Preventive skin analgesia with lidocaine patch for management of post-thoracotomy pain: Results of a randomized, double blind, placebo controlled study.

BACKGROUND: To evaluate whether pre-emptive skin analgesia using a lidocaine patch 5% would improve the effects of systemic morphine analgesia for controlling acute post-thoracotomy pain. METHODS: This was a double-blind, placebo controlled, prospective study. Patients were randomly assigned to receive lidocaine 5% patch (lidocaine group) or a placebo (placebo group) three days before thoracotomy. Postoperative analgesia was induced in all cases with intravenous morphine analgesia. The intergroup differences were assessed in order to evaluate whether the lidocaine patch 5% would have effects on pain intensity when at rest and after coughing (primary end-point) on morphine consumption, on the recovery of respiratory function, and on peripheral painful pathways measured with N2 and P2 laser-evoked potential (secondary end-points). RESULTS: A total of 90 patients were randomized, of whom 45 were allocated to the lidocaine group and 45 to the placebo group. Lidocaine compared with the placebo group showed a significant reduction in pain intensity both at rest (P = 0.013) and after coughing (P = 0.015), and in total morphine consumption (P = 0.001); and also showed a better recovery of flow expiratory volume in one second (P = 0.025) and of forced vital capacity (P = 0.037). The placebo group compared with the lidocaine group presented a reduction in amplitude of N2 (P = 0.001) and P2 (P = 0.03), and an increase in the latency of N2 (P = 0.023) and P2 (P = 0.025) laser-evoked potential. CONCLUSIONS: The preventive skin analgesia with lidocaine patch 5% seems to be a valid adjunct to intravenous morphine analgesia for controlling post-thoracotomy pain. However, our initial results should be corroborated/confirmed by larger studies.

Is pre-emptive administration of ketamine a significant adjunction to intravenous morphine analgesia for controlling postoperative pain? A randomized, double-blind, placebo-controlled clinical trial.

OBJECTIVES: To evaluate if the pre-emptive administration of ketamine would potentiate the effect of intravenous morphine analgesia in the management of post-thoracotomy pain. METHODS: This was a unicentre, double-blind, placebo-controlled, parallel-group, prospective study. Patients were randomly assigned to receive 1 mg/kg ketamine (ketamine group) or an equivalent dose of normal saline (placebo group) before thoracotomy in 1:1 ratio. All patients received postoperatively intravenous morphine administration as additional analgesic regimen. Primary end-point was the pain relief measured with Visual Analogue Scale at rest. The secondary end-points were the reduction of inflammatory response expressed by plasma C-reactive protein levels, the morphine consumption and the rate of side effects. The measurements were carried out 6, 12, 24, 36 and 48 hours postoperatively. RESULTS: A total of 75 patients were randomized of whom 38 were allocated to ketamine group and 37 to placebo group. Baseline characteristics were comparable. Ketamine compared with placebo group showed a significant reduction of pain scores (P = 0.01), C-reactive protein (P < 0.001) and morphine consumption (P < 0.001). No acute psychological side effects related to the use of ketamine were registered. CONCLUSIONS: The administration of ketamine before surgery may be an effective adjunct to intravenous morphine analgesia in acute post-thoracotomy pain management. In ketamine group, satisfaction of pain relief was significantly higher with a significant reduction of inflammatory response and morphine consumption compared with placebo group. Our results, if confirmed by larger studies, may be of clinical relevance in situations where epidural analgesia or other analgesic procedures different from systemic opioid analgesia are unavailable or contraindicated.

Autonomic dysfunction is associated with brief episodes of atrial fibrillation in type 2 diabetes.

BACKGROUND AND AIMS: This study aimed to investigate the relationship between asymptomatic episodes of atrial fibrillation (AF) and abnormalities of the autonomic nervous system in type 2 diabetic patients who did not have evidence of atrial fibrillation at baseline. METHODS AND RESULTS: In a multicentric cross-sectional controlled study, 1992 patients with type 2 diabetes were screened. All underwent ambulatory ECG recording for 48-hour at 3, 6, 9, and 12months. Heart rate variability (HRV) was used as indicator of autonomic activity. One hundred seventy-six diabetics with silent atrial fibrillation episodes (SAFE group) and 288 without silent atrial fibrillation (non-SAFE group) were enrolled. These selected diabetics were matched on clinical and anthropometric data to 120 control subjects without diabetes of the control group. HRV analysis evidenced that LF/HF ratio was significantly higher in the SAFE group than in the non-SAFE group (P<0.05) in the whole period of HM analysis. AF absolute burdens were positively correlated with LF/HF ratio (r=0.31, P<0.001). Multiple regression analysis showed that LF/HF ratio was an independent determinant of AF episodes. CONCLUSIONS: This study originally showed a strong relationship between autonomic dysfunction and silent atrial fibrillation in type 2 diabetes.