A retrospective cohort study of telephone versus face-to-face clinics for the management of new otology referrals

PURPOSE

To compare outcomes of telephone and face-to-face consultations for new otology referrals and discuss the wider use of telemedicine in otology.

METHODS

Retrospective cohort study including new adult otology referrals to our unit, sampled consecutively between March 2021 and May 2021, seen in either a face-to-face or telephone clinic. Primary outcome measure was the proportion of patients with a definitive management outcome (discharged or added to waiting list for treatment) versus the proportion of patients requiring follow-up for further assessment or review.

RESULTS

150 new patients referred for a routine otology consultation (75 telephone, 75 face-to-face) were included. 53/75 patients (71%) undergoing a face-to-face consultation received a definitive outcome following initial review, versus 22/75 (29%) telephone patients (χ² < 0.001, OR 5.8). 52/75 (69%) telephone patients were followed up face-to-face for examination. The mean (SD) number of appointments required to reach a definitive outcome was 1.22 (0.58) and 1.75 (0.73) in the face-to-face and telephone cohorts, respectively (p < 0.001).

CONCLUSIONS

Telephone clinics in otology have played an important role as part of the COVID19 response. However, they are currently limited by a lack of clinical examination and audiometry. Remote assessment pathways in otology that incorporate asynchronous review of recorded examinations alongside audiometry, either conventional or boothless, may mitigate this problem; however, further research is required.

Cochlear implantation under local anesthetic: A systematic review and meta-analysis

OBJECTIVES

As the population ages and implantation criteria are relaxed, more patients with complex comorbidities are becoming eligible for cochlear implantation (CI). These patients have higher risks associated with general anesthesia. This systematic review assesses outcomes and complications following CI under local anesthetic to examine utility for patients deemed not suitable or at high risk for general anesthesia.

METHODS

A systematic review and meta-analysis performed according to the 2020 PRISMA guidelines. Databases searched were MEDLINE, PubMed, EMBASE, CINAHL, Web of Science Core Collection, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials and ClinicalTrials.gov. There were no limitations on year of publication or language.

RESULTS

Then, 132 unique were identified. After screening abstracts and full texts for eligibility criteria a total of 18 articles were included. In the nine studies where audiological data were reported, all patients demonstrated improvement in audiological outcomes following implantation under local anesthetic (LA). Only minor complications of transient vertigo, wound infection, facial nerve paralysis, confusion, and tinnitus were reported but all were transient. Meta-analysis showed surgical time was significantly shorter under LA.

CONCLUSIONS

CI under LA is safe for patients with comorbidities which preclude them from general anesthesia, with minimal complications and an improved cost-effectiveness profile. However, larger scale, robust trials are required to assess this further.

Early versus late oral feeding following total (pharyngo)laryngectomy: Systematic review and meta-analysis

Timing of oral feeding following total laryngectomy is a contentious issue with highly varied practices. Multiple database search was performed to identify studies comparing outcomes of early (≤5 days) versus late (>5 days) oral feeding. Bias assessment was carried out using Cochrane bias tool. Random-effects meta-analysis was used. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The rate of pharyngocutaneous fistula (PCF) in randomized control trials (RCTs) in early versus late feeding was 15.2% versus 11.7% (RR 1.35, 95%CI [0.68-2.7], p = 0.40). The rate of PCF in the cohort studies was 14.1% versus 20.5% (RR 1.0, 95%CI [0.76-1.3], p = 0.98). The length of hospital stay was significantly shorter in the early feeding group (mean difference (days) -4.68 (-6.2 to -3.1, p < 0.0001). Early oral feeding appears to be safe and is associated with shorter hospital stay. However, the quality of evidence is low and the patient characteristics are not representative of current practices.

Outcomes and prognosticators in regionally recurrent cutaneous squamous cell carcinoma of the head and neck

INTRODUCTION

Data regarding regionally metastatic cutaneous squamous cell carcinoma of the head and neck (cSCCHN) is limited and derived almost exclusively from Australian and United States (US) institutions. We report the first United Kingdom perspective, with the aims of benchmarking survival outcomes and identifying clinically relevant prognosticators.

