Chalapathi C. Rao

One-lung pediatric anesthesia.

One-lung anesthesia with the aid of a double-lumen tube is a widely practiced technique in adult patients undergoing pneumonectomy or lobe resection for tumor or abscess. Advantages of endobronchial anesthesia include improvement of surgical exposure, unilateral cessation of respiratory and diaphragmatic excursion to improve surgical exposure, safe inspection of the open bronchus, selective deflation and inflation of the lung, and, most importantly, prevention of transbronchial spread of purulent secretions or blood into the trachea and the dependent lung (1). Although the desirability of one-lung anesthesia in infants and children with a lung abscess is obvious, the use of selective bronchial blockade has been hampered by the unavailability of double-lumen tubes or bronchial blockers for children (2). In 1969 Vale (2) described bronchial blockade with a Fogarty arterial embolectomy catheter in a 14-month-old child. Subsequently Cay et a1 (3) presented details of using a Fogarty catheter as a bronchial blocker in two pediatric patients. Hogg and Lorhan (4) also used the technique successfully in a 3Vz-year-old patient. Only Lines (5) has previously reported the added advantages of endobronchial intubation in addition to Fogarty catheter blockade of the affected bronchus. The age range of the five reported pediatric patients (2-5) in whom a Fogarty catheter was utilized as a bronchial blocker was 14 months to 12 years. This report describes the use of a Fogarty catheter

Increased sensitivity of the isometric contraction of the neonatal isolated rat atria to halothane, isoflurane, and enflurane.

Isolated atria from neonatal (0–5 day old) and adult (50 ± 5 day old) rats were perifused in oxygenated Krebs Henseleit solution at 30 ± 0.5° C and exposed to four different concentrations of halothane, isoflurane, or enflurane while isometric contractile tension was recorded and compared with control atria. ED50 values (mM of anesthetic required to produce 50% reduction in contractile tension) of neonates for halothane (0.18 ± 0.01), isoflurane (0.41 ± 0.05), and enflurane (0.41 ± 0.04) were significantly lower than those of adults (0.35 ± 0.02, 0.80 ± 0.05, and 1.15 ± 0.05, respectively). Furthermore, neonatal ED50 calculated as per cent of adult ED50 was significantly less for enflurane (35%) than for halothane (54%) or isoflurane (51%).

Comparison of cardiovascular effects of thiopental and pentobarbital at equivalent levels of CNS depression.

Thiopental and pentobarbital have been used in high doses to protect the brain from injury following hypoxia or to reduce intracranial pressure. This study was performed to determine whether these barbiturates differ in cardiovascular effects when present in plasma concentrations that produce equivalent CNS effects. The effects of thiopental and pentobarbital on heart rate, stroke volume/kg, cardiac output/ kg, systemic vascular resistance, mean arterial pressure, and central venous pressure were statistically indistinguishable at plasma concentrations of each barbiturate ranging from 50% to 100% of their concentration producing EEG silence. Three of the seven dogs given thiopental developed ventricular bigeminy at plasma concentrations ranging from 45% to 65% of their concentration producing EEG silence. Lidocaine (1.4--2.0 mg/kg intravenously) reversed the bigeminy to sinus rhythm. When given more than the amount needed to produce a flat EEG, five of the seven dogs given thiopental died, but all dogs given pentobarbital survived. Pentobarbital may be a better choice than thiopental when large doses are indicated.

Neonatal Lung Abscess: Resection Using One-Lung Anesthesia

Three neonates with lung abscess unresponsive to antibiotic therapy underwent successful resection of infected lobes with the aid of one-lung anesthesia. This was accomplished by selective endobronchial intubation of the opposite lung and obstruction of the ipsilateral main bronchus with a Fogarty balloon-tipped catheter. This valuable technique provides protection against tracheobronchial spillage of purulent material and results in the rapid recovery of these seriously ill neonates.

Effect of thiopental and succinylcholine on serum potassium concentrations in children.

Succinylcholine increases serum potassium levels in normal adults by 0.25-0.8 mEq/L (1,2). The magnitude of the increase in potassium is decreased when thiopental or methohexital are used for induction of anesthesia (3,4). Pretreatment with diazepam, hexafluorenium, pancuronium, or fazadinium also prevents succinylcholine-induced serum increases in potassium (2,5-7). Henning and Bush found that after halothane induction of anesthesia, succinylcholine increased serum potassium by a mean of 0.45-0.48 mEq/L in children (8). Keneally and Bush reported that potassium increased by an average of 0.23 mEq/L following succinylcholine after thiopental induction (4 mg/kg) in children less than 5 yr old (9). There were no significant changes in children 6-16 yr old. In these studies of children, premedication was not controlled and alveolar ventilation was not monitored. In the present study we examined the effects of succinylcholine on venous serum potassium concentrations after thiopental induction (6 mgkg) of general anesthesia in healthy, unpremedicated children. Ventilation was controlled to maintain end-tidal C02 within the normal range.

