Low-dose fentanyl: haemodynamic response during induction and intubation in geriatric patients

Comparison of fentanil and remifentanil for coronary artery surgery with low ejection fraction

Introduction

In this study, we evaluated patient response and haemodynamic parameters in patients with low ejection fraction undergoing coronary bypass surgery with either fentanil or remifentanil in conjunction with etomidate.

Material and methods

We evaluated 30 cases of coronary artery surgery, which were divided into two treatment groups (n = 15 each). In group F (fentanil group), the following regimen was employed for anaesthesia induction: 1 mg/kg lidocaine, 0.3 mg/kg etomidate, and, following a 1 µg/kg 60 s bolus dose of fentanil, a 0.1 µg/kg/min fentanil infusion was initiated, after which 0.6 mg/kg rocuronium was administered. In group R (remifentanil group), the following regimen was employed for anaesthesia induction: 1 mg/kg lidocaine, 0.3 mg/kg etomidate and, following a 1 µg/kg 60 s bolus dose of remifentanil, a 0.1 µg/kg/min remifentanil infusion was initiated, after which 0.6 mg/kg rocuronium was administered. Systolic artery pressure, diastolic artery pressure, mean arterial pressure, heart rate, SPO₂ (saturation), cardiac output, stroke volume variance, central venous pressure, and systemic vascular resistance values were recorded for all study patients at five minutes before anaesthetic induction (T1), immediately following induction (T2), and immediately following intubation (T3).

Results

The demographic values obtained for both groups were similar. We found that remifentanil use was associated with decreased cardiac output and increased fluctuations in both heart rate and mean values of arterial pressure.

Conclusions

Although many studies have demonstrated remifentanil to be as safe as fentanil when titrated to an appropriate dose, our study suggests that fentanil may be a more appropriate choice during the induction of anaesthesia in patients with a low ejection fraction.

Effects of intravenous administration of fentanyl and lidocaine on hemodynamic responses following endotracheal intubation

OBJECTIVES

To compare the effects of intravenous fentanyl and lidocaine on hemodynamic changes following endotracheal intubation in patients requiring Rapid Sequence Intubation (RSI) in the emergency department (ED).

METHODS

A single-centered, prospective, simple non-randomized, double-blind clinical trial was conducted on 96 patients who needed RSI in Edalatian ED. They were randomly divided into three groups (fentanyl group (F), lidocaine group (L), and fentanyl plus lidocaine (M) as our control group). M was administered with 3 μgr/kg intravenous fentanyl and 1.5 μgr/kg intravenous lidocaine, F was injected with 3g/kg intravenous fentanyl and L received 1.5mg/kg intravenous lidocaine prior to endotracheal intubation. Heart rate (HR) and mean arterial pressure (MAP) were assessed four times with the chi-square test: before, immediately after, 5 and 10 min after intubation. Intervention was discontinued for five people due to unsuccessful CPR.

RESULTS

HR was notably different in F, L and M groups during four time courses (p<0.05). Comparison of MAP at measured points in all groups exhibited no significant difference (p>0.05). In fentanyl group both HR and MAP increased immediately after intubation, and significantly decreased 10 min after intubation (p<0.05).

CONCLUSIONS

Overall, the result of this study shows that lidocaine effectively prevents MAP and HR fluctuations following the endotracheal intubation. According to our findings, lidocaine or the combination of fentanyl and lidocaine are able to diminish hemodynamic changes and maintain the baseline conditions of the patient, thus could act more effectively than fentanyl alone.

Hemodynamic Responses at Intubation, Change of Position, and Skin Incision: A Comparison of Multimodal Analgesia with Conventional Analgesic Regime

Background:

Lumbar spine surgery is associated with hemodynamic variations at intubation, change of position, and skin incision. A balanced anesthesia with multimodal analgesia (MMA) is necessary to attenuate these changes.

