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At least 685 records · Page 38Linked to original sources

PubMed2002

Relationship between pressure-derived collateral blood flow and diabetes mellitus in patients with stable angina pectoris: a study based on coronary pressure measurement.

UNLABELLED: Although the pressure gradient between the normal and stenotic vascular regions is known to be the most important factor for collateral vessel development, factors which are responsible for variations among patients with ischemic heart disease are not well known. Likewise, it is still not clear whether diabetes mellitus (DM) has any effect on coronary collateral development. Coronary angiography, the most commonly used technique for studying collateral circulation, may not be accurate in assessing collateral circulation because most collaterals are situated intramurally or are too small to visualize angiographically. Intracoronary pressure measurement is a new technique to provide accurate and quantitative information about the collateral circulation. Therefore, we sought the effects of DM on coronary collateral vessels in patients with coronary artery disease by using intracoronary pressure measurement technique. METHODS: Study material consisted of 40 patients (20 diabetic) with chronic ischemic heart disease referred to angiography laboratory due to their ischemic symptoms verified previously with at least one non-invasive test. All of the patients had single vessel disease with more than 70% narrowing and had undergone PTCA and/or stent implantation procedure for this vessel. Quantitative coronary angiographic analysis (QCA) and all of the coronary pressure measurements were performed both pre- and post-revascularization procedure. After angiography, a fiber-optic pressure monitoring guidewire (Pressure wire, RADI Medical Systems, Inc., Reading, Massachusetts) was advanced to the stenosis to be dilated. The same wire was used as a guidewire for the angioplasty catheter. During complete occlusion with balloon inflation, distal pressure was recorded as coronary wedge pressure (CWP). As a more valuable parameter, collateral flow index (CFI) was determined by the ratio of simultaneously measured CWP (mmHg) to mean aortic pressure (Pa, mmHg, obtained from the guiding catheter) (CFI: CWP/Pa). RESULTS: Pressure measurements were performed on 20 diabetic and 20 non-diabetic patients. The mean value of CWP was 18.1 8.6 mmHg in the diabetic group and 26.8 +/- 9.6 mmHg in the non-diabetic group; this difference was statistically significant (p < 0.01). Also, the mean value of CFI was significantly higher in the non-diabetic group (0.17 +/- 0.08 in the diabetic group and 0.25 0.09 in the non-diabetic group; p < 0.01). CONCLUSION: This study demonstrated that the coronary collateral vessel development is impaired in diabetic patients compared with non-diabetic patients.

Angina Pectoris↗

PubMed1991

[A study on blood pressure variation--the clinical validation of continuous direct blood pressure recording in patients with pheochromocytoma].

UNLABELLED: Continuous direct arterial blood pressure (intra-brachial) recording (CDPR) was performed in the ward in 7 patients with documented pheochromocytoma (PHEO). They consisted of 4 patients with adrenal medulla and 3 with ectopic PHEO in the urinary bladder. Recordings were also taken from 11 patients with mild and moderate essential hypertension (EHT). The arterial pressure variations throughout the day and night were detected for either 24 hours or 48 hours unrestrictive recording (CDPR) transmitted by telemetry (SANEI INST. 270), and analyzed by signal processor (SANEI 7T17). The measurement through CDPR was repeated in all the patients with PHEO on three occasions; (1) observation period (non-medication period), (2) medical treatment period with prazosin and, (3) post-operative period. RESULTS: (1) In the non-medication period, all the patients with PHEO were characterized by a steep elevation of the arterial pressure and a variability of the high blood pressure events more remarkably than the patients with EHT. The changes in arterial pressure in the patients with PHEO were accompanied by headaches, feelings of fear, trembling, sweating and palpitation. (2) At the medication period, prazosin sufficiently suppressed the sudden elevation of blood pressure. However, the paroxysmal elevation of blood pressure after voiding was not prevented in 2 of 3 patients with ectopic PHEO in the urinary bladder. Urinary and plasma catecholamine (CA) were normal in 2 of our 3 cases. Voiding elevated plasma CA which provided better diagnostic determinant in patients with this bladder tumor as well as the CDPR. (3) The CDPR provided good operative removal results through the 24-hour monitoring, and the recovery was uneventful. CONCLUSION: Evaluation of blood pressure elevation is a clue to the diagnosis of hypertension. Monitoring of the arterial blood pressure variation through 24 hours by CDPR was helpful for detecting a precise arterial pressure fluctuation, since the duration of the elevation was short and was steeply changed especially in patients with PHEO.

