Effect of age on haemodynamic response to tracheal intubation. A comparison of young, middle-aged and elderly patients

Critical hypertension in trauma patients following prehospital emergency anaesthesia: a multi-centre retrospective observational study

BACKGROUND

Critical hypertension in major trauma patients is associated with increased mortality. Prehospital emergency anaesthesia (PHEA) is performed for 10% of the most seriously injured patients. Optimising oxygenation, ventilation, and cerebral perfusion, whilst avoiding extreme haemodynamic fluctuations are the cornerstones of reducing secondary brain injury. The aim of this study was to report the differential determinants of post-PHEA critical hypertension in a large regional dataset of trauma patients across three Helicopter Emergency Medical Service (HEMS) organisations.

METHODS

A multi-centre retrospective observational study of consecutive adult trauma patients undergoing PHEA across three HEMS in the United Kingdom; 2015-2022. Critical hypertension was defined as a new systolic blood pressure (SBP) > 180mmHg within 10 min of induction of anaesthesia, or > 10% increase if the baseline SBP was > 180mmHg prior to induction. Purposeful logistical regression was used to explore variables associated with post-PHEA critical hypertension in a multivariable model. Data are reported as number (percentage), and odds ratio (OR) with 95% confidence interval (95%CI).

RESULTS

30,744 patients were attended by HEMS during the study period; 2161 received PHEA and 1355 patients were included in the final analysis. 161 (11.9%) patients had one or more new episode(s) of critical hypertension ≤ 10 min post-PHEA. Increasing age (compared with 16-34 years): 35-54 years (OR 1.76, 95%CI 1.03-3.06); 55-74 years (OR 2.00, 95%CI 1.19-3.44); ≥75 years (OR 2.38, 95%CI 1.31-4.35), pre-PHEA Glasgow Coma Scale (GCS) motor score four (OR 2.17, 95%CI 1.19-4.01) and five (OR 2.82, 95%CI 1.60-7.09), patients with a pre-PHEA SBP > 140mmHg (OR 6.72, 95%CI 4.38-10.54), and more than one intubation attempt (OR 1.75, 95%CI 1.01-2.96) were associated with post-PHEA critical hypertension.

CONCLUSION

Delivery of PHEA to seriously injured trauma patients risks haemodynamic fluctuation. In adult trauma patients undergoing PHEA, 11.9% of patients experienced post-PHEA critical hypertension. Increasing age, pre-PHEA GCS motor score four and five, patients with a pre-PHEA SBP > 140mmHg, and more than intubation attempt were independently associated with post-PHEA critical hypertension.

Attenuation of the increase in intraocular pressure with dexmedetomidine: Systematic review with meta-analysis and trial sequential analysis

STUDY OBJECTIVE

Whether dexmedetomidine effectively attenuates the increase in intraocular pressure (IOP) remains inconclusive. We aim to evaluate the effects of dexmedetomidine on IOP in adult patients undergoing surgery which requires general anesthesia and endotracheal intubation.

DESIGN

Systematic review and meta-analysis.

INTERVENTIONS

Intravenous administration of dexmedetomidine during surgery.

MEASUREMENTS

Intraocular pressure.

METHODS

We searched PubMed, Embase, Scopus, Web of Science, Cochrane Library, Google Scholar, Wanfang Data, and China National Knowledge Infrastructure from the inception through April 14, 2020. Randomized control trials which involved adult patients undergoing surgery that required general anesthesia and endotracheal intubation, which compared intravenous administration of dexmedetomidine with placebo regarding the IOP levels, which also provided sufficient information for meta-analysis were considered eligible.

MAIN RESULTS

Twenty-nine randomized control trials were included. The IOP levels are significantly lower in patients receiving dexmedetomidine after the administration of dexmedetomidine [mean difference (MD), -2.04 mmHg; 95% confidence interval (CI), -2.40 mmHg to -1.67 mmHg], after the injection of succinylcholine (MD, -3.84 mmHg; 95% CI, -4.80 mmHg to -2.88 mmHg), after endotracheal intubation (MD, -3.64 mmHg; 95% CI, -4.46 mmHg to -2.82 mmHg), after pneumoperitoneum (MD, -3.12 mmHg; 95% CI, -3.93 mmHg to -2.30 mmHg), and after the patients being placed in a steep Trendelenburg position (MD, -4.12 mmHg; 95% CI, -5.39 mmHg to -2.85 mmHg). Trial sequential analyses for these outcomes are conclusive.

