Decompression procedures

The U.S. Navy Standard Air Decompression Tables (USN) have been, and continue to be, used extensively to guide human decompression procedures throughout much of the world. These tables (ref. 408), as well as the French Navy decompression table (FN) and the Japanese Department of Labor standard decompression table (Japan), are all based on the Haldane-ratio principle (ref. 409,410). However, other tables have been developed that do not employ the Haldane-ratio principle to guide decompression, and several of these tables appear to be considerably safer (ref. 411-413). 

The decompressive procedure used most commonly fiar Graves orbitopathy today is the medial inferior decompression through either a transantral or translid approach. In 1992 using a transorbital three-wall decompression... 

The health hazards of work in compressed air and diving are decompression sickness ( the bends ) and aseptic bone necrosis ( bone rot ). Both these illnesses can have long-term effects varying from slight impairment of mobility to severe disablement. The protective measures, including decompression procedures, are laid down in the Work in Compressed Air Special Regulations and these should be observed in conjunction with the medical code of practice for work in compressed air. 

Prepare a written evaluation of the decompression procedure assessment, including any corrective action taken, within 45 days of the incident of decompression sickness. 

Records and documents required by this standard shall be provided upon request to employees, designated representatives, and the Assistant Secretary in accordance with 29 CFR 1910.20 (a)-(e) and (g)-(i). Safe practices manuals ( 1910.420), depth-time profiles ( 1910.422), recordings of dives ( 1910.423), decompression procedure assessment evaluations ( 1910.423), and records of hospitalizations 1910.440 shall be provided in the same manner as employee exposure records or analyses... 

FIGURE 23.17 Styrene-butadiene copolymer (SBR) peel adhesion test piece after first appl3nng a gas decompression (GD) procedure and then peel testing. 

The most common indication for surgery in CP is abdominal pain refractory to medical therapy. Surgical procedures that alleviate pain include a subtotal pancreatectomy, decompression of the main pancreatic duct, or interruption of the splanchnic nerves. 

The rate of resectability is only 15-20% for proximal bile duct carcinomas but up to 70% for distal lesions. In addition, there is little benefit to preoperative decompression of the biliary tree in patients having obstructive jaundice (65,66). However, this procedure is frequently practiced. For proximal cancers, local excision is often possible. In particular, hepatic resection is indicated for upper bile duct cancers with quadrate lobe invasion or unilateral intrahepatic ductal or vascular involvement, and distal and midductal lesions may require pancreatoduodenectomy. Also, biliary-enteric continuity... 

The procedure of the thermobaric treatment consisted of several steps. Initial compression to 1.5 GPa and heating to 270°C resulted in the hydrogen atmosphere in the ampoule. Then pressure was increased to the final value, and the sample was maintained at 350°C overnight (about 20 h), then at 450-490°C for 6-10 h. After cooling to room or liquid-nitrogen temperature and decompression, the recovered samples were stored without access of the ambient atmosphere until measurements. 

Surgery for hemifecial spasm involves microvascular decompression of the fecial nerve by placement of a sponge under posterior fossa vessels (Jannetta procedure). Surgery for hemifecial spasm is associated with cure rates exceeding 80%, and beyond 2 years there appears to be little risk of relapse. However, surgical intervention can have serious complications such as permanent facial paralysis, deafness, stroke, and even death. 

DCl doped D2O ice XII samples were prepared by following a procedure described in ref. 25. First, DCl doped HDA was prepared by compression of D2O ice Ih doped with 0.01 M DCl at 77 HDA was then heated isobarically starting from 77 K at 1.2 GPa at 11 K min to crystallize pure doped D2O ice XII. After cooling from 180 K to 77 K at 0.8 K mm the samples were decompressed, and recovered in liquid nitrogen (cf. Figure 1). 

The development of the TIPS provided a major improvement in the management of refractory or severe cases of esophagogastric variceal bleeding and other complications of portal hypertension. The TIPS procedure involves the placement of one or more stents between the hepatic vein and the portal vein (Fig. 37-6). This procedure is widely used because it provides an effective decompressive shunt without laparotomy, and can be employed regardless of Child-Pugh score. Survival rates with TIPS in patients refractory to endoscopic treatment are comparable to rates achieved with portacaval... 

For reactions that are slow at room temperature, one approach is to initiate reaction and confine the reaction to an autoclave. Following decompression the contents can be analysed to assess the progress of the reaction. This procedure was used to determine the first volume of activation for an inorganic reaction. Apparently only one elevated pressure was used to estimate the value.44 In more current practice repeating the process and arresting the reaction at different time intervals could lead to a reaction profile at a given pressure. The whole procedure would then be repeated at several different pressures, and kinetic data treated according to Equation (9). Obviously such a primitive method is to be avoided, as it is very labour intensive and wasteful of reactants. It would only be satisfactory if the analysis is very rapid compared with the reaction rate or the reaction can be quenched immediately upon decompression. 

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