Sublingual emphysema complicating dental anesthesia

The introduction of gas into soft tissues during dental procedures has been recognized since 1900 (1). Cases of subcutaneous facial emphysema characterized by rapidly progressing unilateral facial swelling have been reported. To our knowledge localized sublingual emphysema without facial involvement after a dental procedure has not been reported. We present two cases of sublingual emphysema, and discuss the etiology and potential hazards of this syndrome.

Anaesthetic implications of neonatal necrotizing enterocolitis

A retrospective analysis of infants with necrotizing enterocolitis was done to evaluate the effects of preoperative abnormalities upon anaesthesia and mortality. Mortality was significantly increased in infants weighing less than 1500 grams (p < .001). Sixty-nine per cent of the infants had hyaline membrane disease and 35 per cent had platelet counts less than 50 x 109 cells/litre (50,000/mm3). Perioperative problems include peritonitis, sepsis, hypovolaemia, acidosis, and prematurity. Other ramifications of prematurity and anaesthesia are discussed.RésuméLes auteurs ont fait la revision des dossiers de trente deux enfants opérés pour entéro-colite nécrosante du nouveau-né. Le but de l’étude était de mettre en évidence l’impact des anomalies pré-opératoires sur la mortalité et la conduite de l’anesthésie. La mortalité totale a été de 53 pour cent (17/32). On a observé entre autres: 1) une mortalité plus élevée (p < 0.001) chez les bébés de moins de 1500 g. 2) un syndrome de membrane hyaline chez 69 pour cent des patients et 3) un décompte plaquettaire inférieur à 50 x 109/litres (50,000/mm3) dans 35 pour cent des cas. Parmi les principaux problèmes péri-opératoires, on a relevé la péritonite, l’état septique, l’hypovolémie, l’acidose et la prématurité. La conduite de l’anesthésie et les problèmes liés à la prématurité sont discutés.

Anesthetic Considerations for Ophthalmic Surgery in the Pediatric Patient

In conclusion our review of 2,187 ophthalmic procedures revealed that even the very young pediatric patient can be anesthetized safely by adhering to basic principles and meticulous attention to detail.

Current Concepts in Pediatric Anesthesia with Emphasis on the Newborn Infant

Pediatric patients, especially neonates, differ anatomically, physiologically, and pharmacologically from adults. Taking these differences into account, the authors discuss the rationale and details of anesthetic management currently employed at James Whitcomb Riley Children’s Hospital. A discussion of malignant hyperthermia that focuses on new therapeutic modalities is also presented.

Effect of age on epinephrine-induced arrhythmias during halothane anaesthesia in pigs

The effect of age on the arrhythmogenicity of epinephrine during halothane anaesthesia was studied in pigs of two different age groups. At a stable alveolar concentration of 0.84 volumes per cent halothane, ventricular arrhythmias could not be elicited in one- to three-day-old pigs by a 100μg·kg-1 infusion of epinephrine. PVCs were pro-duced in 50- to 55-day-old pigs at a mean epinephrine dose of 9.55 μ·kg-1. Heart rate, systolic blood pressure, and rate-pressure product were significantly higher before and during the epinephrine infusion in the 50- to 55-day-old pigs. It is concluded that there is an age dependent effect upon epinephrine induced arrhythmias during halothane anaesthesia in pigs.RésuméOn a étudié l’arythmogénicité de la combinaison épinephrinefhalothane chez des porcs d’d’ges différents. Sous anesthésie stable, à 0.84 vol% d’halothane alvéolaire, aucune arythmie ventriculaire n’a pu être déclenchée par l’infusion de 100 μg·kg-1 d’épinéphrine chez des porcs âgés d’un à trois jours; d’autre pan, chez des porcs âgés de 50 à 55 jours, des extrasystoles ventriculaires ont pu être déclenchées à des doses moyennes d’épinéphrine de 9,55 μg·kg-1. La fréquence cardiaque, la pression artérielle et le produit fréquencelpression étaients plus élevés de façon significative avant et pendant l’infusion d’épinéphrine. On en conclut que l’âge de l’animal joue un rôle dans la genèse des arythmies attribuables à la combinaison épinéphrine/halothane.