CONCLUSIONS

Dexmedetomidine effectively attenuates the increase in IOP levels, and should be considered especially for at-risk patients.

Comparison of hemodynamic responses and QTc intervals to tracheal intubation with the McGRATH MAC videolaryngoscope and the Macintosh direct laryngoscope in elderly patients

Our hypothesis was that intubations with the McGRATH MAC videolaryngoscope in elderly patients would produce less hemodynamic responses and ECG changes than the Macintosh direct laryngoscope. The patients were divided into two groups: patients who were intubated using the McGRATH MAC (Group V, n = 45) and patients who were intubated using the Macintosh direct laryngoscope (Group L, n = 45). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), heart rate (HR) were recorded before induction with anesthesia (baseline), immediately after induction and at 1 min, 3 min, and 5 min after intubation, with simultaneous ECG. When Group L was compared to Group V, there was an increase in the first, third and fitth minutes after intubation in terms of HR. SBP, MAP increased only at 1 min after intubation and DBP increased in the first and third minutes after intubation in Group L. In Group L, there was a significant difference in the HR values immediately after induction and the first minute after intubation compared with the baseline values. There was a difference in the SBP values immediately after induction and at 3 min and 5 min after intubation compared with the baseline values. There was a difference in DBP and MAP values immediately after induction and at 5 min after intubation. When the McGRATH MAC videolaryngoscope was compared with the Macintosh direct laryngoscope in elderly patients, the McGRATH MAC videolaryngoscope decreased the hemodynamic fluctuations due to tracheal intubation.

Effect of Laryngoscopy and Tracheal Intubation on Pulse Pressure and Influence of Age on this Response

The study objective was to measure the change in pulse pressure associated with laryngoscopy and tracheal intubation and to relate these changes to trends in systolic, diastolic and mean blood pressure. The rationale was that the rise in systolic and diastolic blood pressure may be disproportionate and may result in either increase or decrease in pulse pressure. We also looked at the influence of age on this response. This prospective observational study measured the changes in pulse pressure secondary to laryngoscopy and tracheal intubation in eighty adult surgical patients. Two groups of forty patients each were included, young (group A) 18–25 years and middle-aged (group B) 45–55 years. The patients were ASA Class 1 or 2, of either gender, and non-hypertensive. Systolic, diastolic, and mean blood pressure, and heart rate were measured preinduction and 1, 2 and 3 minutes after induction. Thereafter they were measured every minute for five minutes after intubation. Pulse pressure was obtained by subtracting the diastolic from the systolic blood pressure. No pulse pressure change occurred in the young group despite of a significant increase in both systolic and diastolic blood pressures. The middle aged group showed an average rise of +18 mm of Hg in pulse pressure (taken at 1 minute post-intubation) compared to the baseline measurement (P<0.0001). These changes in pulse pressure during anaesthesia may indicate an additional pulsatile stress in vulnerable patients in addition to the changes associated with resistance alone and need to be studied further.

Effects of different doses of remifentanil on hemodynamic response to anesthesia induction in healthy elderly patients

OBJECTIVE

We compared the effects of three different doses of remifentanil infusion, which were performed for the induction of anesthesia in elder patients, on cardiovascular response.

RESEARCH DESIGN AND METHODS

The present study was designed as a randomized, prospective and double-blind study. A total of 90 ASA I-II patients over the age of 65 years were enrolled. The patients were randomly (by lot) assigned to receive one of the three doses of remifentanil infusion (0.1, 0.2 or 0.3 μg/kg/min) for two minutes. Subsequently, 0.5 mg/kg propofol was administered via IV route and 0.5 mg/kg rocuronium was administered via IV route at the time eyelash reflex disappeared. Intubation was performed after 2 minutes. Patients who had an allergy against opioids, were chronic substance users, were obese, expected to have difficult airway, had hypertension, or were receiving any drug influencing the cardiovascular system were excluded.

