Unilateral thoracoscopic reduction pneumoplasty for asymmetric emphysema

OBJECTIVE

We prospectively analyzed the surgical and functional results of unilateral thoracoscopic reduction pneumoplasty which we performed by choice in patients with asymmetric emphysema.

METHODS

Between October 1995 and June 1997, 119 emphysematous patients were examined and 34 were operated upon. Among these, 14 selected patients with asymmetric distribution of emphysema in the lungs underwent unilateral reduction pneumoplasty (ten right, and four left). There were 13 males and one female, with a mean age of 62 years. Eligibility criteria included bullous and non-bullous end-stage emphysema with severe limitation to daily activity.

RESULTS

No patient required conversion to thoracotomy. Mean operative time ranged between 70 and 240 min with a mean of 103 min. There was no postoperative mortality but five patients developed one or more complications: five prolonged air leaks (>7 days); two pulmonary infections; one empyema. No patient required postoperative mechanical ventilation. Median hospital stay was 8 days. At the 3-month follow-up the mean FEV1 increased from 0.8 l to 1.2 l (P < 0.001). Mean FVC increased from 2.6 l to 2.9 l (P < 0.001). The Medical Research Council dyspnea score decreased from a mean of 3.2 to 1.8 (P < 0.001).

CONCLUSIONS

Asymmetric distribution is a frequent finding in patients with severe emphysema. Unilateral thoracoscopic reduction pneumoplasty may represent an ideal approach in this selected group of patients.

Adjuvant pneumomediastinum in thoracoscopic thymectomy for myasthenia gravis

To facilitate initial visualization and subsequent mobilization of the thymus, adjuvant pneumomediastinum was preoperatively induced in 4 patients who underwent video-assisted thoracoscopic thymectomy. Neither mortality nor technique-related morbidity was observed. This experience shows video-assisted thoracoscopic thymectomy to be a safe and reliable procedure. In addition, we believe that adjuvant pneumomediastinum seems to facilitate the dissection maneuvers and could shorten operative time.

The amino acid cerebral pool after toxic doses of lidocaine and mexiletine. An experimental study on guinea pigs

Lidocaine and Mexiletine are two anti-arrhythmic drugs which when administered in toxic doses cause alterations in the central nervous system (convulsions, tremors, coma). An experimental study was carried out to clarify some neurological side-effects caused by these two drugs, by studying the variations of the brain amino acid pool. With Lidocaine one can observe an increase of phenyl-alanine and tyrosine, a decrease of glycine, GABA, alanine, aspartate and glutamate, while taurine and ammonia showed no significant changes. After Mexiletine one can observe an increase of ammonia, a decrease of GABA, glutamine, glycine and alanine, while glutamate, taurine, phenyl-alanine and tyrosine remain within normal values. In conclusion, on the basis of the data obtained by comparing the two drugs, one could say that Lidocaine has a greater interference on the catecholaminic precursors which are little influenced by Mexiletine. For the rest, the data obtained are practically super- imposable .

The brain amino acid pattern in experimental coma due to phenytoin in guinea pigs

An experimental study was carried out on 50 guinea pigs to evaluate the amino acid pattern in the whole brain after a toxic dose of phenytoin (1 g . kg-1 body wt). One group of 25 guinea pigs was treated with the drug which made them comatose, and their brains removed by craniotomy and frozen in liquid nitrogen; 25 guinea pigs were used as a control group. The brain amino acid pattern was determined by ion-exchange chromatography. All the amino acids, except threonine and methionine, decreased. Hypotheses about the particular cerebral metabolic pathways involved are discussed.

Experimental acute hypoxia. Brain preservation by phenobarbital pretreatment. Histological study in guinea pigs

Acute hypoxia was induced by keeping guinea pigs in an atmosphere of 5% O2/95% N2 for 20 min. Four groups of 10 guinea pigs each were used: (A) control; (B) after 20 min of hypoxia; (C) after 20 min of hypoxia and 20 min of oxygen therapy (100%); (D) pretreatment with phenobarbital (100 mg/kg body wt) and 20 min of hypoxia, followed by 20 min of oxygen therapy. The histological study did not show significant differences between barbiturate-treated and untreated hypoxic brains. In fact, the severity of ischemic-hypoxic damage as well as its distribution were similar in all the experimental groups of animals. Lesions predominated in the regions which are known to be more sensitive to hypoxia (3rd and 4th layers of parieto-occipital cortex, Sommer's fields, cerebellum). It is considered that in the experimental conditions barbiturates did not act as a protective agent--at least as assessed morphologically.