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V Dörges

Publications and source records attributed to V Dörges.

25 records · Page 2Linked to original sources

Optimisation of tidal volumes given with self-inflatable bags without additional oxygen.

The European Resuscitation Council has recommended smaller tidal volumes of 500 ml during basic life support ventilation in order to minimise gastric inflation. One method of delivering these tidal volumes may be to use paediatric instead of adult self-inflatable bags; however, we have demonstrated in other studies that only 350 ml may be delivered, using this technique. The reduced risk of gastric inflation was offset by oxygenation problems, rendering the strategy of attempting to deliver tidal volumes of 500 ml with a paediatric self-inflatable bag questionable, at least when using room-air. In this report, we assessed the effects of a self-inflatable bag with a size between the maximum size of a paediatric (700 ml) and an adult (1500 ml) self-inflatable bag on respiratory variables and blood gases during bag-valve-mask ventilation. After induction of anaesthesia, 50 patients were block-randomised into two groups of 25 each. They were ventilated with room-air with either an adult (maximum volume, 1500 ml) or a newly developed medium-size (maximum volume, 1100 ml; Dräger, Lübeck, Germany) self-inflatable bag for 5 min before intubation. When compared with the adult self-inflatable bag, the medium-size bag resulted in significantly lower exhaled tidal volumes and tidal volumes per kg bodyweight (624 + 24 versus 738 +/- 20 ml, and 8.5 +/- 0.3 versus 10.7 +/- 0.3 ml kg(-1), respectively; P < 0.001), oxygen saturation (95 +/- 0.4 versus 96 +/- 0.3%; P < 0.05), and partial pressure of oxygen (78 +/- 3 versus 87 +/- 3 mmHg; P < 0.05). Carbon dioxide levels were comparable (37 +/- 1 versus 37 +/- 1 mmHg). Our results indicate that smaller tidal volumes of about 8 ml x kg(-1) (approximately 600 ml), given with a new medium-size self-inflatable bag and room-air, maintained adequate carbon dioxide elimination and oxygenation during bag-valve-mask ventilation. Accordingly, the new medium-size self-inflatable bag may combine both adequate ventilatory support and reduced risk of gastric inflation during bag-valve-mask ventilation.

Adult↗

Smaller tidal volumes with room-air are not sufficient to ensure adequate oxygenation during bag-valve-mask ventilation.

The European Resuscitation Council has recommended decreasing tidal volume during basic life support ventilation from 800 to 1200 ml, as recommended by the American Heart Association, to 500 ml in order to minimise stomach inflation. However, if oxygen is not available at the scene of an emergency, and small tidal volumes are given during basic life support ventilation with a paediatric self-inflatable bag and room-air (21% oxygen), insufficient oxygenation and/or inadequate ventilation may result. When apnoea occurred after induction of anaesthesia, 40 patients were randomly allocated to room-air ventilation with either an adult (maximum volume, 1500 ml) or paediatric (maximum volume, 700 ml) self-inflatable bag for 5 min before intubation. When using an adult (n=20) versus paediatric (n=20) self-inflatable bag, mean +/-SEM tidal volumes and tidal volumes per kilogram were significantly (P<0.0001) larger (719+/-22 vs. 455+/-23 ml and 10.5+/-0.4 vs. 6.2+/-0.4 ml kg(-1), respectively). Compared with an adult self-inflatable bag, bag-valve-mask ventilation with room-air using a paediatric self-inflatable bag resulted in significantly (P<0.01) lower paO(2) values (73+/-4 vs. 87+/-4 mmHg), but comparable carbon dioxide elimination (40+/-2 vs. 37+/-1 mmHg; NS). In conclusion, our results indicate that smaller tidal volumes of approximately 6 ml kg(-1) ( approximately 500 ml) given with a paediatric self-inflatable bag and room-air maintain adequate carbon dioxide elimination, but do not result in sufficient oxygenation during bag-valve-mask ventilation. Thus, if small (6 ml kg(-1)) tidal volumes are being used during bag-valve-mask ventilation, additional oxygen is necessary. Accordingly, when additional oxygen during bag-valve-mask ventilation is not available, only large tidal volumes of approximately 11 ml kg(-1) were able to maintain both sufficient oxygenation and carbon dioxide elimination.

