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Biomedical subjects

S Malviya

Publications and source records attributed to S Malviya.

At least 37 records · Page 2Linked to original sources
PubMed1999

The effect of a right-to-left intracardiac shunt on the rate of rise of arterial and end-tidal halothane in children.

UNLABELLED: In this prospective study, we evaluated the effect of a right-to-left intracardiac shunt on the rate of rise of end-tidal and arterial halothane concentration in children. Six children aged 23-43 mo undergoing surgical closure of atrial fenestration after Fontan procedure were given 0.8% inspired halothane. End-tidal halothane was recorded at 1-min intervals after the introduction of halothane. Arterial halothane concentrations were determined 0, 1, 3, 5, 10, and 15 min after the introduction of halothane. The sampling was performed before and after closure of the atrial fenestration. The ratio of pulmonary to systemic blood flow (Qp/Qs) increased in this patient population, from 0.58 +/- 0.04 to 0.88 +/- 0.12 (P = 0.01). The rate of rise of end-tidal halothane did not change significantly with a decrease in the magnitude of the right-to-left intracardiac shunt after closure of the atrial fenestration. The ratio of arterial to inspired halothane concentrations at 1, 3, 5, 10, and 15 min were lower before closure of the atrial fenestration compared with after closure (P < 0.05). We conclude that the presence of a right-to-left intracardiac shunt significantly slows the rate of rise of arterial halothane in the face of a constant inspired concentration. The rate of rise of end-tidal halothane is not significantly affected in the presence of a right-to-left intracardiac shunt. IMPLICATIONS: In this prospective study, we found a slower rate of rise of halothane in arterial blood in children with right-to-left intracardiac shunting. Induction of anesthesia by inhalation of volatile anesthetics may therefore be slower in these children.

Anesthesia, General↗
PubMed1998

Evaluation of simethicone for the treatment of postoperative abdominal discomfort in infants.

STUDY OBJECTIVE: To determine whether abdominal discomfort is a cause for distress symptoms in infants following administration of inhalational anesthesia, and to evaluate the effectiveness of simethicone in treating this discomfort. DESIGN: Randomized, double-blinded study. SETTING: Large tertiary care, university-based medical center. PATIENTS: 175 ASA physical status I and II infants under 28 months of age who underwent an inhalational anesthetic for a variety of procedures that were expected to cause relatively little pain. INTERVENTIONS: Children were assessed for the presence of postoperative abdominal discomfort, and, if evident, were randomly given either simethicone or placebo in a double-blinded fashion. MEASUREMENTS AND MAIN RESULTS: Abdominal discomfort was measured using the Faces Legs Activity Cry and Consolability (FLACC) Behavioral Pain Scale. Scores were recorded pre-drug; at 10, 20, and 30 minutes following drug administration; and at discharge. If discomfort had not resolved within 15 minutes after the drug was given, routine analgesics or other medications were administered. Abdominal girth was measured preoperatively, on admission into the postanesthesia care unit (PACU), and at discharge. 21% of infants exhibited symptoms of abdominal discomfort postoperatively. Younger infants were at greater risk for this condition. 36 infants were given either placebo or simethicone, and of these, infants who received simethicone were comfortable earlier and required fewer rescue medications compared with placebo. There were no differences in ability to tolerate oral fluids prior to discharge or in the length of stay in the PACU. CONCLUSIONS: Simethicone is a safe and inexpensive medication that may provide anesthesiologists with an effective treatment choice for suspected postoperative abdominal discomfort in infants.

Abdominal Pain↗
PubMed1998

Prolonged recovery stay and unplanned admission of the pediatric surgical outpatient: an observational study.

STUDY OBJECTIVE: To determine the incidence of and reasons for prolonged length of stay in the postanesthesia care unit and unplanned hospital admissions of children scheduled for outpatient surgery. DESIGN: Prospective, observational cohort study. SETTING: C. S. Mott Children's Hospital, a tertiary care setting. PATIENTS: 168 ASA physical status I, II, and III children (birth to 18 years), 130 of whom experienced a prolonged length of stay and 61 who had an unplanned hospital admissions. MEASUREMENTS AND MAIN RESULTS: 3.9% of annual outpatient population experienced a prolonged length of stay, and 1.9% had an unplanned outpatient admission. Prolonged length of stay was most commonly due to postoperative nausea and vomiting (19%) or respiratory complications (16%), whereas unplanned hospital admissions were primarily for respiratory or surgical reasons (32% and 30%, respectively). Higher ASA status had a significant direct relationship with the incidence of unplanned outpatient admission and respiratory complications. Although most families were satisfied with the length of their child's care, 28% of parents whose children were sent home after a prolonged length of stay would have preferred a short hospital admission, and 16% of parents of children with an unplanned hospital admission would have preferred a longer stay in recovery and discharge home. CONCLUSION: Prolonged length of stay and unplanned hospital admissions were uncommon outcomes following pediatric outpatient surgery. However, the impact of such outcomes on hospital staffing and family convenience may have implications related to cost containment and patient satisfaction.

