How do COPD and healthy-lung patients tolerate the reduced volume ventilation strategy during OLV ventilation.

BACKGROUND: Although a strategy of tidal volume (V(t)) reduction during the one-lung ventilation (OLV) period is advised in thoracic surgery, the influence of the pre-operative respiratory status on the tolerance of this strategy remains unknown. Therefore, the aim of this study was to compare the pulmonary function between chronic obstructive pulmonary disease (COPD) and healthy-lung patients during the operative and the post-operative period. METHODS: Forty-eight patients undergoing a planned lobectomy for cancer and presenting either a healthy lung function (n=24) or a moderate COPD stage (n=24) were ventilated without external positive end-expiratory pressure (PEEP) and received 9 ml/kg V(t) during the two-lung ventilation (TLV) period, secondary reduced to 6 ml/kg during the OLV period. Lung function was assessed by peroperative gas exchange, venous admixture, respiratory mechanical parameters and post-operative spirometric measurements. RESULTS: Although the PaO(2) was superior in the healthy-lung group during the TLV, once the OLV was established, no difference was observed between the two groups. Moreover, the PaO(2)/FiO(2) was proportionally more impaired in the healthy-lung group compared with the COPD group (50 ± 13 vs. 72 ± 19% of the baseline values after exclusion and 32 ± 15 vs. 51 ± 25% after the thoracotomy, P<0.05 for each) as well as the venous admixture. In the post-operative period, a higher decrease was observed in the healthy-lung group for the forced vital capacity and the forced expiratory volume. CONCLUSIONS: Reducing V(t) to 6 ml/kg without the adjunction of external PEEP during OLV is associated with better preservation of lung function in the case of moderate COPD than in the case of healthy-lung status.

Adding ketamine to morphine for patient-controlled analgesia after thoracic surgery: influence on morphine consumption, respiratory function, and nocturnal desaturation.

BACKGROUND: I.V. patient-controlled analgesia (PCA) with morphine is often used for postoperative analgesia after thoracic surgery, but the required doses may increase postoperative respiratory disorders. Adjunction of ketamine could reduce both doses and related respiratory side-effects. METHODS: The main objective of this prospective, randomized double-blinded study was to evaluate the influence of adding ketamine to PCA on morphine consumption and postoperative respiratory disorders. Consecutive patients undergoing lobectomy (n = 50) were randomly assigned to receive, during the postoperative period, either i.v. morphine 1 mg ml(-1) or morphine with ketamine 1 mg ml(-1) for each. Morphine consumption was evaluated by cumulative doses every 12 h for the three postoperative days. Postoperative respiratory disorders were assessed by spirometric evaluation and recording of nocturnal desaturation. RESULTS: The adjunction of ketamine resulted in a significant reduction in cumulative morphine consumption as early as the 36th postoperative hour [43 (SD 18) vs 32 (14) mg, P = 0.03] with a similar visual analogue scale. In the morphine group, the percentage of time with desaturation < 90% was higher during the three nights [1.80 (0.21-6.37) vs 0.02 (0-0.13), P < 0.001; 2.15 (0.35-8.65) vs 0.50 (0.01-1.30), P = 0.02; 2.46 (0.57-5.51) vs 0.55 (0.21-1.00), P = 0.02]. The decrease in forced expiratory volume in 1 s was less marked in the ketamine group at the first postoperative day [1.04 (0.68-1.22) litre vs 1.21 (1.10-0.70) litre, P = 0.039]. CONCLUSIONS: Adding small doses of ketamine to morphine in PCA devices decreases the morphine consumption and may improve respiratory disorders after thoracic surgery.

Effect of thoracic epidural analgesia on gastric blood flow after oesophagectomy.

BACKGROUND: The oesophagectomy procedure includes the formation of a gastric tube to re-establish the continuity of the gastrointestinal tract. The effect of thoracic epidural analgesia (TEA) on gastric mucosal blood flow (GMBF) remains unknown in clinical practice. The aim of this prospective observational study was to assess the microcirculatory changes induced by TEA in the early post-operative course. METHODS: Eighteen consecutive patients who underwent radical oesophagectomy with en-bloc resection and two-field lymphadenectomy for oesophageal cancer, and benefited from TEA during the post-operative course, were studied prospectively, and compared with nine patients who declined the use of TEA in the same period (control group). GMBF was measured using a laser Doppler flowmeter in three consecutive time periods (before and after 1 and 18 h of TEA infusion). Post-operative monitoring also included the measurement of arterial pressure, cardiac output, gas exchange and intrathoracic blood volume index. RESULTS: After the first and 18th hour of infusion, TEA induced an increase in GMBF compared with baseline and the control group. The mean arterial pressure and intrathoracic blood volume index decreased after the first hour of TEA infusion with no influence on the cardiac index. CONCLUSIONS: This clinical study demonstrates that TEA improves the microcirculation of the gastric tube in the early post-oesophagectomy period. The clinical relevance of TEA in this setting should be validated in larger studies focusing on the clinical outcome following oesophagectomy.

[Medium and long-term results of anatomical correction of transposition of the great arteries in Marseille]. / Résultats à moyen et long terme de la correction anatomique de la transposition des gros vaisseaux à Marseille.

The object of this study was to evaluate the results of anatomical correction of transposition of the great arteries (TGA) in an inter-regional centre. The characteristics of 220 patients operated between 1985 and 2002 were analysed. Prenatal diagnosis of TGA was made in 38 patients (17%) including 36 of the 109 patients operated since 1995 (33%) and leading to earlier atrial septostomy in this situation (p= 0.046). Since 1995, the global early mortality of 12.3% has been significantly reduced to 5.5% (N= 6) including 4.4% (3/68 cases) of simple TGA (p= 0.002). In multivariate analysis, the only independent risk factor for early mortality was the occurrence of a major per-operative complication (p< 0.0001). The average follow-up was 4.8 +/- 4.5 years with an 86% survival at 5, 10 and 15 years and 97% survival at 5 years for patients operated after 1995. There were 22 reoperations including 14 on the right ventricular outflow tract. The non-reoperation rate at 10 years was 80% for simple TGA versus 70% in complex TGA (p= 0.0001). Survivors are asymptomatic with a normal ECG and normal LV function on echocardiography. Five patients have significant pulmonary stenosis and 4 have mild aortic regurgitation. The exercise stress tests performed between the ages of 7 and 10 were all normal. The authors conclude that that modern and reproducible management of TGA is possible in an inter-regional centre with results comparable to those of surgical centres of reference.

[Deep lactic acidosis after valproate self-poisoning]. / Acidose lactique majeure secondaire à une intoxication volontaire par valproate.

A sixty-year-old woman was admitted in the ICU after Depamide (Valpromide) self-poisoning (430 mg/kg). Four hours after the ingestion, the patient presented coma (Glagow coma score of 3) with bilateral mydriasis requiring tracheal intubation and mechanical ventilation, hypotension requiring epinephrine infusion (0.9 microg/kg per minute), acidosis and hyperlactatemia (29.7 mmol/l at 12 hours) without any kidney or liver failure. The maximal serum valproic acid concentration measured was 342 mg/l after twelve hours (therapeutic rate: 35-85 mg/l). A continuous infusion of sodium bicarbonate was associated with continuous venovenous haemodiafiltration. Progressive haemodynamic improvement and neurologic recovery leaded to extubation at 36 hours.