Aim:

To assess the relative effectiveness of preemptive MMA compared with the conventional analgesic regime in suppressing the hemodynamic response to endotracheal intubation, prone positioning, and skin incision.

Settings and Design:

A randomized, prospective study involving 42 patients belonging to the American Society of Anesthesiologists Physical Status 1 and II scheduled to undergo elective lumbar spine surgery were allocated into two groups of 21 each.

Materials and Methods:

Forty-two patients were randomly allocated into Groups A and B. Group A (study group) received diclofenac, paracetamol, clonidine, and bupivacaine with adrenaline skin infiltration and Group B (control group) injection paracetamol and saline with adrenaline skin infiltration.

Statistical Analysis Used:

Hemodynamic parameters (heart rate [HR], systolic blood pressure [SBP], diastolic blood pressure [DBP], and mean arterial pressure [MAP]) between the groups following intubation, prone position, and skin incision were noted and compared using repeated measure analysis of variance. One sample t-test was used to compare the standard mean concentration with the means of the study and control groups. P < 5% being considered statistically significant.

Results:

In the study group, HR, SBP, DBP, and MAP were lower at intubation and change of position as compared to the control group and were statistically significant.

Conclusion:

Preemptive MMA with balanced anesthesia is effective in attenuating the hemodynamic responses to multiple noxious stimuli during lumbar spine surgery.

Attenuation of hemodynamic response to laryngoscopy and orotracheal intubation using intravenous clonidine

BACKGROUND AND AIMS

Alpha-2 agonists are being increasingly used as adjuncts in general anesthesia and the present study was carried out to study the effect of clonidine as an adjuvant to low dose fentanyl in attenuating the hemodynamic response to laryngoscopy and orotracheal intubation.

MATERIALS AND METHODS

Ninety female patients belonging to American Society of Anesthesiologists (ASA) physical status I, II, and III in age group 25-65 years, body mass index (BMI) 21-26 kg/m(2), and diagnosed as carcinoma breast scheduled for breast surgery were included in this Prospective, randomized, placebo-controlled study. One-way analysis of variance (ANOVA), paired t-test, and chi-square test was applied where deemed appropriate. P-value at or below the level of 0.05 was considered as statistically significant.

RESULTS

Intravenous (IV) clonidine 1.0 μg kg(-1) and clonidine 2.0 μg kg(-1) significantly attenuated the hyperdynamic response to laryngoscopy and intubation. Clonidine 2.0 μg kg(-1) was associated with adverse effects like hypotension at the time of induction and postoperative sedation which was not observed with clonidine 1.0 μg kg(-1).

CONCLUSIONS

A single intravenous low dose clonidine (1.0 μg kg(-1)) when combined with low dose fentanyl (2 μg kg(-1)) is a practical, pharmacological and safe method with minimal side effects to attenuate the hyperdynamic response to laryngoscopy and intubation.

"Comparative efficacy of different doses of fentanyl on cardiovascular responses to laryngoscopy and tracheal intubation"

BACKGROUND

This study was conducted to determine an effective bolus dose of fentanyl, which would attenuate the cardiovascular response to laryngoscopy and tracheal intubation.

MATERIALS AND METHODS

A randomised double blind controlled study was carried out on 50 healthy adult patients (ASA I and II) undergoing elective surgery under general anaesthesia. The patients were randomly allocated into two groups of 25 each i.e. group A and group B receiving fentanyl 3 μg/kg, 5 μg/kg intravenously three minutes before intubation respectively. The pulse rate, systolic blood pressure was recorded at induction, during intubation and at 1,3, 5 min post intubation.

RESULTS

The study showed that both the doses were equally effective in blunting the pulse rate response, but the 5μg /kg proved significantly effective in blunting the blood pressure response. The rate pressure product, a measure of cardiac O2 consumption was found to be significantly lower in fentanyl 5μg/kg compared to fentanyl 3μg/kg.

