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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In patients ranked ASA 1, laryngoscopy and intubation lead to an average increase in blood pressure of 40 to 50%, and a 20% increase in heart rate. These changes, which are greatest one minute after intubation, last for 5 to 10 min. They are due to sympathetic and adrenal stimulation, which may also result in some arrhythmias. About half the patient with coronary artery disease experience episodes of myocardial ischaemia during intubation when no specific prevention is undertaken. Among the different means available for this, narcotics seem to have a reliable and constant effect, but they may be responsible for postoperative respiratory depression. The protective effect of fentanyl starts at 2 micrograms.kg-1, and is at a maximum at 8 micrograms.kg-1. Lidocaine is the drug used most. Recent studies have questioned its efficacy. In clinical practice, it is particularly effective in preventing the pressor response to tracheal intubation, whatever its route of administration (intravenous or intratracheal), but not the increase in heart rate. Beta blockers with bradycardic, antihypertensive, antiarrhythmic and antiischaemic properties, have been advocated. As opposed to lidocaine, these agents are more effective in preventing the changes in heart rate than the pressor response. Because of their depressor effect on the myocardium, their place still remains to be defined, especially in the cardiac risk patient. Short-acting beta blockers should be preferred. Nitroglycerin is specifically indicated in coronary artery disease. Other agents, such as clonidine or calcium blockers, seem to be less effective or less convenient in preventing the haemodynamic alterations. In clinical practice, prevention will first rely on a sufficient dose of narcotics. In some cases, nitroglycerin or beta blockers may be used so as to decrease the doses of narcotics, without altering their efficacy; however, the risk of hypotension should be constantly borne in mind. If preventing measures have not been taken, short-acting antihypertensive agents (beta blockers, calcium blockers) should be used in patients who develop major hypertension during laryngoscopy and intubation.
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PMID:[Consequences and prevention methods of hemodynamic changes during laryngoscopy and intratracheal intubation]. 135 16

Benzodiazepines for sedation may decrease the PaO2, the arterial O2 saturation (SaO2), and the CO2 response more in the elderly than in the young. The purpose of this study was to assess changes in blood gases due to i.v. midazolam or sublingual flunitrazepam given as premedication in elderly patients for unilateral cataract surgery. METHODS. Fifty patients over 65 years of age with treated arterial hypertension and other co-existing diseases (ASA III-IV) were randomly assigned to have: (1) i.v. midazolam titrated until they became drowsy (17 patients; 2.85 +/- 0.84 mg [mean +/- SD]); (2) sublingual flunitrazepam (16 patients; 0.005 mg/kg); or (3) no sedation (17 patients; controls). On entering the operating theatre, the radial artery was cannulated and the first blood gas analysis was obtained. The premedication was then given. At 5, 10, 20, and 30 min after premedication, before and 10 min after retrobulbar block, before operation, 5 and 15 min after the beginning of the operation, 10 and 20 min after administration of 500 mg acetazolamide i.v. during the operation, and 10 and 20 min after the operation additional arterial blood samples were analysed (a total of 15 measuring points). Pulse oximetry, invasive blood pressure, and ECG were continuously monitored. All patients received oxygen 3 l/min during the operation by nasal cannula. Differences between the three groups were analysed by Student's t-test or U-test and a P value < 0.05 was considered significant. RESULTS. The patient demography, including duration of anaesthesia and operation, was similar in the three groups (Table 1). No significant differences were seen in heart rate, mean arterial pressure, PaO2, pulse-oximetric oxygen saturation (SpO2), base excess, or serum bicarbonate levels. The PaCO2 increased in patients after midazolam (P < 0.01) and flunitrazepam (P < 0.05) until the beginning of the operation compared with the control group (Fig. 3); 20 min after the operation there was still a significant difference between the midazolam group and the controls. SaO2 was significantly (P < 0.05) lower in the midazolam group 10 and 20 min after administration of premedication compared with the control group, but was within physiological limits (Fig. 5). Despite titration, 2 patients had severe respiratory insufficiency 3 min after midazolam: the SpO2 decreased below 85% and the paO2 below 55 mmHg. The paCO2 was higher (P < 0.05) in the midazolam group 10 min after acetazolamide compared with the controls. CONCLUSIONS. The results of the study show the potential hazards of i.v. midazolam in the elderly. If sedation is required for cataract surgery under local anaesthesia, we recommend sublingual flunitrazepam or the use of benzodiazepines with lower hypnogenic effects in the elderly. A thorough preoperative discussion of anaesthesia and the operation might be an adequate substitute for any premedication in high-risk patients; the best blood gas analysis results were obtained in the control group.
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PMID:[Premedication in retrobulbar anesthesia. A blood gas analysis comparison of sublingual flunitrazepam and intravenous midazolam]. 146 54

