Perioperative management of total parenteral nutrition, glucose containing solutions, and intraoperative glucose monitoring in paediatric patients: a survey of clinical practice.

Infants and children, particularly those who are chronically ill and maintained on total parenteral nutrition (TPN), are at risk for perioperative hypoglycaemia [blood glucose < 2.2 mmol x l(-1) (40 mg x dl(-1))] and hyperglycaemia [blood glucose > 11 mmol x l(-1) (200 mg x dl(-1))]. We surveyed paediatric anaesthesiologists regarding their perioperative management of blood glucose and TPN in paediatric patients to determine the current practice and its perceived success. Questionnaires were mailed to all members of the Study Group on Pediatric Anesthesia and the response rate was 70%. Results indicate that the current perioperative management of blood glucose and TPN is somewhat varied. Furthermore, greater than 10% of those surveyed report that their management results in a variable response in the maintenance of normoglycaemia. While the detrimental effects of perioperative hypoglycaemia and hyperglycaemia are rare, they are serious. A Medline search shows that no studies have been published regarding perioperative management of paediatric patients receiving TPN, although it appears that clinical study is warranted.

Intramuscular atropine sulfate in children: comparison of injection sites.

In children undergoing inhaled induction of anesthesia with halothane who suffer bradycardia, submental glossal injection of atropine may result in more rapid onset of vagolysis than traditional intramuscular sites. We compared the intervals between injection and onset of heart rate acceleration (tHR increases) after intramuscular injection of atropine into the deltoid, vastus lateralis, and glossa in children between 1 mo and 10 yr of age scheduled for elective surgery. The tHR increases was determined by measuring the interval between atropine injection and the time point at which the slope of the heart rate curve initially became positive. To ensure that the drug had taken effect before surgical stimulation, heart rate observation was continued until it increased at least 5% above baseline with evidence of continuing acceleration. Anesthesia was induced in all subjects by mask with nitrous oxide and halothane. After tracheal intubation, constant inspired concentrations of the anesthetics were administered for 3 min. While heart rate was monitored, atropine (0.02 mg/kg) was injected into one of the three sites. Each patient's end-tidal anesthetic concentrations were recorded, and minimum alveolar anesthetic concentrations (MAC) were subsequently calculated and adjusted for age. The tHR increases was recorded and averaged for each group. The study groups did not differ by age, weight, end-tidal anesthetic concentrations, age-adjusted MAC, or heart rate at the time atropine was administered. After submental glossal injection (n = 11), tHR increases increase was fastest (3.0 +/- 1.1 min) and was significantly faster than that found with deltoid injection (n = 16; 4.4 +/- 1.1 min) or vastus lateralis injection (n = 8; 6.4 +/- 2.4 min) (P < 0.05 compared with both). The tHR increases also differed significantly between the deltoid and the vastus lateralis (P < 0.05). We conclude that submental glossal injection of atropine results in a more rapid onset of vagolysis than injection at traditional intramuscular sites.

Pulse oximetry monitoring can change routine oxygen supplementation practices in the postanesthesia care unit.

Routine use of supplemental oxygen (O2) in the postanesthesia care unit (PACU) traditionally has been used to minimize the incidence of hypoxemia. However, with the advent of continuous noninvasive monitoring by pulse oximetry, is routine administration of O2 necessary? We hypothesized that administering O2 as needed, based on pulse oximetry data, would effect considerable cost savings without compromising patient care. Five hundred adult (> or = 18 yr) patients breathing room air when arriving in the PACU were enrolled in the study. During PACU care, when O2 saturation (SpO2) was continuously more than 94%, no supplemental O2 was given. When SpO2 was less than 94%, supplemental O2 was given at an inspired O2 concentration (FIO2) that would increase it to above 94%. Also, when preoperative SpO2 was less than 94% and postoperative SpO2 was more than the preoperative SpO2, no supplemental O2 was given. Supplemental O2 was unnecessary in 63% of patients for the duration of their PACU stay. Cost savings to the 307 patients in one study not receiving O2 was $31,928 if it had been billed separately from the PACU global charge. The annualized figure for patients in our hospital (approximately 10,000 cases) would be an additional $623,272. Inasmuch as pulse oximetry monitoring is now standard in the PACU, perhaps it is time to apply the objective data it supplies, thereby creating cost savings while maintaining patient care standards.

Umbilical catheters and arterial blood pressure monitoring.

The natural frequencies, damping coefficients, and accuracies of umbilical artery catheters were determined. The damping coefficients for the 3.5, 5.0, and 8.0 French catheters were 0.40 +/- 0.04 (mean +/- SD), 0.42 +/- 0.05, and 0.19 +/- 0.02, respectively. The natural frequencies were 24.2 +/- 3.2 Hz (mean +/- SD), 18.4 +/- 3.5 Hz, and 26.8 +/- 2.9 Hz, respectively. Measurements obtained with 3.5 and 8.0 French catheters were within 6% of the reference pressure at all pressures and rates tested. With the 5.0 French catheter, however, error greater than 10% from the reference pressure occurred when the rate was 200 pulses per minute or greater and the applied maximum pressure was 100 mm Hg or more.

