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Biomedical subjects

S A McClave

Publications and source records attributed to S A McClave.

At least 19 recordsLinked to original sources
PubMed2001

Should indirect calorimetry be used as part of nutritional assessment?

The use of indirect calorimetry in the design of nutritional support regimens is poorly appreciated by clinicians, who fail to recognize the importance of providing a sufficient volume of enteral feeding to critically ill patients. In contrast to the overfeeding that routinely occurred in the past with the provision of total parenteral nutrition, patients placed on the enteral route of support tend to be underfed because of problems with intolerance and frequent cessation. Clearly identifying and coming as close as possible to the caloric goal may be required to achieve the therapeutic endpoints of enteral tube feeding (which include maintenance of gut integrity, attenuation of the stress response, prophylaxis against stress-induced gastropathy, and stimulation of immune function). Indirect calorimetry is a convenient, accessible, and highly accurate instrument for the measurement of caloric requirements and is a valuable tool for the optimization of nutritional support in the intensive care unit.

Calorimetry, Indirect↗
PubMed2001

Dissecting the energy needs of the body.

The majority of the resting energy expenditure can be explained by the energy needs of a few highly metabolic organs, making up a small percentage of the body by weight. The relationship of the specific size, individual metabolism, and proportional contribution to the actual body weight and total energy expenditure for each of these organs is a dynamic process throughout growth and development, the onset of disease, and changes in nutritional status. Defining the energy needs of the individual tissues and organ systems immeasurably enhances our understanding of the body's response to these clinical processes, which otherwise could not easily be evaluated by focusing solely on total energy expenditure, fat-free mass, nitrogen imbalance, or actual body weight. Recently reported studies have served mainly to reinforce concepts described previously, and clarify some areas of controversy.

Body Composition↗
PubMed2000

Artificial nutrition in pancreatic disease: what lessons have we learned from the literature?

Acute pancreatitis is a disease process that begins with an initial injury to the pancreatic acinar cell due to the erroneous premature activation and intracellular release of digestive enzymes. The local injury is amplified through the induction of a systemic inflammatory response, mediated by the generation and release of cytokines and an aggressive inflammatory cell recruitment. Failure to maintain gut integrity may exacerbate the stress response and the systemic inflammatory reaction associated with this process, worsening the overall clinical severity of the pancreatitis and contributing further to complications of organ failure and nosocomial infection. Emphasis in the clinical nutritional management of these patients has shifted from efforts to minimize stimulation of the gland, to attaining enteral access, starting tube feeds low in the gastrointestinal tract, and monitoring tolerance. While clinical guidelines help identify those patients with acute pancreatitis at greatest need for aggressive nutritional support, the proper timing to initiate feeding, the optimal composition of the enteral formula, and whether or not enteral feeding is better than no nutritional therapy is still not clear from the current literature.

Acute Disease↗
PubMed2000

Mistakes on EUS staging of colorectal carcinoma: error in interpretation or deception from innate pathologic features?

BACKGROUND: Because endoscopic ultrasound (EUS) accuracy for staging gastrointestinal tract tumors is limited by many factors, this study was designed to analyze potential sources of error in the EUS staging of colorectal carcinoma. METHODS: All patients referred for EUS evaluation of colorectal carcinoma were staged prospectively by one ultrasonographer and retrospectively by two others with EUS videotape recordings. Pathologic staging was done independently in a blinded fashion. Deceptive pathologic features were defined for T staging by presence of inflammation extending beyond tumor or microscopic spread without inflammation extending to a level consistent with the next stage, and for N staging by large (> or = 10 mm) benign lymph nodes or small (< 10 mm) malignant lymph nodes. RESULTS: Of 22 patients entered into the study, an inflammatory reaction around microscopic tumor spread thought to actually enhance detection by EUS was present in 57.1% of cases. Nine deceptive pathologic lesions were present in 36.4% (8 of 22) of patients (5 T stage, 4 N stage lesions). Of 40 T and N stage mistakes made by the three physicians, 45% were made in the presence and 55% in the absence of deceptive pathologic lesions. Accuracy increased significantly from the presence to absence of deceptive pathologic lesions, from 53.3% to 83.7% (p = 0.029) for T stage, and 8.3% to 73. 1% for N stage (p = 0.0001). Confidence of T staging correlated significantly with accuracy, increasing from 63.3% when unsure to 88. 2% with staging certainty (p = 0.017), an effect not seen for N staging. CONCLUSIONS: Inflammation and desmoplasia around colorectal carcinoma are often present, but may actually enhance EUS detection of microscopic tumor spread. Deceptive pathologic lesions are present in only one third of patients, but account for almost half (45%) of the errors in T and N staging by EUS. Diagnostic accuracy for EUS was increased with confidence in T stage assessment (but not N stage) and in the absence of deceptive pathologic lesions. Errors in interpretation still accounted for the majority of mistakes (55%) made in EUS staging of colorectal carcinoma.

