Pharmacokinetic differences between peripheral and central drug administration during cardiopulmonary resuscitation

Comparison between internal jugular vein access using midline catheter and peripheral intravenous access during cardiopulmonary resuscitation in adults

Objectives

Vascular access is an important procedure for drug administration during the resuscitation of a patient with cardiac arrest; however, it can be challenging under emergent conditions. This study aimed to investigate the efficiency of ultrasound-guided internal jugular venous access using a midline catheter versus peripheral intravenous access during cardiopulmonary resuscitation.

Methods

This was a prospective single-center observational study among patients who received cardiopulmonary resuscitation. The primary outcomes were the success rate of first attempt and the time taken for vascular access via the internal jugular and peripheral veins. We also measured the diameter of the internal jugular and peripheral veins at the access point and the distance from the access point to the heart.

Results

In all, 20 patients were included in the study. Internal jugular and peripheral venous access had a first-attempt success rate of 85% and 65%, respectively (p = 0.152). The time to access the internal jugular and peripheral veins was 46.4 ± 40.5 s and 28.8 ± 14.7 s, respectively (p = 0.081). The diameter of the internal jugular and peripheral veins was 10.8 ± 2.6 mm and 2.8 ± 0.8 mm, respectively (p < 0.001). The distance from the vascular access point to the heart was 20.3 ± 4.7 cm and 48.8 ± 13.1 cm for the internal jugular and peripheral veins, respectively (p < 0.001).

Conclusions

There was a trend toward higher success rates in the internal jugular vein rather than the peripheral intravenous approach, which was not statistically significant.

Comparison of success rate and time to obtain venous cannulation by cutdown technique at 3 locations using canine cadavers

OBJECTIVE

To compare the success rates and time taken to cannulate the jugular, cephalic, and lateral saphenous veins using a cutdown technique by personnel with 4 different levels of experience.

DESIGN

Prospective ex vivo study.

SETTING

Veterinary university teaching hospital.

ANIMALS

Eighteen canine cadavers.

INTERVENTIONS

Recently euthanized canine patients that were donated to the hospital for research purposes between October 2019 and March 2020 were enrolled. Four groups of personnel participated in the study to give 4 varying levels of experience: 8 final year veterinary students, 2 registered veterinary nurses, 1 emergency and critical care intern and 1 ACVECC diplomate. Each cannula placer had 5 minutes to attempt cannulation by venous cutdown at each site. Time to venous cannulation (VC) was compared for each site and group and complications encountered during each attempt recorded.

MEASUREMENTS AND MAIN RESULTS

The overall success rate for cannulation of the jugular, cephalic, and lateral saphenous veins were 81%, 84%, and 87%, respectively. The median times for venous cutdown for all personnel were as follows: jugular vein 119 s (range 51-280 s), cephalic vein 82 s (range 39-291 s), and lateral saphenous vein 110 s (range 41-294 s). There was no difference in time to VC between veins. When comparing personnel at the 3 cannulation sites, the ACVECC diplomate was faster than the registered veterinary nurses and students (P = 0.042 and P = 0.048, respectively). No differences were found between any other groups. Complications encountered often related to cadaver factors such as hematoma from antemortem venipuncture.

CONCLUSIONS

All groups were able to perform venous cutdown at each site with good overall success even without prior experience of the technique. VC by cutdown technique of the jugular, cephalic, or lateral saphenous veins may be considered in an emergency setting by personnel of various skill levels.

Accelerated treatment with rtPA for pulmonary embolism induced circulatory arrest

Patients with circulatory arrest due to pulmonary embolism (PE) should be treated with fibrinolytics. Current guidelines do not specify which regimen to apply, and it has been suggested that the regimen of 100 mg rtPA/2 h should be used, because this is recommended for hemodynamic instable PE in the ESC/ERS Guideline. This two hour regimen, however, is incompatible with key principles of cardiopulmonary resuscitation (CPR), such as employment of interventions that allow fast evaluation of effectiveness, and limitation of the total duration of CPR to avoid poor neurological outcomes. Additionally, the low flow-state during CPR has important consequences for the pharmacokinetic properties of rtPA. Arguably, the volume of distribution is lower, the metabolism reduced and the half life time longer. Therefore, these changes largely discard the rationale to use high dosages of rtPA over a prolonged period of time. More importantly, these changes highlight that the guideline recommendations, based on studies in patients without circulatory arrest, cannot be easily translated to the situation of circulatory arrest. An accelerated regimen of rtPA (0.6 mg/kg/15 min., max 50 mg) is mentioned by the 2019 ESC/ERS Guideline. However, empirical support or a rationale is not provided. Due to the rarity of the situation and ethical difficulties associated with randomizing unconscious patients, a randomized head-to-head comparison between the two regimens is unlikely to ever be performed. With this comprehensive overview of the pharmacokinetics of rtPA and current literature, a strong rationale is provided that the accelerated protocol is the regimen of choice for patients with PE-induced circulatory arrest.

