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W J Chwals

Publications and source records attributed to W J Chwals.

36 records · Page 2Linked to original sources
PubMed1993

Relationship of metabolic indexes to postoperative mortality in surgical infants.

Acute injury is known to evoke a metabolic stress response, characterized by cytokine release and reprioritization of hepatic protein synthesis to increase acute phase proteins at the expense of visceral proteins. The impact of these evolving, stress-induced, perioperative metabolic changes on clinical outcome in surgical infants has not yet been determined. The cytokine (tumor necrosis factor [TNF]), acute phase protein (C-reactive protein [CRP]), and visceral protein (prealbumin [PA]) responses to acute metabolic stress were evaluated in 41 infants (average age, 47 days) preoperatively and on postoperative days 1 through 7 (POD 1 to 7) following major surgery. Infants were retrospectively grouped according to whether they survived (group 1) or died within 30 days of surgery (group 2). Peak CRP values in the postoperative period were also included for both groups. Peak CRP levels (14.9 +/- 5.5 v 8.1 +/- 5.7 mg/dL) were significantly increased (P = .0056) and preoperative prealbumin levels (6.0 +/- 2.7 v 11.0 +/- 5.2 mg/dL) were significantly decreased (P = .0005) in group 2 (nonsurvivors) compared with group 1 (survivors). Though serum TNF levels were substantially increased in nonsurvivors compared with survivors, both preoperatively (16.5 +/- 35.2 v 0.6 +/- 2.6 pg/mL) and on POD 1 (3.6 +/- 6.8 v 0.6 +/- 2.7 pg/mL), these values did not reach statistical significance (P > .05). The most significant difference (P = .0001) was observed in persistently depressed late (POD 4 to 7) prealbumin levels in nonsurvivors relative to survivors (5.3 +/- 3.1 v 10.5 +/- 4.3 mg/dL), suggesting an increased risk of poor outcome if acute metabolic stress had not abated by this time.(ABSTRACT TRUNCATED AT 250 WORDS)

C-Reactive Protein↗
PubMed1993

Hormonal response of the premature primate to operative stress.

There are few data on the hormonal response to operation in the premature infant. Studies examining the response of newborn human infants have been performed on patients beyond the first few days of life, where some adaptation to postnatal life has occurred. This study evaluated the response of the newly born premature primate to surgical stress. Premature baboons (75% gestation) were intubated, mechanically ventilated and underwent thoracotomy at 2 hours of life with exposure of the ductus arteriosus (PDA). In group 1, formalin was infiltrated to keep the ductus patent. In group 2, the PDA was ligated. Controls had no operation. Blood was drawn at 0, 6, 24, 48, 72, and 96 hours of age. Echocardiograms were performed to confirm patency or closure of the ductus and to monitor cardiac function. Epinephrine, norepinephrine, renin, and cortisol levels were measured. Cortisol levels rose in all groups. Operation stimulated a marked increase in catecholamine and renin levels in both operative groups, which was more marked in the group with PDA ligation at 24 hours. These data reflect expected pathophysiology since early PDA ligation exerts additional hemodynamic demand on the heart. In conclusion, the premature primate is able to mount a significant and severity-dependent endocrine response to stress.

Animals↗
PubMed1992

Hirschsprung's disease: a possible cause of anastomotic failure following repair of intestinal atresia.

Despite several reported cases, the association of Hirschsprung's disease and intestinal atresia is not widely recognized. We describe three patients with jejunoileal atresia who all had a preoperative barium enema that failed to show a transition zone. All three patients developed an anastomotic leak of the atresia repair, and required a temporary diverting enterostomy. Two patients had total colonic Hirschsprung's disease and in one, the transition zone was in the midtransverse colon. Histological examination of the appendix at the time of repair may be helpful in patients with small intestinal atresia. In patients who develop an anastomotic breakdown, rectal biopsy should be performed to rule out Hirschsprung's disease.

Anastomosis, Surgical↗
PubMed1992

Serum visceral protein levels reflect protein-calorie repletion in neonates recovering from major surgery.

