ISSN NUMBER: 1938-7172
Issue 12.10 VOLUME 12 | NUMBER 10

Editor:
Michael A. Fiedler, PhD, CRNA

Contributing Editor:
Dennis Spence, PhD, CRNA

Assistant Editor
Jessica Floyd, BS

A Publication of Lifelong Learning, LLC © Copyright 2018

New health information becomes available constantly. While we strive to provide accurate information, factual and typographical errors may occur. The authors, editors, publisher, and Lifelong Learning, LLC is/are not responsible for any errors or omissions in the information presented. We endeavor to provide accurate information helpful in your clinical practice. Remember, though, that there is a lot of information out there and we are only presenting some of it here. Also, the comments of contributors represent their personal views, colored by their knowledge, understanding, experience, and judgment which may differ from yours. Their comments are written without knowing details of the clinical situation in which you may apply the information. In the end, your clinical decisions should be based upon your best judgment for each specific patient situation. We do not accept responsibility for clinical decisions or outcomes.

Table of Contents

GENERAL
Comparison of anesthetic management and outcomes of robot-assisted vs pure laparoscopic radical prostatectomy
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PATIENT SAFETY
Withholding versus continuing angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers before noncardiac surgery: An analysis of the Vascular events In noncardiac Surgery patients cohort evaluation prospective cohort
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REGIONAL ANESTHESIA
Preprocedural ultrasound assessment does not improve trainee performance of spinal anesthesia for obstetrical patients: a randomized controlled trial
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None of the editors or contributors have any real or potential conflicts of interest to disclose.
 
This program has been prior approved by the American Association of Nurse Anesthetists for 20 Class A CE credits; Code Number 1035464; Expiration Date 10/31/2020.

General
Comparison of anesthetic management and outcomes of robot-assisted vs pure laparoscopic radical prostatectomy

J Clin Anesth 2016;35:281-286

DOI: 10.1016/j.jclinane.2016.08.014

Yonekura H, Hirate H, Sobue K


Abstract

 

Purpose   The purpose of this study was to compare the anesthetic management and incidence of adverse outcomes after robotic-assisted laparoscopic prostatectomy (RALP) or laparoscopic prostatectomy (LRP).

 

Background   Over the last 20 years, prostatectomy surgical technique has evolved from open to laparoscopic procedures. In more recent years, robot-assisted prostatectomy has become the most common technique performed because of faster recovery and decreased blood loss compared to open or non-robotic laparoscopic procedures. However, robot-assisted prostatectomy requires extreme Trendelenburg position and a prolonged pneumoperitoneum. There is limited published data comparing anesthetic management and the incidence of adverse outcomes after robot-assisted prostatectomy compared to non-robotic surgical techniques.

 

Methodology   This was a retrospective single-center comparative study conducted at a hospital in Japan. Patients included either those who underwent non-robotic laparoscopic prostatectomy between January 2010 and December 2012 or robot-assisted prostatectomy from May 2011 to December 2011. The first 35 patients who underwent robot-assisted prostatectomy were excluded to account for the steep learning curve with this surgical technique.

 

All patients received propofol 1-2 mg/Kg, remifentanil 0.2-0.5 µg/Kg/min, and rocuronium 0.6 mg/Kg for induction and intubation. Anesthesia was maintained with volatile anesthetics or total intravenous anesthesia. Additional boluses of fentanyl and rocuronium were administered as needed throughout the procedure. Fentanyl was used in the postanesthesia care unit. For robot-assisted prostatectomy the da Vinci Robot Surgical System was used, patients were positioned with a 30-degree head-down position. For non-robotic laparoscopic prostatectomy, 20-degree head-down was used.

 

Data was obtained from medical records to compare groups.

  • demographics
  • intraoperative data
  • fluid & blood given
  • surgery duration
  • fentanyl µg
  • postoperative data
  • hypoxia
  • mechanical ventilation
  • cardiovascular complications
  • infection
  • length of stay
  • PONV

A P < 0.05 was considered significant.

 

Result   There were 126 patients in the robot-assisted prostatectomy group and 97 in the non-robotic laparoscopic prostatectomy group. Baseline demographics were similar. Outcomes are presented in Table 1.