MATERIALS AND METHODS

Ninety-one patients with regionally recurrent cSCCHN treated with curative intent over a ten-year period (2009-2018) were studied retrospectively. Time-to-event analyses were used to estimate oncological outcomes, and log-rank statistics and Cox proportional hazards models used to examine potential prognosticators. Receiver operating characteristics were also used to analyse the influence of nodal disease burden.

RESULTS

Parotid involvement (with or without neck involvement) was most common (79.2%), and time to recurrence in those with parotid disease alone significantly shorter than for any other disease distribution (p = 0.034). Respective five-year overall, disease-specific, and disease-free survival estimates were 43.8%, 63.8%, and 36.2%. Extracapsular spread (ECS) portended reduced DFS and DSS (p = 0.012 and p = 0.005 respectively). Increasing nodal burden (≥4 involved nodes) also reduced DSS (p = 0.020), while parotid disease alone predicted more favourable DSS (p = 0.008). ECS and isolated parotid involvement remained significant on multi-variate analysis (p = 0.014 and p = 0.028 respectively).

CONCLUSIONS

Oncological outcomes were unfavourable but broadly consistent with previous reports, notionally lending support to a more proactive approach in managing the clinically node negative neck/parotid in selected high-risk cases. Our data also support distinct parotid classification and consideration of involved lymph node number in future staging systems.

The importance of covalent coupling in the synthesis of high performance composite anodes for lithium ion batteries

We present a direct comparison between identical electrostatically and covalently assembled Si–graphene composites for lithium ion battery anodes.

Decoration of graphitic surfaces with Sn nanoparticles through surface functionalization using diazonium chemistry

Composites of tin nanoparticles (Sn NP) and graphene are candidate materials for high capacity and mechanically stable negative electrodes in rechargeable Li ion batteries. A uniform dispersion of Sn NP with controlled size is necessary to obtain high electrochemical performance. We show that the nucleation of Sn particles on highly ordered pyrolitic graphite (HOPG) from solution can be controlled by functionalizing the HOPG surface by aryl groups prior to Sn deposition. On the contrary, we observe heterogeneous deposition of micrometer sized Sn islands on HOPG subjected to oxidation prior to deposition in the same conditions. We demonstrate that functional groups act as nucleation sites for Sn NP nucleation, and that homogeneous nucleation of small particles can be achieved by combining surface functionalization with diazonium chemistry and appropriate stabilizers in solution.

Genetic linkage analysis of nerve growth factor (beta) in familial Alzheimer's disease

Recent studies have not shown linkage of late-onset (mean age, greater than 60 years) familial Alzheimer's disease (FAD) to the chromosome 21 locus reported linked to early-onset FAD. Beta nerve growth factor (beta-NGF) has been considered a candidate gene in the pathogenesis and therapy of FAD, based on its localization in the cortex and hippocampus and its ability to enhance the growth and survival of cholinergic neurons. A 1.5-kb fragment of the beta-NGF gene was used to detect a BglII restriction fragment length polymorphism, which was then used for linkage analysis. A total of 30 families (27 late onset) with 147 affected members were studied. Close linkage (theta less than or equal to 0.03, z less than or equal to -2.00) of late-onset FAD with beta-NGF was excluded. Two apparent obligate crossovers between affected members were detected in different autopsy-confirmed families. Based on these results, beta-NGF is not the gene responsible for late-onset FAD in the families analyzed.

The effect of a mechanical venous pump on the circulation of the feet in the presence of arterial obstruction

A boot of single layer, flexible vinyl sheeting and a pneumatic cuff encircling its top at the ankle, each independently inflatable, constitute a mechanical venous pump. Inflation of the cuff to the desired boot pressure is followed immediately by inflation of the boot from a reservoir with higher available pressure than that in the cuff. When the boot pressure reaches cuff pressure, the excess air escapes from the boot under the cuff. A low venous pressure at the foot could be maintained by compressing the foot for 2 seconds every 15 seconds with a pressure which is 10 millimeters of mercury above initial venous pressure. In seated patients with arterial obstruction whose supine ankle blood pressure was 60 milimeters of mercury or less, the rate of blood flow in the skin of the forefoot was increased by 104.1 +/- 43.7 per cent S.E.M., p less than 0.05, during venous pumping. In these patients, a change in posture alone from supine to sitting increased the rate of blood flow by 81.7 +/- 19.47 per cent, p less than 0.002. The combined effect of the erect posture and venous pumping was an increase of 185.7 +/- 49.63 per cent, p less than 0.01. Rest pain was relieved by the combined effect.