CONCLUSION

So, we conclude that both blood pressure and rate pressure product were completely abolished by a bolus dose of fentanyl 5μg /kg in comparison with fentanyl 3μg/kg following laryngoscopy and intubation.

Comparison of different doses of intranasal nitroglycerine in attenuation of pressor response to laryngoscopy and intubation

AIMS

To observe the various pressor responses to laryngoscopy and intubation in normotensive patient undergoing elective surgery under general anesthesia and use of three different attenuating doses (400, 800, 1200 mcg) of intranasal nitroglycerine administered five minutes before laryngoscopy and intubation, to observe the efficacy and safety.

SETTINGS AND DESIGN

Randomized study.

MATERIALS AND METHODS

The study was carried out in a total of 60 patients. ASA grade 1 and II patients posted for elective surgeries under general anesthesia were included. Patients received different doses of intranasal nitroglycerine five minutes before induction as given below Group 1-received 400 micrograms-20 patients Group 2-received 800 micrograms-20 patients Group 3-received 1200 micrograms-20 patients.

STATISTICAL ANALYSIS

Student's t test.

RESULTS AND SUMMARY

Results were statistically analyzed. All three groups effectively attenuated the pressor response to laryngoscopy and intubation. Maximum rise in heart rate was seen in group III (23.86%). Maximum fall in systolic (19.6%), diastolic (30.76%), and mean arterial blood pressure (25.53%) was observed in group III at 10(th) minute of laryngoscopy and intubation.

CONCLUSION

Best results of attenuation of pressor response were seen with 400 and 800 micrograms of intranasal nitroglycerine. One thousand and two hundred micrograms dose caused maximum increase in heart rate and caused maximum fall in blood pressure, hence it is advisable to use increased dose with caution in attenuation of pressor response to laryngoscopy and intubation.

Comparison of effects of fentanyl and remifentanil on hemodynamic response to endotracheal intubation and myoclonus in elderly patients with etomidate induction

BACKGROUND

Etomidate has a stable hemodynamic profile after induction, but hypertension and tachycardia are frequent after intubation as well as myoclonus. We compared the effects of fentanyl and remifentanil on the hemodynamic response to intubation and myoclonus during etomidate induction in elderly patients.

METHODS

Ninety ASA I or II patients aged over 65 were randomly assigned to 3 groups. Group C received normal saline 10 ml (n = 30), group F and R were pretreated with fentanyl 1.0 µg/kg (n = 30) or remifentanil 1.0 µg/kg with continuous infusion of 0.1 µg/kg/min (n = 30) 1 min before induction with etomidate 0.2 mg/kg. Endotracheal intubation was performed after administration of rocuronium 0.8 mg/kg. Systolic blood pressure (SBP), mean arterial pressure, diastolic blood pressure (DBP), heart rate (HR), and the incidence and intensity of myoclonus were recorded.

RESULTS

After intubation, group R showed significant decreases compared with groups C and F for all of the hemodynamic variables measured. The incidences of increases in SBP and HR of more than 30% of the baseline levels, SBP of > 200 mmHg, and HR of > 120 beats/min were significantly lower in group R (0%, 10%, 0%, and 0%, respectively) compared with groups C (83%, 83%, 30%, and 13%, respectively) and F (63%, 77%, 13%, and 7%, respectively). The frequency and intensity of myoclonus were significantly decreased in both groups F and R compared with group C.

CONCLUSIONS

Pretreatment with remifentanil suppressed cardiovascular reactions to endotracheal intubation more effectively than that of fentanyl during etomidate induction. Both opioids reduced the incidence of myoclonus.

The frequency of fentanyl-induced cough in children and its effects on tracheal intubation

STUDY OBJECTIVE

To determine if fentanyl-induced cough was dose-dependent in children and whether it could affect tracheal intubation.

DESIGN

Prospective, randomized, double-blinded study.

SETTING

Operating room of a university-affiliated hospital.