Protein catabolism resulting from acute metabolic stress causes significant postoperative decreases in visceral proteins, including albumin (Alb) and prealbumin (PA). Although clinical trials have suggested an advantage of PA over Alb in monitoring the visceral protein response to nutritional supplementation following surgery, the capability of the neonate to generate such a response has yet to be evaluated. Therefore, this study was undertaken to determine if PA is superior to Alb in assessing postoperative repletion of the visceral protein pool in neonates. Serum Alb and PA levels were measured and energy balance (EB) and protein intake (PI) were recorded in 10 neonates less than 48 hours after major surgery and again following 4 consecutive days of positive EB. Resting energy expenditure (REE) was measured using indirect calorimetric methodology. Mean PI (g/kg/d) was lower (0.78 +/- 0.78) and mean EB (kcal/kg/d) was negative (-2.92 +/- 10.05) less than 48 hours postoperatively compared with mean PI (2.52 +/- 0.57; P = .0006) after 4 consecutive days of positive EB (34.84 +/- 16.5; P = .0004). Mean percent change (mean% delta) from negative EB to positive EB was significantly greater for PA (100%; P = .0002) as compared with Alb (18.5%). These data appear to support the conclusion that serial serum PA levels are superior to Alb to monitor the visceral protein response to nutritional supplementation in neonates following surgery.

Energy Intake↗
PubMed1992

A comparison of total body water measurements using whole-body magnetic resonance imaging versus tritium dilution in primates.

Standard techniques conventionally used to assess body composition have various drawbacks which include a requirement for specialized equipment and expertise not widely available, radiation exposure, extensive study time periods, and limited clinical utility. Anthropometric methods, which are more clinically feasible, also involve substantially greater calculation error. This study was designed to compare a newly developed whole-body magnetic resonance (MR) imaging technique with standard tritium dilution (THO) to measure total body water (TBW) in eight primates (Macaca fascicularis). Sedated primates underwent whole-body MR imaging (10-12 contiguous 50-mm slices) and TBW was computed using a previously validated program. After 5 days to allow for primate recovery and stabilization, TBW measurements were repeated using THO methodology. Linear regression analysis of TBWMRI (72.1 +/- 5.7% body wt) compared with TBWTHO (73.8 +/- 3.2% body wt) yielded a Pearson correlation of r = 0.8145, P = 0.02 with a mean squared error of 2.14. Whole-body MR imaging determination of TBW correlates well with THO, requires less time (20 min versus 24 hr), and does not expose the subject to radiation. This study suggests that whole-body MR imaging is an accurate technique for in vivo body composition analysis. As demonstrated by the body size of this investigational primate model, the technique maybe particularly applicable to the study of human infants.

Animals↗
PubMed1992

Metabolism and nutritional frontiers in pediatric surgical patients.

The successful treatment of pediatric surgical disease requires an understanding of the acute metabolic stress response. Poor clinical outcome can result when the metabolic demands of acute injury exceed the ability of endogenous host mechanisms to compensate. Appropriate exogenous supplementation may provide the metabolic and nutritional support crucial to recovery. As knowledge in this area grows, more effective treatment strategies are evolving. The potential for further advances, especially in the infant critical care population, offers the hope for substantial progress in the near future.

Adolescent↗
PubMed1992

Indirect calorimetry in mechanically ventilated infants and children: measurement accuracy with absence of audible airleak.

OBJECTIVE: To establish the effect of an audible airleak (around an endotracheal tube) on oxygen consumption (VO2) measurements in pediatric ICU patients. DESIGN: Prospective trial comparing VO2 measurements before and after deflation of the endotracheal tube cuff. SETTING: Pediatric ICU in a large pediatric tertiary care center. PATIENTS: Twenty critically ill infants and children receiving mechanical ventilatory support via cuffed endotracheal tube. INTERVENTIONS: Deflation of endotracheal tube cuff. MEASUREMENTS AND MAIN RESULTS: The presence (group 1, n = 9) or absence (group 2, n = 11) of an audible airleak with the cuff deflated was confirmed by two independent observers. The percent difference in VO2 was calculated for both groups using the following formula: ([VO2 cuff up - VO2 cuff down]/VO2 cuff up) x 100. An audible airleak associated with cuff deflation (group 1) caused a significant (p = .0012) reduction of VO2 by 45.6% (mean difference in VO2 = 45.6%). In contrast, with no audible airleak after cuff deflation (group 2), only minimal changes in VO2 (mean difference in VO2 = -0.4%) were observed. CONCLUSIONS: These data suggest that if no audible airleak is detected, VO2 determined by indirect calorimetry may be reliably measured in infants and children with a noncuffed endotracheal tube.

Calorimetry, Indirect↗
PubMed1992

Dexamethasone treatment during ventilator dependency: possible life threatening gastrointestinal complications.

