Journal Article Annotations
2020, 2nd Quarter

Delirium

Annotations by Maalobeeka Gangopadhyay, MD
April, 2020

Ultrasound-guided Continuous Thoracic Paravertebral Block Alleviates Postoperative Delirium in Elderly Patients Undergoing Esophagectomy: A Randomized Controlled Trial.
Effect of Perioperative Low-Dose Dexmedetomidine on Postoperative Delirium After Living-Donor Liver Transplantation: A Randomized Controlled Trial.
Association Between Perioperative Hypotension and Delirium in Postoperative Critically Ill Patients: A Retrospective Cohort Analysis.

PUBLICATION #1 — Delirium

Ultrasound-guided Continuous Thoracic Paravertebral Block Alleviates Postoperative Delirium in Elderly Patients Undergoing Esophagectomy: A Randomized Controlled Trial.

Liang Jin, Rui Yao, Lei Heng, Bo Pang, Fu-Guo Sun, Ying Shen, Jun-Feng Zhong, Pan-Pan Zhao, Cong-You Wu, Bei-Ping Li .

Abstract: Medicine (Baltimore). 2020 Apr;99(17):e19896. doi: 10.1097/MD.0000000000019896

Background
Delirium is a common postoperative complication in older patients undergoing thoracic surgery and presages poor outcomes. Postoperative pain is an important factor in the progression of delirium. The purpose of this study was to test whether continuous thoracic paravertebral block (PVB), a more effective approach for analgesia, could decrease the incidence of delirium in elderly patients undergoing esophagectomy.

Methods
A total of 180 geriatric patients undergoing esophagectomy were randomly divided into 2 groups and treated with PVB or patient-controlled analgesia (PCA). Perioperative plasma CRP, IL-1β, IL-6, and TNF-α levels were detected in all patients. Pain intensity was measured by a numerical rating scale. Delirium was assessed using the confusion assessment method.

Results
The incidence of postoperative delirium was significantly lower in the PVB group than in the PCA group. Patients in the PVB group had lower plasma CRP, IL-1β, IL-6, and TNF-α levels and less pain when coughing after surgery.

Conclusions
Ultrasound-guided continuous thoracic paravertebral block improved analgesia, reduced the inflammatory reaction and decreased the occurrence of delirium after surgery.

Annotation

The finding
Use of continuous paravertebral block compared to PCA for analgesia led to improved pain control, decreased inflammation, and decreased incidence of postoperative delirium.

Strengths and weaknesses
Randomized controlled trial that measured multiple inflammatory markers. The study has only limited generalizability given there was only one kind of surgery examined and many exclusion criteria. The study sample was small, and the investigators were unable to do double blinding due to presence of catheter. Inflammatory factors in serum are not directly reflective of neuroinflammation.

Relevance
This study demonstrates that effective pain control is associated with less inflammation and less delirium. In addition, this delivery of analgesia was associated with less atelectasis, reduced use of intraoperative anesthetic, and reduced used of opiates postoperatively.

Type of study
Randomized Controlled Trial

PUBLICATION #2 — Delirium

Effect of Perioperative Low-Dose Dexmedetomidine on Postoperative Delirium After Living-Donor Liver Transplantation: A Randomized Controlled Trial.

Hannah Lee, Seong Mi Yang, Jaeyeon Chung, Hye-Won Oh, Nam Joon Yi, Kyung-Suk Suh, Seung-Young Oh, Ho Geol Ryu .

Abstract: Transplant Proc. Jan-Feb 2020;52(1):239-245. doi: 10.1016/j.transproceed.2019.11.015. Epub 2019 Dec 26.

Background
Postoperative delirium after liver transplantation (LT) is associated with increased hospital length of stay and higher morbidity and mortality. Dexmedetomidine is a recommended and widely used sedative in critically ill patients with reports of potential for delirium prevention.

Methods
A randomized controlled clinical trial was performed to investigate whether perioperative low-dose dexmedetomidine infusion would decrease delirium after living-donor LT. Dexmedetomidine (0.1 mcg/kg/hour) was administered during anesthesia and through postoperative day 2 for patients in the dexmedetomidine group, whereas 0.9% saline was administered at the same rate for the same duration for patients in the control group. The incidence of delirium after LT was compared between the 2 groups. Delirium duration, mechanical ventilation duration, intensive care unit (ICU) and hospital length of stay, and in-hospital and 3-month mortality were also compared.

