David D. Cohen

Silent regurgitation and aspiration during general anesthesia.

URING anesthesia, vomiting need not D be obvious for gastric material to enter the respiratory tract.lz2 In 1949, Weiss3 and, in 1951, Culver and associates4 investigated the incidence of “silent” regurgitation under inhalation anesthesia in a small series of unselected surgical patients. Both studies revealed a 26 percent incidence of regurgitation. Of those patients regurgitating, 76 percent in the former and 62 percent in the latter study also aspirated. In 1953, Berson and Adrianij made observations on a total of 926 patients scheduled for elective surgical procedures, finding an overall incidence of 14 percent regurgitation. About half of those regurgitating also aspirated.

DERMAL ANESTHESIA BY THE TOPICAL APPLICATION OF TETRACAINE BASE DISSOLVED IN DIMETHYL SULFOXIDE

Anesthesia of the intact skin, as distinguished from the mucous membranes, has not been attainable by topical application of local anesthetics. The purpose of this paper is to report on the use of DMSO and tetracaine base to achieve topical anesthesia of the intact skin. Recently an organic solvent, dimethyl sulfoxide, was introduced for investigative purposes. Preliminary reports indicated that DMSO not only possesses remarkable solvent properties, but also readily penetrates the intact skin and other tissue.’-3 The use of DMSO as a carrying agent for transmembranal administration of medications has been r e p ~ r t e d . ~ ’ ~ Since local anesthetic salts are somewhat soluble and the bases are very readily soluble in DMSO, it seemed possible that local anesthesia of the intact skin could be achieved by topical application of a solution of anesthetic dissolved in DMSO. Other investigators, however, have reported failure in attempts to produce topical anesthesia of the skin with the hydrochloride salt of lidocaine dissolved in DMS0.3 Since the active form of local anesthetic agent is the base and, further, since tetracaine is approximately ten times as potent as lidocaine in the production of anesthesia, we proceeded to investigate the possibility of producing topical dermal anesthesia by using tetracaine base dissolved in DMSO. Our investigations have indicated that topical dermal anesthesia is possible if a potent local anesthetic agent in the form of a base is dissolved in DMSO.

EFFECTIVE TREATMENT OF HICCUP WITH INTRAVENOUS METHYLPHENIDATE.

SummaryThe causes and treatments of hiccup are discussed Twenty-two cases of hiccup occurring under anaesthesia are reviewed in which intravenous methylphemdate was used as treatment Hiccup stopped in every case, recurred in three, and persisted in one Twenty milligrams of methylphemdate administered intravenously was the most effective dose A mechanism of action of the drug is postulatedRésuméAu cours de l’anesthésie, le hoquet cause habituellement des ennuis au chirurgien II faut distinguer le hoquet de l’effort que fait le malade pour tousser lorsqu’il a un tube dans la trachéeNous avons essayé plusieurs traitements préconisés antérieurement, mais aucun ne nous a donné satisfaction Récemment, le phémdafe de méthyl a été sugge;ré L’étude que nous avons faite confirme l’efficacité de cette substance dans le traitement du hoquet, nous avons obtenu promptement des résultats positifs dans 22 cas consécutifs Chez trois malades, le hoquet est 1 éapparu, mais, après avioir répété l’injection, il est disparu chez deux maladesLa dose optimale semble être de 20 mg, administrée par voie endoveineuse, en 20 secondes II est possible d’observer un hausse temporaire de la pression sanguine Nous n’avons pas observé d’autres effets secondairesNous avons émis une opinion sur le mécanisme d’action de cet agent

Rhinoplethysmography: pulse monitoring at the nasal septum.

The reliability of the pulse wave is diminished in peripheral vasoconstriction due to hypothermia, planned or incidental, or to endogenous or exogenous vasoconstrictors. The scope of the information given by these sites is small. The significance of the amplitude of the pulse waves is, at best, little understood. Although it is important to know the rate and amplitude of the peripheral pulse, of much greater importance would be a running account of the status of cerebral blood flow. Rhinoplethysmography-pulse monitoring at the nasal septum-can, perhaps, give the anesthesiologist a wider scope of knowledge of the patient’s condition than monitoring at the usual areas. Though hypothermia and vasoconstrictors do alter the amplitude of the pulse waves monitored at the nasal septum, the wave does not fade to imperceptibility as frequently occurs with the ear, finger, and toe tracings.

Neonatal apnea associated with respiratory distress syndrome: a case report.

Downes and his associates3 recently proposed a scoring system as a guide to therapy for infants with RDS. This involves rating, on a scale of from 0 to 2, the signs of respiratory rate, cyanosis, intercostal retraction, grunting, and auscultation of inspiratory breath sounds at the midaxillary line (table). Approximately 60 per cent mortality was associated with a score of 7 in their study, while no infant scoring less than 6 died. The following case report describes management of an infant with a Downes score of 7, using intermittent positive pressure ventilation-infants (IPPV/I) after multiple apneic periods.

Neural injury resulting from epidural injection of dimethylsulfoxide and procaine base.

ECENTLY a method was proposed for proR ducing prolonged epidural nerve block in dogs by injection of mixtures of procaine base and dimethylsulfoxide (DMSO).l In that proposal, demyelination of nerves was described as not occurring if a solution of 7 per cent bicarbonate were injected epidurally prior to the injection of DMSO-promine base solution. We have investigated this further and now believe that this drug combination and method of administration in dogs does indeed cause an extensive demyelination of peripheral nerves. The purpose of this paper is to describe this new evidence and correct early impressions of the usefulness of DMSO.

Blood pressure monitoring in the anesthetized patient: a new stethoscope device.

HE co N V E N T I O N A L stethoscope head, T made of hard material, is generally placed beneath a blood pressure cuff prior to the start of an anesthetic procedure. This is done so that blood pressure determinations can be recorded, using the Korotkoff sounds for end points. At the end of a procedure it is not uncommon to see the discolored impression of the stethoscope disc in the patient’s skin. Repeated pressure of more than 200 mm. of mercury by a hard object against the neurovascular bundle in the arm is potentially harmful, and patients occasionally complain of soreness at the site for several days.