Corticosteroids in high doses have been used effectively to decrease the duration of ventilator dependency in very low birthweight infants at risk for chronic lung disease. Randomised prospective studies have shown benefit, with only minimal complications being reported. However, review of our experience over 2.5 years with high dose steroids in 80 premature neonates yielded three major complications: one case each of perforated duodenal ulcer, perforated gastric ulcer, and upper gastrointestinal haemorrhage. Two of the three patients died. Thus the use of steroids in neonates may not be without risk, and significant complications can occur. When high dose corticosteroids are to be used in very low birthweight neonates, H2 receptor antagonist treatment and gastric pH monitoring are recommended. The physician must remain alert to the possibilities of upper gastrointestinal bleeding and ulcer perforation in these patients.

Dexamethasone↗
PubMed1990

Transanal mucosal sleeve resection for the treatment of rectal prolapse in children.

This is a report of a simple transanal operation performed on six patients (age range, 19 months to 18 years), who underwent unsuccessful nonoperative management of complete rectal prolapse for at least 1 month (range, 1 month to 13 years). All patients had normal sweat chloride levels, normal chest radiographs, and normal barium enemas. None of the patients were neurologically compromised. At the time of surgery, all but one patient had occurrence of reducible prolapse with minor straining or with every bowel movement. No severe mucosal ulcerations were present. Surgical therapy consisted of the transanal mucosal sleeve resection described herein. In this series, there were no anastomotic leaks, no clinically evident strictures and no recurrence of prolapse in 1.5- to 19-year follow-up. Surgical therapy for rectal prolapse in infants and children is rarely necessary. Various complicated or ineffective operations for the treatment of this condition have been recommended in the past. This technique offers a simple, safe, and effective method of treating complete, medically intractable rectal prolapse in children.

Adolescent↗
PubMed1990

Long-term follow-up of brachial artery ligation in children.

Ligation of the brachial artery in the antecubital fossa in children can be performed without limb loss, but the effect on subsequent limb growth is unknown. From 1969 to 1974, brachial artery ligation for insertion of a Scribner shunt was performed in 27 patients with a mean age of 8.4 years (range, 3 to 15 years). We examined 11 patients, all with functional renal transplants, a mean of 15.8 years (range, 13 to 18 years) after ligation. Nine patients had unilateral ligation and two had bilateral ligation. The patients were examined for arm length and circumference, resting blood pressure at the wrist, neurologic function of the arm, and exercise tolerance. A significant difference in resting arterial pressures in the ligated extremity was uniformly noted (mean systolic pressure 106 mmHg versus 123 mmHg in 7 patients, p less than 0.01). Although no patient specifically complained of problems with the ligated side, six of nine patients with unilateral ligation experienced arm discomfort on stress testing. There was no significant difference in limb circumference or length between the ligated and unligated extremity. Ligation of the brachial artery in growing children with renal disease caused diminished resting pressure and mildly decreased exercise tolerance but did not lead to limb loss or subsequent growth abnormalities.

Adolescent↗
PubMed1989

Use of magnetic resonance imaging in planning the separation of omphalopagus conjoined twins.

Magnetic resonance imaging (MRI) was used for the first time in the preoperative planning for separation of conjoined twins. In these omphalopagus infants, MRI showed normal biliary and cardiovascular structures and demonstrated, in detail, a relatively avascular plane through the liver bridge, which enabled safe separation with minimal blood loss at 3 1/2 months of age. A single MRI study supplied information superior to that obtained with multiple previously available imaging studies. MRI should be an essential part of the preoperative workup of all types of conjoined twins.

Abdomen↗
PubMed1989

Percutaneous insertion of subclavian venous catheters in infants and children.

All attempts at subclavian venous catheterization by the Pediatric Surgery Service done during a one and one-half year period at the Children's Hospital of Los Angeles were prospectively studied. Catheterization was attempted in 107 patients with a mean age of 9.8 years. Cannulation of the vein was successful 89 times (71 per cent) with the major complications being arterial puncture (8.0 per cent), pneumothorax (2.4 per cent) and abnormal position (12.8 per cent). Fluoroscopy was a valuable adjunct when used, resulting in an 86 per cent success rate. The serious complication rate was similar between left and right-sided attempts, but more catheters were abnormally positioned during right-sided attempts (15.7 versus 5.2 per cent). Percutaneous insertion of subclavian venous catheters can be accomplished in infants and children with low morbidity. Cannulation of the left subclavian vein can be accomplished with a similar success rate and a lower malposition rate than the right side. Fluoroscopy is a useful tool to assist in the correct placement of the catheter.