Adrenal Gland Neoplasms↗

PubMed1990

Oscillometric finger blood pressure versus brachial auscultative blood pressure recording.

In this study, a recently marketed proprietary finger blood pressure monitor, the Marshall, Astro F-88, was compared with the standard auscultative brachial mercury sphygmomanometer on 125 subjects. Measurements were undertaken according to the standards set by the American Heart Association. Sensitivity of the finger blood pressure measurement was 76% for systolic and 75% for diastolic blood pressure in diagnosis of high blood pressure (systolic greater than 140 mm Hg and diastolic greater than 90 mm Hg). Specificity was 86% for systolic and 82% for diastolic blood pressure. Positive predictive values were 58% for systolic and 38% for diastolic blood pressure in the study population in which prevalence of hypertension was 12%. The correlation coefficient (Pearson) for systolic values between devices was 0.76 (P less than .0001) and 0.57 (P less than .0001) for diastolic pressure. Values obtained by the finger monitor were found to be higher than those obtained by the mercury sphygmomanometer. Mean differences and standard deviations (paired t test) for systolic and diastolic pressures between the two devices were 2.3 +/- 14.9 mm Hg (P less than .08) and 2.9 +/- 14.5 mm Hg (P less than .02), respectively. These values are not in accordance with the proposed national standards because only 48% of the systolic and 37% of the diastolic blood pressure measurements were within 5 mm Hg of the mercury sphygmomanometer measurements. Therefore, although these differences may well be due to different techniques of monitoring employed by the devices, this device is not recommended for evaluation of blood pressure.

Adolescent↗

PubMed1990

[Evaluation of antihypertensive therapy by ambulatory blood pressure monitoring and establishment of the level of antihypertensive goal on the circadian rhythm of blood pressure].

We have developed a new method for the evaluation of antihypertensive therapy on the circadian rhythm of blood pressure and attempted to determine the indications for antihypertensive therapy and the level of antihypertensive goal. Blood pressures were measured for 24 hours by the use of ambulatory blood pressure monitoring using 630 (ABPM-630) in 50 normotensives, 50 untreated hypertensives and 50 hypertensives undertreatment with various antihypertensive drugs (110 males and 40 females, with a mean age of 53.4 +/- 13.3 yrs). Blood pressure profiles were prepared for determination of the hyperbaric and hypobaric indexes. According to the WHO's definitions for blood pressure, the hyperbaric index was defined as the area above 140 mmHg in systolic blood pressure or 90 mmHg in diastolic blood pressure, and the hypobaric index, as the area below 100 mmHg or 60 mmHg, respectively. The criteria of the hypobaric index was obtained from the mean basal blood pressure (the lowest blood pressure during sleep) of the 50 normotensives. The mean hyperbaric index of the 50 normotensives was 20.4 +/- 40.2/5.5 +/- 15.3 (systole/diastole) mmHg.hour/day and the mean hypobaric index, 12.2 +/- 22.5/9.0 +/- 24.0 mmHg.hour/day. The 50 untreated hypertensives showed a mean hyperbaric index of 281.8 +/- 197.0/156.0 +/- 126.1 mmHg.hour/day and a mean hypobaric index of 0.1 +/- 0.6/0.3 +/- 1.5 mmHg.hour/day. Comparison of the indexes before and after treatment with various antihypertensives showed that a decrease in the hyperbaric index without an increase in the hypobaric index was the most optimal reduction of blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Average daily blood pressure, not office blood pressure, determines cardiac function in patients with hypertension.