MAIN OUTCOME MEASURES

In this study after recording baseline values of heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP) and mean arterial pressure (MAP), these values were recorded at the 1st, 2nd, 3rd, 4th and 5th minutes of induction.

RESULTS

A significant increase was observed in heart rate at the 1st and 2nd minutes of induction versus baseline in the Remi 0.1 group and at the 2nd minute of induction versus baseline in the Remi 0.2 group, with no additional significant change in heart rate. A significant decrease was determined in the systolic, diastolic and mean arterial pressures in all groups from the 1st minute of induction of anesthesia to the pre-intubation period compared to baseline (p < .05).

CONCLUSIONS

It was determined that each dose of remifentanil used was quite high for patients of this age-group. ClinicalTrials.gov trial number: NCT02763098.

Effect of the McGRATH MAC® Video Laryngoscope on Hemodynamic Response during Tracheal Intubation: A Retrospective Study

BACKGROUND

Hypertension often occurs after tracheal intubation using a Macintosh laryngoscope and may lead to rare but serious complications. The Macintosh laryngoscope may increase the incidence of hypertension because it requires forced alignment of the oral and pharyngeal axes in order to view the glottis. In contrast, the McGRATH MAC video laryngoscope does not require this manipulation. The objective of this study was to evaluate the incidence of hypertension after tracheal intubation using a McGRATH laryngoscope compared with a Macintosh laryngoscope.

METHODS

Data of 360 consecutive patients who underwent general anesthesia with tracheal intubation by Macintosh laryngoscope or McGRATH video laryngoscope were obtained retrospectively. A total of 16 variables including patient characteristics, anesthetic drug used, and intubation techniques were extracted as potential factors affecting the incidence of hypertension after intubation. The incidence of hypertension after tracheal intubation was defined as an increase in systolic blood pressure (SBP) >20% of values immediately before intubation. Propensity scoring with inverse probability weighting was used to calculate the odds ratio for the incidence of hypertension after intubation with a McGRATH video laryngoscope as the primary outcome. The mean difference in SBP change between the two laryngoscopes was also calculated.

RESULTS

A McGRATH laryngoscope was used in 68 of 360 patients (18%). The numbers of patients who increase in systolic blood pressure of more than 20% was 189 patients (53%). The odds ratio for the use of a McGRATH laryngoscope was 0.43 (95% confidence interval (CI), 0.19-0.96; P = 0.04). The mean difference in SBP change between the two laryngoscopes was -8.6 mmHg (95% CI, -17.4 to 0.2; P = 0.06).

CONCLUSIONS

The use of a McGRATH laryngoscope may reduce the incidence of hypertension after tracheal intubation compared to the Macintosh laryngoscope.

Comparison of the efficacy of dexmedetomidine with that of esmolol in attenuating laryngoscopic and intubation response after rapid sequence induction

CONTEXT

Laryngoscopy and tracheal intubation produce sympathetic overdrive by catecholamine release resulting in hypertension and tachycardia. Various agents are being tried to combat the intubation response over years.

AIMS

This study is aimed at comparing dexmedetomidine which is a highly selective alpha-2 agonist with an ultra-short acting beta blocker, esmolol to see which among the two is better in attenuating the hemodynamic response to laryngoscopy and tracheal intubation.

SETTINGS AND DESIGN

This was a prospective randomized double-blind control study.

SUBJECTS AND METHODS

Sixty patients scheduled for general anesthesia were divided into two groups, D and E with 30 patients in each group. Group-D patients received dexmedetomidine 0.5 mcg/kg and Group-E patients received esmolol 0.5 mg/kg as intravenous premedication over 5 min before a rapid sequence induction and tracheal intubation. Systolic, diastolic and mean arterial pressures along with heart rate were measured using invasive arterial line at various time points. The percentage change of hemodynamic parameters at those time points from the baseline was compared between the groups.

STATISTICAL ANALYSIS USED

Descriptive and inferential statistical methods were used to analyze the data.

RESULTS

The percentage change of all hemodynamic parameters from base line were less in the dexmedetomidine group than in esmolol group at all-time points of measurement. However, a statistically significant difference was observed often at the time points within 1 min after tracheal intubation.

