Tehran University Medical Journal

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Background: We report a case with apparent resistance to local anesthetics. While regional anesthetics failure are often attributed to technical failure, the clinical presentation and medical history of this patient suggests a true resistance to local anesthetics.
Case report: A 28 years old man was scheduled for elective orthopedic surgery for right sided tibial bone fracture, and decision of spinal anesthesia was made. There was a questionable history of multiple prior episodes of local anesthetic unresponsiveness (Interscalan block, local infiltration for lipoma resection and dental surgery). Spinal anesthesia was performed and sensory or motor blockade was not obtained despite any evidence of technical problems. The surgical procedure performed under general anesthesia and skin analgesia (local infiltration of lidocaine 2% and bupivacaine 0.5% to forearm), did not achieve, the day after surgery.
Conclusion: While the failure rate of spinal anesthesia has been shown range from 4 to 13% and is often attributed to technical failure, this particular case showed a true resistance to local anesthetics.

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Background: Cardiac herniation is a fatal post pneumonectomy complication. We report the signs, clinical findings, diagnosis and management of a patient with post pneumonectomy cardiac herniation.

Case report: A 34-year-old man with lung cancer underwent left pneumonectomy with partial pericardiectomy in the right lateral decubitus position. At the end of the surgery, cardiovascular collapse, severe bradycardia, desaturation and elevated airway pressure occurred just after repositioning the patient to the supine position. This patient survived as we returned him to the right lateral decubitus position and avoided the use of positive pressure ventilation.

Conclusions: Attention to the acute complications of pneumonectomy, diagnosis and rapid therapeutic interventions is essential in post pneumonectomy care.

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Background: The risk of atherosclerosis and cancer is high in hemodialysis (HD) patients. There is evidence that HD causes oxidative stress. However, the causative factors of oxidative stress are unknown. It has been suggested that HD imposes an additional oxidative stress on patients with chronic renal failure by activation of granulocytes on dialyzer membranes resulting in an imbalance between oxidants and antioxidants. In this regard, a number of reports, either measuring specific analytes or enzymes, or estimating the total antioxidant activity of the plasma have given contradictory and inconclusive results. To investigate the oxidative stress status in Iranian HD patients, in this study, we evaluated GSH and FRAP levels along with Ca and pH in the blood of these patients.

Methods: Along with 20 healthy age and gender matched control subjects, 24 patients underwent dialysis, three times per week, for four hours in each session. Before and after dialysis, blood was taken for biochemical and liver function tests and to evaluate oxidative stress markers and measure Ca and pH levels.

Results: There was a significant decrease in FRAP and GSH levels after dialysis compared to those before treatment. Dialysis caused an increase in pH and Ca levels compared to levels in control subjects after dialysis.

Conclusion: In general, before dialysis, there is a balance between oxidants and antioxidants however, due to higher levels of oxidants as well as the possible binding of antioxidants to the dialyzer membrane during dialysis, an imbalance occurs. The instability in the balance of oxidants and antioxidants may be the major cause of cellular oxidative damage found in HD patients. This study indicates that there is a significant level of oxidative stress in renal chronic patients and this stress is augmented by dialysis. Antioxidant therapy should be considered in these patients.