PATIENTS

160 ASA physical status I pediatric patients, aged two to 14 years, scheduled for elective surgery during general anesthesia and requiring orotracheal intubation.

INTERVENTIONS

Patients were divided into two groups. Group 1 patients were given fentanyl at a dosage of one microg/kg; Group 2 patients received two microg/kg of fentanyl. Induction of anesthesia was conducted immediately following cough cessation or one minute after the end of injection with propofol 2.5 mg/kg. At loss of eyelash reflex, rocuronium 0.6 mg/kg was given intravenously (IV). Two minutes later, tracheal intubation was started.

MEASUREMENTS

Onset and degree of cough and intubating conditions were observed and recorded.

MAIN RESULTS

No statistically significant differences in frequency of coughing or in intubating conditions between the two groups were noted. Cough severity in Group 1 was statistically lower than that of Group 2 (P < 0.05). Onset of cough in Group 2 (12.2 +/- 3.4 sec) was statistically shorter than in Group 1 (16.9 +/- 7.6 sec, P < 0.05).

CONCLUSION

Fentanyl at doses of one and two microg/kg may induce coughing in pediatric patients.

[Bolus administration of fentanyl vs continuous perfusion of remifentanil for control of hemodynamic response to laryngoscopy and orotracheal intubation: a randomized double-blind trial]

OBJECTIVES

To compare the efficacy and safety of fentanyl and remifentanil in the prevention of hemodynamic responses to direct laryngoscopy and orotracheal intubation, and to compare the effects of these techniques on peripheral blood oxyhemoglobin saturation in normotensive women undergoing scheduled gynecologic surgery.

MATERIAL AND METHODS

Prospective clinical trial in ASA 1-2 patients undergoing gynecologic surgery. The patients were randomized to 2 groups: the remifentanil group received a perfusion of 1 microg x kg(-1) x min(-1) until intubation whereas the fentanyl group received a bolus dose of 2 microg x kg(-1). Etomidate (0.3 mg x kg(-1)) and rocuronium bromide (0.6 mg x kg(-1)) were used for anesthetic induction. Seven serial measurements of systolic, diastolic, and mean arterial pressure were recorded in addition to heart rate and peripheral blood oxyhemoglobin saturation at the following times: baseline, denitrogenation, postinduction, and 3 more times at consecutive 2-minute intervals.

RESULTS

Fifty-four patients were enrolled. A statistically significant attenuation of the postintubation hemodynamic response was observed in the remifentanil group. The effect was evident on arterial pressure (P=.0001) and heart rate (P=.031) with respect to baseline values. That protective effect was not seen in the fentanyl group. No differences in peripheral blood oxyhemoglobin saturation were observed.

CONCLUSIONS

Remifentanil provides greater hemodynamic control than fentanyl at the doses utilized. No adverse effects attributable to these opioids were observed in either group.

Effects of esmolol, lidocaine and fentanyl on haemodynamic responses to endotracheal intubation: a comparative study

BACKGROUND AND OBJECTIVE

Predicting the haemodynamic changes that may result in myocardial ischaemia for patients undergoing laryngoscopy and tracheal intubation will help to avoid events that trigger ischaemia and allow immediate treatment. The objective of this study was to compare the effects of esmolol with those of lidocaine (lignocaine) and fentanyl on prevention of tachycardia and hypertension caused by endotracheal intubation.

METHODS

This was a prospective, randomised, double-blind study. The study was conducted at the Adnan Menderes University Hospital in Aydin, Turkey and involved 120 patients of American Society of Anesthesiologists physical status I or II aged 20-50 years. The patients were randomised into four equal groups. The control group (group C) received dextrose 5% 5 mL, the esmolol group (group E) received esmolol 1.5 mg/kg, the fentanyl group (group F) received fentanyl 1 microg/kg and the lidocaine group (group L) received lidocaine 1.5 mg/kg 2 minutes before endotracheal intubation. Heart rate (HR), mean arterial pressure (MAP) and rate-pressure product (RPP) were recorded before and after induction of anaesthesia, immediately after intubation, and 1, 3, 5, 7 and 10 minutes after intubation.