Adult↗

[Intraoperative management of unexpected arterial hypotension during lumbar diskectomy].

An anesthesiological management is difficult in surgical procedures in which the operative situs is not to be seen by the anesthesist. Therefore specific knowledge of the operative procedure and related hazards are mandatory for optimal anesthesiological care. By describing the anesthesiologic proceduces in two lumbar discectomys, the specific problems in recognition and treatment of severe injuries of retroperitoneal vascular structures are explained. In addition, the differential diagnosis of intraoperative arterial hypotension is described. The communication between all disciplines involved is mandatory, especially in cases of severe complications. The management of such complications can only be solved through in-time interdisciplinary cooperation of all involved disciplines.

Aged↗

Effects of smaller tidal volumes during basic life support ventilation in patients with respiratory arrest: good ventilation, less risk?

OBJECTIVE: When ventilating an unintubated patient in cardiac or respiratory arrest, smaller tidal volumes of 500 ml instead of 800-1200 ml may be beneficial to decrease peak airway pressure, and to minimise stomach inflation. The purpose was to determine the effects of small (approximately 500 ml) versus large (approximately 1000 ml) tidal volumes given with paediatric versus adult self-inflatable bags and approximately 50% oxygen on respiratory parameters in patients during simulated basic life support ventilation. METHODS: While undergoing induction of anaesthesia, patients were randomised to three minutes of ventilation with either an adult (n = 40) or paediatric (n = 40) self-inflatable bag. RESULTS: When compared with an adult self-inflatable bag, the paediatric bag resulted in significantly lower mean (+/- standard deviation) exhaled tidal volume (365 +/- 55 versus 779 +/- 122 ml; P < 0.0001), peak airway pressure (20 +/- 2 versus 25 +/- 5 cm H2O; P < 0.0001), but comparable oxygen saturation (97 +/- 1% versus 98 +/- 1%; NS (nonsignificant)). Stomach inflation occurred in five of 40 patients ventilated with an adult self-inflatable bag, but in no patients who were ventilated with a paediatric self-inflatable bag (P = 0.054). CONCLUSION: Administering smaller tidal volumes with a paediatric instead of an adult self-inflatable bag in unintubated adult patients with respiratory arrest maintains good oxygenation and carbon dioxide elimination while decreasing peak airway pressure, which makes stomach inflation less likely.

Adult↗

[Behavior of free catecholamines in blood and urine of ambulance men and physicians during quick responses].

Free urine adrenaline, noradrenaline, (additional free plasma catecholamines in the physicians), and blood lactate were determined in 11 ambulance men and 5 physicians to assess stress during medical service. Stress was evaluated employing a stress index, based on difficulties in driving, traffic, severity of injuries or illness. Emergency cases with seriously injured subjects or reanimation were judged to have a 4-fold higher stress index than routine cases where strong physiological or psychological stress was absent. Urine catecholamines and stress indices were estimated in 3-h intervals. The calculations were based on the stress induced catecholamine concentrations minus the basal excretion during the same 3-h interval. Urine adrenaline and noradrenaline in ambulance men and physicians correlated directly with the stress index, as well as the plasma catecholamines of the physicians. Lactate levels showed similar behaviour and a descriptive direct correlation with the plasma catecholamines. Urine adrenaline increased more--dependent on the stress index--than urine noradrenaline. This over-proportional adrenaline response may be an indicator for the additional psychological stress in emergency cases. Therefore physicians showed--based on the same stress index--a tendency to higher urine adrenaline excretion and blood lactate levels than the ambulance men, which might be the consequence of the overall responsibility of the physicians. Because of the observed catecholamine responses during medical service, coronary insufficiency or hypertension might be contra-indications for participation in the medical service; regular clinical investigations including ergometric tests are advisable.

Adult↗