Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract
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J. Gastrointest. Surg. · Sep 1998
Production and systemic absorption of toxic byproducts of tissue combustion during laparoscopic cholecystectomy.
Among the potential hazards of laparoscopic surgery using electrocautery is the release of chemical by-products of incomplete tissue combustion into the pneumoperitoneum with subsequent transperitoneal absorption into the bloodstream and/or release into the operating room. The purpose of this study of patients undergoing laparoscopic cholecystectomy (LC) was twofold: (1) to assess the relationship between intraperitoneal concentration of carbon monoxide (CO) and blood levels of carboxyhemoglobin (COHb) and methemoglobin (MetHb), and (2) to assess the surgeon's inhalation of CO resulting from ambient smoke exposure. During LC with monopolar electrocautery, 21 patients were evaluated intraoperatively for intraperitoneal [CO] by sampling gas from a trocar, whereas arterial [COHb) and [MetHb] were determined perioperatively. ⋯ Although LC using electrocautery increases intraperitoneal [CO] to "hazardous" levels, systemic [COHb] and [MetHb] are not elevated by generation of intraperitoneal smoke. The surgeon's exposure to CO by the evacuation of smoke through laparoscopic ports is negligible. Production of smoke during LC using monopolar electrocautery, therefore, does not appear to pose a threat to either the patient or the surgeon.
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J. Gastrointest. Surg. · Sep 1998
Are vitamin B12 and folate deficiency clinically important after roux-en-Y gastric bypass?
Although iron, vitamin B12, and folate deficiency have been well documented after gastric bypass operations performed for morbid obesity, there is surprisingly little information on either the natural course or the treatment of these deficiencies in Roux-en-Y gastric bypass (RYGB) patients. During a 10-year period, a complete blood count and serum levels of iron, total iron-binding capacity, vitamin B12, and folate were obtained in 348 patients preoperatively and postoperatively at 6-month intervals for the first 2 years, then annually thereafter. The principal objectives of this study were to determine how readily patients who developed metabolic deficiencies after Roux-en-Y gastric bypass responded to postoperative supplements of the deficient micronutrient and to learn whether the risk of developing these deficiencies decreases over time. ⋯ Lack of symptoms of vitamin B12 and folate deficiency suggests that these deficiencies are not clinically important after RYGB. Conversely, iron deficiency and anemia are potentially serious problems after RYGB, particularly in younger women. Hence we recommend prophylactic oral iron supplements to premenopausal women who undergo RYGB.
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J. Gastrointest. Surg. · Sep 1998
Reasons for intracranial hypertension and hemodynamic instability during acute elevations of intra-abdominal pressure: observations in a large animal model.
In previous studies we reported that an acute elevation in intra-abdominal pressure (IAP) is responsible for the elevation in intracranial pressure (ICP) and mean blood pressure (MBP). Thus far, the reasons for the increased ICP during an acute elevation in IAP and the combined effects of increased IAP and ICP on hemodynamics have not been reported. Five large animals (swine) were studied. ⋯ Cavograms performed on animals in the supine position with increased IAP showed a narrowing of the IVC at the level of the diaphragm. Increases in IAP will increase ICP and MBP without altering the cerebral perfusion pressure. A mechanical effect mediated by compression of the inferior vena cava at the level of the diaphragm with increased central venous pressure and decreased drainage from the lumbar plexus and central nervous system is responsible for this effect.