The effect of clonidine on vascular reactivity to angiotensin, noradrenaline, and vasopressin in conscious rats

The critical opening pressure (COP) of small vessels in the tails of conscious rats was measured by the spectroscopic technique as an index of arteriolar smooth muscle contraction force. In 11 rats acute intramuscular injection of clonidine (15 μg/kg) decreased systolic blood pressure (SBP) and COP by 13.7 ± 1.7 (SEM) and 7.6 ± 1.1 mmHg, respectively, in intact rats but increased SBP by 30.4 ± 2.6 and COP by 25.9 ± 3.5 mmHg in six ganglion-blocked rats. Reactivity of arteriolar muscle was measured as the increase in COP of the vessels in response to intravenous infusion at three or four dose levels of angiotensin II (2–12 ng kg−1 min−1), noradrenaline (30–120 ng kg−1 min−1), or lysine-8-vasopressin (0.085–0.34 mU kg−1 min−1). The dose–response relationship was considered to be essentially linear and increases in COP in clonidine-treated and control rats were compared directly. Acute administration of clonidine (1, 3, or 10 μg/kg, im) decreased vascular reactivity to each of these agents in both the intact and ganglion-blocked rat. For example, in ganglion-blocked rats total increases in COP were as follows: (1) during infusion of angiotensin (8 ng kg−1 min−1), 22.3 ± 1.3 (SEM) mmHg in clonidine-treated rats and 40.3 ± 3.7 in controls (p < 0.01); (2) during infusion of noradrenaline (120 ng kg−1 min−1), 8.4 ± 1.7 mmHg in clonidine-treated rats and 30.0 ± 2.6 in controls (p< 0.001); and (3) during infusion of vasopressin (0.34 mU kg−1 min−1), 24.8 ± 0.3 mmHg in clonidine-treated rats and 47.8 ± 0.9 in controls (p < 0.001). Chronic treatment of rats with clonidine (20 μg kg−1 day−1) for 7 or more days had a similar effect on vascular reactivity. This apparently nonspecific reduction of vascular reactivity could play an important part in the antihypertensive effect of clonidine hydrochloride.

Experimental aldosterone hypertension in the rat

We previously showed that hypertension induced in rats by administration of desoxycorti-costerone acetate and replacement of the drinking water by 1% NaCl solution (DOCA-NaCl hypertension) was associated with an increased critical opening pressure (COP) of tail vessels and an increased arteriolar smooth muscle reactivity to intravenous infusion of angiotensin II or norepinephrine. In the present investigation hypertension was induced in rats by administration of aldosterone (5 μg/100 g per day) and replacement of drinking water with 1% NaCl solution (aldosterone–NaCl hypertension). The hypertension was associated with an increase in COP of tail vessels when measured both before and after ganglionic blockade, but the reactivity of the smooth muscle of these vessels to angiotensin II or to norepinephrine was not increased. Administration of aldosterone alone by intramuscular injection in sesame oil induced hypertension, whereas it was previously shown that similar treatment of rats with DOCA alone did not. The onset of hypertension and increased COP of tail vessels in the rats so treated with aldosterone was usually delayed by 4 or more days. To define more precisely the time course of the changes in blood pressure and COP induced by aldosterone hypertension was induced in rats by continuous subcutaneous infusion of aldosterone in an alcohol – 5% dextrose in water vehicle. Under these circumstances the rise in blood pressure and COP occurred after a delay of 2 days when measured after ganglionic blockade. On termination of the infusion the hypertension was rapidly reversed, the blood pressure declining smoothly to normal levels within 7 days.These results confirm that aldosterone alone can in fact induce hypertension in rats and suggest that the mechanism(s) by which aldosterone produces hypertension may differ in certain important respects from that involved in DOCA hypertension.

