Vasopressin in vasodilatory shock: ensure organ blood flow, but take care of the heart!

Supplementary arginine vasopressin infusion in advanced vasodilatory shock may be accompanied by a decrease in cardiac index and systemic oxygen transport capacity in approximately 40% of patients. While a reduction of cardiac output most frequently occurs in patients with hyperdynamic circulation, it is less often observed in patients with low cardiac index. Infusion of inotropes, such as dobutamine, may be an effective strategy to restore systemic blood flow. However, when administering inotropic drugs, systemic blood flow should be increased to adequately meet systemic demands (assessed by central or mixed venous oxygen saturation) without putting an excessive beta-adrenergic stress on the heart. Overcorrection of cardiac index to hyperdynamic values with inotropes places myocardial oxygen supply at significant risk

The relationship between extravascular lung water and oxygenation in three patients with influenza A (H1N1)-induced respiratory failure

Zusammenfassung: Diese Fallsammlung berichtet über die Korrelation zwischen extravaskulärem Lungenwasser (EVLW) und dem arteriellen Sauerstoffpartialdruck/fraktionierten inspiratorischen Sauerstoffkonzentration (PaO2/FiO2) Quotienten bei drei Patienten mit schwerem Influenza A (H1N1)-induziertem Lungenversagen. Alle Patienten erlitten eine ausgeprägte Hypoxie (PaO2, 26-42 mmHg), mussten mit dem Biphasic Airway Pressure Mode (PEEP, 12-15 mmHg; FiO2, 0,8-1) mechanisch beatmet werden und wurden in 12 stündlichen Intervallen in die Bauchlage gedreht. Alle Patienten waren während 8-11 Tagen mit dem PICCO® System monitorisiert. Während der mechanischen Beatmung wurden ingesamt 62 simultane Bestimmungen des PaO2/FiO2 Quotienten und des EVLW durchgeführt. Es zeigte sich ein signifikanter Zusammenhang zwischen dem EVLW und dem PaO2/FiO2 Quotienten (Spearman-rho Korrelationskoeffizient, -0,852; p < 0,001). Bei allen Patienten war eine Abnahme des EVLW von einer Verbesserung der Oxygenation begleitet. Die Serumkonzentrationen der Laktatdehydrogenase waren bei allen Patienten erhöht und korrelierten signifikant mit dem EVLW während des Intensivaufenthaltes (Spearman-rho Korrelationskoeffizient, 0,786; p < 0,001). Zusammenfassend erscheint es, dass das EVLW bei Patienten mit schwerem H1N1-induziertem Lungenversagen erhöht ist und dabei eng mit Einschränkungen der Oxygenationsfunktion korrelier

Comparison of lactated Ringer's, gelatine and blood resuscitation on intestinal oxygen supply and mucosal tissue oxygen tension in haemorrhagic shock

Objectives. To evaluate the effects on intestinal oxygen supply, and mucosal tissue oxygen tension during haemorrhage and after fluid resuscitation with either blood (B; n=7), gelatine (G; n=8), or lactated Ringer's solution (R; n=8) in an autoperfused, innervated jejunal segment in anaesthetized pigs. Methods. To induce haemorrhagic shock, 50% of calculated blood volume was withdrawn. Systemic haemodynamics, mesenteric venous and systemic acid-base and blood gas variables, and lactate measurements were recorded. A flowmeter was used for measuring mesenteric arterial blood flow. Mucosal tissue oxygen tension (PO2muc), jejunal microvascular haemoglobin oxygen saturation (HbO2) and microvascular blood flow were measured. Measurements were performed at baseline, after haemorrhage and at four 20 min intervals after fluid resuscitation. After haemorrhage, animals were retransfused with blood, gelatine or lactated Ringer's solution until baseline pulmonary capillary wedge pressure was reached. Results. After resuscitation, no significant differences in macrohaemodynamic parameters were observed between groups. Systemic and intestinal lactate concentration was significantly increased in animals receiving lactated Ringer's solution [5.6 (1.1) vs 3.3 (1.1) mmol litre−1; 5.6 (1.1) vs 3.3 (1.2) mmol litre−1]. Oxygen supply to the intestine was impaired in animals receiving lactated Ringer's solution when compared with animals receiving blood. Blood and gelatine resuscitation resulted in higher HbO2 than with lactated Ringer's resuscitation after haemorrhagic shock [B, 43.8 (10.4)%; G, 34.6 (9.4)%; R, 28.0 (9.3)%]. PO2muc was better preserved with gelatine resuscitation when compared with lactated Ringer's or blood resuscitation [20.0 (8.8) vs 13.8 (7.1) mm Hg, 15.2 (7.2) mm Hg, respectively]. Conclusion. Blood or gelatine infusion improves mucosal tissue oxygenation of the porcine jejunum after severe haemorrhage when compared with lactated Ringer's solutio