To determine the presence of cardiac disease in hypertensive patients with disparities between physician and out-of-office blood pressures, we prospectively studied three groups of age-matched patients identified by both casual (office) and ambulatory blood pressures: (1) office blood pressure greater than 140/90 mm Hg and awake ambulatory blood pressure of 130/80 mm Hg or less ("office" hypertensives); (2) office blood pressure less than 135/85 mm Hg and awake ambulatory blood pressure of 130/80 mm Hg or less (normotensives); and (3) office blood pressure greater than 140/90 mm Hg and awake ambulatory blood pressure of 140/90 mm Hg or greater ("daytime" hypertensives). In the patients with office hypertension, both the left atrial index and left ventricular mass index were significantly less than in patients with daytime hypertension and not statistically different from those of the normotensive subjects. Left ventricular filling rate at rest and ejection fraction at peak exercise were significantly greater in the office hypertensive group than in the daytime hypertensive group but were no different from those of the normotensive subjects. These findings demonstrate that patients with blood pressure elevation only in the physician's office have cardiac size and function similar to those of normotensive individuals. Thus, the average daily blood pressure best predicts cardiac end-organ damage.

Adult↗

PubMed1985

Doctor-elicited blood pressure rises at the time of sphygmomanometric blood pressure assessment persist over repeated visits.

Blood pressure assessment by a doctor triggers an alerting reaction which may raise patients' blood pressure to a marked degree. Because this may lead to an overestimation of the prevalence of hypertension, it is important to determine whether attenuation of this blood pressure rise occurs with repetition of the doctor's visit. In 16 ambulant inpatients with mild essential hypertension, blood pressure was recorded intra-arterially for 2 days, using the Oxford method. During the recording the patients had four 10-min visits during which blood pressure was repeatedly measured by a sphygmomanometer. The visits to each patient were made by a doctor who had never seen him or her before and were regularly distributed over the total daytime available. In nearly all patients intra-arterial blood pressure and heart rate were elevated throughout the 10 min of each visit, with a peak during the first 4 min and a subsequent decline. The peak mean blood pressure rises were 22.6 +/- 1.8, 20.3 +/- 2.4, 19.3 +/- 2.4 and 21.4 +/- 3.1 mmHg (means +/- s.e.m.) in the four visits. Respective peak heart rate rises were 17.7 +/- 1.7, 20.7 +/- 2.4, 19.8 +/- 2.2 and 17.0 +/- 1.9 beats/min. The reduced pressor and tachycardic responses observed at the 10th min of the visit were also similar in the four visits (blood pressure: 19, 15, 28 and 24% of the peak response; heart rate 21, 13, 24 and 9% of the peak response, respectively). These findings show that the blood pressure rise often accompanying sphygmomanometric blood pressure assessment by the doctor persists after several visits spaced at close time intervals.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

An animal model and computer-controlled surface pressure delivery system for the production of pressure ulcers.

Pressure ulcers continue to be a major health care problem. This paper describes an animal model and surface pressure delivery system for the production of experimentally derived pressure ulcers. A method for inducing dermal pressure lesions on the fuzzy rat was developed using a computer-controlled displacement column which produced a constant tissue interface pressure. The pressure column consists of a force transducer located between two 0.5-in (1.27-cm) diameter metal cylinders. The desired cutaneous pressure is maintained by a computer-controlled miniature stepper motor which displaces the column with the aid of interactive software. The force transducer signal is converted from analog to digital form, amplified, and recorded. Blood perfusion is monitored using a laser Doppler flowmeter (located in the tip of the column) during the application of pressure. The application of 145 mmHg pressure for 5 consecutive 6-hr sessions resulted in a greater than 90% incidence of pressure ulcers. The implications of our model and contributions of earlier animal models are discussed. This model provides a tightly controlled and measured environment making possible the scientific study of ulcer development and the evaluation of potential preventative or curative compounds.

Animals↗

PubMed1995

Epidural pressure measurements. Relationship between epidural pressure and posture in patients with lumbar spinal stenosis.

STUDY DESIGN: The relationship between epidural pressure and lumbar posture was assessed in patients with lumbar spinal stenosis. OBJECTIVES: This study was performed to assess the relationship between epidural pressure and lumbar posture in patients with lumbar spinal stenosis. METHODS: The study was performed on 10 patients who had cauda equina symptoms at the L4-L5 level. The catheter transducer was inserted into the epidural space through L5-S1 interlaminar space and placed at the L4-L5 disc level. This transducer was connected with an amplifier and a recorder. Epidural pressure was continuously measured in various postures. RESULTS: Local epidural pressure at the stenotic level was low in lying and sitting postures, and high in standing postures. Pressure was increased with extension, but decreased with flexion. The highest pressure was 116.7 +/- 38.4 mm Hg in standing with extension. CONCLUSION: Epidural pressure was significantly related to posture. These pressure changes correlated with the development of cauda equina symptoms. The increase of epidural pressure by posture may induce compression of the cauda equina. These pressure changes may explain the postural dependency in eliciting symptoms.