 

Anesthesia time (P = 0.03), pneumoperitoneum (P = 0.008), and operative time (P = 0.04) were all significantly longer in the robot-assisted prostatectomy group. Estimated blood loss (P < 0.001), colloid (P < 0.001), and blood product administration (P < 0.001) were all significantly greater in the non-robotic laparoscopic prostatectomy group. Patients in the robot-assisted prostatectomy group received approximately 35 µg more fentanyl per hour compared to the non-robotic laparoscopic prostatectomy group (P < 0.001). All three patients who required ICU admission were in the non-robotic laparoscopic prostatectomy group (P = NS). They were admitted for airway observation secondary to subcutaneous emphysema in the upper chest and neck. PostOperative Nausea and Vomiting were significantly more frequent in the robot-assisted prostatectomy group (P = 0.007). There were no significant differences in respiratory or cardiovascular complications. PACU length of stay was similar between groups.

 

Table 1. Intraoperative & Postoperative Outcomes

 

Robot (n = 126)

No-Robot (n = 97)

Anesthesia Time (min)*

276 (253-304)

259 (235-310)

Operation time (min)*

220 (193-214)

172 (151-242)

Pneumoperitoneum (min)*

194 (171-214)

172 (151-214)

EBL (mL)*

200 (74-400)

550 (278-750)

Blood transfusion*

0.79%

24%

Crystalloids (mL)*

1950 (1600-2363)

1900 (1600-2700)

Colloids (mL)*

0 (0-500)

500 (113-1000)

Total fentanyl (ug/hr)*

130 (105-151)

95 (63-142)

ICU Admission*

0%

3.1%

Opioids in PACU

13%

11%

PONV*

33%

16%

PACU Stay (min)

58 (46-74)

59 (49-69)

Notes: EBL = estimated blood loss. *P < 0.05. All other comparisons were not significantly different.

 

Conclusion   Robot-assisted prostatectomy was associated with significantly less blood loss and longer operative time compared to non-robotic laparoscopic prostatectomy. Patients undergoing robot-assisted prostatectomy had significantly higher rates of PONV.

 

Comment

 

Robotic-assisted laparoscopic prostatectomy is quickly becoming the most common technique for removal of the prostate because of better visualization and the ability to finely dissect the tissues with the articulating arms. This study confirmed that compared to a pure laparoscopic technique, the robotic-assisted technique resulted in significantly lower blood loss, as well as colloid and blood product requirements. However, the trade off was a longer operative time and a higher rate of PONV.

 

I recall at my institution when we first started doing robotic-assisted laparoscopic prostatectomies our surgeons’ operative times were very long. However, as they became more proficient their times decreased. 

 

These cases are challenging because patients are in extreme Trendelenburg and it is difficult to access the airway. If there is an emergency, it does take a few minutes to disengage the robot. Occasionally the trachea can get compressed and cause a right mainstem intubation secondary to the extreme positioning. Having a bronchoscope and one-way side swivel access port available can be helpful if a right mainstem intubation occurs in the middle of the case. Other anesthetic concerns include potential for edema in the face and airway, and potential for postoperative visual loss secondary to increased intraocular pressure. Some centers will flatten patients out periodically during the procedure to minimize these risks. Because the arms are tucked, you need to make sure you have good free flowing IVs. Additionally, surgeons usually like to minimize fluid administration until after reanastomosis of the ureters because too much fluid administration increases urine output and can obscure their view of the surgical field. After the ureters are reconnected, I usually give a fluid bolus of around a liter or liter and a half of crystalloid. Finally, I treat the patients with at least two antiemetics (decadron and ondansetron) and like to run a background infusion of propofol (10-20 µg/Kg/min) to prevent PONV.

 

Dennis Spence, PhD, CRNA


The views expressed in this article are those of the author and do not reflect official policy or position of the Department of the Navy, the Department of Defense, the Uniformed Services University of the Health Sciences, or the United States Government.