Critical opening pressure and reactivity of tail vessels in conscious hypertensive rats

The possible role of increased vascular reactivity in the mechanism of experimental hypertension was studied by measurements of the critical opening pressure (COP) of tail vessels in conscious rats. In hypertension induced by administration of desoxycorticosterone acetate (DOCA) and replacement of the drinking water by 1% NaCl solution (DOCA-NaCl hypertension), and in one-kidney Goldblatt renovascular hypertension, the raised level of blood pressure was associated with an increased COP of the tail vessels when measured both before and after ganglionic blockade. In rats treated with either DOCA alone or 1% NaCl alone there was no significant increase in systolic blood pressure (SBP) or COP relative to the corresponding controls. In all four experimental series intravenous infusion of angiotensin or norepinephrine in conscious ganglion-blocked rats produced dose-dependent increases in SBP and COP. In DOCA-NaCl hypertensive rats but not in renovascular hypertensives, nor in rats treated with DOCA alone or 1% NaCl alone, the increase in COP for a given increment in dose of angiotensin or norepinephrine was significantly greater than in the control rats. It is concluded that in DOCA-NaCl hypertension there is a true increase in the reactivity of the smooth muscle of the resistance vessels to angiotensin and norepinephrine. In renovascular hypertension this is not the case and other factors must therefore be involved in causing the increased blood pressure and COP.

Assessment of arterial obstruction in vessels supplying the fingers by measurement of local blood pressures and the skin temperature response test--correlation with angiographic evidence

The systolic blood pressure measured in the fingers and wrists by the spectroscopic method and in the arm by auscultation were correlated with angiographic evidence of organic arterial obstruction in 29 patients. The pressures also were measured in 14 normal people. Results in the normal people suggest that a difference of more than 15 mm. Hg between the pressure measured simultaneously in corresponding fingers (or any two or more fingers), an absolute digital pressure less than 70 mm. Hg, or wrist-to-digit gradient of more than 30 mm. Hg, all in the warm subject and warmed hand, indicated the presence of organic obstruction. These criteria indicated the presence of organic arterial obstructive disease in 25 of 26 hands with definite angiographic evidence of it. The pressures were "normal" in five hands with no angiographic evidence of organic arterial obstruction. The digital skin temperature response to indirect heating was much less successful than were pressure measurements in identifying fingers with organic arterial obstructive disease.

The influence of lysine-8-vasopressin, oxytocin, and adrenaline on vascular smooth muscle in the human finger

Lysine-8-vasopressin, oxytocin, or adrenaline was administered by intravenous infusion to young women, and their effect on the critical opening pressure (COP) of digital vessels, vascular resistance in the finger, and systemic blood pressure was measured. All doses of lysine-8-vasopressin between 0.001 and 0.08 U/min increased the COP of digital vessels but only the largest dose raised blood pressure slightly. A dose of 0.04 U/min had little if any effect on overall vascular resistance in the finger. Nevertheless the smallest dose given (0.001 U/min), which is within the physiological range of secretion rate by the pituitary gland, increased the COP of digital vessels substantially. Oxytocin at doses of 5–160 mU/min had no apparent effect on COP or vascular resistance of digital vessels or on blood pressure. Adrenaline at 4 μg/min increased the COP of digital vessels substantially. The latter observation is consistent with the absence of β receptors in vessels of the skin of the fingers.

The importance of penile blood pressure in cases of impotence

It appears that the normal penile systolic blood pressure, as measured by a spectroscopic method, is equal to or greater than the calculated brachial mean blood pressure. A pressure definitely lower than this in impotent patients indicates obstruction to blood flow in the main vessels supplying the penis. On this basis, obstruction to blood flow was identified as a cause of impotence in patients with little other evidence of peripheral vascular disease.

