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Biomedical subjects

R K Kanter

Publications and source records attributed to R K Kanter.

At least 37 records · Page 2Linked to original sources
PubMed1989

A comparison of infant ventilation methods performed by prehospital personnel.

By comparing mouth-to-mouth ventilation to other methods, we tested whether there are significant differences among infant mannequin ventilation methods performed by emergency medical technicians-paramedics (EMT-Ps). Fifty-nine participants were evaluated in the performance of six ventilation methods; methods studied were mouth-to-mouth; two mouth-to-mask devices; and infant, pediatric, and adult bag-valve-mask devices. By measuring each breath, the percentage of acceptable ventilations in predetermined ranges, 5 to 25 mL/kg or 10 to 20 mL/kg, was calculated. Methods were compared using repeat measures ANOVA testing. Correlation between ventilation performance and the experience of personnel was expressed as the Pearson correlation coefficient. There were no significant differences in performance between methods, except for inadequate ventilation with the Laerdal Pocket Mask (P less than .05) from poor mask fit. The correlation between years of prehospital experience and the number of resuscitations versus ventilation performance was poor. Single rescuer, EMT-Ps can successfully ventilate an infant mannequin with various size resuscitation bags. The Laerdal Pocket Mask is an ineffective device for infant mannequin ventilation and should not be recommended for infant resuscitation.

Adult↗
PubMed1989

Anatomy of femoral vessels in infants and guidelines for venous catheterization.

This study was performed to formulate femoral venous catheterization guidelines for infants from ultrasound observations. Femoral vessels were evaluated on both sides in 75 infants, 2 weeks to 24 months of age. The site of the greatest probability of successful venipuncture 1 cm below the skin crease at the groin is located 4 to 5 mm medial to the femoral artery pulse. If it is assumed that entry into the central half of the vein will result in successful catheterization, successive attempts 5 mm and 6 mm medial to the pulse would result in cumulative successful insertion in 53% and 61%, respectively, with no arterial punctures. A third attempt 4 mm medial to the pulse further increases cumulative success to 78%, but 3% arterial punctures would occur. These guidelines are intended to facilitate achievement of femoral venous catheterization, minimizing arterial punctures and number of needle passes required.

Bloodletting↗
PubMed1989

Adverse events during interhospital transport: physiologic deterioration associated with pretransport severity of illness.

The relationship between severity of illness or injury before interhospital transport and the incidence of physiologic deterioration during transport was studied in 117 pediatric patients. Transports were done by referring hospital personnel. Pretransport severity was expressed as the Pediatric Risk of Mortality score for all patients and as the Modified Injury Severity Score for trauma patients. For 71 patients with Pediatric Risk of Mortality scores less than 10, deterioration during transport occurred in 3 (4%) and hospital mortality occurred in 2 (3%). For 10 victims of trauma with Modified Injury Severity Scores less than 10, none had deterioration during transport or hospital mortality. The rare occurrence of serious problems related to transport in low-risk patients indicates that referring hospital personnel are capable of safely transporting such patients. The incidence of physiologic deterioration during transport was significantly greater (P less than .01) with greater pretransport severity of illness or injury. Failure to intubate the trachea was not a major preventable cause of deterioration. The most common preventable problem occurred for 6 of 79 patients with endotracheal tubes that became occluded with secretions, leading to cyanosis in 2 patients. Our data concerning high-risk patients with specified pretransport severity provide a basis for comparison for further evaluation of the benefit of specialized pediatric transport services.

Child↗
PubMed1988

Arterial-end tidal PCO2 equilibration in the cat during acute hypercapnia.