The effect of lipid emulsion on pharmacokinetics and tissue distribution of bupivacaine in rats

BACKGROUND

While lipid emulsion may reverse the systemic toxicity of bupivacaine, the pharmacokinetics and tissue distribution of bupivacaine after lipid emulsion infusion are not clear. In this study, we assessed the influence of lipid emulsion administration on the pharmacokinetics and tissue distribution of bupivacaine.

METHODS

Rats in the lipid group were administered IV bupivacaine at the rate of 2 mg·kg(-1)·min(-1) for 4 minutes, and then were treated with an infusion of 30% lipid emulsion at the rate of 3 mL·kg(-1)·min(-1) for 5 minutes; saline was substituted in the control group (n = 6 for pharmacokinetics). We then randomly assigned 100 rats into the lipid group and control group (n = 50 for distribution). The toxicity model and treatment were the same as the pharmacokinetic portion. Plasma and tissues including brain, heart, liver, spleen, lung, kidney, omentum, and muscle were collected. The plasma concentration and tissue content of bupivacaine were measured by a liquid chromatography-tandem mass spectrometric method. A 2-compartmental analysis was performed to calculate the pharmacokinetics of bupivacaine.

RESULTS

All data are shown as mean ± SD. After treatment with the lipid emulsion, t1/2β of bupivacaine in the lipid group was significantly shorter (110 ± 25 minutes vs 199 ± 38 minutes, P = 0.001), the clearance was higher (14 ± 4 mL·mg(-1)·kg(-1) vs 9 ± 4 mL·mg(-1)·kg(-1), P = 0.038), and the t1/2α was longer than that of the control group (4 ± 1 minutes vs 2 ± 1 minutes, P = 0.014); the K12 in the lipid group was less than that of the control group (0.13 ± 0.04 vs 0.32 ± 0.13, P = 0.011). In the lipid group, the bupivacaine content in heart, brain, lung, kidney, and spleen was lower than that in the control group, but higher in the liver at 20, 30, and 45 minutes.

CONCLUSION

The lipid sink phenomenon was observed in this study. The use of a lipid emulsion accelerated the elimination of bupivacaine.

Potassium induced cardiac standstill during conventional cardiopulmonary resuscitation in a pig model of prolonged ventricular fibrillation cardiac arrest: a feasibility study

AIM OF THE STUDY

Potassium-based cardioplegia has been the gold standard for cardioprotection during cardiac surgery. We sought to evaluate the feasibility and the effects of potassium-induced cardiac standstill during conventional cardiopulmonary resuscitation (CPR) in a pig model of prolonged ventricular fibrillation (VF).

METHODS

VF was induced in 20 pigs, and circulatory arrest was maintained for 14 min. Animals were then resuscitated by standard CPR. Coincident with the start of CPR, 20 ml of saline (control group) or 0.9 mequiv.kg(-1) of potassium chloride diluted to 20 ml (potassium group) was administered into right atrium.

RESULTS

Administration of potassium resulted in asystole lasting for 1.0 min (0.2) in the potassium group animals. VF reappeared in all but one animal, in which wide QRS complex bradycardia followed. Restoration of spontaneous circulation (ROSC) was attained in two animals (20%) in the control group and in seven animals (70%) in the potassium group (p=0.070). Resuscitated animals in the potassium group required fewer countershocks (3, 4 vs. 2 (1-2)), smaller doses of adrenaline (1.84, 1.84 vs. 0.94 (0.90-1.00)mg), and shorter duration of CPR (8, 10 vs. 4.0 (4.0-4.0)min) than did the control group. Potassium concentrations normalised rapidly after ROSC in both groups, and the potassium concentrations at 5 min (5.5, 6.6 vs. 6.8 (6.5-7.8)mequiv.l(-1)) and 4h (4.9, 5.4 vs. 5.9 (5.1-6.4)mequiv.l(-1)) after ROSC were similar in the both groups.

