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Post-cesarean section pain secondary to intussuscepting colonic adenocarcinoma.

The differential diagnosis for lower abdominal and pelvic pain following Cesarean section includes many causes, such as endometritis, abscess, pelvic hematoma, wound complications, pelvic vein thrombophlebitis, gastrointestinal dysfunction and obstruction. Colonic obstruction secondary to intussusception is a rare cause. We present a case of post-Cesarean section pain in a 26-year-old patient due to obstructing colonic intussusception secondary to colonic adenocarcinoma. Review of the literature failed to identify a previous case report of colonic adenocarcinoma with intussusception presenting early in the postpartum period. The diagnosis was initially made by ultrasound, and later corroborated by computed tomography, barium enema and laparotomy.

Adenocarcinoma↗

Tolerance and efficacy of intravenous iron saccharate for iron deficiency anemia in children and adolescents receiving long-term parenteral nutrition.

UNLABELLED: The aim of this study was to evaluate the safety and efficacy of intravenous iron saccharate administration in iron-deficient anemic children, under long-term parenteral nutrition, who are unable to tolerate oral iron supplementation or are unresponsive to oral supplementation because of gastrointestinal dysfunction or iron malabsorption. METHODS: Twenty-two infants and children aged 5 months-17 years (median: 38 months) receiving long-term parenteral nutrition and presenting with iron deficiency anemia were included. Total iron to be infused was determined by the formula: total iron (mg) = 0.6 x W (100 - Hb x 100/12) (W: weight, Hb: hemoglobin). Intravenous iron saccharate was given at the hospital. Each patient received a test dose of 25 mg of iron saccharate prior to the initiation of the infusion. Hemoglobin values, reticulocytes count, serum iron, and serum ferritin were determined before iron administration (day 1), as well as 15 and 45 days after iron administration. RESULTS: Tolerance of intravenous iron saccharate was good except in one patient who developed transient exanthema and hypotension after completion of the last iron saccharate infusion. Intravenous iron led to a significative increase in hemoglobin concentration of 2.2 g/dl within 45 days (range: 0.4-4.3 g/dl). CONCLUSION: Intravenous iron supplementation with iron saccharate is an efficient procedure, replenishing iron body stores and significantly increasing the hemoglobin concentration. The possible occurrence of allergic reactions emphasizes the need for close medical supervision.

Adolescent↗

Cost considerations in sedation, analgesia, and neuromuscular blockade in the intensive care unit.

Sedation of critically ill patients is a costly endeavor. Costs of commonly used intensive care unit (ICU) sedatives range from pennies to more than $500 per day. Although the agents account for some of this expense, complications related to the use of these drugs in the ICU produce even greater costs. Prolongation of mechanical ventilation and length of stay are some of the common complications resulting from non-ideal use of these drugs. Sedative agents also impair neurological evaluation in many critically ill patients, which may mask detection of acute delirium resulting from intercurrent illness or intracranial catastrophes and can lead to excessive diagnostic testing. Opiates may result in gastrointestinal dysfunction with resulting malnutrition and perhaps bacterial translocation and sepsis. Neuromuscular blocking agents may cause prolonged paralysis and disability in critically ill patients who receive them. Simple dosing strategies based on pharmacological principles may decrease the incidence of these costly problems.

Journal Article↗

The effects of ibuprofen on the physiology and survival of patients with sepsis. The Ibuprofen in Sepsis Study Group.

BACKGROUND: In patients with sepsis the production of arachidonic acid metabolites by cyclooxygenase increases, but the pathophysiologic role of these prostaglandins is unclear. In animal models, inhibition of cyclooxygenase by treatment with ibuprofen before the onset of sepsis reduces physiologic abnormalities and improves survival. In pilot studies of patients with sepsis, treatment with ibuprofen led to improvements in gas exchange and airway mechanics. METHODS: From October 1989 to March 1995, we conducted a randomized, double-blind, placebo-controlled trial of intravenous ibuprofen (10 mg per kilogram of body weight [maximal dose, 800 mg], given every six hours for eight doses) in 455 patients who had sepsis, defined as fever, tachycardia, tachypnea, and acute failure of at least one organ system. RESULTS: In the ibuprofen group, but not the placebo group, there were significant declines in urinary levels of prostacyclin and thromboxane, temperature, heart rate, oxygen consumption, and lactic acidosis. With ibuprofen therapy there was no increased incidence of renal dysfunction, gastrointestinal bleeding, or other adverse events. However, treatment with ibuprofen did not reduce the incidence or duration of shock or the acute respiratory distress syndrome and did not significantly improve the rate of survival at 30 days (mortality, 37 percent with ibuprofen vs 40 percent with placebo). CONCLUSIONS: In patients with sepsis, treatment with ibuprofen reduces levels of prostacyclin and thromboxane and decreases fever, tachycardia, oxygen consumption, and lactic acidosis, but it does not prevent the development of shock or the acute respiratory distress syndrome and does not improve survival.

