Optimal concentration of epinephrine for vasoconstriction in ear surgery.

OBJECTIVE: To determine the optimal concentration of epinephrine required for vasoconstriction in ear surgery by evaluating changes in laser doppler blood flow. STUDY DESIGN: Prospective, randomized, double-blinded. METHODS: Forty subjects undergoing surgical procedures under general anesthesia were injected in a standard posterior external auditory canal block with 1 mL of 1% lidocaine containing varying concentrations of epinephrine (nil, 1:50,000, 1:100,000, or 1:200,000) determined by randomization. Ear canal blood flow measurements were then made at 1-minute intervals for a 10-minute period using a laser doppler flow meter and compared with baseline blood flow. RESULTS: The control solution of 1% lidocaine had a significantly higher blood flow than the epinephrine-containing solutions with an actual 200% increase in blood flow for the first 5 minutes before returning to baseline. All epinephrine-containing solutions had an approximately 50% decrease in blood flow from baseline over the 10-minute period as compared with the control which was statistically significant (P < .0001). There was no significant difference between the blood flow reduction of 1:50,000, 1:100,000, and 1:200,000 epinephrine-containing solutions (P = .8875). CONCLUSIONS: One percent lidocaine control exhibited the expected initial vasodilatory effect for approximately 5 minutes. In this experimental model, using a lower concentration of 1:200,000 epinephrine would supply equivalent vasoconstriction in the ear compared with higher concentrations, thus reducing the possible systemic toxicity and related morbidity.

Oral and oropharyngeal squamous cell carcinoma in young adults: a report on 13 cases and review of the literature.

OBJECTIVE: Squamous cell carcinoma (SCC) of the head and neck is rare in patients younger than 45 years. Patients aged 18 to 45 years with SCC of the oral cavity (OC) and oropharynx (OP) were retrospectively compared with older control subjects. METHODS: Twenty of 127 patients with OC/OP SCC were young adults. Thirteen patients (10 men) comprise the present series; 9 had OC lesions. Seven case controls were identified. RESULTS: Overall, 15.75% of patients with OC/OP SCC were 18 to 45 years old. Seven OC lesions were early stage, and 2 were late stage; OP lesions were evenly divided. Eleven of 13 patients were disease free at the time of their last visit; 2 died of disease. Thirty-one percent of young patients were heavy drinkers; 77% of them smoked. CONCLUSIONS: Young adults' survival rate resembles that reported for all patients with head and neck cancer stage for stage. Tobacco and alcohol abuse prevention among young people is imperative. Health care providers who encounter a young patient with a suspicious head or neck lesion must include malignancy in their differential diagnosis.

Thoracic duct injury during anterior cervical discectomy: a rare complication. Case report.

Chylous fistula resulting from intraoperative injury to the cervical thoracic duct is well described as a complication of neck dissection. However, injury to the thoracic duct during spinal surgery is rarely reported. The authors present the first case of thoracic duct injury occurring during cervical discectomy and fusion via an anterior approach. The anomalous location of the terminal arch of the thoracic duct in this patient contributed to the complication. The morbidity of chyle leakage is minimized by its early recognition, a thorough understanding of lymphatic system anatomy, and aggressive management of the thoracic duct injury.

Wood smoke inhalation increases pulmonary microvascular permeability.

The effect of wood smoke inhalation (SI) on pulmonary vascular permeability was studied in open-chested, anesthetized dogs. Animals were divided into two groups. A prenodal lymphatic vessel was cannulated in group I (n = 7), and baseline (BL) lung lymph flow (QL) and lymph (CL) and plasma (CP) protein concentrations were measured. The animals' lungs were then ventilated with wood smoke for 5 minutes. Left atrial pressure (Pla) was increased above baseline (mean 16.7 +/- 2.2 mm Hg), and the ratio of CL to CP was used to assess endothelial permeability at high lymph flows. There was little change in either QL (BL: 27 +/- 9; SI: 27 +/- 5 microliters/min) or CL/CP (BL: 0.76 +/- 0.03; SI: 0.74 +/- 0.02) after SI at normal Pla. Elevation of Pla caused a significant increase in QL (136 +/- 15 microliters/min), but CL/CP (0.67 +/- 0.02) failed to decrease significantly at high lymph flows. In group II (n = 15) total protein concentration of airway fluid was compared with that of plasma after smoke inhalation, intravenous alloxan, and increased Pla. The ratio of protein concentration in airway fluid to plasma after SI (0.70 +/- 0.07) was greater than that obtained with increased Pla (0.64 +/- 0.07) but less than that after alloxan (0.85 +/- 0.04). These data indicate that SI in the dog results in a moderate increase in pulmonary vascular permeability that is less severe than that induced by alloxan.

Microvascular membrane permeability in high surface tension pulmonary edema.

Pulmonary edema was induced in dogs by an aerosol of detergent dioctyl sodium sulfosuccinate. The permeability of the pulmonary microvascular membrane was assessed by cannulating an afferent tracheobronchial lymphatic and comparing the lymph-to-plasma total protein concentration (CL/CP) during high lymph flows induced by increasing left atrial (LA) pressure after detergent aerosol. Base-line CL/CP of 0.69 +/- 0.02 fell to 0.55 +/- 0.03 with increased LA pressure alone. CL/CP fell to 0.47 +/- 0.02 when LA pressure was increased following detergent, 0.51 +/- 0.04 following an aerosol of the vehicle in which the detergent was dissolved, and 0.73 +/- 0.10 following intravenous alloxan. In additional animals protein concentration of the airway edema fluid was compared with that of plasma. The ration of protein concentration of airway fluid to plasma was 0.63 +/- 0.08 following detergent aerosol, 0.64 +/- 0.10 following increased LA pressure, and 0.94 +/- 0.09 following administration of alloxan. These data indicate no major increase in pulmonary microvascular permeability following detergent aerosol and support the concept that pulmonary edema is the consequence of reduced interstitial perimicrovascular hydrostatic pressure caused by increased alveolar surface tension.