CONCLUSION

In a pig model of untreated VF cardiac arrest for 14 min, resuscitation with potassium-induced cardiac standstill during conventional CPR was found to be feasible.

Pharmacotherapy considerations in advanced cardiac life support

Cardiac arrest and sudden cardiac death remain major causes of mortality. Early intervention has been facilitated by emergency medical response systems and the development of training programs in basic life support and advanced cardiac life support (ACLS). Despite the implementation of these programs, the likelihood of a meaningful outcome in many life-threatening situations remains poor. Pharmacotherapy plays a role in the management of patients with cardiac arrest, with new guidelines for ACLS available in 2005 providing recommendations for the role of specific drug therapies. Epinephrine continues as a recommended means to facilitate defibrillation in patients with pulseless ventricular tachycardia or ventricular fibrillation; vasopressin is an alternative. Amiodarone is the primary antiarrhythmic drug that has been shown to be effective for facilitation of defibrillation in patients with pulseless ventricular tachycardia or fibrillation and is also used for the management of atrial fibrillation and hemodynamically stable ventricular tachycardia. Epinephrine and atropine are the primary agents used for the management of asystole and pulseless electrical activity. Treatment of electrolyte abnormalities, severe hypotension, pulmonary embolism, acute ischemic stroke, and toxicologic emergencies are important components of ACLS management. Selection of the appropriate drug, dose, and timing and route of administration are among the many challenges faced in this setting. Pharmacists who are properly educated and trained regarding the use of pharmacotherapy for patients requiring ACLS can help maximize the likelihood of positive patient outcomes.

Haemodynamic effects of adrenaline (epinephrine) depend on chest compression quality during cardiopulmonary resuscitation in pigs

BACKGROUND

Adrenaline (epinephrine) is used during cardiopulmonary resuscitation (CPR) based on animal experiments without supportive clinical data. Clinically CPR was reported recently to have much poorer quality than expected from international guidelines and what is generally done in laboratory experiments. We have studied the haemodynamic effects of adrenaline during CPR with good laboratory quality and with quality simulating clinical findings and the feasibility of monitoring these effects through VF waveform analysis.

METHODS AND RESULTS

After 4 min of cardiac arrest, followed by 4 min of basic life support, 14 pigs were randomised to ClinicalCPR (intermittent manual chest compressions, compression-to-ventilation ratio 15:2, compression depth 30-38 mm) or LabCPR (continuous mechanical chest compressions, 12 ventilations/min, compression depth 45 mm). Adrenaline 0.02 mg/kg was administered 30 s thereafter. Plasma adrenaline concentration peaked earlier with LabCPR than with ClinicalCPR, median (range), 90 (30, 150) versus 150 (90, 270) s (p = 0.007), respectively. Coronary perfusion pressure (CPP) and cortical cerebral blood flow (CCBF) increased and femoral blood flow (FBF) decreased after adrenaline during LabCPR (mean differences (95% CI) CPP 17 (6, 29) mmHg (p = 0.01), FBF -5.0 (-8.8, -1.2) ml min(-1) (p = 0.02) and median difference CCBF 12% of baseline (p = 0.04)). There were no significant effects during ClinicalCPR (mean differences (95% CI) CPP 4.7 (-3.2, 13) mmHg (p = 0.2), FBF -0.2 (-4.6, 4.2) ml min(-1)(p = 0.9) and CCBF 3.6 (-1.8, 9.0)% of baseline (p = 0.15)). Slope VF waveform analysis reflected changes in CPP.

CONCLUSION

Adrenaline improved haemodynamics during laboratory quality CPR in pigs, but not with quality simulating clinically reported CPR performance.

Recent progress in advanced cardiac life support

The revised guidelines for advanced cardiac life support (ACLS) from the American Heart Association are anticipated in the fall of 2000. Although dramatic changes in the approach to adult basic and ACLS are not anticipated, several controversies and new drugs on the horizon may radically change our approach to emergent cardiac resuscitation. This article features some of the evolving thinking on the emergent treatment of the adult with ventricular fibrillation or ventricular tachycardia, the critical rhythms seen in most cases of acute cardiac distress. Approaches to airway therapy drug administration and new agents also are described.