Acidosis, Lactic↗

Enteral glutamine supplementation and morbidity in low birth weight infants.

OBJECTIVE: To determine if glutamine-supplemented enteral nutrition decreased the incidence of nosocomial sepsis in neonates. METHODS: In a multicenter (n = 20) clinical trial, we randomly allocated infants (n = 649) with birth weight between 500 and 1250 g, who were <7 days of age, and had no major anomalies to receive enteral glutamine supplementation (0.3 g/kg/day) or sterile water (placebo) for the first 28 days. The primary outcome variable was the number of infants who had blood culture-proven nosocomial sepsis between 7 days' and 36 weeks' postmenstrual age. RESULTS: Infants were assigned to placebo (n = 335) or to glutamine supplementation (n = 314). Neonates assigned to glutamine were similar to those assigned placebo for demographic characteristics and nutritional support during the first week. There was no difference in the occurrence of culture-proven nosocomial sepsis (33.7% vs 30.9%) or suspected sepsis (51.6% vs 47.1%) between the placebo and glutamine groups; however, neonates treated with glutamine less often had gastrointestinal dysfunction (7.5% vs 2.5%, P <.01) and severe neurologic sequelae (15.1% vs 10.4%, P =.08). CONCLUSIONS: At a dose of 0.3 g/kg/day, enteral glutamine does not appear to reduce nosocomial sepsis in premature neonates.

Adolescent↗

Outcome of gastrointestinal complications after liver transplantation for familial amyloidotic polyneuropathy.

BACKGROUND: Gastrointestinal disturbances are important prognostic factors for mortality and morbidity after liver transplantation for familial amyloidotic polyneuropathy (FAP). However, the impact of liver transplantation on malabsorption and bacterial small-bowel contamination has not been evaluated. METHODS: Twenty-three FAP patients were available for the study. They were examined for gastrointestinal disturbances as a part of the evaluation for liver transplantation for FAP. Bile acid malabsorption was diagnosed with the [75Se]-homocholic acid taurate (SeHCAT) test; fat malabsorption by measuring faecal fat excretion; and bacterial small-bowel contamination with the hydrogen breath test (HBT). RESULTS: No significant improvement of malabsorption test results were noted from the pre-transplant evaluation 8 months (range, 2-20 months) before transplantation to the post-transplant evaluation performed a median of 20 months (range, 9-62 months) after the procedure. The SeHCAT test result became abnormal in two patients and normal in one, and changes in the test correlated with the time the patients were waiting for transplantation. Faecal fat excretion after transplantation correlated with duration of the disease and with fat excretion before transplantation. A significantly increased fat excretion was noted at the post-transplant evaluation. A change in HBT result was noted in only one patient, in whom the test result became normal; pre-transplant values correlated with those obtained after transplantation. CONCLUSION: For most FAP patients no improvement in gastrointestinal function was found after transplantation. The finding underlines the importance of an early transplantation before the patients have developed gastrointestinal dysfunction.

Adult↗

Gallbladder contraction in familial dysautonomia.

The impaired function of the autonomic nervous system in patients with familial dysautonomia (FD) is frequently associated with gastrointestinal dysfunction. This study sought to determine whether gallbladder contraction is also affected in these patients. Nine consecutive patients with FD were assessed by real-time ultrasonography for gallbladder volume and calculated percentage of gallbladder contraction before and 45-60 min after a 50 g fatty meal, and compared with nine healthy control patients, matched for age and gender. Gallbladder volume before the fatty meal was found to be larger in healthy controls than in FD patients (25.4+/-9.5 and 15.4+/-7.4 ml3, respectively; p = 0.024). No significant difference was demonstrated between the groups after the fatty meal (controls: 12.1+/-6.0; FD: 9.0+/-6.6 ml, respectively) and the calculated percentage of gallbladder contraction was similar in both groups (controls: 53.4+/-16.6; FD: 44.8+/-18.8%). These results indicate that gallbladder function in FD patients does not differ from the general population and preventive measures for gallstone formation are not required.