Adult↗
PubMed1999

Enteral tube feeding in the intensive care unit: factors impeding adequate delivery.

OBJECTIVE: To evaluate those factors that impact on the delivery of enteral tube feeding. DESIGN: Prospective study. SETTING: Medical intensive care units (ICU) and coronary care units at two university-based hospitals. PATIENTS: Forty-four medical ICU/coronary care unit patients (mean age, 57.8 yrs; 70% male) who were to receive nothing by mouth and were placed on enteral tube feeding. INTERVENTIONS: Rate of enteral tube feeding ordered, actual volume delivered, patient position, residual volume, flush volume, presence of blue food coloring in oropharynx, and stool frequency were recorded every 4 hrs. Duration and reason for cessation of enteral tube feeding were documented. MEASUREMENTS AND MAIN RESULTS: Physicians ordered a daily mean volume of enteral tube feeding that was 65.6% of goal requirements, but an average of only 78.1% of the volume ordered was actually infused. Thus, patients received a mean volume of enteral tube feeding for all 339 days of infusion that was 51.6% of goal (range, 15.1% to 87.1%). Only 14% of patients reached > or = 90% of goal feeding (for a single day) within 72 hrs of the start of enteral tube feeding infusion. Of 24 patients weighed before and after, 54% were noted to lose weight on enteral tube feeding. Declining albumin levels through the enteral tube feeding period correlated significantly with decreasing percent of goal calories infused (p = .042; r2 = .13). Diarrhea occurred in 23 patients (52.3%) for a mean 38.2% of enteral tube feeding days. In >1490 bedside evaluations, patients were observed to be in the supine position only 0.45%, residual volume of >200 mL was found 2.8%, and blue food coloring was found in the oropharynx 5.1% of the time. Despite this, cessation of enteral tube feeding occurred in 83.7% of patients for a mean 19.6% of the potential infusion time. Sixty-six percent of the enteral tube feeding cessations was judged to be attributable to avoidable causes. CONCLUSIONS: The current manner in which enteral tube feeding is delivered in the ICU results in grossly inadequate nutritional support. Barely one half of patient caloric requirements are met because of underordering by physicians and reduced delivery through frequent and often inappropriate cessation of feedings.

Energy Intake↗
PubMed1999

Indirect calorimetry: can this technology impact patient outcome?

This review of 23 papers involving indirect calorimetry published over the past 18 months shows how our understanding of the metabolic response to injury has changed, highlights the problems introduced by use of predictive equations and alterations in indirect calorimetry testing protocol, and emphasizes the need to monitor cumulative energy balance by comparing daily caloric intake to energy expenditure.

Calorimetry, Indirect↗
PubMed1999

Preoperative issues in clinical nutrition.

Allowing a patient's nutritional state to deteriorate through the perioperative period adversely affects measureable outcome related to nosocomial infection, multiple organ dysfunction, wound healing, and functional recovery. Careful preoperative nutritional assessment should include a determination of the level of stress, an evaluation of the status of the GI tract, and the development of specific plans for securing enteral access. Patients already demonstrating compromise of nutritional status (defined by > 10% weight loss and serum albumin level < 2.5 g/dL) should be considered for a minimum of 7 to 10 days of nutritional repletion prior to surgery. Widespread use of total parenteral nutrition in unselected patients is unwarranted, may actually worsen outcome, and should be reserved for preoperative nutritional support only in severely malnourished patients in whom the GI tract is unavailable. Compared with the parenteral route, use of perioperative enteral feeding has been shown to provide more consistent and beneficial results, and can be expected to promote specific advantages in long-term morbidity and mortality.

Enteral Nutrition↗
PubMed1998

Nutritional management in acute and chronic pancreatitis.