Mock drug delivery to the proximal aorta during cardiopulmonary resuscitation: central vs peripheral intravenous infusion with varying flush volumes

OBJECTIVE

To compare mock drug deliveries to the proximal aorta during CPR after peripheral vs central i.v. administration when the mock drug is followed by different postinfusion flush volumes.

METHODS

Delivery of indocyanine green (ICG) dye to the proximal aorta of an instrumented 20-kg canine cardiac arrest model was examined. The ICG administration (2.5 mg) preceded either a 2-mL or a 10-mL saline flush, for either a central or a peripheral i.v. route of dye administration. Five dogs each underwent three sets of the four possible route/flush-volume combinations in a stratified randomized order. Real-time dye-absorbance-vs-time curves, as sampled from the proximal aorta, modeled central-circulation drug delivery. Systolic and diastolic blood pressures (BPs) were monitored, and the absorbance-vs-time curve upstroke phases were used to estimate cardiac output during arrest.

RESULTS

Times (mean +/- SD) to onset of dye appearance did not differ significantly between peripheral/10 mL (126 +/- 35 sec) and central/10 mL (108 +/- 35 sec), or between central/2 mL (123 +/- 31 sec) and central/10 mL. Times to onset of dye appearance did differ between peripheral/2 mL (161 +/- 70 sec) and central/10 mL [analysis of variance (ANOVA) p = 0.032]. Times to peak dye concentration did not differ significantly between peripheral/10 mL (230 +/- 88 sec) and either central/10 mL (202 +/- 88 sec) or central/2 mL (215 +/- 83 sec), but differed between peripheral/2 mL (326 +/- 134 sec) and every other route/flush-volume combination (ANOVA p = 0.009). Peak dye concentrations and systolic/diastolic BPs (averaging 23/10 for all route/flush-volume combinations) did not differ significantly between any route/flush-volume combinations.

CONCLUSION

An adequately sized postinfusion crystalloid flush (0.5 mL/kg) permits peripherally administered model drug to reach the central circulation as quickly and in equivalent concentration as centrally administered drug during CPR in a canine cardiac arrest model.

Pharmacologic controversies in CPR

Since the 1985 Emergency Cardiac Care Conference, numerous controversies about the pharmacology of CPR have arisen (eg, questions about the pharmacokinetics and pharmacodynamics of drugs during CPR, the optimal vehicle for delivery of medications, and the dose of atropine in brady-asystolic cardiac arrest). This article has three objectives: 1) to critically explore these controversies, 2) to provide recommendations for clinical practice, and 3) to identify areas for future study. The ideal route is one which combines rapid access with quick delivery of drug to the central circulation. Because of hemodynamic changes during CPR, administration of drugs into the central circulation is preferable when compared with peripheral venous injection. Whenever drugs are administered from a peripheral i.v. site, the extremity should be elevated, and a 20-mL bolus of i.v. fluid should be given to facilitate access of the agent to the central circulation. If there is a delay in obtaining venous access, epinephrine, lidocaine, and atropine may be administered through the endotracheal tube at 2.5 times the i.v. dose. When administering these drugs through the endotracheal tube, dilute the drug in 10 mL of saline or water and inject it through a long catheter beyond the tip of the endotracheal tube. Dextrose 5% water is the primary vehicle for drug delivery during CPR. However, the administration of glucose during CPR is controversial because of the potentially detrimental effects of hyperglycemia on neuronal function during periods of ischemia. Data are inconclusive regarding the effects of glucose levels on neurologic outcome following resuscitation. Hyperglycemia may be a marker for prolonged resuscitation with subsequent impairment in insulin release.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of alternate routes of epinephrine delivery in experimental bradycardia-hypotension

The magnitude and rapidity of response to epinephrine given by various routes were evaluated using a new model of bradycardia and hypotension. In ten animals, left ventricular (LV) injection of 10 micrograms/kg of epinephrine was superior to right ventricular (RV) injection in regard to time to attain a 20% increase in heart rate (HR), a 10% increase in mean arterial pressure (MAP) and time to reach peak MAP, although the peak MAP itself did not significantly differ. Similar results occurred with a 15 micrograms/kg dose. Aortic injection in seven of the animals resulted in a much longer time to target HR, an equal time to target MAP and a longer time to peak MAP compared to LV injection. LV injection of epinephrine results in a significantly more rapid onset of action than RV injection in the bradycardic, hypotensive animal. Epinephrine's beneficial effect appears to be derived from its vasoconstrictive, chronotropic and inotropic properties.