© Copyright 2018 Anesthesia Abstracts · Volume 12 Number 10, July 2, 2018




Patient Safety
Withholding versus continuing angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers before noncardiac surgery: An analysis of the Vascular events In noncardiac Surgery patients cohort evaluation prospective cohort

Anesthesiology 2017;126:16-27

DOI: 10.1097/ALN.0000000000001404

Roshanov PS, Rochwerg B, Patel A, Salehian O, Duceppe E, Belley-Côté EP et al.


Abstract

 

Purpose   The purpose of this study was to determine if withholding angiotensin-converting enzyme inhibitors (ACE) or angiotensin II receptor blockers (ARB) before noncardiac surgery would decrease the risk of vascular events after noncardiac surgery. Vascular events were defined as 30-day composite outcome of all-cause death, myocardial injury after noncardiac surgery, and stroke.

 

Background   Administration of ACE and ARBs within 24 hours of surgery is associated with intraoperative hypotension and may increase the risk of perioperative cardio-vascular adverse events. Current American College of Cardiology and American Heart Association guidelines recommend continuing ACE and ARBs during the perioperative period. However, some studies suggest holding these medications preoperatively; therefore many anesthesia providers tell patients to hold these medications 24 hours prior to surgery. This study sought to examine if withholding ACE and ARBs decreased the risk of major vascular events after noncardiac surgery.

 

Methodology   This was a secondary analysis of prospectively collected data from patients enrolled in the Vascular events In noncardiac Surgery patIents cOhort evaluatioN Prospective Cohort study (VISION Study). Patients >45 years of age undergoing noncardiac surgery at 12 centers in 8 countries were enrolled in the study. Patients were excluded if they underwent monitored anesthesia care. Only patients who were taking an ACE or ARB within the 7 days prior to their surgery were included in the analysis. The primary outcome was a 30-day composite outcome of all-cause death, myocardial injury after noncardiac surgery (MINS; irrespective of any clinical ischemic signs or symptoms), and stroke. MINS was defined as any peak non-high sensitivity cardiac troponin T value greater than or equal to 0.03 ng/mL resulting from myocardial ischemia (i.e., without evidence of a nonischemic etiology). Cardiac troponin T levels were drawn at 6 to 12 hours postoperatively and again for the first three days after surgery. Stroke was defined as new focal neurologic deficit thought to be vascular in origin with signs and symptoms lasting more than 24 h. Hypotension, intraoperative or postoperative 0-3 days, was defined as systolic blood pressure less than 90 mm Hg for any duration for which an intervention was initiated. Outcomes were compared in patients who did or did not take an ACE/ARB within 24 hours of their surgery. A P < 0.05 was significant.

 

Result   There were 4,802 patients included in this analysis (n = 3,557 took ACE/ARB and n = 1,245 held ACE/ARB). Preoperative systolic blood pressure was statistically significantly higher in those who held their ACE/ARB preoperatively (145 vs. 142 mm Hg, P < 0.001). No difference in preoperative glomerular filtration rate was found. Patients who held their ACE/ARBs were significantly more likely to hold all other antihypertensive agents and nitrates on the day of surgery (P < 0.001 for each):

  • beta blockers: 44% vs. 6%
  • calcium channel blockers: 46% vs. 12%
  • alpha-2 agonists: 57% vs. 6%
  • long-acting nitrates: 38% vs. 7%

 

Patients who held their ACE/ARB were significantly less likely to undergo major urogenital surgery (10% vs. 12%, P = 0.02) and more likely to undergo major general surgery (20% vs. 16%, P = 0.01) and urgent/emergent surgery (15% vs. 12%, P < 0.05).

 

The rate of intraoperative hypotension was significantly higher in those who continued their ACE/ARB preoperatively; 29% vs. 23% (P < 0.001). Patients who took their ACE/ARB were statistically significantly more likely to experience the 30-day composite outcome of death, myocardial injury after noncardiac surgery, or stroke; 13 % vs. 12% (P = 0.01; Figure 1). Examination of individual outcomes revealed that patients who took their ACE/ARB had slightly higher rates of myocardial injury after noncardiac surgery (11.3% vs. 10.6%, P = 0.05) but similar rates of death (2.1% vs. 2%), stroke (0.7% vs. 0.6%), and myocardial infarction (4.2% vs. 4.6%, P = NS) compared to those who held their ACE/ARB.