Adolescent↗
PubMed1998

Factors that influence parents' decisions to consent to their child's participation in clinical anesthesia research.

UNLABELLED: There is concern that the environment in which consent for anesthesia research is sought may be coercive. We therefore designed this study to determine the factors that parents consider in consenting to their child's participation in clinical anesthesia research. The study sample consisted of 246 parents who had been approached for permission to allow their child to participate in a clinical anesthesia study. Parents were asked to complete a questionnaire detailing the reasons for their decision to consent or decline their child's participation. There were no differences in the demographics of the consenters (n = 168) and nonconsenters (n = 78). Perceived risk and the importance of the study were the primary factors in the parents' decisions to consent or decline. Only 2.8% of nonconsenters strongly considered a lack of privacy as a deciding factor; 15.3% stated that they had insufficient time in which to make a decision, and 0% reported having felt pressured. Furthermore, only 3.1% of consenters strongly considered an obligation to consent. Results of this survey highlight factors that influence parents' decisions to consent to their child's participation in clinical anesthesia research. We hope that this information will be important to researchers in providing an appropriate environment for obtaining consent for clinical anesthesia research studies. IMPLICATIONS: Parents who are approached for permission for their child to participate in a research study must be fully informed and under no pressure to consent. This study describes factors that influence parents' decisions to consent to their child's participation in clinical anesthesia research.

Adult↗
PubMed1998

Use of the laryngeal mask airway in children with upper respiratory tract infections: a comparison with endotracheal intubation.

UNLABELLED: Several studies suggest that placement of an endotracheal tube (ETT) in a child with an upper respiratory infection (URI) increases the risk of complications. However, the development of the laryngeal mask airway (LMA) has provided anesthesiologists with an alternative means of airway management. This study was therefore designed to evaluate the use of the LMA in children with URIs and to compare it with the ETT. The study sample consisted of 82 pediatric patients (3 mo to 16 yr of age) who presented for elective surgery with an URI. Patients with URIs were randomly allocated to receive either an ETT (n = 41) or a LMA (n = 41) and were followed for the appearance and severity of any perioperative complications. The two groups were similar with respect to age, gender, anesthesia and surgery times, number of attempts at tube placement, and presenting URI symptoms. There were no differences between groups in the incidence of cough, breath-holding, excessive secretions, or arrhythmias. Although one patient in the ETT group required a muscle relaxant for laryngospasm, the overall incidence of laryngospasm was similar between the two groups. There was, however, a significantly greater incidence of mild bronchospasm in the ETT group compared with the LMA group (12.2% vs 0%, P < 0.05). The incidence of major arterial oxygen desaturation events (SpO2 <90%) during placement of the airway device was also significantly increased in the ETT group (12.5% vs 0%, P < 0.05). Furthermore, the total number of all episodes of respiratory complications, i.e., breath-holding, laryngospasm, bronchospasm, and major oxygen desaturation, was significantly greater in the ETT group (35 vs 19, P < 0.05). Despite this, all respiratory complications were easily managed, and there were no adverse sequelae. Although the risks associated with anesthetizing a child with an URI remain controversial, results from this study suggest that the LMA offers a suitable alternative to the ETT for use in children with URIs. IMPLICATIONS: This study compares the use of the laryngeal mask airway with the endotracheal tube for airway management in children with upper respiratory infections. Results suggest that if the decision is made to proceed with anesthesia for the child with an upper respiratory infection, then the laryngeal mask airway provides a suitable alternative to the endotracheal tube.

Adolescent↗
PubMed1997

Effects of anesthetic technique on side effects associated with fentanyl Oralet premedication.