RESULTS

Compared with control, HR decreased significantly in group E after induction, immediately after intubation and 1 minute after intubation (p < 0.0083). In group F there was an increase in MAP immediately after intubation, but the increase was less than in other groups. Compared with control, RPP decreased significantly in groups E and F after induction, immediately after intubation and 1 minute after intubation (p < 0.0083). RPP was significantly lower in group E than in controls and group L 3 minutes after intubation (p < 0.0083), and it was significantly lower in group F than in controls 10 minutes after intubation (p < 0.0083).

CONCLUSION

It can be concluded that administration of esmolol 1.5 mg/kg 2 minutes before intubation prevents tachycardia and an increase in RPP caused by laryngoscopy and tracheal intubation, and can be beneficial when administered before laryngoscopy and tracheal intubation in patients with tachycardia.

Assessment of small-dose fentanyl and sufentanil blunting the cardiovascular responses to laryngoscopy and intubation in children

BACKGROUND

The authors found no study assessing the efficacy of small-dose narcotics on the cardiovascular response from intubation in children, so they observed the effects of fentanyl 2 microg x kg(-1) and sufentanil 0.2 microg x kg(-1) on the cardiovascular changes during laryngoscopy and intubation in children.

METHODS

Ninety-three children aged 3-9 years were randomized to one of three groups to receive the following treatments in a double-blind manner: normal saline (group C), fentanyl 2 microg x kg(-1) (group F) and sufentanil 0.2 microg x kg(-1) (group S) 2 min before induction. Noninvasive blood pressure (BP) and heart rate (HR) were recorded before anesthesia induction (baseline value), immediately before intubation (postinduction values), at intubation and 5 min after intubation at 1-min interval.

RESULTS

Tracheal intubation caused significant increases in BP and HR in the three groups compared with baseline values. BP and HR at intubation and after intubation and their maximum values during observation were significantly lower in groups F and S than in group C (P < 0.05). The mean percent increases of systolic blood pressure (SBP) and HR at intubation were significantly lower in group S, 7% and 10%, than in group F, 17% and 25% (P < 0.05). The increases in SBP and HR of more than 30% of baseline values during the observation period were significantly higher in group F, 27% and 43%, than in group S, 0% and 3% (P < 0.05).

CONCLUSIONS

When used as part of anesthesia induction with propofol in children, sufentanil 0.2 microg x kg(-1) 2 min before induction is more effective in attenuating the cardiovascular intubation response than fentanyl 2 microg x kg(-1).

Massive esophageal variceal hemorrhage triggered by complicated endotracheal intubation

Esophageal variceal hemorrhage is frequently a catastrophic event. The specific events that trigger variceal rupture are not well understood. Acute elevations in systemic blood pressure and increased splanchnic blood flow, however, may lead to increased intravariceal pressure followed by variceal rupture and hemorrhage. This report describes a strong temporal association between complicated endotracheal intubation and abrupt onset of life-threatening variceal hemorrhage. A 52-year-old man with a history of portal hypertension was intubated emergently for airway protection because of respiratory insufficiency due to sepsis. Intubation was complicated by initial inadvertent esophageal intubation and by a peak mean arterial blood pressure of 155 mmHg. At the conclusion of the procedure, the patient sustained large volume hematemesis due to esophageal variceal rupture. This case suggests a risk of triggering variceal hemorrhage as a result of intubation-induced increase in blood pressure. A number of agents, including fentanyl, have been shown to be effective in attenuating the cardiovascular response to intubation. This case report provides strong evidence in support of administering fentanyl, or a suitable alternative adjunctive medication, before intubation of patients with documented portal hypertension and a history of esophageal variceal hemorrhage.