 

Holding ACE/ARBs resulted in an 18% reduction in the 30-day composite outcome of death, myocardial injury after noncardiac surgery, or stroke (P = 0.01) and 16% reduction in the rate of myocardial injury after noncardiac surgery (P = 0.048). Investigators estimated that holding ACE/ARB on day of surgery would decrease the rate of death, myocardial injury after noncardiac surgery, and stroke within 30 days of the operation by 6% (95% CI, 1.2 to 10.1).

 

Figure 1. Outcomes

 

Conclusion   Withholding ACE/ARB on the day of surgery decreased the 30-day all-cause death, myocardial injury after noncardiac surgery, and stroke rate in patients undergoing noncardiac surgery. Anesthesia providers should consider recommending patients withhold their ACE/ARB 24 hours prior to surgery.

 

Comment

 

At my institution we recommend patients hold their ACE/ARB 24 hours prior to surgery to reduce the risk of severe post-induction hypotension. In a perfect world this would always occur. However, patients do not always do what we tell them, and in some cases they may get conflicting information from surgeons, nurses, and anesthesia providers as they move through the preoperative screening process. Some patients will hold their ACE/ARBs for 24 hours, while others might take it the night before surgery but not the morning of surgery; others will take their ACE/ARB but hold all of their other medications (including important ones like beta blockers). This latter issue is demonstrated in this study’s results; a vast majority of patients who held their ACE/ARBs also held their other cardiovascular medications. In my opinion, this can be even more problematic, especially if patients do not take their beta blocker, as this may increase their risk for a myocardial event.

 

The results of this study are not terribly impressive for the 30-day composite outcome. The investigators only found that patients who took their ACE/ARB within 24 hours of surgery had 20% higher rate of intraoperative hypotension when compared to those who held these medications; however, the only significant difference in the composite outcome was in the MINS (myocardial injury after noncardiac surgery), which was based on an elevated troponin T test within the first 3 days after surgery. While the investigators controlled for a number of confounding variables, there still may be other unaccounted for variables that could have increased the postoperative troponin levels. In fact, the rate of myocardial infarction was slightly lower in those who took their ACE/ARB (4.2% vs. 4.6%, P = NS). The rate of death and stroke were only 0.1% different between the groups. Therefore, I am not convinced the evidence in this study strongly supports having all patients hold or continue their ACE/ARBs to prevent these outcomes. Withholding them will decrease intraoperative hypotension. Until large scale randomized controlled trials are completed to definitely tell us if holding ACE/ARBs for 24 hours decreases morbidity and mortality, I would not recommend changing any local practices with regard to holding or continuing ACE/ARBs. If you have patients hold these medications, make sure they are given clear instruction to continue their other cardiovascular medications you wish them to take (i.e., beta blockers). If they do take their ACE/ARB, then be prepared to treat intraoperative hypotension after induction of general anesthesia.

 

Dennis Spence, PhD, CRNA


The views expressed in this article are those of the author and do not reflect official policy or position of the Department of the Navy, the Department of Defense, the Uniformed Services University of the Health Sciences, or the United States Government.


© Copyright 2018 Anesthesia Abstracts · Volume 12 Number 10, July 2, 2018




Regional Anesthesia
Preprocedural ultrasound assessment does not improve trainee performance of spinal anesthesia for obstetrical patients: a randomized controlled trial

J Clin Anesth 2017;37: 21-24

DOI: 10.1016/j.jclinane.2016.10.034

Turkstra TP, Marmai KL, Armstrong KP, Kumar K, Singh SI


Abstract

 

Purpose   The purpose of this study was to determine if an ultrasound examination prior to spinal anesthesia in healthy obstetric patients for cesarean delivery decreased the number of attempts or the time needed for placement.

 

Background   Spinal anesthesia can be challenging in obstetric patients due to pregnancy related changes. Preprocedural ultrasonography has been shown to aid experienced anesthesia providers and trainees in placing epidural catheters in laboring patients. However, recent studies have not demonstrated benefit for placement of spinal anesthesia in non-obstetric patients. The investigators hypothesized that preprocedural ultrasonography, performed by an experienced anesthesia provider, would decrease the number of attempts needed by anesthesia trainees to place a spinal anesthetic in healthy obstetric patients undergoing elective cesarean delivery.