Patients with severe pancreatitis, characterized by multiple organ failure and pancreatic necrosis on CT scan (identified by an Acute Physiology and Chronic Health Evaluation II score of > or = 10 with > or = 3 Ranson criteria), most likely require aggressive nutritional support. Use of the enteral route of feeding may help contain the hypermetabolic stress response, reduce morphologic change and atrophy of the gut, and theoretically decrease late complications of nosocomial infection and organ failure. Evidence that decreasing degrees of stimulation of the pancreas occur as the site of feeding descends in the gastrointestinal tract and evidence from perspective, randomized trials suggest that jejunal feeding appears at least as safe and well tolerated as total parenteral nutrition in acute pancreatitis.

Acute Disease↗
PubMed1998

Pyogenic liver abscesses: a comparison of older and younger patients.

OBJECTIVE: To evaluate whether older patients with pyogenic liver abscess have distinctive presenting features or if their management differs from that of younger patients. DESIGN: Retrospective chart review of all cases occurring from 1982 to 1992. SETTING: A regional trauma centre and two large community hospitals. PATIENTS: A total of 38 individuals with a final diagnosis of pyogenic liver abscess. Seventeen patients aged 70 or older comprised the study group and 21 patients under age 70 the comparison group. MEASUREMENTS: Clinical features, laboratory data, therapeutic interventions and outcomes were sought. The presumed aetiology of the abscess was determined. RESULTS: The study group had fewer men (47% vs 81%, P=0.028), less abdominal tenderness on physical examination (41% vs 76%, P=0.028) and fewer positive blood cultures in those sampled (31% vs 67%, P=0.04) than the comparison group. No study group patient had a history of trauma. Times to diagnosis were 3.2 and 5.9 days (P=0.14) and lengths of stay 21.6 and 29.3 days (P=0.08) for study and comparison groups, respectively. There were no differences in mortality or other demographic, clinical, laboratory or pathological variables. CONCLUSIONS: Elderly patients with pyogenic liver abscess have some subtle differences in clinical and laboratory presentation, but these do not appear to delay diagnosis. Active management is tolerated well, with no difference in mortality.

Adolescent↗
PubMed1997

Clinical nutrition in pancreatitis.

In patients with acute pancreatitis or an acute flare of chronic pancreatitis, a discrepancy exists between increased protein/calorie requirements induced by a hypermetabolic stress state and reduced ingestion/assimilation of exogenous nutrients, which promotes progressive nutritional deterioration. Patients with severe pancreatitis (defined by > or =3 Ranson criteria, an APACHE II score of > or =10, development of major organ failure, and/or presence of pancreatic necrosis) are more likely to require aggressive nutritional support than patients with mild disease. The type of formula and level of the gastrointestinal tract into which nutrients are infused determine the degree to which pancreatic exocrine secretion is stimulated. Animal studies and early prospective randomized controlled trials in humans suggest that total enteral nutrition via jejunal feeding may be the preferred route to parenteral alimentation in this disease setting.

Acute Disease↗
PubMed1997

AIDS-related non-Hodgkin's lymphoma of the pancreas.

Non-Hodgkin's lymphoma is a common complication in patients with human immunodeficiency virus infection that most frequently affects the gastrointestinal tract. We describe the first case report of non-Hodgkin's lymphoma primarily involving the pancreas in a 27-yr-old white man who presented with epigastric pain, weight loss, and jaundice (and was later found to be HIV seropositive). Endoscopic ultrasound and CT scan of the abdomen showed a large mass arising from the body and head of the pancreas obstructing the common bile duct. An attempted ERCP was unsuccessful due to extrinsic compression and distortion of the second part of the duodenum. A percutaneous CT-directed true-cut needle biopsy of the pancreas revealed a small noncleaved B-cell lymphoma. The patient was started on combination chemotherapy. His pancreatic mass, epigastric symptoms, and jaundice resolved completely. This case report illustrates an otherwise rare presentation of isolated pancreatic involvement of non-Hodgkin's lymphoma in a patient with acquired immunodeficiency syndrome. An approach to its diagnosis and management is summarized.

Adult↗
PubMed1996

Exercise-induced asthma. Is gastroesophageal reflux a factor?