Small-dose fentanyl: optimal time of injection for blunting the circulatory responses to tracheal intubation

This study was designed to examine the optimal time of injection of a small dose of fentanyl during anesthetic induction to attenuate circulatory responses to laryngoscopy and tracheal intubation. One hundred seventy patients were randomly assigned to one of five groups. In Groups II, III, IV, and V, patients received fentanyl (2 microg/kg) 1, 3, 5, or 10 min before tracheal intubation, respectively. Group I patients did not receive fentanyl and served as the control group. In Groups III and IV, blood pressures were not increased, except diastolic pressure in Group III, significantly postintubation compared with preinduction values; but Groups I, II, and V showed a significant increase (P < 0.05). The 1-min postintubation values of systolic, diastolic, and mean arterial pressure in Groups III and IV were less than those in the control group (P < 0.05). Increases of heart rate in Group IV were less (P < 0.05) than those in the control group, but significant differences were not observed in Groups II, III, and V. The number of patients with tachycardia and dysrhythmia was significantly smaller in Group IV than in the control group (P < 0.05). We conclude that the most effective time to administer fentanyl to protect circulatory responses to laryngoscopy and tracheal intubation is 5 min before tracheal intubation.

IMPLICATIONS

Fentanyl is often used to reduce the hemodynamic response to tracheal intubation. However, large doses may cause unwanted side effects. Administration of fentanyl at the optimal time reduces the dose required. Our results indicate that optimal injection time of fentanyl for intubation is 5 min before intubation.

Controlling the hemodynamic response to laryngoscopy and endotracheal intubation

The hemodynamic response to the stress of laryngoscopy and endotracheal intubation does not present a problem for most patients. However, patients with cardiovascular or cerebral disease may be at increased risk of morbidity and mortality from the tachycardia and hypertension resulting from this stress. These hemodynamic effects gained notice after the introduction and use of muscle relaxants, such as curare and succinylcholine, for endotracheal intubation at the time of anesthesia induction. A variety of anesthetic techniques and drugs are available to control the hemodynamic response to laryngoscopy and intubation. The method or drug of choice depends on many factors, including the urgency and length of surgery, choice of anesthetic technique, route of administration, medical condition of the patient, and individual preference. The possible solutions number as many as the medications and techniques available and depend on the individual patient and anesthesia care provider. This paper reviews these medications and techniques to guide the clinician in choosing the best methods.

Analgesics and ENT surgery. A clinical comparison of the intraoperative, recovery and postoperative effects of buprenorphine, diclofenac, fentanyl, morphine, nalbuphine, pethidine and placebo given intravenously with induction of anaesthesia

1. Vomiting and restlessness following ENT and eye surgery are undesirable, and may be related to the emetic and analgesic effects of any analgesic given to augment anaesthesia during surgery. 2. To rationalise the choice of analgesic for routine ENT surgery we examined the intraoperative, recovery and postoperative effects following the administration of either buprenorphine (3.0 to 4.5 micrograms kg-1), diclofenac (1 mg kg-1), fentanyl (1.5 to 2.0 micrograms kg-1), morphine (0.1 to 0.15 mg kg-1), nalbuphine (0.1 to 0.15 mg kg-1), pethidine (1.0 to 1.5 mg kg-1) or saline (as control) given with the induction of anaesthesia in 374 patients. A standardised anaesthetic technique with controlled ventilation using 0.6-0.8% isoflurane in nitrous oxide and oxygen was employed. The study population constituted 7 similar groups of patients. 3. Intraoperatively, their effects on heart rate and blood pressure, airway pressure and intraocular pressure, were similar. This implies, most surprisingly, that neither their analgesic nor their histamine releasing effects were clinically evident during surgery. By prolonging the time to extubation at the end of anaesthesia, only buprenorphine, fentanyl, morphine and pethidine provided evidence of intraoperative respiratory depression. 4. Postoperatively, buprenorphine was associated with severe respiratory depression, prolonged somnolence, profound analgesia and the highest emesis rate. Diclofenac exhibited no sedative, analgesic, analgesic sparing, emetic or antipyretic effects. Fentanyl provided no sedative or analgesic effects, but was mildly emetic. Morphine provided poor sedation and analgesia, delayed the requirement for re-medication and was highly emetic. Nalbuphine and pethidine produced sedation with analgesia during recovery, a prolonged time to re-medication and a mild emetic effect. None provided evidence, from analysis of postoperative re-medication times and analgesic consumption, of any pre-emptive analgesic effect. 5. We conclude that nalbuphine (mean dose 0.13 mg kg-1) and pethidine (mean dose 1.35 mg kg-1), given individually as a single i.v. bolus during induction of anaesthesia, are the most efficacious analgesics for routine in-patient ENT surgery.