STUDY OBJECTIVES: To evaluate the efficacy of 5 to 10 micrograms/kg of oral transmucosal fentanyl citrate (OTFC) as an anesthetic premedication, and to determine whether propofol induction reduces postoperative nausea and vomiting (PONV) in pediatric patients premedicated with OTFC undergoing outpatient surgery. DESIGN: Prospective, randomized, double-blinded study. SETTINGS: University of Michigan Health Care Systems and University of Arizona. PARTICIPANTS: 62 ASA physical status I and II children aged 4 to 14 years (8.9 +/- 0.5 years). INTERVENTIONS: Subjects were randomly assigned to one of four groups: (1) OTFC premedication and halothane induction; (2) OTFC premedication and propofol induction; (3) placebo premedication and halothane induction; and (4) placebo premedication and propofol induction. OTFC or placebo was administered 30 minutes prior to induction, and activity (sedation), apprehension, and cooperation scores were recorded before, at 15 and 30 minutes after study drug, and on induction. All perioperative adverse events were recorded. MEASUREMENTS AND MAIN RESULTS: Children who received OTFC became drowsier and had a significant change from baseline in combined activity, apprehension, and cooperation scores, whereas those who received placebo became less cooperative at induction. Patients who received OTFC experienced more adverse events overall (p < 0.001) than patients who received placebo. Additionally, OTFC patients experienced more vomiting (p < 0.001) and pruritus (p = 0.049) than controls. The incidence of PONV in patients who received OTFC and halothane induction was 50%, compared to 30% in patients receiving OTFC and a propofol induction (p = NS). CONCLUSIONS: OTFC in doses of 5 to 10 micrograms/kg was effective in producing sedation and facilitating cooperation with induction; however, it was associated with significant PONV in our study. Although propofol induction did not significantly reduce PONV in our study, further study with a larger sample, and with propofol as the sole anesthetic, may be warranted.

Administration, Oral↗
PubMed1997

Evaluation of a case management model for preanesthesia screening.

Case management (CM) is a health care model implemented to reduce health care costs while improving the quality of patient outcomes. Using a CM framework, a preoperative screening program was developed to improve the coordination of care of pediatric patients scheduled for ambulatory surgery or admission on day of procedures at C.S. Mott Children's Hospital. Pediatric patients and their families who attended the preoperative program experienced fewer preoperative delays, perceived less stress, and felt better prepared for surgery and discharge than those who did not participate in the program. Findings from this study showed that the CM preanesthesia screening program was effective in reducing delays because of incomplete workups, and in improving the overall preparedness of families.

Adolescent↗
PubMed1997

Monitoring and management of anticoagulation in children requiring extracorporeal circulation.

Pharmacologic manipulation of hemostasis is a prerequisite for cardiac surgery with cardiopulmonary bypass (CPB) to prevent clot formation in the extracorporeal circuit. Children who require surgical correction of congenital heart defects are at increased risk for prolonged and excessive bleeding after separation from CPB. Heparin remains the anticoagulant of choice for surgery requiring CPB. Traditional regimens of empiric heparin dosing and a fixed-dose ratio of protamine to heparin for reversal of anticoagulation do not account for individual differences in the half-life of heparin, clearance of heparin, and duration of CPB, particularly in children. In addition, the use of prolongation of the activated clotting time (ACT) as a measure of adequate anticoagulation does not account for alterations in ACT by factors unrelated to heparin activity, including hemodilution and hypothermia, that are frequently present during CPB. This manuscript reviews the pitfalls in the management of anticoagulation for children undergoing surgery that requires CPB. Pertinent literature related to the use of aprotinin, a serine protease inhibitor that has been shown to improve hemostasis during and after CPB, is discussed. It is hoped that this article will provide a practical guideline for the rational management of anticoagulation in children with congenital heart disease undergoing CPB surgery.

Anticoagulants↗
PubMed1997

Adverse events and risk factors associated with the sedation of children by nonanesthesiologists.