An acid-induced cholinergic esophagobronchial reflex has been described whereby acid refluxing into the esophagus causes bronchospasm. Reports of exertional gastroesophageal acid reflux prompted us to study the possibility that exercise-induced asthma (EIA) could be related to gastroesophageal reflux (GER). Following an overnight fast, 10 athletes with a history of EIA (nine men, one woman; mean age 31) were studied. Continuous monitoring of intraesophageal pH and motility, ECG, and arterial oxygen saturation was done. After baseline monitoring at rest for 15 min, subjects underwent treadmill exercise for 10 min followed by continuous monitoring for 30 min after exercise. Spirometry was done at baseline prior to exercise, then repeated every 5 min after exercise for 30 min. Two subjects were retested at a later date following a standard test meal. All 10 subjects demonstrated a decrease in FEV1 in response to exercise, but only half met criteria for EIA. Although 60% (6/10) showed some evidence GER, only three subjects demonstrated a pathologic degree of GER. In the two subjects retested postprandially, change in FEV1 was no different in one and improved in the other despite worsening of GER in both. There was no significant correlations between GER and EIA (P = 0.2). EIA correlated inversely with amplitude of esophageal contractions (P = 0.029) and was directly related to the percentage of multipeaked contractions and the duration of peristaltic contractions (P = 0.08). EIA is not associated with exertional GER.

Adolescent↗
PubMed1996

Does fluoroscopic guidance for Maloney esophageal dilation impact on the clinical endpoint of therapy: relief of dysphagia and achievement of luminal patency.

BACKGROUND: Use of fluoroscopy for Maloney esophageal dilation is controversial. We designed this prospective, randomized, single-blinded study to determine whether fluoroscopic guidance has an impact on relief of dysphagia and achievement of luminal patency. METHODS: Patients with benign esophageal strictures were randomized to undergo Maloney dilation with or without fluoroscopic guidance. Strictures were dilated to size 48F. Dysphagia scores were obtained before and 1 week after dilation. RESULTS: Eighty-three patients underwent 100 dilation sessions with fluoroscopic guidance being used for 50 sessions (156 dilations) and blinded technique for 50 (161 dilations). A 12.5 mm barium pill passed after dilation following 62.0% of the fluoroscopic dilation sessions and 42.0% of the blinded dilations (p = 0.045). Dysphagia was improved in 93.0% of patients receiving fluoroscopic dilations and 69.0% of patients receiving blinded dilations (p = 0.006). The mean improvement in dysphagia score was -2.10 points for the fluoroscopic group versus -1.50 points for the blinded group (p = 0.057). Differences in these parameters between techniques were even greater in 12 patients re-randomized to both techniques at different sessions. CONCLUSIONS: The use of fluoroscopic guidance impacts favorably on the efficacy of Maloney dilation, resulting in greater relief of dysphagia and increased luminal patency compared to the blinded technique. Based on these results, use of fluoroscopy is recommended when Maloney esophageal dilation is performed.

Catheterization↗
PubMed1996

Standardization of clinical criteria required for use of the 12.5 millimeter barium tablet in evaluating esophageal lumenal patency.

BACKGROUND: Although the barium tablet is commonly used in evaluating lumenal patency of the esophagus, the conditions under which the tablet should traverse a normal esophagus have not been established. This study was designed to standardize the minimal criteria required to ensure successful esophageal transit of a commercially available barium tablet in normal subjects. METHODS: Each of 20 volunteers swallowed a standard 12.5 mm barium tablet under fluoroscopy in the supine, 45 degrees incline, and upright positions. Tablets were swallowed dry and with fixed volumes of water (15, 30, 60, and 100 cc). Success of pill passage into the stomach was determined by fluoroscopy at 20, 40, 60, and 90 seconds. RESULTS: Successful pill passage correlated significantly with position (passing 17.0%, 66.5%, and 69.7% in the supine, incline, and upright position, respectively; p < .0001) and volume of water ingested (passing 9.1% when swallowing dry, and 38.7%, 55.8%, 70.0%, and 81.6% with 15, 30, 60, and 100 cc of water, respectively; p < or = .004). Duration of time beyond 20 seconds failed to affect rate of pill passage. Ingestion of 60 cc of water in the incline position was associated with a 95% pill passage, a rate significantly greater than any position at lower volumes. Increasing water volume above 60 cc or assuming the upright position did not increase this passage rate further. CONCLUSIONS: The minimum criteria required to optimize successful transit of a 12.5 mm barium tablet through a normal esophagus is to perform the test in the 45 degrees incline position with 60 cc of water for a period of 20 seconds. Failure of the pill to pass under these conditions may suggest a true structural abnormality of the esophagus.

Administration, Oral↗