CONCLUSIONS

Dexmedetomidine is superior to esmolol in attenuating the hemodynamic response to laryngoscopy and tracheal intubation.

Tactile stimulation of the oropharynx elicits sympathoexcitation in conscious humans

Tactile stimulation of the oropharynx (TSO) elicits the gag reflex and increases heart rate (HR) and mean arterial pressure (MAP) in anesthetized patients. However, the interaction between upper-airway defense reflexes and the sympathetic nervous system has not been investigated in conscious humans. In Experiment 1, beat-by-beat measurements of HR, MAP, muscle sympathetic nerve activity (MSNA), and renal vascular resistance (RVR) were measured during TSO and tactile stimulation of the hard palate (Sham) in the supine posture. In Experiment 2, TSO was performed before (pre) and after (post) inhalation of 4% lidocaine via nebulizer. Rate pressure product (RPP) was determined. Compared with Sham, TSO elicited the gag reflex and increased RPP [absolute change (Δ)36 ± 6 vs. 17 ± 5%], MSNA (Δ122 ± 39 vs. 19 ± 19%), and RVR (Δ55 ± 11 vs. 4 ± 4%). This effect occurred within one to two cardiac cycles of TSO. The ΔMAP (12 ± 3 vs. 6 ± 1 mmHg) and the ΔHR (10 ± 3 vs. 3 ± 3 beats/min) were also greater following TSO compared with Sham. Lidocaine inhalation blocked the gag reflex and attenuated increases in MAP (Δpre: 16 ± 2; Δpost: 5 ± 2 mmHg) and HR (Δpre: 12 ± 3; Δpost: 2 ± 2 beats/min) in response to TSO. When mechanically stimulated, afferents in the oropharynx not only serve to protect the airway but also cause reflex increases in MSNA, RVR, MAP, and HR. An augmented sympathoexcitatory response during intubation and laryngoscopy may contribute to perioperative cardiovascular morbidity and mortality.

Availability of preoperative anxiety scale as a predictive factor for hemodynamic changes during induction of anesthesia

Background

The current study evaluated whether the level of preoperative anxiety assessed by the state-trait anxiety inventory (STAI) affects cardiovascular response during anesthetic induction. Furthermore, we evaluated the utility of the preoperative anxiety scale as a predictive factor for hemodynamic changes.

Methods

One hundred twenty patients who were scheduled to undergo elective surgery under general anesthesia were enrolled in this prospective study. The patients were asked to fill out STAI questionnaires the night before the day of surgery. For 5 minutes after tracheal intubation, changes in vital signs were recorded. The correlation between STAI scores and the percent changes in vital signs during the induction of anesthesia for each subgroup was assessed. In addition, the predictability of the 20% change in vital signs by STAI scores was analyzed using receiver operating characteristics curves.

Results

The state anxiety scores of patients 45 years of age or older showed a significant correlation with percent changes in mean blood pressure and heart rate, whereas the state anxiety scores in other subgroups showed no significant correlation with changes in vital signs during the induction of anesthesia. Furthermore, the state anxiety scores in patients 45 years of age or older were shown to be useful in predicting a 20% change in vital signs during anesthetic induction.

Conclusions

The state anxiety scores of patients 45 years of age or above could be a useful tool for predicting changes in vital signs during anesthetic induction. Thus, physician should be mindful of preoperative anxiety.

The circulatory responses to tracheal intubation in children: a comparison of the oral and nasal routes

The circulatory responses to laryngoscopic tracheal intubation in 62 healthy children undergoing surgery requiring tracheal intubation were studied. They were randomly assigned to receive either the oral or nasal route for intubation. Baseline non-invasive blood pressure and heart rate were recorded following induction of anaesthesia, at intubation and then every minute for 5 min. The percentage changes of systolic blood pressure and heart rate during the measurement period were calculated. The results demonstrated that intubation time was significantly longer in the nasal group. Both oral and nasal intubation caused significant increases in blood pressure and heart rate compared to baseline and postinduction values. However, there were no significant differences found between the two groups in relation to blood pressure and heart rate. The two groups were similar with respect to the percentage changes of systolic blood pressure and heart rate during the observation period. It is concluded that oral and nasal intubation using a direct laryngoscopy can result in a similar circulatory response in anaesthetised children.