Adolescent↗
PubMed1988

Measured energy expenditure in critically ill infants and young children.

Technological limitations have impeded accurate energy expenditure assessment in critically ill infants and young children. Instead, a predicted energy expenditure (PEE) is derived based on weight, heat loss, activity, growth requirements, and degree of stress. This study compared actual measured energy expenditure (MEE) with conventional predicted values in 20 critically ill infants and children using a validated metabolic cart designed for use in this age group. All patients were studied either within 4 days of major surgery or during an acute disease process necessitating intensive care. All were severely stressed clinically and were studied while mechanically ventilated in a temperature-controlled environment. The study interval ranged from 1 to 12 hr and averaged 4 hr after a stabilization period of 30 min. The mean MEE was significantly lower than the mean PEE (52.2 +/- 16 kcal/kg/day vs 101.8 +/- 17 kcal/kg/day, P less than 0.001) with a mean MEE/PEE of 52.6 +/- 17% (range 26 to 92%). In a subgroup of 7 paralyzed patients, the mean MEE was significantly lower than in the 13 nonparalyzed patients when compared with PEE and predicted basal metabolic rate (PBMR). The coefficient of variance, conventionally recognized to be approximately 15% for PEE, averaged 6.35% for MEE in this study. These data indicate that if PEE is used as the sole guide for caloric repletion in the stressed infant or child, these patients will be substantially overfed.

Basal Metabolism↗
PubMed1986

Perioperative nutritional support in the cancer patient.

Cancer patients in whom elective surgical intervention is planned are frequently malnourished. Moreover, the tumor itself may be responsible for additionally altering metabolism in the host, although the mechanisms by which this occurs are not clear. All preoperative cancer patients should be carefully surveyed for indices of malnutrition. Patients with a history of inadequate oral protein and calorie intake, an unintentional weight loss of greater than 10 pounds, or a serum albumin level of less than 3.5 gm per dl should undergo a thorough nutritional assessment, including anthropometric measurements, 24-hour urinary urea nitrogen and creatinine measurements, and recall skin antigen testing. Surgical risk may be predicted by using indices that are sensitive and specific in assessing preoperative parameters of malnutrition. Adequate nutritional support for 7 to 10 days prior to surgery should be provided to all patients falling into the high-risk category and has been shown to significantly reduce the rate of postoperative complications and death in this group. Generally, a serum albumin of less than 3 gm per dl, a recent unintentional weight loss of greater than 10 to 15 per cent of normal body weight, and/or skin test anergy should be considered to designate high risk. In the formulation of a nutritional plan, estimates of daily energy requirements are essential and can be made by use of the Harris-Benedict equation, metabolic cart measurements, and perhaps 24-hour urinary creatinine values. Generally, 30 to 45 kcal per kg of body weight with 1.2 to 1.5 gm of protein per kg of body weight daily, regardless of the route of delivery, will provide adequate nutritional support. Patients should be fed by the enteral route if possible. Although oral intake is preferable, many malnourished cancer patients will be unable to achieve necessary protein and calorie requirements in this manner.(ABSTRACT TRUNCATED AT 250 WORDS)

Anthropometry↗
PubMed1985

Complications after use of the Angelchik antireflux prosthesis.

We report two cases of severe complications after insertion of an Angelchik antireflux prosthesis. In one case, the prosthesis migrated into the pelvis. In the other, severe dysphagia resulted from its insertion. In both instances, surgical removal was required. The high incidence of complications following the use of this prosthesis would suggest that other safer antireflux operations should be the preferred form of therapy.

Aged↗
PubMedDate not supplied

Broad line quantitative chemical shift spectroscopy.

Proton NMR spectroscopy was applied to quantitate the measurement of total body water/fat distributions in vivo. A special MR protocol was developed to excite a thick slab of tissue and display the magnitude NMR spectrum of the collected response signal. Very short echo time TE (8 ms) and long repetition time TR (4000 ms) were used to minimize relaxation damping of the signal intensities. The spectrum was then decomposed into individual lines and proton densities of different species were calculated. Proton density information was converted into weight percentage data using stoichiometrical and physiological information. The technique was validated using phantoms that contained different mixtures of water/maize oil. A high-resolution NMR spectrum of maize oil samples was used to determine the stoichiometric information. The test results showed good agreement with the known composition of the phantom within the whole range of water content (0-100%). This method is very fast since no phase encoding of data is required. Preliminary results for monkeys show promising potential in clinical applications.

Adipose Tissue↗