Total lung lavage for pulmonary alveolar proteinosis in an infant without the use of cardiopulmonary bypass.

Pulmonary alveolar proteinosis is a rare disease that usually affects the adult patient, but is now being recognized as a possible cause of neonatal respiratory distress. In the adult patient, whole lung lavage, as described by Ramirez-R in 1965, is considered the most effective therapy for management of this condition. The lavage can be accomplished safely and with relative ease by using a Carlens or Robertshaw tube to isolate and lavage one lung while ventilating the other. The unavailability of a small double-lumen tube makes this procedure impossible in the pediatric age group. Therefore, whole lung lavage has been possible in only a few children in the past with the help of cardiopulmonary bypass to allow simultaneous oxygenation during the pulmonary lavage. Due to the hazards and technical difficulties of cardiopulmonary bypass, total pulmonary lavage can not be considered a practical option in the very small infant. A 15-week-old infant is reported, weighing 2 kg with a diagnosis of pulmonary alveolar proteinosis, who underwent total pulmonary lavage safely on three different occasions without employing cardiopulmonary bypass. A double-lumen Swan-Ganz catheter, introduced transbronchoscopically through the side-arm of a rigid, 3.5-mm Storz bronchoscope was used to isolate and lavage one lung while ventilation to the other lung was maintained through the bronchoscope. A Nellcor oximeter, utilized for transcutaneous monitoring, revealed satisfactory oxygen saturation during the entire pulmonary lavage. The transbronchoscopic lavage was monitored under direct vision with a video monitor, ensuring correct position of the bronchoscope and the catheter at all times.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheters for arterial pressure monitoring in pediatrics.

To evaluate the accuracy of an underdamped catheter transducer recorder used to measure arterial blood pressure, natural frequency and damping ratio were determined by transient testing with two types of 22-ga and 24-ga catheters. Damping coefficients were considerably higher and resonant frequencies lower with the 24-ga catheters. The difference between waveforms of known pressure and HR and the output waveforms produced by the catheter transducer systems was determined by using a BP systems calibrator. Catheter size did not affect the difference in recorded pressures.

Prolonged use of high-frequency jet ventilation for a pediatric patient.

A 10-yr-old boy who developed postoperative respiratory failure with evidence of significant barotrauma was treated with high-frequency jet ventilation (HFJV). HFJV reduced peak inflation pressure, enhanced oxygenation, and improved ventilation. The patient could not be weaned from HFJV by decreasing drive pressure. Instead, he was successfully weaned by decreasing the HFJV rate to 80 cycle/min and then switching to conventional intermittent mandatory ventilation at initially similar rate and pressure levels.

Aspiration in intubated premature infants.

A recent study has shown a 77% incidence of tracheal aspiration in children (mean age 13.4 months) who are intubated with uncuffed endotracheal tubes. To determine both the incidence of such aspiration among premature infants and whether continuous positive airway pressure (CPAP) has any preventive effect, 20 tracheally intubated neonates were evaluated for the presence of tracheal aspiration of orally placed Evan's blue dye. The overall incidence of aspiration was 80%. Eighteen of these infants were tested during both 4 cm and 6 cm H2O continuous positive airway pressure, and the incidences of aspiration were 72% and 50%, respectively, which is not a statistically significant difference (P less than .17). Ten of these 18 patients were also studied when 2 cm H2O was applied and 60% aspirated. Among all infants who aspirated, compared with those who did not, there was a small but statistically significant decrease in transcutaneous PO2 (P less than .05) as well as an increase in respiratory (P less than .001) and pulse (P less than .01) rates. It is concluded that tracheally intubated neonates frequently aspirate and that clinically useful levels of continuous positive airway pressure are not likely to prevent aspiration.

Continuous positive airway pressure improves oxygenation in dogs after the aspiration of blood.

Fourteen dogs were anesthetized, intubated, and breathed room air spontaneously. We then instilled 2 ml/kg of fresh nonheparinized donor blood into their tracheas. Seven dogs received no treatment and served as controls (group A); respiratory rate (RR) increased from 25 +/- 11 (mean +/- SD) to 103 +/- 33 breath/min, HR decreased from 179 +/- 28 to 136 +/- 42 beat/min, PaO2 decreased from 82 +/- 10 to 30 +/- 4 torr, pulmonary venous admixture (Qsp/Qt) increased from 0.14 +/- 0.10 to 0.72 +/- 0.06, and venous oxygen tension (PVO2) decreased from 46 +/- 4 to 22 +/- 5 torr 10 min after the aspiration of blood; all changes were statistically significant (p less than .05). After 4 h, RR and HR returned to control values, but PaO2 was only 58 +/- 10 torr. Cardiac output, oxygen consumption (VO2), and pulmonary and systemic BP and resistances were not significantly affected. Thirty-five min after the other 7 dogs aspirated blood (group B), 10 cm H2O of continuous positive airway pressure (CPAP) was applied while they breathed spontaneously. CPAP reduced Qsp/Qt to 0.31 +/- 0.10 and 0.15 +/- 0.11 30 and 90 min after its application, respectively (p less than .05). By 4 h, the PaO2 of group B dogs was 81 +/- 15 torr (p less than .05 compared with group A). CPAP also increased arteriovenous oxygen content difference (C[a-v]O2) compared with the nontreated dogs. Four hours after the aspiration of blood, all dogs were extubated. Twenty-four hours later, arterial blood gases were normal in all dogs of both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Near-drowning: correlation of level of consciousness and survival.