In a randomized double-blind study, the effects of clonidine premedication as a sedative, anxiolytic, analgesic and oculohypotensive agent were studied in 100 elderly patients (62 to 65 +/- 10 years, ASA grade I-II) undergoing elective intraocular surgery under local anaesthesia. The control group (Group A, n = 50) received oral diazepam 0.15 mg/kg 120 min before surgery and Group B (n = 50) received oral clonidine 300 micrograms 120 min before surgery. Two hours after the premedication, there was significantly more sedation (P less than 0.05) and less subjective anxiety (P less than 0.05) in the clonidine group than in the control group. There was a significant fall in intraocular pressure (IOP) from 20 +/- 0.5 to 13 +/- 0.5 mmHg (P less than 0.05) and significant reduction in systolic and diastolic blood pressure (BP) and heart rate (HR) (P less than 0.05) in the clonidine group as compared to the control group. Perioperatively, significantly more supplementation with i.v. diazepam was given in the control group than in the clonidine group (P less than 0.01). The incidence of intra-operative hypertension (P less than 0.01) and tachycardia (P less than 0.05) was significantly greater in the control group than in the clonidine group. A significantly larger number of patients in the clonidine group scored a Post-Anaesthesia Recovery (PAR) score of 10 as compared to the control group (P less than 0.01). There was no statistical difference in the postoperative Visual Analogue Scale (VAS) scores for pain, number of analgesic requests and emesis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Oral clonidine premedication for elderly patients undergoing intraocular surgery. 154 37

Eighty patients undergoing abdominal surgery were studied to evaluate ECG changes in perioperative period and also identify the factors influencing the incidence and the severity of postoperative ventricular arrhythmia. Holter ECG was recorded with CM5 and NASA leads from the night before operation to the night of the 2nd postoperative day. Tachycardia (greater than or equal to 100 beats.min-1) was found in 46.3% of the patients preoperatively and in 55% postoperatively. Bradycardia (less than or equal to 50 beats.min-1) was found in 30% of the patients mostly in the night prior to the operation, while only 1 patient (1.3%) demonstrated bradycardia postoperatively. SVPCs were observed in high incidence ranging from 75% preoperatively to 85% postoperatively. Two patients had paroxysmal supraventricular tachycardia postoperatively. VPCs were observed in 42.5% of the patients preoperatively and in 53.8% postoperatively. Warning arrhythmias which were ranked as more dangerous than Lown 2 were observed in 15% of the patients preoperatively, in 11.3% intraoperatively and in 23.8% postoperatively. Serious arrhythmias which needed immediate treatment were found in 6.3% of the patients preoperatively, in 10% intraoperatively and in 11.3% postoperatively. ST depression was recorded in 11 patients at CM5 and 2 patients at NASA leads. Chi-square and Hayashi's multidimensional quantification analyses were applied to determine the relationship between postoperative VPCs and pre- and intra-operative clinical factors. Factors such as age, type of surgery, intraoperative VPCs, ASA classification, ischemic changes in preoperative ECG, intraoperative blood loss, operation time, Goldman score, untreated hypertension as well as ischemic heart disease and abnormal findings of Master ECG were considered to be contributing to the high incidence and the severity of post-operative VPCs. When multidimensional quantification analysis is applied to the data, the occurrences of no VPCs, occasional VPCs, warning VPCs and serious VPCs could be predicted in postoperative patients.
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PMID:[Holter electrocardiographic findings in surgical patients during the perioperative period]. 156 May 81