Abdominal Pain↗

Disseminated intravascular coagulation in pediatric patients: clinical and laboratory features and prognostic factors influencing the survival.

Although disseminated intravascular coagulation (DIC) has been a well-known disorder for many years, there is lack of sufficient number of clinical trials about incidence, frequency of underlying disorders, and prognosis of DIC in children. The aim of this study was to evaluate the frequency, etiologic factors, and clinical and laboratory findings of DIC and to determine the prognostic factors influencing the mortality in hospitalized pediatric patients. Medical records of 5535 children who were hospitalized were investigated. Sixty-two patients who were diagnosed as acute DIC were enrolled. The frequency of DIC was 1.12%. The underlying etiologic factors were infection in 59 patients (95.2%) and major trauma in 3 patients (4.8%). The frequency of bleeding and thrombosis was 48.8 and 4.8%. Respiratory, cardiovascular, hepatic, renal, neurologic, and gastrointestinal dysfunction was present in 71, 67.7, 35.5, 16.1, 16.1 and 11.3% of patients, respectively. Respiratory and cardiovascular dysfunctions were significantly associated with mortality. Multiorgan dysfunction syndrome (MODS) was present in 85.5% of the patients, and 54.8% of the patients had developed acute respiratory distress syndrome (ARDS). Mortality rate was significantly high in patients with MODS and ARDS. In multivariete logistic regression analysis, only ARDS and cardiovascular dysfunction had predictive and prognostic value on mortality. None of the diagnostic laboratory tests had predictive or prognostic value and the degree of abnormality of these tests did not show any correlation with mortality. In conclusion, DIC is not a rare disorder in hospitalized children, especially in patients with sepsis, and MODS, ARDS, and respiratory and cardiovascular system dysfunctions are poor prognostic factors.

Acute Disease↗

Biochemistry of cyclooxygenase (COX)-2 inhibitors and molecular pathology of COX-2 in neoplasia.

Several types of human tumors overexpress cyclooxygenase (COX) -2 but not COX-1, and gene knockout transfection experiments demonstrate a central role of COX-2 in experimental tumorigenesis. COX-2 produces prostaglandins that inhibit apoptosis and stimulate angiogenesis and invasiveness. Selective COX-2 inhibitors reduce prostaglandin synthesis, restore apoptosis, and inhibit cancer cell proliferation. In animal studies they limit carcinogen-induced tumorigenesis. In contrast, aspirin-like nonselective NSAIDs such as sulindac and indomethacin inhibit not only the enzymatic action of the highly inducible, proinflammatory COX-2 but the constitutively expressed, cytoprotective COX-1 as well. Consequently, nonselective NSAIDs can cause platelet dysfunction, gastrointestinal ulceration, and kidney damage. For that reason, selective inhibition of COX-2 to treat neoplastic proliferation is preferable to nonselective inhibition. Selective COX-2 inhibitors, such as meloxicam, celecoxib (SC-58635), and rofecoxib (MK-0966), are NSAIDs that have been modified chemically to preferentially inhibit COX-2 but not COX-1. For instance, meloxicam inhibits the growth of cultured colon cancer cells (HCA-7 and Moser-S) that express COX-2 but has no effect on HCT-116 tumor cells that do not express COX-2. NS-398 induces apoptosis in COX-2 expressing LNCaP prostate cancer cells and, surprisingly, in colon cancer S/KS cells that does not express COX-2. This effect may due to induction of apoptosis through uncoupling of oxidative phosphorylation and down-regulation of Bcl-2, as has been demonstrated for some nonselective NSAIDs, for instance, flurbiprofen. COX-2 mRNA and COX-2 protein is constitutively expressed in the kidney, brain, spinal cord, and ductus deferens, and in the uterus during implantation. In addition, COX-2 is constitutively and dominantly expressed in the pancreatic islet cells. These findings might somewhat limit the use of presently available selective COX-2 inhibitors in cancer prevention but will probably not deter their successful application for the treatment of human cancers.

Animals↗

Effects of lead on Na(+)-K(+) ATPase and Ca(+2) ATPase activities and lipid peroxidation in blood of workers.