The erect posture as an aid to the circulation in the feet in the presence of arterial obstruction

When the main artery in the lower limb is occluded and narrow collateral vessels by-passing the obstruction offer the limiting resistance to blood flow, the increase in arterial pressure at the ankle on assuming the erect posture is greater than would be predicted by consideration of the hydrostatic factors. In seven patients with femoral artery occlusion the pressure at the ankle was greater than expected in all and on the average by 8.0 mm. Hg+/-1.5 S.E. when sitting, (P<0.01) and in the four patients tested, by 12.4 mm. Hg+/-0.5 S.E. when standing (P<0.01). Rate of blood flow in subdermal tissue of the forefoot estimated by xenon-133 clearance was an average of 21% less when sitting than when supine in five limbs of four normal subjects while in five limbs with occlusion or severe stenosis of the superficial femoral artery the rate of flow was an average of 44% greater.

The effect of repeated cold exposure of the hand on the reactivity of digital vessels

One hand of each of 10 subjects was immersed in stirred water at 4 °C for 1 h per day, 5 days per week, for 3 weeks, to produce local acclimatization to cold. The opposite hand was immersed at the same time in water at 32 °C. The reactivity of digital vessels in a finger of each hand was measured as the increase in the critical opening pressure of the vessels in response to an intravenous infusion of noradrenaline at 2 and 5 μg/min. The reactivity of digital vessels in the test hand was compared with that in the control hand both before and after the repeated cold exposure of the test hand to see whether the cold exposure altered the reactivity of vessels in the test hand relative to that in the control hand. No evidence of such a relative change was obtained. Resting blood flow at 21 and 32 °C in the test hand was compared with that in the control hand both before and after the repeated cold exposure. No change in the relative flow rate in the two hands was observed as a result of the cold exposure. Roentgen studies of the hands did not reveal any effect of the repeated cold exposure on the mineralization of the bones of the hands.

Digital vascular response to angiotensin II in normotensive and hypertensive subjects. Evidence for a qualitatively abnormal response to angiotensin in essential hypertension

The critical opening pressure (COP) of digital vessels after digital nerve block and the change in COP caused by angiotensin at 4 mµg/kilo per min intravenously after the block were compared in 9 normotensive subjects, 8 patients with essential hypertension and 7 patients with various kinds of renal hypertension. The COP after nerve block was less than 20 mm Hg in the normotensives and in 6 renal hypertensives, but more than 20 mm Hg in 7 essential hypertensives. The angiotensin reduced the COP in 7 of the normotensives, increased it substantially in 7 essential hypertensives, but had little effect in 6 renal hypertensives. A significantly greater increase in systemic blood pressure occurred in the essential hypertensives than in the normotensive subjects. In normotensive subjects doses of intravenous angiotensin from 2 to 16 mµg/kilo per min decreased the COP whether preceded by digital nerve block or not. Angiotensin at 8 mµg/kilo per min increased total digital vascular resistance as estimated by venous occlusion plethysmography. The results indicated that angiotensin relaxed smooth muscle in digital vessels of normal subjects but increased vascular resistance. In patients with essential hypertension angiotensin caused contraction of the smooth muscle, a response apparently qualitatively different from normal. In renal hypertensives the smooth muscle had little response to the exogenous angiotensin.

The effect of local temperature on the reactivity to noradrenaline of digital vessels

The effect of local temperature on the in vivo reactivity of vascular smooth muscle was studied. Reactivity was measured as the increase in critical opening pressure (COP) of digital vessels caused by intravenous infusion of 5 μg of noradrenaline per minute. With one hand cool (22 °C) and the other warm (34 °C) in test experiments or both hands either cool or warm in control experiments, simultaneous measurements were made of the increase in COP of vessels in both middle fingers in response to the noradrenaline. In control experiments the mean increase in COP was similar in right and left fingers, but in test experiments the mean increase was greater in the warm finger than in the cool one. Warm vessels were more reactive to noradrenaline than cool ones (p < 0.01). Because a short period of ischemia is involved in the measurement of COP, other experiments were performed in which the effect of duration of ischemia on the COP, with and without a continuous intravenous infusion of noradrenaline, was ascertained. They suggested that the estimated COP would, in most cases, be about 3 mm Hg less than the COP existing just before the measurement. These results also indicated that although the rate of fall of COP during ischemia was slightly greater for a higher initial COP, the ischemia involved did not invalidate the comparison of the increases in COP caused by noradrenaline in warm and cool fingers, as an index of relative arteriolar reactivity in the test reactivity experiments.