Laryngoscopy and intubation cause an adrenergic response manifested by tachycardia and hypertension. Various pharmacological agents, including fentanyl, have been administered prior to induction in an attempt to attenuate the adrenergic response but they all have limitations. Esmolol, an ultrashort-acting cardioselective beta blocker, has been administered by infusion to successfully protect surgical patients from the stresses of intubation. The objective of our study was to determine if esmolol would be equally effective when administered in a bolus with and without fentanyl. Forty-four ASA I and II females undergoing elective surgery were randomly divided into four groups and received the following agents prior to intubation: Group 1-esmolol 1 mg/kg and fentanyl 2 micrograms/kg, Group 2-placebo (normal saline), Group 3-esmolol 1 mg/kg and Group 4-fentanyl 3.5 micrograms/kg. Groups 1 and 4, which received fentanyl, demonstrated significantly less elevation in blood pressure. Esmolol appeared to attenuate increases in heart rate. Esmolol has a tissue distribution time of 2 minutes and an elimination half-life of 9 minutes. The window of its availability to the tissues is narrow, and timing of bolus administration is more critical than in administration by infusion. Doses in excess of 1 mg/kg appear to be necessary for effective control of heart rate. However, when used with fentanyl, esmolol provides effective protection against the adrenergic response to laryngoscopy and intubation.
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PMID:Evaluation of esmolol and fentanyl in controlling increases in heart rate and blood pressure during endotracheal intubation. 167 49

Little information is available about the incidence of severe adverse outcomes, and even less information is available about the identification and quantification of independent predictors of severe perioperative adverse outcomes. The purpose of this study was to identify and quantitate independent predictors of severe perioperative adverse outcomes in a prospective randomized clinical trial of general anesthesia in 17,201 patients. Twenty-nine prognostic variables for 15 severe outcomes in 847 patients were tested by multiple stepwise logistic regressions from which 20 significant (P less than 0.05) predictors were identified. A history of cardiac failure or myocardial infarction less than or equal to 1 yr; ASA physical status 3 or 4; age greater than 50 yr; cardiovascular, thoracic, abdominal or neurologic surgery; and the study anesthetics were significant predictors of "any severe outcome, including death." There were 17 significant predictors for 10 severe cardiovascular outcomes in 608 patients, including a history of ventricular arrhythmia, hypertension, cardiac failure, myocardial ischemia, myocardial infarction less than or equal to 1 yr or myocardial infarction greater than 1 yr, and smoking; ASA physical status; age; cardiovascular, thoracic, abdominal, eyes-ears-nose-throat/endocrine, neurologic, musculoskeletal, or gynecologic surgery; and the study anesthetics. There were 9 significant predictors for 4 severe respiratory outcomes in 163 patients, including a history of cardiac failure, myocardial ischemia, or chronic obstructive pulmonary disease; obesity; smoking; male gender; ASA physical status; abdominal surgery; and the study anesthetics. Colinearity between related prognostic variables (such as disease and ASA physical status) was assessed using progressively segregated groups of variables in eight stepwise logistic regressions. We conclude that the comprehensive stepwise logistic regression of 29 prognostic variables reported here provides a valid estimate of the risks of severe perioperative outcomes associated with general anesthesia.
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PMID:Multicenter study of general anesthesia. III. Predictors of severe perioperative adverse outcomes. 172 12

Changes in intraocular pressure (IOP) and mean arterial pressure (MAP) were studied in fifty patients, ASA 1 or 2, aged more than 60 years and scheduled for surgery of the anterior chamber of the eye. The exclusion criteria were: arterial hypertension, raised IOP, obesity, renal or hepatic disease, treatment likely to alter IOP, and a possibly difficult intubation. The patients were randomly assigned to groups P1 (n = 25) and P2 (n = 25). All were given lorazepam 1 mg orally 90 min before induction, which was carried out with propofol 1.5 mg.kg-1 and vecuronium 0.1 mg.kg-1. Patients in group P1 were intubated as soon as the train-of-four response (TOF) had been abolished. Those in group P2 were given an additional 0.7 mg.kg-1 dose of propofol before intubation. MAP, heart rate and IOP were measured before and after induction, and 1, 2 and 3 min after intubation. IOP decreased after induction, and remained below the baseline values at all times in both groups. MAP had a similar course in both groups up to 1 min after intubation: a decrease after induction followed by an increase after intubation. In group P1, MAP remained above control values 2 and 3 min after intubation, whereas in P2 it remained below. From this study, it can be concluded that using an additional dose of propofol in elderly patients was not useful for avoiding the rise in IOP due to endotracheal intubation. This was all the more so as the haemodynamic effects of such a dose of propofol could have deleterious effects in these patients.
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PMID:[Effects of an additional dose of propofol on intraocular pressure in patients over 60 years of age]. 185 53