UNLABELLED: After implementation of hospital-wide monitoring standards, a quality assurance (QA) tool was prospectively completed for 1140 children (aged 2.96 +/- 3.7 yr) sedated for procedures by nonanesthesiologists. The tool captured data regarding demographics, medications used, adequacy of sedation, monitoring, adverse events, and requirement for escalated care. The medical records of children who experienced adverse events were reviewed. Most (99%) children were monitored with pulse oximetry. Chloral hydrate was the most frequently used sedative (74.9% of cases). Of the children, 239 (20.1%) experienced adverse events related to sedation, including inadequate sedation in 150 (13.2%) and decrease in oxygen saturation in 63 (5.5%). Five of these children experienced airway obstruction and two became apneic. No adverse event resulted in long-term sequelae. Of the 854 children who received chloral hydrate, 46 (5.4%) experienced decreased oxygen saturation (> or = 90% of baseline). Children experienced desaturation after the use of chloral hydrate had received the recommended doses of chloral hydrate (38-83 mg/kg). ASA physical status III or IV and age < 1 yr were predictors of increased risk of sedation-related adverse events. These data underscore the importance of appropriate monitoring that includes pulse oximetry to permit early detection of adverse events. IMPLICATIONS: This quality assurance study highlights the risks associated with the sedation of children and emphasizes the importance of appropriate monitoring by trained personnel. Children with underlying medical conditions and those who are very young are at increased risk of adverse events, which indicates that a greater degree of vigilance may be required in these patients.

Adolescent↗
PubMed1996

Should pregnancy testing be routine in adolescent patients prior to surgery?

The reliability of the preoperative history obtained from adolescent patients in ruling out pregnancy was prospectively evaluated. Four hundred forty-four patients who underwent 525 procedures were questioned preoperatively regarding the possibility of pregnancy. Regardless of the history, a urine pregnancy test was ordered in accordance with institutional practice. In 508 cases, patients denied the possibility of pregnancy. Eight patients stated that they might be pregnant, and in six cases the parents responded for the patients and denied the possibility of pregnancy. Seventeen patients were not tested due to patient/parent refusal (n = 9) or inability to void (n = 8). All pregnancy tests were negative except one that was questionably negative. This patient had denied the possibility of pregnancy and had been anesthetized prior to test results. Follow-up revealed that the patient was not pregnant. Our data demonstrate that the preoperative history obtained from adolescent patients at our institution regarding their pregnancy status was in agreement with pregnancy test results. We suggest that a detailed history regarding last menstrual period, contraception, sexual activity, and the possibility of pregnancy be obtained in all postmenarchal patients presenting for surgery. Although in other populations history and pregnancy testing did not agree 100% of the time, for our adolescent population, human chorionic gonadotrophin (HCG) testing appears to be necessary only if indicated by patient history.

Adolescent↗
PubMed1995

Vomiting after outpatient tonsillectomy and adenoidectomy in children: the role of nitrous oxide.

The role of nitrous oxide anesthesia in causing postoperative vomiting (POV) was studied in 60 children undergoing outpatient tonsillectomy and adenoidectomy. In this controlled, randomized, double-blind investigation, anesthesia was induced by inhalation of a volatile anesthetic in both groups. The nonnitrous oxide group received no nitrous oxide, even during induction of anesthesia. Designated nurses in the postanesthesia care unit (PACU) who were blinded to the anesthetic technique evaluated the incidence and the severity of the patient's emetic symptoms, both in the PACU as well as after discharge. Pharmacologic intervention was administered on the basis of evaluation by the nurses. Although a high incidence of POV was noted in both groups, there was no difference in either the incidence or the severity of POV between the group receiving nitrous oxide and the group receiving no nitrous oxide.

Adenoidectomy↗
PubMed1993

Are all preterm infants younger than 60 weeks postconceptual age at risk for postanesthetic apnea?

BACKGROUND: Preterm and ex-preterm infants are at risk for life-threatening apnea after general anesthesia. The authors attempted to define the postconceptual age beyond which apnea is less likely to occur and to identify the factors that predispose to postanesthetic apnea. METHODS: Ninety-one infants younger than 60 weeks postconceptual age undergoing 101 general anesthetics were prospectively studied. All infants were admitted to the hospital for cardiorespiratory monitoring overnight. The presence of coexistent medical conditions that could influence the incidence of apnea was determined by a review of current and previous medical records and by history. RESULTS: Of 38 procedures performed in 35 infants younger than 44 weeks postconceptual age, 10 (26.3%) procedures in 9 infants were associated with postanesthetic apnea. In eight of these, apnea did not resolve spontaneously: four infants required stimulation, and four required continuous positive airway pressure by face mask. Apnea occurred after 2 of 63 procedures performed in infants 44 weeks postconceptual age or older. Both episodes occurred in one patient who had neurologic disease. Of the remaining 61 procedures in the latter age group, 7 were associated with episodes of bradycardia (lowest heart rate was 79 beats/min) postoperatively without apnea. These episodes lasted up to 5 s, were not associated with apnea or cyanosis, and resolved spontaneously in all cases. All infants with postanesthetic apnea and/or bradycardia experienced their first episode within 12 h after surgery. CONCLUSIONS: Ex-preterm infants younger than 44 weeks postconceptual age are at greater risk for apnea after general anesthesia than are infants older than 44 weeks postconceptual age. Based on these results, the maximum long-run risk of postanesthetic apnea in preterm infants older than 44 weeks postconceptual age is 5% with 95% confidence.