This paper reports a retrospective review of 121 cases of near-drowning treated at university hospitals in Miami and Gainesville. The series included 57 adults and 64 children who were classified into three categories, Category A (Awake), Category B (Blunted) and Category C (Comatose), based on their level of consciousness on arrival at the primary hospital. Results based on the total 121 patients showed 87 per cent survived with apparently normal brain function, two per cent survived with impaired brain function and 11 per cent died. The survival rate of all patients who were awake when they entered the hospital was significantly greater than that of both those who were admitted and blunted consciousness (p = 0.05) and those who were comatose when admitted (p less then 0.0001). Further, the group whose members had blunted consciousness had a significantly greater number of normal survivors than the group whose members were comatose on admission (p less than 0.002). All treated adults survived without permanent neurological damage and only three surviving children in the series suffered residual brain damage. Whether the course of the seven patients, three adults and four children, who died without return of brain function, would have been altered by deliberate attempts to preserve the brain is a matter of speculation.

A new concept in controlled ventilation of children with the Bain anesthetic circuit.

The Bain anesthesia circuit was studied as a semi-open or partial rebreathing system during controlled ventilation in 16 children weighing from 7.5 to 48 kg. During anesthesia the lungs were ventilated with a volume ventilator set at three times the calculated alveolar ventilation to provide optimum mixing in the exhalation tube of the Bain circuit. Fresh gas inflow rates initially were set equal to the calculated alveolar ventilation, and after 30 to 45 min, PCO2, PO2 and pH values were measured. At the same time, the fractional concentration of mixed expired carbon dioxide (FECO2) was recorded from a capnograph inserted between the ventilator and the Bain circuit. After initial readings, the fresh gas inflow was varied over a range of 1,400-3,000 ml/m2/min at 20-min intervals, with the arterial blood-gas values and FECO2 recorded at each setting. The results indicate that a lower fresh gas inflow than previously recommended can be used safely in children. When the minute ventilation is three times the fresh gas inflow, values for FECO2 correlate closely with PaCO2 values; with a fresh gas inflow of 2,500 ml/m2/min,PaCO2 values can be maintained near 40 torr.

Clinical course of 91 consecutive near-drowning victims.

Hospital records of 91 consecutive near-drowning victims were studied retrospectively. Eight-one (89 percent) of these patients survived. Patients who were alert on arrival at the emergency room survived, but those who were comatose and had fixed dilated pupils died. Other states of consciousness were unreliable predictors of survival. All patients with a normal chest roentgenogram on admission survived; however, values for arterial oxygen tension (PaO2) did not necessarily correlate with the chest roentgenograms. Values for arterial blood gas tensions and pH varied widely, as follows; PaO2, 25 to 465 mm Hg; arterial carbon dioxide tension (PaCO2), 17 to 100 mm Hg; pH, 6.77 to 7.50; and arterial bicarbonate level, 6.6 to 29.7 mEq/L. The ratio of PaO2 to the fractional concentration of oxygen in the inspired gas (FIo2), which was calculated to standardize PaO2 data for varying concentrations of inspired oxygen, ranged from 30 to 585 mm Hg. Only one patient with a ratio of PaO2/FIo2 greater than 150 mm Hg on admission subsequently died; this was a neurologic rather than a pulmonary death. Serum electrolytic concentrations and values for hemoglobin level and hematocrit reading neither predicted survival nor indicated that a threat to life existed. Steroid and prophylactic antibiotic therapy did not appear to increase the chance of survival. Observations on these patients are discussed in light of previous experiments in animals, and an approach to therapy is suggested.

Intraocular pressures in children during isoflurane and halothane anesthesia.

The effects of isoflurane and halothane on intraocular pressure (IOP) were studied in 28 children. Measurements were made during spontaneous ventilation and at a various levels of reduced PaCO2 achieved by controlled ventilation. Control IOP values were determined prior to anesthesia following premedication with chloral hydrate, pentobarbital, pentobarbital with meperidine. At roughly equivalent levels of anesthesia, mean IOP values during spontaneous ventilation ranged frm 16.3 to 17.6 torr for each anesthetic. These values were significantly less (P less than 0.01) than control values only in those patients receiving chloral hydrate who did not cooperate. In contrast, no significant change in IOP was found in more sedated and cooperative patients who received pentobarbital and meperidine. Moderate hypocarbia and hypercarbia over a range of PaCO2 greater than 42 torr had little influence on IOP. We conclude that IOP's during isoflurane and halothane anesthesia do not differ significantly from IOP in the sedated, cooperative, healthy pediatric patient.