Results
There was no significant difference in delirium incidence in the dexmedetomidine group compared to the control group (9% vs 5.9%; P = .44). Duration of delirium and mechanical ventilation, ICU and hospital length of stay, and in-hospital and 3-month mortality were comparable between the 2 groups.

Conclusions
Perioperative low-dose dexmedetomidine infusion did not reduce the incidence of delirium in living-donor LT.

Annotation

The finding
In living donor liver transplantation, perioperative low dose dexmedetomidine did not reduce incidence or duration of delirium.

Strengths and weaknesses
The study was a randomized controlled trial; Less use of benzodiazepines; use of nonpharmacologic interventions; limited pharmacology reducing confounding; preoperative assessment done with psychiatrists in addition to screen with CAM-ICU. Weaknesses include that the study population had less severity of illness compared to others going through liver transplantation (lower APACHE II scores, less alcoholic cirrhosis, less preoperative hepatic encephalopathy) and lower MELD scores. Patients tended to be younger. The sample size is small compared to other studies.

Relevance
Nonpharmacologic interventions and limiting use of benzodiazepines contributes to lowering delirium incidence. The use of low dose dexmedetomidine does not lower delirium in all surgical populations.

Type of study
Randomized Controlled Trial

PUBLICATION #3 — Delirium

Association Between Perioperative Hypotension and Delirium in Postoperative Critically Ill Patients: A Retrospective Cohort Analysis.

Kamal Maheshwari, Sanchit Ahuja, Ashish K Khanna, Guangmei Mao, Silvia Perez-Protto, Ehab Farag, Alparslan Turan, Andrea Kurz, Daniel I Sessler

Abstract: Anesth Analg. 2020 Mar;130(3):636-643. doi: 10.1213/ANE.0000000000004517.

Background
Postoperative delirium is common in critically ill patients, with a reported incidence of 11%-43%, and is associated with significant morbidity and cost. Perioperative hypotension and consequent brain hypoperfusion may contribute. We, therefore, tested the hypotheses that intraoperative and postoperative hypotension are associated with critical care delirium.

Methods
We included 1083 postoperative patients who were admitted directly from an operating room to the surgical intensive care unit. Delirium was assessed with the Confusion Assessment Method for Intensive Care Unit patients at 12-hour intervals. We used a confounder-adjusted Cox proportional hazard survival model to assess the association between the amount of intraoperative hypotension, which was measured as the time-weighted average of mean arterial pressure <65 mm Hg, and delirium while in critical care. Thereafter, we used a Cox model with the lowest mean arterial pressure on each intensive care day as a time-varying covariate to assess the relationship between critical care hypotension and delirium, adjusted for confounders and amount of intraoperative hypotension.

Results
Three hundred seventy-seven (35%) patients had delirium within the first 5 postoperative days in the surgical intensive care unit. Intraoperative hypotension was moderately associated with higher odds of postoperative delirium. The adjusted hazard ratio associated with 1 mm Hg increase in time-weighted average of mean arterial pressure <65 mm Hg was 1.11 (95% confidence interval [CI], 1.03-1.20; P = .008). Postoperatively, a 10 mm Hg reduction in the lowest mean pressure on each day in the critical care unit was significantly associated with a higher hazard of delirium, with an adjusted hazard ratio 1.12 (95% CI, 1.04-1.20; P = .003).

Conclusions
Both intraoperative and postoperative hypotension are associated with delirium in postoperative critical care patients. The extent to which these relationships are causal remains unknown, but to the extent that they are, hypotension prevention may help reduce delirium and should be studied in prospective clinical trials.

PMID: 31725024

Annotation

The finding
Intraoperative and postoperative hypotension was associated with postoperative delirium in this restrospective cohort analysis of intensive care unit patients

Strengths and weaknesses
The study population was well monitored with RASS and CAM-ICU; there were no statistical differences between groups in terms of benzodiazepine and opioid use. That a variety of surgicla patient populations were included represents a strength.

Nevertheless, this is a retrospective single center study. This was a non cardiac population, and delirium was not categorized as hypoactive or hyperactive.

Relevance
Hypotension during and after surgery should be considered as a risk factor for delirium.

Type of study
Retrospective cohort analysis