Table 1 Experimental setup.

1. Induction of inhalation anesthesia with 2% isoflurane

2. Placement of intravenous access at one ear

3. Intravenous sedation with midazolame 0.1 mg/kg. Continuous infusion with ketamine (1 ml + 9 ml NaCl 0.9%): 0.6 ml/h → 6 mg/h, midazolame (purely) 0.6 ml/h → 3 mg/h. Monitoring using ECG and pulse oximetry at all four extremities

4. Placement of second venous access at the other ear

5. Intravenous parenteral dextrose infusion with Pädiafusin® I/Ringer®-Lsg. (Baxter, Unterschleißheim, Germany). Premedication for intubation with pentobarbital (1 ml + 15 ml NaCl 0.9%) 1 ml → 10 mg intravenously, fentanyl (1 ml + 9 ml NaCl) 2 ml → 10 mg intravenously

6. Intubation with 3.5 mm endotracheal tube with surfactant channel up to tag 11

7. Initial ventilation via manual ventilation bag, then with respirator (frequency 40, p max 15, flow 8, PEEP 5), later p max 10 over 60 min

8. Vital parameter measurement: conventional via ECG and pulse oximetry and via MIM. Measurement of arterial access with subsequent BGA monitoring of respiratory settings. Blood pressure monitoring via arterial access

9. Malposition of endotracheal tube: ventilation of animal is stopped five times each for 1 min, while vital parameters are measured both conventionally and via MIM

10. Atelectasis: the tube is introduced into the right lung → position check via X-ray. Synchronously, vital parameters are measured conventionally and by MIM in different positions. Thereafter, the “reopening” of the lung is documented via electrical impedance tomography if possible

11. Pneumothorax: placement of an intrapleural catheter, position check via X-ray. Then, intrapleural insufflation of 20 ml of air → radiological check of the degree of pneumothorax

12. Aspiration: 20 ml of NaCl 0.9% is applied intrapleurally and 10 ml is applied intrapulmonarily via surfactant channel

13. Finalization of the animal experiment with 70 mg of pentobarbital intravenously

During monitoring, as required:

Bolus midazolame = 0.5 ml ≙ 0.5 mg

Bolus ketamine = 0.4 ml ≙ 4 mg

Bolus fentanyl = 2 ml ≙ 10 µg

Bolus pentobarbital = 1 ml ≙ 10 mg

Continuous infusion: 10 ml of ketamine in 50 ml (concentration 10 mg/ml); 10 ml midazolame in 50 ml (concentration 5 mg/ml)

Bolus administration:

• 20 ml syringe midazolame (concentration 1 mg/ml); 20 ml syringe ketamine (concentration 10 mg/ml)

• 20 ml syringe fentanyl (concentration 5 µg/ml)

• 20 ml syringe pentobarbital (concentration 10 mg/ml)

• Midazolame (Dormicum®) (pure) 5 mg/ml® 1 ml + 4 ml NaCl 0.9% for 1 mg/ml

• Ketamine (pure) 100 mg/ml® 1 ml + 9 ml NaCl 0.9% for 10 mg/ml

• Fentanyl (pure) 50 µg/ml® 1 ml + 9 ml NaCl 0.9% for 5 µg/ml

• Pentobarbital (Narcoren®) (pure) 160 mg/ml; 1 ml + 15 ml NaCl 0.9% for 10 mg/ml