The effect of local cooling on the sensitivity to noradrenaline of vessels in the feet

Local cold markedly reduces the rate of blood flow in the extremities. Experiments were performed to see whether it also increased the sensitivity of vascular smooth muscle to noradrenaline in terms of a reduced threshold dose. Rate of blood flow in the feet was measured by venous occlusion plethysmography. The plethysmographs were filled with water at 21 °C for the left foot and 34 °C for the right. Noradrenaline in doses of 0.1, 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 μg/minute were infused intravenously for periods of 5 to 7 minutes. Rate of flow during noradrenaline infusion was expressed as a percentage of the rate just before noradrenaline. Fifteen experiments on 13 subjects were performed but not all doses were administered in each experiment. The mean of the percentage flow rates for all infusions at a given dose of noradrenaline was not less than 100% for either foot until 0.8 μg/minute was administered, when flow was reduced in both warm and cool feet. Thus, cooled vessels were not shown to be more sensitive than warm vessels. Noradrenaline infused at 3.2 μg/minute caused a significantly greater reduction in flow rate in the cool than in the warm feet but this is not interpreted as a greater reactivity of the cooler vessels to the drug.

The relative influence of nervous control and of local warming on arteriolar muscle during indirect vasodilatation

The relative importance of the inhibition of vasoconstrictor nerves and of concomitant local warming in the production of indirect vasodilatation was investigated in terms of the decrease in critical opening pressure (COP) of digital vessels during body heating. The COP of vessels in a finger of each hand was measured when both hands were kept at about 21 °C during body heating in control experiments and when one of the hands was allowed to warm in air in test experiments. In eight control experiments the COP's of vessels in both fingers fell together. In 25 test experiments they fell together in both fingers until the hand in air began to warm. The COP then fell more rapidly and farther in the finger which warmed. In the test experiments the difference between the reductions in COP in the two fingers was attributed to the effect of local warming. The total reduction in the hand which was prevented from warming was ascribed to inhibition of neurogenic smooth muscle tone. On the average, local warming reduced the COP by 1.3 mm Hg for each increase of 1 °C. Warming occurred when the COP was reduced to about 25 to 35 mm Hg. However, much higher values of COP can exist in the constricted subject. Therefore the initial smooth muscle constricting force may have to be greatly reduced by inhibition of vasoconstrictor nerves before appreciable warming occurs. Then local warming may play an important role in determining the degree of vasodilatation that occurs.

The effect of local temperature on indirect vasodilatation in the feet

Lewis and Pickering reported in 1933 that warming occurred later in cool than in warm fingers in response to body heating. Factors which may be responsible were investigated. Measurement of rate of blood flow in the feet by venous occlusion plethysmography during body heating showed that vasodilatation in the feet occurred at the same time in a cool foot (18 to 23 °C) as in a warm (30 to 35 °C) but that warming of the cooler foot might be delayed for some time until the increase in flow was 0.5 ml/100 ml of foot per minute or more. In control experiments, with both feet in cool water or both in warm, the increase in blood flow during body heating started at the same time in both feet. Warming also began at the same time in both feet, but in the cool control experiments, warming often began later than did increase in flow. It is suggested that precooling of arterial blood may account for the delay in warming when the extremity is initially cool and the increase in blood flow is at first small during indirect vasodilatation.

