levels - infectious/ non-infectious origin - correlate with the severity of the infection (in sepsis it attains 500 ng/ml)

7 Acute pancreatitis The disease is diagnosed based on the increased pancreatic enzymes (amylase and lipase at least 3x) and the clinical symptoms amylase levels do NOT correlate with the severity of the disease amylase may increase also in other diseases presenting as acute abdomen (mesenterial ischaemia, ileus, ulcer, cholecystitis) sensitivity and specificity of lipase exceeds those of amylase increased lipase is characteristic mainly for alcoholic pancreatitis

8 Acute pancreatitis Certain serum parameters (markers) reflect the severity of the inflammation and indicate the possibility of necrosis Check C-reactive protein; one criterium for severe pancreatitis is if CRP exceeds 150 mg/l Procalcitonine is a well-applicable prognostic marker, - its increase forewarns of the severity of the disease already in the first 48 hours, - it s sensitive for the bacterial infection of the necrotized glandular tissue - parallelly with septic symptoms its elevated value (over 5 ng/ml) confirms the superinfection of the necrosis

9 Acute pancreatitis serum calcium is low ( mmol/l) glucose elevated triglycerid markedly increased (10-15 mml/l) systemic inflammation: Erythrocyte sedimentation rate CRP WBC count Fat necrosis Necrtotizing pancratitis

10 Acute appendicitis the white blood cell count typically increases to , (in elderly it s often not present) elevation of CRP Catarrhal appendicitis Phlegmonous appendicitis Gangraenous appendicitis

11 Case report

12 Acute appendicitis Differential diagnosis Peptic ulcer, pancreatitis, tumor of the cecum, ureteral stone, terminal ileitis, cholecystitis, pyelonephritis, diseases of eckel s diverticulum, enterocolitis, stenosing diseases of the colon, obturator hernia or other internal hernias, lower lobe pneumonia, mesenterial tosion, mesenterial infarction, epiploic artery infarction, arterial and/or venous mesenterial diseases. Gynecological conditions: adnexitis, extrauterine gravidity, torsion of ovarian cyst, corpus luteum rupture. urine (urinalysis + sediment) Urolithiasis on the right side

13 Liver dysfunction Hyperbilirubinemia Increase of indirect bilirubin Increase of direct bilirubin Hemolysis? Increase of ALT, AST > Increase of ALP, γ-gt Yes No Yes No DIC, TTP, HUS, autoimmune origin, erythrocyte membrane or enzyme disorder, abnormal form of hemoglobin Physiological jaundice, breast milk feeding, Gilbert s syndrome, Crigler-Najjar s syndrome Viral hepatitis, autoimmune hepatitis, toxins, alcohol, Wilson s disease Cholestasis, cholangitis, biliar carcinoma Common origin: Pancreatitis, pancreatic carcinoma, liver tumor

14 Cholecystitis The process can be characterized by bacterial invasion and acute inflammation of the tissues, bacteria can be cultured from bile. WBC count is markedly elevated, serum bilirubin is moderately elevated alcalic phosphatase is increased

15 Choledocholithiasis Stones in the common bile duct origin mainly from the gallbladder Primary bile duct stones develop over bile duct stenosis due to biliary stasis and bacterial superinfection Charcot s triad: cramps, jaundice, fever. In 50% of bile duct stones jaundice is present. alcalic phosphatase serum bilirubin level?

16 Obstructive jaundice bile stone (40%) malignant tumor (35%) benign stenoses, external compression (20%) congenital and inflammatory causes (5%) serum bilirubin (direct/indirect) urine bilirubin alcalic phosphatase gamma-gt serum transaminase enzymes prothrombin time

17 Gastrointestinal bleeding Hematemesis elena Hematochezia Blood can get secondarily in the gastrointestinal tract (nose, pharynx, bronchi, trachea, lungs etc.) Occult bleeding: daily blood loss is less than ml assive bleeding: bleeding causes shock

18 Gastrointestinal bleeding regular monitoring of blood count*, blood (group) typing, coagulation parameters, liver function tests, pregnancy test in young women (extrauterine gravidity!) *Hematocrite alone is not decisive, because there is not enough time for the blood becoming attenuated hematocrite can be even normal

19 Clinical one-sided blood typing One-sided only the antigenic properties of the erythrocytes are examined It is based on the antigen-antibody reaction with the anti-a, anti-b and anti-ab test serum leading to hemagglutination One drop of saline should be given to the dried antibodies, then one drop of blood to each field.