We have studied the problem of pulmonary capillary-alveolar CO2 exchange in the cat during acute hypercapnia. Three cats, anesthetized with xylazine and pentobarbital sodium and prepared with acute tracheostomy and femoral arterial catheter, and three awake cats, prepared with a small tracheal catheter and femoral arterial catheter, were subjected to acute hypercapnia (FICO2 = 0.00, 0.06, and 0.08). During steady states, end tidal PCO2 was determined with an infrared analyzer, and arterial PCO2 was measured with a Radiometer ABL-2 analyzer in simultaneously drawn samples. In vitro studies indicated that our blood sampling techniques resulted in a 6% reduction in PCO2. Blood PCO2 readings were corrected for (1) non-ideal performance of the analyzer as determined by tonometry, (2) 6% reduction due to sampling, and (3) differences between electrode and rectal temperature. Mean arterial-end tidal PCO2 differences were not significantly different from zero in any condition in either group (except for 0.08 CO2 in the awake group when the difference was 2.0 Torr). These findings in the cat agree with the classical view that PCO2 in pulmonary capillary blood approaches PCO2 in alveolar gas. Further, our findings provide evidence that CO2 loss from blood samples is an important technical factor which can cause systematic underestimation of blood PCO2 and, hence, contribute to the observation of negative PCO2 gradients.

Acute Disease↗
PubMed1987

Efficiency of intensive care. A comparative analysis of eight pediatric intensive care units.

To calculate overall pediatric intensive care unit (PICU) efficiency rates, 1668 patients representing 6962 patient-days were studied in eight PICUs. The contributions to inefficiency by two patient groups--low-risk monitored patients and potential early-discharge patients--were quantified using measures of daily mortality risk and therapeutic assessments. Low-risk monitored patients never received a unique PICU therapy and had daily mortality risks less than 1%. Potential early-discharge patients were similar to the low-risk monitored patients except that their unnecessary PICU use came only on their last consecutive day(s) of PICU stay. Efficiency ratings ranged from 0.894 to 0.547 in the eight PICUs. Low-risk monitored patients constituted from 16% to 58% of the PICU patient populations and used from 5.4% to 34.5% of the total days of care. Potential early-discharge patients constituted from 12% to 29% of the populations and the potential early-discharge days of care ranged from 5.1% to 17.2% of the total days of care. These results indicate that large disparity exists in efficiency among PICUs. Efficiency rates of greater than 0.80 seem to be a reasonable goal.

Child↗
PubMed1987

Evaluation of mask-bag ventilation in resuscitation of infants.

Performance of mask-bag ventilation was evaluated on an infant resuscitation mannequin to resolve uncertainty regarding the proficiency of pediatric resuscitation personnel in this technique and to determine whether the type of resuscitation bag used would affect performance. Performance using a self-inflatable resuscitation bag was generally adequate. Forty-six of 50 operators achieved an adequate minute ventilation, and 48 of 50 operators achieved a mean tidal volume exceeding that of the mask plus simulated physiologic dead space. Wide variation with a tendency to hyperventilate and to use excessive pressures indicate the need for improved standard training methods. Technical difficulties with an anesthesia bag impaired performance, suggesting that only self-inflatable bags should be used for mask-bag ventilation during pediatric resuscitation, unless the staff's proficiency with anesthesia bags is clearly demonstrated.

Equipment Design↗
PubMed1987

Initial mechanical ventilator settings for pediatric patients: clinical judgement in selection of tidal volume.

Guidelines for selection of initial mechanical ventilator settings for pediatric patients were evaluated. Protocols specifying tidal volume or peak inspiratory pressure are difficult to apply for infants and children because of leaks at uncuffed endotracheal tubes, compression loss in ventilators, and inaccuracy of settings for intended tidal volume. To avoid these difficulties, the selection of tidal volume was based on subjective clinical observations: visible chest excursion and audible air entry at least simulating normal breathing. In 76 consecutive patients, use of the guidelines resulted in satisfactory PaCO2 for 97% and PaO2 for 89% of infants and children with a wide variety of respiratory disorders. Adequacy of gas exchange was not related to the patient's age, type of ventilator, tightness of fit of the endotracheal tube, or presence of spontaneous breathing. These results support a simple, versatile method of teaching selection of initial mechanical ventilator settings, relying on clinical judgment for regulation of tidal volume.