Lead is considered one of the major environmental toxicants that causes hematological, neurological, and gastrointestinal dysfunction. In this study, the authors examined the relationship between lead and lipid peroxidation, lead and Na(+)-K(+) ATPase activity, and lead and Ca(+2) ATPase activity in blood of workers. The working group consisted of 30 male workers occupationally exposed to lead at least for 10 years. The control group consisted of 20 healthy male individuals not involved with job-related lead exposures. Blood lead content of the control group and the working group were 10.0 +/- 1.8 microg/dl and 317.3 +/- 47.6 microg/dl, respectively. Malondialdehyde (MDA) value of the working group (0.57 +/- 0.30 nmol MDA/ml) was significantly greater than MDA value of the control goup (0.17 +/- 0.02 nmol MDA/ml). In the working group, both Na(+)-K(+) ATPase activity (105.0 +/- 47.0 nmol Pi. mg protein(-1) x h(-1)) and Ca(+2) ATPase activity (58.0 +/- 40.0 nmol Pi. mg protein(-1) x h(-1)) were lower compared with the corresponding values of Na(+)-K(+) ATPase activity (247.0 +/- 41.0 nmol Pi. mg protein(-1) x h(-1)) and Ca(+2) ATPase activity (230.0 +/- 41.0 nmol Pi. mg protein(-1) x h(-1)) of normal controls. The results show that lead exposure causes inhibition of Na(+)-K(+) ATPase and Ca(+2) ATPase activities and also results in increased lipid peroxidation.

Adult↗

Subacute myelo-optico-neuropathy (SMON) following pneumonitis. Serologic confirmation three and a half years after death.

A case of fulminant subacute myelooptico-neuropathy that occurred in a native American women following pneumonitis instead of the usual gastrointestinal dysfunction is reported. After the acute stage, which left the patient paraplegic and partially blind, she suffered an exacerbation which resulted in her death 11 months after the onset of illness. Autopsy disclosed symmetric optic and spinal demyelination. Neutralizing antibody titer against subacute, myelo-optico-neuropathy virus was determined on postmortem serum 3 1/2 years after death and found significantly elevated.

Abdomen↗

The effects of balanced versus saline-based hetastarch and crystalloid solutions on acid-base and electrolyte status and gastric mucosal perfusion in elderly surgical patients.

UNLABELLED: The IV administration of sodium chloride solutions may produce a metabolic acidosis and gastrointestinal dysfunction. We designed this trial to determine whether, in elderly surgical patients, crystalloid and colloid solutions with a more physiologically balanced electrolyte formulation, such as Hartmann's solution and Hextend, can provide a superior metabolic environment and improved indices of organ perfusion when compared with saline-based fluids. Forty-seven elderly patients undergoing major surgery were randomly allocated to one of two study groups. Patients in the Balanced Fluid group received an intraoperative fluid regimen that consisted of Hartmann's solution and 6% hetastarch in balanced electrolyte and glucose injection (Hextend). Patients in the Saline group were given 0.9% sodium chloride solution and 6% hetastarch in 0.9% sodium chloride solution (Hespan). Biochemical indices and acid-base balance were determined. Gastric tonometry was used as a reflection of splanchnic perfusion. Postoperative chloride levels demonstrated a larger increase in the Saline group than the Balanced Fluid group (9.8 vs 3.3 mmol/L, P = 0.0001). Postoperative standard base excess showed a larger decline in the Saline group than the Balanced Fluid group (-5.5 vs -0.9 mmol/L, P = 0.0001). Two-thirds of patients in the Saline group, but none in the Balanced Fluid group, developed postoperative hyperchloremic metabolic acidosis (P = 0.0001). Gastric tonometry indicated a larger increase in the CO2 gap during surgery in the Saline group compared with the Balanced Fluid group (1.7 vs 0.9 kPa, P = 0.0394). In this study, the use of balanced crystalloid and colloid solutions in elderly surgical patients prevented the development of hyperchloremic metabolic acidosis and resulted in improved gastric mucosal perfusion when compared with saline-based solutions. IMPLICATIONS: This prospective, randomized, blinded trial showed that, in elderly surgical patients, the use of balanced IV solutions can prevent the development of hyperchloremic metabolic acidosis and provide better gastric mucosal perfusion compared with saline-based fluids.

Acid-Base Equilibrium↗

Continent urinary diversion. A 5 1/2 year experience.