[Consequences and prevention methods of hemodynamic changes during laryngoscopy and intratracheal intubation]

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.

Emergency management of the airway outside the operating room

Successful emergency airway intervention incorporates the anaesthetist's basic skills in airway management with the knowledge of the special nature of the clinical problems that arise outside the operating room. While a thorough but rapid evaluation of the key anatomical and physiological factors of an individual patient may result in an obvious choice for optimal management, clinical problems often arise in which there is not an evident "best approach." In these less clear-cut situations, the anaesthetist may do well to employ those techniques with which she/he has the greatest skills and experience. At times, however, some degree of creative improvisation is required to care for an especially difficult problem.

Cardiovascular responses to fiberoptic intubation: A comparison of orotracheal and nasotracheal intubation

We compared the cardiovascular responses between nasal and oral intubation with a fiberoptic bronchoscope under the combination of neuroleptic analgesia (NLA) and topical anesthesia. The 16 patients studied were divided into 2 groups: the nasal intubation group (N group: 8 patients) and the oral intubation group (O group: 8 patients). There were significant changes in systolic, diastolic and mean arterial pressures in the N group and in the pressure rate quotient in the O group. Diastolic arterial pressure and heart rate were significantly higher in the N group than in the O group before induction of general anesthesia. The rate pressure product (RPP) was significantly higher in the N group than in the O group at some points during the procedure. The individual RPP in both groups was relatively stable except for one patient in the N group, who had a marked increase in RPP during the procedure. We conclude that, under the combination of NLA and topical anesthesia, the cardiovascular responses to oral fiberoptic intubation are less severe than those to the nasal approach. The oral approach is recommended, especially in patients with coronary artery disease, taking into consideration of the cardiovascular responses to fiberoptic intubation.

Haemodynamic responses to laryngoscopy and tracheal intubation in geriatric patients: effects of fentanyl, lidocaine and thiopentone

The haemodynamic responses to laryngoscopy and intubation after induction of anaesthesia with thiopentone alone or in combination with 1.5 mg.kg-1 lidocaine and/or 1.5 or 3.0 microgram.kg-1 fentanyl were measured in 150 patients over 64 years of age to determine whether lidocaine, fentanyl or both lidocaine and fentanyl attenuated the pressor response. Fentanyl reduced the rises in systolic, diastolic and mean arterial pressures, heart rate, and rate pressure product and lidocaine decreased the rises in arterial blood pressure and rate pressure product (P less than 0.05). Fentanyl decreased the incidence of marked fluctuations in haemodynamic variables, often seen in geriatric patients (P less than 0.05). The haemodynamic effects of lidocaine and fentanyl were independent of each other. Complications occurred in all groups. Lidocaine-treated patients had fewer cardiac dysrhythmias (P less than 0.05) and 34 per cent of them had tinnitus. Fentanyl-treated patients had a higher incidence of hypotension (P less than 0.05). Respiratory depression developed in only one per cent of the fentanyl-treated patients. Both lidocaine and fentanyl are recommended adjuncts to induction of anaesthesia with thiopentone in geriatric patients.