Age Factors↗
PubMed1992

Adequacy of caudal analgesia in children after penoscrotal and inguinal surgery using 0.5 or 1.0 ml.kg-1 bupivacaine 0.125%.

To determine the optimal volume of bupivacaine 0.125% for postoperative caudal analgesia, we compared the effectiveness of 0.5 ml.kg-1 and 1 ml.kg-1 of bupivacaine 0.125% with 1:200,000 epinephrine in 80 children undergoing penoscrotal and inguinal surgery. The adequacy of caudal analgesia and supplemental analgesic requirements did not differ between the two groups at any time during the first 12 hr after surgery. We conclude that 0.5 ml.kg-1 of bupivacaine 0.125% with 1:200,000 epinephrine is as effective as 1 ml.kg-1 of the same solution and recommend its use for penoscrotal surgery. The evidence for effectiveness of 0.5 ml.kg-1 of bupivacaine 0.125% for inguinal surgery, however, is inconclusive because of an insufficient number of patients studied.

Analgesia, Epidural↗
PubMed1990

The blood/gas solubilities of sevoflurane, isoflurane, halothane, and serum constituent concentrations in neonates and adults.

To determine the effect of prematurity on the solubility of volatile anesthetics in blood, the authors measured the blood/gas partition coefficients of sevoflurane, isoflurane, and halothane and the serum concentrations of albumin, globulin, cholesterol, and triglycerides in umbilical venous blood from ten preterm and eight full-term neonates and in venous blood from eight fasting adult volunteers. The authors found that the blood/gas partition coefficient of sevoflurane did not differ significantly among the three age groups. The partition coefficients of isoflurane and halothane in preterm neonates did not differ significantly from those in full-term neonates. However, the partition coefficients of both anesthetics in neonates were significantly less than those in adults. The blood/gas partition coefficients of the three volatile anesthetics in preterm neonates did not change significantly with gestational age. The blood/gas partition coefficients of sevoflurane, isoflurane and halothane for all three age groups combined correlated only with the serum concentration of cholesterol. The authors conclude that the blood/gas partition coefficients of isoflurane, halothane, and sevoflurane in preterm neonates are similar to those in full term neonates and that gestational age does not significantly affect the blood/gas solubility.

Adult↗
PubMed1989

Anaesthetic experience with paediatric interventional cardiology.

Anaesthetic and sedation techniques, complications and outcomes were reviewed in 176 children undergoing 184 interventional cardiologic procedures. Techniques included sedation only, and ketamine, inhalational or narcotic anaesthesia. Ketamine infusion was the technique most frequently used. Ketamine was associated with a higher incidence of respiratory complications (P less than 0.05) than the other techniques. The higher incidence of hypercarbia (15.6 per cent), which did not affect outcome, may be attributable to the use of supplemental sedatives. The incidence of upper airway obstruction (7.8 per cent) was similar to that of previous studies. Vascular compromise resulted from the procedure in 33 patients, necessitating surgical correction in 16. Cardiac perforation occurred in four cases, causing one death. Pulmonary valve stenosis was most amenable to balloon dilatation and aortic valve stenosis least amenable. ketamine was the anaesthetic agent preferred by cardiologists for use in the catheterisation suite when general anaesthesia was required. Vigilant monitoring by anaesthetic staff is necessary during the procedure, and avoidance of concomitant narcotics is recommended if a ketamine technique with spontaneous ventilation is used.

Adolescent↗
PubMed1989

Increased susceptibility of lead exposed chickens to experimental infection of Ascaridia galli.

Two sets of one day old, white leghorn (Victoria Strain) chickens were each orally exposed to 1.0 mg lead nitrate daily for 7 days and subsequently infected with 15 and 30 A. galli eggs. These experimental chickens exposed to lead harboured significantly greater worm burden when compared to unexposed controls leading strong support to the view that lead exposure significantly suppressed their immune response to A. galli infection. It also indicated that exposure of lead prior to infection greatly impaired weakened the immune capability of such chickens.

Animals↗