From August 1982 through March 1988, 531 patients have undergone continent urinary diversion using an ileal reservoir constructed according to the method of Kock. For the past year, the Division of Urology at the USC School of Medicine in Los Angeles has used the principle of Kock reservoir construction for primary lower urinary tract reconstruction after cystectomy in 39 highly selected male patients by means of a ureteroileal urethrostomy. Early complications occurred in 86 of 531 patients (16.2%), resulting in an operative mortality rate of 1.9% (ten of 531). The early complication rate was 16.5% in patients undergoing single stage cystectomy and Kock pouch construction and 15.2% among patients undergoing Kock pouch conversion. Late complications have been analyzed in a group of 489 patients who have undergone Kock cutaneous diversion. The complications unique to continent urinary diversion, their incidence, and the effect of technical modifications in reducing the number of late complications are discussed. Since the time of the last modification, in July 1985, the overall incidence of late complication has dropped to 22%. Based on this ongoing experience, the authors conclude that: 1) the continent ileal reservoir as conceived by Kock remains the best internal reservoir for bladder replacement in terms of volume, accommodation with the lowest internal pressures compared with other alternative reservoir construction, 2) the intussuscepted ileal nipple valve mechanism is a reproducible, highly effective mechanism that prevents reflux in 95% of patients and produces excellent continence, 3) our enthusiasm remains tempered by the need for reoperation in approximately 10-15% of patients, usually due to a pinhole fistula or false passage at the base of the efferent nipple valve mechanism, 4) electrolyte abnormalities rarely occur and gastrointestinal dysfunction is unusual in the absence of radiation, and 5) continent urinary diversion is a viable long-term concept that provides a real alternative in terms of quality of life and self-image for the patient undergoing urinary diversion.

Adolescent↗

Anabolic therapy with growth hormone accelerates protein gain in surgical patients requiring nutritional rehabilitation.

OBJECTIVE: The authors investigated the effects of exogenous growth hormone (GH) on protein accretion and the composition of weight gain in a group of stable, nutritionally compromised postoperative patients receiving standard hypercaloric nutritional therapy. SUMMARY BACKGROUND DATA: A significant loss of body protein impairs normal physiologic functions and is associated with increased postoperative complications and prolonged hospitalization. Previous studies have demonstrated that standard methods of nutritional support enhance the deposition of fat and extracellular water but are ineffective in repleting body protein. METHODS: Fourteen patients requiring long-term nutritional support for severe gastrointestinal dysfunction received standard nutritional therapy (STD) providing approximately 50 kcal/kg/day and 2 g of protein/kg/day during an initial 7-day equilibrium period. The patients then continued on STD (n = 4) or, in addition, received GH 0.14 mg/kg/day (n = 10). On day 7 of the equilibrium period and again after 3 weeks of treatment, the components of body weight were determined; these included body fat, mineral content, lean (nonfat and nonmineral-containing tissue) mass, total body water, extracellular water (ECW), and body protein. Daily and cumulative nutrient balance and substrate oxidation studies determined the distribution, efficiency, and utilization of calories for protein, fat, and carbohydrate deposition. RESULTS: The GH-treated patients gained minimal body fat but had significantly more lean mass (4.311 +/- 0.6 kg vs. 1.988 +/- 0.2 kg, p < or = 0.03) and more protein (1.417 +/- 0.3 kg vs. 0.086 +/- 0.1 kg, p < or = 0.03) than did the STD-treated patients. The increase in lean mass was not associated with an inappropriate expansion of ECW. In contrast, patients receiving STD therapy tended to deposit a greater proportion of body weight as ECW and significantly more fat than did GH-treated patients (1.004 +/- 0.3 kg vs. 0.129 +/- 0.2 kg, p < 0.05). GH administration altered substrate oxidation (respiratory quotient = 0.94 +/- 0.02 GH vs. 1.17 +/- 0.05 STD, p < or = 0.0002) and the use of available energy, resulting in a 66% increase in the efficiency of protein deposition (13.37 +/- 0.8 g/1000 kcal vs. 8.04 g +/- 3.06 g/1000 kcal, p < or = 0.04). CONCLUSIONS: GH administration accelerated protein gain in stable adult patients receiving aggressive nutritional therapy without a significant increase in body fat or a disproportionate expansion of ECW. GH therapy accelerated nutritional repletion and, therefore, may shorten the convalescence of the malnourished patient requiring a major surgical procedure.

Adult↗

Regional analgesia in the critically ill.