Airway Resistance↗
PubMed1987

Mortality associated with multiple organ system failure and sepsis in pediatric intensive care unit.

Seven hundred twenty-six patients from five pediatric intensive care units were studied to determine the association of multiple organ system failure (MOSF) with mortality and to test the hypothesis that MOSF associated with sepsis has a higher mortality rate than MOSF without sepsis. There were 177 (24%) patients with MOSF and 83 (11%) nonsurvivors of MOSF. The mortality rates for two, three, or four or more failed organ systems were 26%, 62%, and 88%, respectively (P less than 0.001). Eighty-four (47%) patients with MOSF had associated sepsis. Sepsis (both bacteremia and clinical sepsis syndrome) did not significantly increase mortality rates in the groups with organ system failure. Mortality rates for patients with sepsis before or within 24 hours of development of MOSF (early sepsis) did not differ from mortality rates for those patients with onset of sepsis more than 24 hours after developing MOSF (late sepsis, 53% vs 33%, P = NS). We conclude that underlying pathophysiologic mechanisms of MOSF other than sepsis are as important as sepsis in critically ill pediatric patients.

Child↗
PubMed1987

Evaluation and stabilization of the critically ill child.

Because the timely treatment of children in accidents or with serious illnesses usually is successful, it is vital that the life-threatening problem promptly be recognized. Although the principles of resuscitation are identical in the child and adult, age-related differences in anatomy and pathophysiology may make this task challenging for the physician who usually cares for adults. In this article, a systematic approach to evaluation and initial stabilization of the pediatric patient is discussed. Decisions and methods in safely transferring a critically ill pediatric patient are also reviewed.

Cardiovascular Diseases↗
PubMed1986

Pediatric emergency intravenous access. Evaluation of a protocol.

Effectiveness of a protocol for intravenous (IV) access during pediatric resuscitation was prospectively evaluated to determine whether utilization of a specified sequence of measures would reduce IV access time compared with resuscitations deviating from the protocol. The protocol involved rapid sequential attempts at percutaneous femoral vein catheterization, saphenous vein cutdown, and intraosseous infusions if initial percutaneous peripheral IV insertion failed. While no single technique provided completely reliable and rapid IV access, utilization of all techniques per protocol significantly improved IV access time. When initial percutaneous peripheral IV attempts failed, resuscitations in compliance with the protocol achieved IV access more rapidly (median, 4.5 minutes) than those deviating from the protocol (median, 10.0 minutes). Even with incomplete compliance, 66% of resuscitations achieved IV access within the first five minutes. Our experience indicates that IV access during pediatric resuscitation should rarely be delayed beyond the fifth minute if all available IV techniques are used.

Adolescent↗
PubMed1986

Prolonged mechanical ventilation of infants after open heart surgery.

Records of 140 infants younger than 2 yr of age who had undergone open heart surgery were studied to evaluate the duration of postoperative mechanical ventilation (MV), to determine the relationship between prolonged MV and mortality, and to identify variables predisposing the patient to prolonged MV. MV was required beyond the first postoperative day in 56 infants, and was prolonged for at least 7 days in 19 infants. Mortality was approximately the same (16% to 17%) whether or not MV was required for more than 7 days. Preoperative and intraoperative variables associated with longer MV included younger age, longer cardiopulmonary bypass time, longer aortic cross-clamp time, and preoperative MV. Multiple predisposing factors increased the probability of prolonged MV. Postoperative variables including premature extubation and a second surgical procedure also were associated with prolonged MV. The consequences of prolonged MV may be minimized by early nutritional support, aggressive surveillance for treatable complications, and avoidance of premature extubation.

Cardiac Surgical Procedures↗
PubMed1986

Central venous catheter insertion by femoral vein: safety and effectiveness for the pediatric patient.