Aged↗

PubMed1994

A comparison of systolic blood pressure measurement obtained using a pulse oximeter, and direct systolic pressure measurement in anesthetized sows.

Systolic blood pressure measurement obtained with a pulse oximeter has been compared to values obtained by other indirect methods in man. Direct pressure measurement is subject to less error than indirect techniques. This study was designed to compare systolic pressure values obtained using a pulse oximeter, with values obtained by direct arterial pressure measurement. The pulse oximeter waveform was used as an indication of perfusion. A blood pressure cuff was applied proximal to the pulse oximeter probe. The cuff was inflated until the oximeter waveform disappeared, this value was recorded as the systolic pressure at the disappearance of the waveform (SPD). The cuff was inflated to a pressure > 200 mmHg, then gradually deflated until the waveform reappeared, this value was recorded as the systolic pressure at reappearance of the waveform (SPR). The average of the two values, SPD and SPR, was calculated and recorded as SPA. The study was performed in sows (n = 21) undergoing cesarean section under epidural anesthesia and IV sedation. A total of 280 measurements were made of SPD, SPR and SPA. Regression analysis of SPA and direct measurement revealed a correlation coefficient (r) of 0.81. Calculation of mean difference (bias) and standard deviation of the bias (precision) for direct pressure--SPA revealed a value of 1.3 +/- 12.1. When compared with direct measurement, the correlation of this technique was similar to that recorded for other indirect techniques used in small animals. This indicates that this technique would be useful for following systolic pressure trends.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Epidural↗

PubMed1996

[Relationship between end-systolic aortic pressure and mean aortic pressure in adults].

The mean blood pressure is an accurate estimate of the end-systolic aortic pressure in children. The aim of this study was: 1) to assess the relationship between the pressure at the incisura (PIAo) and the mean (MAoP) and pulse (PAoP) pressures of the supravalvular aorta in adults: and 2) to evaluate MAoP as an estimate of PIAo in adults. High fidelity pressure recordings were carried out in the supravalvular aorta in 17 men. The pressures were measured at rest in 10 consecutive beats and. In 6 subjects, during a Valsalva manoeuvre. At rest, PIAo was greater than the MAoP (109 +/- 17.9 versus 99.6 +/- 12.5 mmHg, p = 0.0001). There was a positive linear correlation between PIAo and MAoP (r = 0.93) and between PIAo and PAoP (r' = 0.77) whereas no correlation was observed between PIAo and heart rate, cardiac output or estimated total systemic arterial compliance. A beat-to-beat relationship was observed between PIAo and MAOP: 1) at rest in 16 of the 17 subjects and 2) in each subject who performed a Valsalva manoeuvre. Both at rest and during Valsalva, MAOP underestimated PIAo significantly, especially when PIAo was increased (p = 0.0001). The authors conclude that end-systolic supraaortic pressure is mainly related to the mean component of aortic pressure. MAOP slightly but constantly underestimated PIAo and this should lead to caution in assimilating MAOP to end-systolic aortic pressure in adults, especially in subjects with very high aortic pressures.

Adult↗

PubMed1976

[Effects of solcoseryl on the cerebral blood flow, intracranial pressure, systemic blood pressure and EEG in acute intracranial hypertensive cats (author's transl)].