OBJECTIVE: The objective of this review is to analyze and describe the use of regional analgesia in the critically ill. DATA SOURCE: A Medline search from 1966 to 2004 using the search terms critically ill, nerve blocks, regional analgesia, and regional anesthesia, as well as a search in the Cochrane library, was performed, and standard international textbooks related to critical care and regional anesthesia were searched for practice recommendations. STUDY SELECTION: Studies, case reports, and review articles relevant to the topic were included. DATA EXTRACTION AND SYNTHESIS: Data were extracted and analyzed in a descriptive fashion. CONCLUSION: Regional analgesia using single-injection regional blocks and continuous neuraxial and peripheral catheters can play a valuable role in a multimodal approach to pain management in the critically ill patient to achieve optimum patient comfort and to reduce physiologic and psychological stress. By avoiding high systemic doses of opioids, several complications like withdrawal syndrome, delirium, mental status changes, and gastrointestinal dysfunction can be reduced or minimized. Because of limited patient cooperation during placement and monitoring of continuous regional analgesia, indications for their use must be carefully chosen based on anatomy, clinical features of pain, coagulation status, and logistic circumstances. High-quality nursing care and well-trained physicians are essential prerequisites to use these techniques safely in the critical care environment.

Analgesia, Epidural↗

Pathogenesis and consequences of HIV-associated wasting.

Weight loss is a negative prognostic indicator in patients infected with HIV. Mortality rates rise measurably with as little as 3-5% weight loss over 6 months. The sensitivity of this measure is at least partly due to the correlation between weight loss and a metabolic cachexia that has been observed with other infections, trauma, and some cancers. However, the cachexia in patients with HIV, commonly termed wasting, may also be due to, or exacerbated by, reduced caloric intake, gastrointestinal dysfunction, or metabolic abnormalities independent of abnormal energy expenditure. In patients with HIV wasting, therapies should be directed both at reversing the underlying source of protein energy malnutrition and at other factors that may be contributing to weight loss.

Antiretroviral Therapy, Highly Active↗

The gall of subordination: changes in gall bladder function associated with social stress.

Diverse physiological and behavioural mechanisms allow animals to effectively deal with stressors, but chronic activation of the stress axis can have severe consequences. We explored the effects of chronic social stress on agonistic behaviour and gall bladder function, a critical but widely neglected component of stress-induced gastrointestinal dysfunction. Prolonged cohabitation with dominant individuals elicited behavioural modifications and dramatically increased bile retention in subordinate convict cichlid fish (Archocentrus nigrofasciatum). The key predictor of gall bladder hypertrophy was social subordination rather than status-related differences in food intake or body size. Stress-induced inhibition of gall bladder emptying could affect energy assimilation such that subordinate animals would not be able to effectively convert energy-rich food into mass gain. These results parallel changes in gall bladder function preceding cholesterol gallstone formation in humans and other mammals. Thus, social stress may be an important diagnostic criterion in understanding pathologies associated with gall bladder dysfunction.

Agonistic Behavior↗

Wavelet-based enhancement of lung and bowel sounds using fractal dimension thresholding--Part II: application results.

The application of the wavelet transform-fractal dimension-based (WT-FD) filter of Part I of this paper to real bioacoustic data, which include explosive lung sounds (ELS) and explosive bowel sounds (EBS) recorded from patients with pulmonary or gastrointestinal dysfunction, respectively, is presented in this paper. The objective of the latter is the evaluation of the performance of the WT-FD filter on different types of bioacoustic signals, varying not only in their structural morphology but also in the degree of their noise contamination. As it is thoroughly described in Part I of this paper, the WT-FD filter uses the fractal dimension to form an efficient way of thresholding the WT coefficients at different resolution scales, keeping, thus, only those that can contribute to the accurate reconstruction of the ELS and EBS signals. Quantitative and qualitative analysis of the experimental results show an efficient performance of the WT-FD filter to circumvent the noise presence (100% detectability rate, 100% sensitivity, 100% specificity) by faithfully extracting the authentic structure of ELS and EBS from the background noise. The WT-FD filter does not require any noise reference signal or noise reference templates. The results from a noise stress test (mean cross-correlation index of the original and the estimated signal converging to 100%; mean normalized maximum amplitude error converging to 0.7%) prove its robustness to various noise levels (0-20 dB), enabling its potential use in similar noise cases met in everyday clinical medicine. Furthermore, the efficient performance of the WT-FD filter facilitates the physician to better interpret the auscultation findings. Due to its simplicity and low computational cost, the WT-FD filter can possibly be implemented in a real-time context to serve as a tool for the continuous ELS and EBS screening.

Adult↗