Michael H. M. Dykes

Fiberoptic nasotracheal intubation--incidence and causes of failure.

Although flexible fiberscopes have been used to facilitate difficult tracheal intubations (1-3), there is little information on the incidence and causes of failure with use of flexible fiberscopes for this purpose. All elective nasotracheal intubations in this institution, including those in patients with proven difficulty of intubation, are performed with fiberscopes. This paper reports the incidence of difficult fiberoptic nasotracheal intubation (FNI) and the failure rate in 423 consecutive carefully monitored such intubations.

Statistical methods in anesthesia articles: An evaluation of two American journals during two six-month periods

Simple criteria were used to evaluate the statistical analyses in 243 articles from two American anesthesia journals published in the latter six months of 1981 and 1983. Eighty-two percent of the articles reported the use of control measures and 37% reported randomization of treatment, where they were possible. Data were classified as nominal, ordinal, or interval; as independent or related samples; as two-sample or more-than-two-sample cases. The descriptive, inferential, and correlative tests used were evaluated for appropriate application and primary errors were identified. Nine percent of the 722 descriptive statistics had major errors, most of which were a description of ordinal data as though they were interval. The incidence of erroneous applications of 394 inferential statistical tests was 78%. Nearly three-quarters of the 308 primary inferential statistical errors involved either use of a test for independent samples on related data (and vice versa) or multiple applications of an uncorrected test to the same data. Only 4% of the 113 statistics of association were considered erroneous, most because the method was not identified. No differences were detected in the incidence of errors in either experimental design or statistical analysis across time or across the two anesthesia journals. Fifteen percent of the 243 articles in both journals at both times were without major errors in statistical analysis. Recognition of potential sources of error should make it easier for investigators to use experimental designs and statistical analyses appropriate to their needs.

Blood pressure and heart rate changes during awake fiberoptic nasotracheal intubation

Hypertension and tachycardia associated with orotracheal intubation may result from direct laryngoscopy (1,2), placement of the endotracheal tube (1,2), and succinylcholine if used (3). With awake fiberoptic nasotracheal intubation (FNI) the stimulation of rigid laryngoscopy and succinylcholine are avoided. All elective nasotracheal intubations in our institution are performed with the patient sedated and using topical anesthesia and a flexible fiberscope. This report analyzes changes in mean arterial pressure (MAP) and heart rate (HR) during 200 such intubations to determine whether avoidance of rigid laryngoscopy and succinylcholine decreases the incidence and the severity of hypertension and tachycardia that are associated with tracheal intubation.

Sudden cessation of cardiac output during spinal fusion.

E RECENTLY reported development of W severe posttransfusion pulmonary edema in a patient following multiple laminectomies and osteotomies of three fused thoracic vertebrae and insertion of a Harrington rod (T5-12) .l Extreme intraoperative hypotension, clearly associated with excessive blood loss, developed on three occasions. The total blood loss m.easured 5225 ml., and was replaced by 7500 ml. of whole blood. In the recovery room the patient developed pulmonary edema associated with profound cyanosis and loss of consciousness. This was treated with trimethaphan camphorsulfonate and intermittent positive pressure breathing, with immediate improvement.

Multiple neuro-muscular blocking agents and reversal in a patient with absent plasma cholinesterase

The detailed clinical response of a patient with absent plasma cholinesterase (genotype1s Ef) who received tubocurarine (3 mg), succinylcholine (120 mg), pancuronium (2mg), and reversal with neostigmine (3 mg) is reported. The patient–s responses were compared to the responses of a group of patients with genotype Ela Ela evaluated prospectively, and with eight other genotype Els Els patients reported in the literature. The present patient demonstrated evidence of a phase II block before and after attempted reversal, suggesting that free succinylcholine was present in her plasma and a mixed block was present at that time. Conservative supportive therapy was continued and a complete recovery resulted five hours and 30 minutes after the succinylcholine administration.RésuméLa réponse clinique détaillée d’une patiente présentant une absence de cholinestérase plasmatique (génotype E1s E1s J qui a recu de la tubocurarine (3 mg), succinylcholine (120 mg), pancuronium (2 mg), et renversee par néostigmine (3 mg), est rapportée. Les réponses de la patiente ont été comparées avec les réponses d’un groupe de patients présentant un génotype E1a E1a évalués prospectivement ainsi qu’avec huit autres présentant un génotype E1aE1a rapportés dans la littérature. La patiente adémontré de l’évidence d’un bloc phase II avant et après une tentative de renversement du bloc, suggérant que la succinylcholine libre était présente dans son plasma et qu’un bloc mixte était présent en même temps. Une thérapie conservatrice de support était continuée et un rétablissement complet s’en est suivi cinq heures et trente minutes après l’administration de succinylcholine.

Evaluation of nitrous oxide and a nondepolarizing muscle relaxant for prolonged surgery.

esthesia and surgical procedures, Fiskl noted that it is almost impossible to asseas clearly and objectively the importance of the time factor, but nevertheleas favored light general anesthesia, apparently referring to the thiopental-relaxant-nitrous oxide technic, over deep general anesthesia. Vandam2 noted that it is difficult to separate some of the adverse effects of anesthesia from those of surgery, and warned of the subtle degrees of paralysis, which may persist long after surgical relaxation is no longer required, following the use of some muscle relaxants.

Anaesthetic management of pheochromocytoma: a case report.

SummaryThe anaesthetic management of a patient with pheochromocytoma is discussed. The following points should be considered when treating such patients:1.Preoperative preparation with adrenergic blocking agents, following the criteria of Harrisonet al.42.Use of an anaesthetic agent (methoxyflurane or fluroxene) which is not associated with release of endogenous catecholamines and does not sensitize the myocardium to high levels of circulating catecholamines.3.Adequate fluid and blood administration, including preoperative transfusion if necessary.4.Careful monitoring during surgery, including direct arterial pressure, central venous pressure, electrocardiogram, urinary output, and blood gas determinations.5.Ready availability of all pharmacological agents appropriate for the control of hypertension, hypotension, and cardiac arrhythmias.

Prolonged anesthesia and surgery: an essay on a subjective experience.

HAVE HEARD it said that all surgeons I should undergo surgery once a year, in order that they might be reminded annually of the “real” nature of the experience to which they subject their patients. In view of a recent enlightening experience, I feel that if there is any merit in the above suggestion, which is highly questionable, there is equal merit in the suggestion that all anesthesiologists should undergo anesthesia once a year.