The experiment was performed on 86 cases under intraperitoneal pentobarbital anesthesia. One balloon was placed in the extradural space of right frontal region, and the other balloon was placed in the left extradural space and the intracranial pressure was measured. A needle was stereotaxically inserted into the subcortical area in order to measure the cerebral blood flow. Systemic blood pressure was recorded by inserting a catheter into the femoral artery, and electrocorticogram was also recorded. An expanding intracranial lesion was made by inflating the extradural balloon with physiological saline. The animals were arbitrarily divided into two groups.: 1) light or moderate groups which intracranial pressure before the injection of drug was below 400 mmH2O. 2) severe groups above 400 mmH2O. After the maintenance of the pressure, Solcoseryl was infused intravenously. The investigation was focused to observe whether Solcoseryl reveales any potent effect on cerebral blood flow, intracranial pressure, systemic blood pressure and on electroencephalogram in acute intracranial hypertension. Results 1) Intravenous injection of Solcoseryl had the effect of lowering intracranial pressure in the light or moderate and severe groups. Particularly, dose of 80 mg/kg showed the marked effect, though with a rebound phenomenon in the light or moderate groups. Furthermore, the effect was more marked and lasting by drip infusion of Solcoseryl and also by intravenous injection of Solcoseryl after pretreatment with hydrocortisone, and at this time no rebound phenomenon was recognized. 2) Solcoseryl had the effect of increasing the cerebral blood flow accompained with the lowering of intracranial pressure. 3) Systemic blood pressure was transiently lowered by the injection of Solcoseryl 20 mg/kg or 80 mg/kg and recovered immediately. 4) Solcoseryl had no effect on electroencephalogram in the severe groups. Conclusion On the basis of these results, it is rational to conclude that Solcoseryl could be superior agent render to lower intracranial pressure and to improve cerebral blood flow in acute intracranial hypertension.

Actihaemyl↗

PubMed1998

Ambulatory blood pressure monitoring--comparison with office blood pressure in patients on antihypertensive therapy in private practice.

INTRODUCTION: Available data on the use of 24-hour ambulatory blood pressure recordings in private practice are limited. For this purpose we studied 39 consecutive hypertensive patients on treatment in a private practice. METHOD: Office blood pressure, 24-hour ambulatory blood pressure, daytime ambulatory blood pressure and M-mode echocardiography were undertaken in 39 consecutive hypertensive patients (21 men, 18 women) on treatment. RESULTS: Mean 24-hour ambulatory blood pressure and mean daytime ambulatory blood pressure were lower than office blood pressure, similar to findings seen in academic settings. A blood pressure load of more than 50% was seen in 12 out of 39 patients (31%). Left ventricular hypertrophy, assessed by means of Framingham criteria, was seen in 33% of patients. A white-coat effect was seen in 15.4% of patients. CONCLUSIONS: A large proportion (33%) of patients on treatment for hypertension had left ventricular hypertrophy, despite normal electrocardiograms. Ambulatory blood pressure measurements identified a blood pressure load of more than 50% in 31% of patients on treatment for hypertension.

Analysis of Variance↗

PubMed1983

Threshold pressure for the pressure-dependent renin release in the autoregulating kidney of conscious dogs.

The effect of varying renal artery pressure between 160 and 40 mm Hg on renal blood flow and renin release was studied in seven conscious foxhounds under beta-adrenergic blockade receiving a normal sodium diet (4.1 mmol/kg/day). Pressure was either increased by bilateral common carotid occlusion or reduced in steps and maintained constant by a control-system using an inflatable renal artery cuff. Carotid occlusion itself had no influence on renal blood flow and renin release when renal artery pressure was kept constant and the beta-receptors in the kidney were blocked. Between 160 mm Hg and resting pressure there was no change in renal blood flow; between resting blood pressure and the lower limit of autoregulation (average 63.9 mm Hg) renal blood flow increased slightly (average 7%) indicating a high efficiency of renal blood flow autoregulation. The relationship between renal artery pressure and renin release could be approximated by two linear sections: a low sensitivity to a pressure change (average slope: -0.69 +/- 0.26 ng AI/min/mm Hg) was found above a threshold pressure (average: 89.8 +/- 3.3 mm Hg) and a high sensitivity to a pressure change (average slope: -64.4 +/- 20.8 ng AI/min/mm Hg) was observed between threshold pressure and 60 mm Hg. There was no further increase of renin release between 60 and 40 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗

PubMed2006

The relationship of urethral resistance pressure and pressure flow parameters in women with lower urinary tract symptoms.

