Acid base and blood gas analyser Vocabulary warm-up 1 Match the words in English with their translations: 1 unknown a) ponořit 2 inner side b) tenká vrstva 3 coated c) dosáhnout 4 immerse d) neznámý 5 plastic jacket e) nylonová síťka 6 basically f) vnitřní strana 7 nylon net g) plastikový obal 8 uncharged molecules h) tím 9 pass through i) v zásadě 10 thin layer j) projít skrz 11 reach k) nenabité molekuly, molekuly bez náboje 12 thereby l) potažený Reading 1 Practice pronouncing the following terms: chloride – silver chloride – bicarbonate – carbon dioxide – acid – acidic – solution – equilibrium – diffuse – electrolyte – electrolysis – micrometer – electrode – oxygen – nitrogen – hydrogen – ion – proton 2 Read the text and complete the gaps with the words from the box: electrode uncharged partial analysers diffuse electrolyte solution Most acid base and blood gas ___________(1) measure pH, pCO[2], pO[2] by means of selective electrodes. pH electrode A pH electrode is a glass ________(2) with a pH-sensitive glass membrane to seal its tip. On the inner side of the membrane is a buffer solution with constant pH. A silver wire coated with AgCl is immersed in this solution and, via a plug, connected to the measuring instrument. On the other side of the glass membrane is a ___________(3) of unknown pH (the sample). pCO[2] electrode pCO[2] is defined as the _________ (4) pressure of CO[2] in a gas phase in equilibrium with the blood, and is measured by a pCO[2] electrode. A pCO[2] electrode is a combined glass and silver/silver chloride (Ag/AgCl) reference electrode placed in a plastic jacket, which is filled with a bicarbonate_________ (5). The jacket is covered with a 20 μm silicon membrane placed on a 50 μm nylon net. The pCO[2] electrode is basically a pH electrode with a silicon membrane added. This membrane allows only ___________(6) molecules (i.e. CO[2], O[2], N[2]) to pass through it. Charged ions, such as H^+, will not pass. Consequently, dissolved CO[2] from the sample will __________(7) into the thin layer of bicarbonate electrolyte until equilibrium is reached. 2 Now answer these questions: 1 What are the electrodes made of? 2 Where on the electrode is the glass membrane? 3 Does the pH in the buffer solution change? 4 What is the role of the silver wire? 5 Where is the bicarbonate electrolyte situated? 6 What is the difference between a pCO[2] electrode and a pH electrode? 7 What kind of molecules pass through the silicon membrane? 8 How long do the CO[2] molecules move into the bicarbonate electrolyte? Listening A Pre-listening warm-up. Put the words in the correct order. 1 blood do a gas 2 sure gloves you have your make on 3 in password put your 4 machine put syringe into the the 5 hit “analyse” button the 6 the for patient ask ID 7 scanner use a 8 it manually put in 9 syringe the remove 10 the sharps syringe in container a discard B Watch and answer these questions: 1 What is the first thing you should do before running the test? 2 Does the machine require a password? 3 Which type of blood is being tested? 4 How can you read the patients ID? 5 How long does the testing take? 6 How do you know the test is over? 7 How do you get your results? 8 What do you have to do with the syringe? 9 What is the last thing you do? Grammar point A Adjectives and Adverbs – Comparison Complete the sentences using comparative or superlative forms: 1. This coffee is very weak. I like it a bit …. ......... 2. The hotel was surprisingly big. I expected it to be …. …………… 3. The hotel was surprisingly cheap. I expected it to be …. ……………… 4. Don’t worry. The situation isn’t so bad. It could be …. ……………. 5. This is the …. film I have ever seen. 6. You were a bit depressed yesterday, but you look …............... today. (good) 7. My mother is ……………….. than my father. (old) 8. Our shop has the …. …………….prices. (low) 9. Frying is the ……………... way of cooking. (healthy) 10. Spring is …………………. of the four seasons. (beautiful) B Modified comparison