Prospective observations made during surveillance of routine central venous catheterizations for hemodynamic monitoring were evaluated to determine the safety and effectiveness of femoral insertion of central venous catheters and to demonstrate the feasibility of teaching pediatric residents to perform this procedure. During a 19-month period of observation, 29 pediatric patients requiring a central venous catheter underwent attempted percutaneous femoral vein catheterization. Femoral catheterization was successful in 86% of patients attempted, and insertions by pediatric residents were successful in 68% of patients attempted. Arterial puncture was the only significant complication of insertion, occurring in 14%, and was not associated with adverse sequelae. During 33 months of observations, complications of indwelling femoral central venous catheters did not significantly exceed the frequency for internal and external jugular, subclavian, and antecubital central venous catheters. During more than 4 years of observation, the significant complications associated with indwelling femoral central venous catheters were swelling of the leg or documented thrombosis in 11% of 74 critically ill patients. These observations indicate safety and effectiveness of femoral central venous catheters which compares favorably to central venous catheter insertion by other routes. In contrast to previous reports of central venous catheter insertion via subclavian and internal jugular veins, we observed no cardiorespiratory compromise as a result of femoral central venous catheter complications. Skill in this technique is a feasible educational goal for pediatric residents.

Accident Prevention↗
PubMed1985

Hypophosphatemia and Reye's syndrome.

Hypophosphatemia may occur in Reye's syndrome. We retrospectively studied 42 patients with Reye's syndrome to determine the frequency and degree of hypophosphatemia, to identify possible causes, and to determine whether hypophosphatemia was related to the severity of disease or mortality. Nineteen (46%) patients were hypophosphatemic at the time of hospital admission. Five of these had a serum phosphorus level less than 2.5 mg/dl and three were 1.5 mg/dl or less. During the subsequent hospital course, 32 (78%) patients developed hypophosphatemia. It was of moderate degree (2.5 mg/dl or less) in 20 patients, and was severe (1.5 mg/dl or less) in eight patients. Hypophosphatemia correlated with concurrent hyperglycemia but not with other potential causes studied. The degree of hypophosphatemia during treatment roughly paralleled the severity of illness but was not a predictor of outcome. The need for treatment of hypophosphatemia in Reye's syndrome has not been established, and hypocalcemia as a complication of excess phosphate infusion should be avoided.

Adolescent↗
PubMed1985

Infectious complications and duration of intracranial pressure monitoring.

We studied 65 children with acute brain injury to determine how the risk of infectious complications changed with duration of intracranial pressure (ICP) monitoring. More than half of the 72 monitors inserted in these patients were in place at least 7 days (range 1 to 28). Nine infections occurred on days 2 through 11. The overall risk was 1.5 infections per 100 monitor-days. After day 6 the risk of subsequent infection diminished, as did the percent of monitors which subsequently became infected. The declining risk of infection over time suggests that infection is introduced at the time of monitor insertion. These findings justify a protocol in which a single ICP monitoring device is used as long as necessary, with reinsertion of a new monitor only if a malfunction occurs, or if daily surveillance cultures demonstrate an infection. Routine reinsertion of a new monitor might increase risk by unnecessarily re-exposing the patient to contamination at the time of insertion.

Bacterial Infections↗
PubMed1985

Association of arterial hypertension with poor outcome in children with acute brain injury.

We studied intensive care unit (ICU) records of 42 comatose children with acute brain injuries to define the relationship between high arterial blood pressure and poor neurologic recovery. Diagnoses included head trauma, anoxia, Reye's syndrome, and central nervous system infection. The highest systolic blood pressure in all 42 patients exceeded the 95th percentile. In those whose highest systolic pressure exceeded 95th percentile by more than 20 torr, severe neurologic deficit or death occurred in 19 of 34 (56%), while in those with milder hypertension, poor outcome occurred in only one of eight (13%, p = 0.0316). Of those with high blood pressure persisting until ICU discharge, 14 of 19 (74%) had poor outcome, while those with blood pressure normalizing prior to ICU discharge had poor outcome in only six of 23 (26%, p = 0.0026). High blood pressure was not usually a reflex effect of elevated intracranial pressure. This finding suggests that measures to control high blood pressure are indicated in the management of the acutely brain-damaged child.

Acute Disease↗