This prospective study aims to evaluate the relationship between urethral resistance pressure (URP) and pressure flow parameters in women with lower urinary tract symptoms (LUTS). Consecutive women with LUTS attending three tertiary referral urodynamic clinics were asked to undergo urodynamic evaluation, pressure flow studies and URP measurement. The pressure flow parameters such as detrusor pressures at the start of flow (ODP), detrusor pressure at peak flow rate (PdetQmax), peak flow rate (Qmax) and detrusor pressure at the end of flow (CDP) were measured. The relationship between URP and pressure flow parameters was evaluated as well as differences between each urodynamic group. Two hundred seventy-nine women attended for urodynamic investigations. Two hundred twenty-three (79.9%) women had good quality pressure flow measurements and were included in the study. The mean age was 58 years (range 21-83). Women with urodynamic stress incontinence had significantly lower URP and ODP than those with detrusor over-activity [54.8 (+/-17.9) and 12.4 (+/-4.1) cmH(2)O, respectively, vs 85.6 (+/-21.4) and 33.7 (+/-13.3) cmH(2)O, respectively) (p<0.05, Bonferroni test). Furthermore, women with urodynamic stress incontinence have significantly lower PdetQmax values as well as higher Qmax than women with competent urethral sphincters (p<0.05, Bonferroni test). There was a significant correlation between ODP, PdetQmax, Qmax and URP measurements. In urodynamic stress incontinence, both URP and pressure flow parameters are reduced. Although the trend for values of both tests were similar and there was a significant correlation between these tests, we should consider that urethral function at rest differ from that during voiding due to activation of additional mechanisms. Therefore, further study is needed to confirm our results.

Adult↗

PubMed2003

Upper extremity peripheral venous pressure measurements accurately reflect pulmonary artery pressures in patients with cavopulmonary or Fontan connections.

After the bidirectional cavopulmonary or Fontan operation, the physiologic consequence is passive flow of the systemic venous return to the pulmonary arteries. Knowledge of pulmonary artery pressure (PA) is valuable in the management of these patients, and obtaining this information without the need for a central line or cardiac catheterization would be advantageous. The aim of this study was to evaluate the correlation between upper extremity peripheral venous (PV) pressures and PA or superior vena cava (SVC) pressures in patients who have undergone cavopulmonary or Fontan connections. During cardiac catheterization, 19 patients with complex cyanotic heart disease who had undergone a cavopulmonary shunt or Fontan procedure were studied. Simultaneous pressure measurements were obtained from the peripheral intravenous line placed prior to the procedure and the SVC or PA. The mean pressures were compared. The mean PV pressure was 17.5 +/- 5.6 mmHg. The mean SVC or PA pressure was 16.1 +/- 5.4 mmHg. The mean difference was 1.5 +/- 1.5 mmHg ( p < 0.001). The correlation coefficient PV to SVC or PA pressure was 0.97 ( p < 0.001). PV pressure measurements taken from an upper extremity accurately reflect PA pressures in patients who have undergone a cavopulmonary shunt or Fontan procedure.

Adolescent↗

PubMed2005

Effect of awake Carotid Endarterectomy under local anaesthesia on peri-operative blood pressure: blood pressure is normalised when carotid stenosis is treated under local anaesthesia.

BACKGROUND: Carotid Endarterectomy can be performed under local, regional or general anaesthesia. One of the most important effects of the type of anaesthetic used is on the systemic blood pressure. Although variations in blood pressure during and following carotid endarterectomy have been studied previously, the effects of awake carotid endarterectomy under local anaesthesia on blood pressure and its comparison with similar procedures under similar types of anaesthesia have not. METHODS: Peri-operative blood pressure measurements were collected from the records of 25 consecutive patients for each of the following five procedures; Carotid Endarterectomy under general anaesthesia (CEAGA), Anterior Cervical Discectomy and Fusion under general anaesthesia (ACDF), Cerebral Angiography under local anaesthesia (ANG), Carotid Endarterectomy patients under local anaesthesia who were symptomatic (CEALAS) and Carotid Endarterectomy patients under local anaesthesia who were asymptomatic (CEALAA). The recordings were then analysed to find out if there were any clinically significant variations in peri-operative blood pressure. FINDINGS: There is a significant and consistent difference when the pre-operative value was compared with the 4 hour and 24 hour post-operative recordings between the local and general anaesthetic groups for carotid endarterectomy. Carotid endarterectomy reduces the systolic and diastolic blood pressures post-operatively when performed under local anaesthesia and only the diastolic pressure was reduced when performed under general anaesthesia. CONCLUSION: The study provides evidence about the effect of carotid endarterectomy on the systemic blood pressure and its variations when performed under different types of anaesthesia. There is significant post-operative reduction in both the systolic and diastolic blood pressure values and the intraoperative fluctuation is minimal when local anaesthesia is used. Further studies are required to find out how this affects the long-term blood pressure and clinical outcome of the patient.