THE MEASUREMENT OF BLOOD PRESSURE, THE CRITICAL OPENING PRESSURE, AND THE CRITICAL CLOSING PRESSURE OF DIGITAL VESSELS UNDER VARIOUS CIRCUMSTANCES

A spectroscopic technique for the estimation of the critical opening pressure (COP) or critical closing pressure (CCP) of small vessels in the finger is described. The spectroscopic method of estimation of the systolic blood pressure, which is part of the technique and which involves the detection of reappearance of oxyhemoglobin absorption bands in the spectrum of reflected light from the skin distal to a blood pressure cuff that is slowly deflated, was compared to the auscultatory technique in 38 subjects on 53 occasions and gave the same results. The COP of small vessels in the finger estimated by the spectroscopic technique was decreased by body heating and by digital nerve block as had been previously shown by the microscopical method. The COP of vessels in the finger after digital nerve block in 43 normotensive young women between the ages of 18 and 22 years ranged from 2 to 19 mm Hg with a mean of 9.5 ± 4.6 (S.D.) mm Hg. When the COP was estimated in many of the same subjects after preparation as for measurement of the basal metabolic rate, in most cases it fell within the range of values obtained after nerve block. The COP in 26 subjects ranged from 1 to 22 mm Hg with a mean of 10.9 ± 5.0 (S.D.). The values for CCP estimated by the spectroscopic method in 81 individuals were not significantly different from those for COP estimated on the same occasion.

THE BRACHIAL TO DIGITAL BLOOD PRESSURE GRADIENT IN NORMAL SUBJECTS AND IN PATIENTS WITH HIGH BLOOD PRESSURE

The brachial and digital blood pressures were estimated by auscultatory techniques in 10 patients with essential hypertension and in a group of 6 subjects with normal blood pressure who were in a state of regulated peripheral vasoconstriction and again when they were in a state of regulated vasodilatation. The brachial to digital systolic and diastolic pressure gradients in both control subjects and hypertensive patients were greater when the individuals were heated than when they were cooled. The brachial to digital diastolic pressure gradient in the hypertensive patients was not significantly different from that in the subjects with normal blood pressure. However, the systolic pressure gradient was greater in the hypertensive patients than in the control group both when the individuals were heated and when they were cooled.

AN AUSCULTATORY TECHNIQUE FOR MEASURING THE DIGITAL BLOOD PRESSURE

The digital systolic and diastolic blood pressures in human subjects were estimated by means of an auscultatory technique similar to the clinical auscultatory method of measuring brachial blood pressure. The stethoscope was modified by substituting a digital plethysmograph (into which the finger was sealed) for the usual diaphragm. Korotkoff sounds were heard through the stethoscope as a pneumatic cuff around the base of the finger was deflated from a suprasystolic level. In comparison of this method with the plethysmographic method of measuring digital systolic pressure and with a method involving direct observation of resumption of blood flow in capillary loops of the nailfold as an end point when a cuff on the finger was deflated from a supra-systolic level, it was found that the first sound is as reliable an index of systolic pressure as those used in the other methods.

AN AUSCULTATORY TECHNIQUE FOR MEASURING THE DIGITAL BLOOD PRESSURE

The digital systolic and diastolic blood pressures in human subjects were estimated by means of an auscultatory technique similar to the clinical auscultatory method of measuring brachial blood pressure. The stethoscope was modified by substituting a digital plethysmograph (into which the finger was sealed) for the usual diaphragm. Korotkoff sounds were heard through the stethoscope as a pneumatic cuff around the base of the finger was deflated from a suprasystolic level. In comparison of this method with the plethysmographic method of measuring digital systolic pressure and with a method involving direct observation of resumption of blood flow in capillary loops of the nailfold as an end point when a cuff on the finger was deflated from a supra-systolic level, it was found that the first sound is as reliable an index of systolic pressure as those used in the other methods.

THE BRACHIAL TO DIGITAL BLOOD PRESSURE GRADIENT IN NORMAL SUBJECTS AND IN PATIENTS WITH HIGH BLOOD PRESSURE

The brachial and digital blood pressures were estimated by auscultatory techniques in 10 patients with essential hypertension and in a group of 6 subjects with normal blood pressure who were in a state of regulated peripheral vasoconstriction and again when they were in a state of regulated vasodilatation. The brachial to digital systolic and diastolic pressure gradients in both control subjects and hypertensive patients were greater when the individuals were heated than when they were cooled. The brachial to digital diastolic pressure gradient in the hypertensive patients was not significantly different from that in the subjects with normal blood pressure. However, the systolic pressure gradient was greater in the hypertensive patients than in the control group both when the individuals were heated and when they were cooled.