We have examined the safety of induced hypotension produced by extradural anaesthesia in patients with medically controlled hypertension. The haemodynamic response to induced hypotension was assessed in 38 non-hypertensive and 31 controlled hypertensive patients. All received extradural anaesthesia to T4 or above which decreased mean arterial pressure to 52 mm Hg and 55 mm Hg in normotensive and hypertensive patients, respectively. Cardiac output (thermodilution) was maintained by low dose i.v. infusions of adrenaline (1-5 micrograms min-1). No differences in the haemodynamic response to induced hypotension were observed in hypertensive patients. Data were collected also from 987 consecutive patients (353 hypertensive and 634 non-hypertensive) undergoing total hip replacement. Patients with hypertension were significantly older (68 vs 60 yr; P less than 0.001) and had greater ASA ratings (P less than 0.001). The smallest recorded systolic pressures were reduced more in patients with hypertension (57% vs 52%, respectively; P less than 0.001). The mean duration of maintained intraoperative hypotension (100 and 98 min) and estimated intraoperative blood loss (278 vs 281 ml) were similar in each group. After operation, two patients developed myocardial infarctions. None developed acute renal failure or stroke. There were three deaths; one of a patient who had hypertension. This suggests that induced hypotension with extradural anaesthesia is a safe technique for patients with medically controlled hypertension undergoing total hip arthroplasty.
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PMID:Haemodynamic effects and outcome analysis of hypotensive extradural anaesthesia in controlled hypertensive patients undergoing total hip arthroplasty. 154 Apr 75

20 patients (ASA I to III) scheduled for microlaryngoscopy were randomly allocated to receive by infusion either 12-15 mg/kg/h propofol alone (group A) or 6-9 mg/kg/h with fentanyl supplementation (group B). All patients were premedicated with oral diazepam one hour before the procedure; they received an induction dose of 2 mg/kg propofol, preceded in group B by a bolus dose of fentanyl 1 microgram/kg. Significant hypotension was observed at induction in both groups to a similar degree (A:--26%; B:--30.2% compared to baseline). Placement of the laryngoscope induced sustained hypertension throughout the procedure in both groups (A: +28%; B: +20%) subsiding only at the removal of the instrument. Heart rate was never significantly altered. Arterial blood concentrations of propofol at induction reached high peak values (A: 16.82 +/- 8.52 micrograms/ml--B: 19.52 +/- 8.87 micrograms/ml--mean +/- SD) then remained stable throughout the procedure (A: 5.44 +/- 1.40 micrograms/ml--B: 2.91 +/- 1.06 micrograms/ml). At awakening, they were lower in group B (0.62 +/- 0.2 micrograms/ml) than in group A (1.17 +/- 0.55 micrograms/ml--p less than 0.05). Recovery was a little faster in group A (at the limit of significance). Though patients may present some excitation at awakening, recovery was usually very pleasant and characterized by swift return to consciousness, alertness and of all reflexes. We conclude that a propofol infusion is particularly suitable for microlaryngeal surgery. The addition of a narcotic agent allows reduction of the propofol dose range and does not alter recovery significantly. The proper dose of narcotic agent necessary to abolish cardiovascular reactivity to laryngoscopy must still be ascertained.
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PMID:Propofol infusion with or without fentanyl supplementation for microlaryngoscopy. 208 82

3905 patients of more than 60 years of age who underwent surgical, urological, orthopaedic or opthalmologic interventions, were retrospectively investigated with respect to preoperative condition, intraoperative peculiarities and postoperative complications. Only 3.2% of the old patients (of more than 75 years of age), but 7.2% of elderly patients (between 60 and 74 years of age) had no coexisting disease. Preexisting diseases were myocardial (54.5%) and respiratory diseases (41.3%), hypertension (32.6%), dysrhythmia (30.8%) and diabetes mellitus (17.6%). From the old patients, 58.1% were classified into ASA physical status III to V but only 43.2% from the elderly patients. Peculiarities during anaesthesia and recovery period were (in total): dysrhythmia (8.3%), blood pressure decrease (5.9%) and increase (1.6%) that were significantly more often seen in old than in elderly patients whereas bleeding (4.5%) in the old was not different from the elderly. Independent of age, 11.6% of patients were monitored postoperatively on an intensive-care unit. 47.3% of all patients did not develop any postoperative complication. The incidence of postoperative cardiac, respiratory, central nervous, and lethal complications was not significantly higher in old than in elderly patients. However, the incidence of complications increased significantly with ASA physical status. Mortality of elderly and old patients after emergency interventions was 17.8% and 24.7% respectively and about 10 times that high as after elective surgery (2% in both groups.)
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PMID:[Perioperative morbidity and mortality of geriatric patients. A retrospective study of 3905 cases]. 230 98


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