Electrical resistance and current leakage of appliances for transurethral resection.

Urethral stricture following transurethral resection of the prostate (TUR-P) is closely related to the electrical resistance and current leakage of appliances. Electrical resistance and leakage were therefore investigated in 7 old bipolar loops, 3 new bipolar loops (1, 2 and 3) used for TUR-P, 2 new bipolar loops (4 and 5) for TUR-bladder tumor (TUR-Bt), and 4 new monopolar loops (6 through 9) for TUR-P. Two of the 7 old bipolar loops were found to be positive and 5 negative for current leakage. The 2 positive loops had resistances of 4.4 and 17 ohm . Before use, the electrical resistance of the 5 new bipolar loops (1 to 5) ranged from 0.5 to 0.6 ohm. The resistance of loop 1 was less than 5 ohm after the sixth use, and that of loop 3 was 2.8 ohm after the fifth use. By contrast, loop 2 exhibited resistance of 115 ohm after the third use. The average operation time for loops 1, 2 and 3 were 66, 64 and 62 minutes. Loop 4 showed resistance of 14 ohm after the third use, and loop 5 1 ohm even after the sixth use. Furthermore, none of the 5 loops showed current leakage. On the other hand, all 4 monopolar loops (6 through 9) exhibited current leakage after the first use, and showed relatively high electrical resistance. These findings demonstrate the necessity of timely replacement of bipolar loops and the exchange of monopolar loops after the first use.     

Charcot foot and ankle reconstruction: current thinking and surgical approaches

The surgical repair of unstable diabetic neuropathic osteoarthropathy of the midfoot or the hindfoot and ankle remains a challenge with little guidance available in the medical literature. The authors present their proposed surgical intervention techniques regarding the use of external fixation with or without combined internal fixation. A step-by-step guide through the authors' preferred technique for these difficult limb salvage cases is presented in detail.     

Implantable defibrillators. Sudden death: high risk

INCIDENCE: The incidence of sudden death remains high. The basic causes are related to ischemic heart disease and heart failure. Automatic defibrillation is the best treatment, as first conceived and implanted by Mirovski twenty years ago. MARKERS OF RISK OF SUDDEN DEATH: Left ventricular dysfunction, functional class and spontaneous and induced ventricular hyperexcitability identify a high-risk population. THERAPEUTIC APPROACH: Drug treatments used in the post infarction period or for heart failure (beta-blockers, converting enzyme inhibitors and amiodarone) have demonstrated a certain efficacy in preventing sudden death. However, different therapeutic trials comparing the efficacy of defibrillators and drug treatments have demonstrated the 20 to 46% superiority of defibrillation in terms of reduced mortality.     

The current situation of anesthesiology and recovery in Spain. A national survey (IV): Extrasurgical activity

It is showed the results of an inquest carried out at 170 departments of anesthesia about their extrasurgery activities. Training programs, systematic and available preoperative assessment, controls at the delivery, pediatric anesthesia, neonatal resuscitation, pain treatment units, recovery units and hospitalization wards, emergency service, transportation of critical patients and available human resources are analysed.     

Pacemakers and defibrillators: anaesthetic implications

Editor—I read with interest the review article concerningthe anaesthetic implications of pacemakers and defibrillators,by Salukhe, Dob and Sutton.¹ I enjoyed reading the article     

Influence of AC and DC Electrical Stimulation on Wound Healing in Pigs: A Biomechanical Analysis

To evaluate the effects of electrical stimulation on the mechanical properties of healing skin, 20 Hanford mini-pigs weighing 10–15 kg with trochanteric pressure ulcers were subjected to electrical stimulation. Examination of the biomechanical properties of the skin and changes in wound area and volume was done on previously wounded and healing pigskin subject to AC or DC electrical stimulation. The behavior of normal pigskin was compared to (1) denervated controls, (2) denervated AC-stimulated skin, and (3) denervated DC-stimulated skin. A denervated limb trochanteric pressure sore model developed in house permitted the use of a 6.5-mm percutaneous cancellous screw for wound formation and a 3-cm-diameter spring compression indentor to create reproducible and uniformly controlled grade 3 or higher tissue ulcers in the monoplegic hind limbs. Denervation was accomplished by right unilateral extradural rhizotomies from L2 to S1 nerve roots. Electrodes were placed 1 cm distal and proximal to the wound periphery, and wounds were stimulated 2 h/day, 5 days/week for 30 days. Dumbbell-shaped skin specimens with a length to width ratio of 3:1 were uniaxially loaded in tension until failure at an extension rate of 150 mm/min. The stiffness values for skin samples oriented parallel to the current flow were reduced by nearly half the values obtained for normal controls. Statistical differences (P <. 05) were found for stress, Young modulus, and stiffness when compared to normal skin. Samples oriented in the perpendicular direction were comparable to normal skin (P= NS). Both AC- and DC-stimulated wounds showed (1) a reduced healing time when compared to controls, and (2) that electrical stimulation may orient new collagen formation in a pattern similar to normal skin, even in the absence of neural influences.     

The operating microscope. IV. Documentation

The methods of documenting microsurgical procedures with 35-mm photography, Super 8 (8-mm) and 16-mm motion pictures, and television are discussed for the Zeiss OPMI 1, OPMI 6-S and OPMI 7 P/H.