Anesthesia, General↗

PubMed1987

The influence of positive end-expiratory pressure on intrapericardial pressure and cardiac function after coronary artery bypass surgery.

The hemodynamic effects of positive end-expiratory pressure (PEEP) were studied in coronary artery bypass patients by recording intrapericardial and intracardiac pressures, measuring cardiac output by thermodilution, and determining left ventricular volumes by nuclear radiography. An elevation of PEEP to 5, 10, and 15 cm H2O led to a decrease in cardiac output (15% decrease at PEEP 15) as intrapericardial pressure increased and transmural left atrial pressure decreased. Modest volume loading (an increase in left atrial pressure of 3 mm Hg) greatly attenuated the deleterious effects of 15 cm H2O PEEP. There was an excellent correlation between pulmonary capillary wedge pressure and left atrial pressure at PEEP 0 and 5 (r = .85 and r = .83). This correlation was not nearly as reliable at PEEP 15 (r = .54). A predictable increase in intrapericardial pressure was observed as PEEP was applied in these patients. The magnitude of this increase can be estimated by multiplying the change in PEEP (in cm H2O) by 0.4 to estimate the change in intrapericardial pressure (in mm Hg). Using this estimation as a guide, modest volume loading can be used to maintain transmural filling pressures (and cardiac output) when PEEP is used after coronary artery bypass surgery.

Coronary Artery Bypass↗

PubMed1996

Intravenous trimethaphan during epidural plus general anesthesia decreases the direct radial artery pressure lower than the brachial artery pressure.

STUDY OBJECTIVE: To determine whether vasodilators such as sodium nitroprusside (SNP) and trimethaphan (TMP) produce a pressure difference between the radial artery and the brachial artery during epidural plus general anesthesia or simple general anesthesia. DESIGN: Randomized study and prospective study. SETTING: Operating rooms of two hospitals. PATIENTS: 36 and 6 adult patients in the first and second studies, respectively, who received spherical acetabular osteotomy with induced hypotensive anesthesia. INTERVENTIONS: In the first study, 18 patients received epidural plus general anesthesia (epidural group) and 18 patients received general anesthesia alone (general group). All patients received the hypotensive drugs for more than 50 minutes each. In the second study, 6 patients received TMP-induced hypotension for 20 minutes under epidural plus general anesthesia. MEASUREMENTS AND MAIN RESULTS: In the first study, radial intra-arterial blood pressure (RIBP) and tonometric blood pressure (TBP) calibrated with oscillometric blood pressure of the arm were compared. In the second study, RIBP and the brachial intra-arterial blood pressure (BIBP) were compared. In the first study, the bias between RIBP and TBP for systolic, mean and diastolic blood pressure were significantly less during TMP-induced hypotension in the epidural group (-11.5 +/- 2.5 (mean +/- SD), -6.0 +/- 3.1, and -2.8 +/- 3.7 mmHg, respectively] than during SNP-induced hypotension in the epidural group and SNP- and TMP-induced hypotension in the general group (p < 0.01). The precision of systolic and mean pressures were significantly greater during TMP-induced hypotension in the epidural group (11.8 +/- 2.3 and 7.1 +/- 1.9 mmHg, respectively) than the other three hypotension groups (p < 0.01). In the second study, the bias between RIBP and BIBP for systolic, mean, and diastolic pressures were significantly less (p < 0.01), and precision was significantly greater during hypotension than during normotension (p < 0.01). CONCLUSIONS: Our results demonstrate that TMP decreases the direct radial artery systolic and mean pressures to levels below the brachial artery systolic and mean pressures in patients who received epidural plus general anesthesia.

Adult↗