 

Methodology   This was a prospective, randomized controlled trial. It was conducted at two obstetric teaching hospitals in Canada. Anesthesia residents in their first or second year with 3 to 25 obstetric spinal anesthetics were consented. Patients enrolled were undergoing elective cesarean delivery. Excluded patients were those with morbid obesity (BMI ≥ 40 Kg/m2), emergency cesarean delivery, multiple gestation, significant scoliosis, previous spinal surgery, or history of failed spinal anesthesia.

 

Patients were positioned in the sitting position by the attending anesthesiologist. Patients in the preprocedural ultrasound group had their backs palpated by the anesthesia resident and they marked the ideal insertion point. Next, an investigator anesthesiologist performed an ultrasonound in the longitudinal paramedian and transverse views, demonstrating anatomy and distance to the resident, estimated the depth from skin to dura and approximate needle angle, and then marked the ideal insertion point. In the control group, the anesthesia resident only used the landmark technique to identify the optimal insertion point. The investigator anesthesiologist left the room and the attending anesthesiologist supervising the resident returned to observe the procedure performed by the resident. The attending anesthesiologist was blinded to the group assignment.

 

A blinded anesthesiologist recorded the number of attempts, defined as 1 attempt if the introducer was placed and the spinal needle advanced in one continuous movement. If the introducer or spinal needle was withdrawn or repositioned, this counted as an additional attempt. Placement duration was defined as the time from placement of the introducer to presence of spinal fluid in the needle hub. Other outcomes included staff intervention, incidence of paresthesias, and resident subjective ease of spinal anesthesia placement (0 to 100-mm scale, 0 = difficult and 100 = easy). A P < 0.05 was significant.

 

Result   There were 17 residents who consented to participate and 80 patients randomized to the two groups. No significant differences in demographics were reported. No significant differences were found in the median number of attempts in the ultrasound vs. control groups (3 vs. 3). No significant difference was reported in placement duration (92 sec. vs. 75 sec.). Eight percent (8%) of patients experienced a paresthesia in the ultrasound group compared to 3% in the control group (P = NS). No differences in procedure completion by the staff were reported (15% vs. 10%, P = NS). Ease of spinal anesthesia placement was similar in the two groups.

 

Conclusion   In this study, preprocedural ultrasonography performed by an attending anesthesiologist to provide residents with additional information in women undergoing cesarean delivery did not decrease the number of attempts or the time needed to place a spinal anesthetic.

 

Comment

 

A number of years ago I conducted a similar study in obese parturients undergoing epidural anesthesia and found the same thing these investigators did - that preprocedural ultrasonography did not aid junior anesthesia trainees in the placement of a neuraxial anesthetic. A possible reason for this is that the ultrasound information may cause excessive cognitive load for the novice anesthesia trainee and may impact performance. If the patients had “difficult backs,” it is possible different outcomes may have been found.

 

There are a few limitations in this study. First, the investigators should have attempted to stratify placement by anesthesia trainee and/or they should have controlled for anesthesia trainee experience in their analysis. The study may have been underpowered, and the investigators suggest a “Hawthorne Effect” because the residents were aware the primary outcome was number of attempts so they may have been more deliberate and potentially slower when performing the spinals.

 

I do believe preprocedural ultrasonography can aid in the placement of neuraxial anesthetics in patients with known or suspected “difficult backs” or can be used after multiple unsuccessful attempts. However, there is a learning curve, so I encourage readers to practice scanning on volunteers and bring the ultrasound in for “easy backs” to gain experience before progressing to more “difficult” backs.1

 

Dennis Spence, PhD, CRNA


1. Spence D, Nations R, Rivera O, Bowdoin S, Hazen B, Orgill R, Maye J. Evidence based anesthesia: the use of pre-procedural ultrasonography to facilitate labor epidural placement. AANA J 2012;80:1-8.


The views expressed in this article are those of the author and do not reflect official policy or position of the Department of the Navy, the Department of Defense, the Uniformed Services University of the Health Sciences, or the United States Government.


© Copyright 2018 Anesthesia Abstracts · Volume 12 Number 10, July 2, 2018