20 Blood type Laboratory or double-sided blood typing Test sera and evaluated red blood cell Test RBCs and evaluated serum anti-a anti-b anti-ab A1 A2 B A B AB Rh-determination One drop of 50% RBC and serum suspension of the evaluated sample is given to one drop of anti-d (Ig) serum

21 Urgent blood transfusion ay be necessary due to major bleeding and the consequent rapid volume loss Biologic testing cannot be evaluted as usual Clinical blood typing of the donor and the recipient cannot be quit even in emergency When there is no time for even the the bedside serologic test, the transfusion has to be done with O, RhD negative blood (max. 2 units!) Obtain blood before starting the transfusion for the laboratory Risk of mistakes increases

22 Case report 56 year old male Signs of hemorrhagic shock after successful operation due to hiatal hernia Urgent endoscopy is unsuccessful, because there is so much blood in the stomach, that it cannot be sucked out, and therefore, the source of bleeding cannot be defined Urgent operation RBC count 1.03x10 12 /l, Hb 24 g/l, Hct 0.08, CV 75.7, CHC 308 g/l, Platelets 365x10 9 /l, WBC count 12.5x10 12 /l.

23 Case report

24 Urolithiasis Stones cause complaints due to the irritation of the mucosa Heavy pain starting suddenly in the kidney area radiating to the inguinal region along the ureter Colic develops if the stone gets stuck in the ureter, while urine is still produced in the kidneys, because stasis will occur in the renal pelvis. The secondary smooth muscle spasm due to the stasis causes pain. Fever and chills will develop, if the urine is infected and the increased pressure presses the bacteria in the kidney parenchyma.

25 Renal colic Hematuria - Other urinary condition may also cause; malignant tumors, infections - First colic followed by hematuria - 1 ml blood in 1000 ml urine presents already as macroscopic hematuria Urine - Nitrites content suggests bacteria Blood sample - Ca, P and uric acid to exclude metabolic origin - Qualitative blood count, platelet count, ESR - CRP, procalcitonine

26 Ectopic pregnancy Acute rupture of the fallopian tube sudden, severe pain in the lower abdomen backpain bleeding from the uterus (80 %) resistence on examination (70 %) collapse, shock Lab tests Pregnancy test Beta-HCG Blood count

27 Case report Haemoglobin count 12.3 x 10 3 g/l, white cell was 7.5 x 10 9 g/l

28 POCT: Point of care testing It consists of all lab tests that are done outside traditional central laboratories: for example directly at the bedside on the ward, in a family doctor practice in primary care or at home performed by the patient.

29 History - Urine test strip - Blood glucose test strips

30 POCT categories Bedside testing Self monitoring POCT Critical care testing Special testing

31 Bedside testing fecal occult blood test, serological tests, crossmatching (detection of blood group-incompatibility), glucose test, monitoring of ESR, general urinalysis Serve our comfort Relieve the load of central laboratories

32 Critical care testing One condition of the succesful treatment of critical care patients is the fast and continuous monitoring of their vital functions and laboratory parameters. blood ph and ABG, sodium, potassium, calcium, glucose, lactate, hemoglobin, hematocrite, osmolality, basic coagulation parameters

33 ABG

34 Self monitoring Glucose test Non-invasive blood glucose monitor LH (ovulation test) HCG (pregnancy test Glucose and lactate test Continuous Lactate monitoring designed for athletes

35 POCT for special testings Smaller offices Blood count, urinalysis, Fecal occult blood test, glucose, HbA1c, cholesterol, triglyceride, CRP, Prothrombin time Alcohol breath test Allergy Total IgE, specific IgE Active agents of biological or chemical weapons

36 Capillary sampling on adults for blood gas analysis

37 POCT and the future Today almost 50 to 60 parameters can be measured with POCT technique In certain countries (e.g. Scandinavian countries) 30-40% of all lab tests are done with POCT This ratio may increase to 50-60% in the near future