Broad subcutaneous emphysema with airway obstruction during robot-assisted partial nephrectomy: A case report and literature review.

Introduction: Subcutaneous emphysema is a relatively common complication in laparoscopic surgery. However, airway obstruction secondary to subcutaneous emphysema is rare. Case presentation: A 63-year-old woman with a 56-mm left renal tumor underwent a robot-assisted partial nephrectomy. The operative time was 155 min, the insufflation time was 108 min, and the estimated blood loss was 70 mL. The pneumoperitoneum pressure was maintained at 12 mmHg, except at 15 mmHg for 19 min during tumor resection. The end-tidal CO2 was <47 mmHg throughout the procedure. Postoperatively, broad subcutaneous emphysema from the thigh to the eyelid was observed. Computed tomography revealed airway obstruction, and extubation was aborted. On postoperative day 1, emphysema around the trachea and neck improved and the intubation tube was successfully removed. Conclusion: Both laryngeal emphysema and physical compression secondary to emphysema can cause airway obstruction. To reduce gas-related complications, the risk of developing subcutaneous emphysema should be properly assessed during robot-assisted laparoscopic surgery.

Advantages of enhanced recovery after surgery program in robot-assisted radical cystectomy.

Radical cystectomy is a gold-standard treatment for muscle-invasive bladder cancer. We recently introduced robot-assisted radical cystectomy (RARC) with perioperative enhanced recovery after surgery (ERAS). The medical records of patients with bladder cancer who underwent open radical cystectomy (ORC) or RARC/ERAS at NTT Medical Center Tokyo were retrospectively reviewed to compare the surgical outcomes, hospital stay, and medical costs between groups. Multidisciplinary full ERAS items were provided for the RARC/ERAS group. The median estimated blood losses in the ORC and RARC/ERAS groups were 650 and 100 mL, and the median operative times were 312 and 445 min, respectively. In addition, the median times to liquid food intake in these groups were 6 and 0 days, the median times to first flatus and first defecation were 2 and 1 day, and 3 and 1.5 days, respectively. The rates of postoperative ileus in the ORC and RARC/ERAS groups were 27.5% and 4.5%, and the median postoperative hospital stays was 26.5 and 12 days, respectively. Medical costs excluding surgery were significantly lower in the RARC/ERAS group. In conclusion, RARC/ERAS represents a safe treatment option for muscle-invasive bladder cancer with decreased perioperative complications and lower medical costs.

[Combined subarachnoidal block and continuous femoral nerve block for two patients undergoing bilateral simultaneous total knee arthroplasty].

We administered combined spinal anesthesia plus bilateral femoral nerve block in two cases undergoing bilateral simultaneous total knee arthroplasty. Although epidural catheters must be removed before anticoagulant treatment can be performed after surgery, femoral nerve block, poses minimal hindrance to anticoagulant therapy. Because femoral nerve block alone cannot provide sufficient postoperative pain relief after total knee arthroplasty, additional sciatic nerve block, spinal anesthesia, opioid administration, or some other means of analgesia is necessary. A combined femoral nerve block plus sciatic nerve block is useful. A large quantity of local anesthetic is required for this purpose, and its application is difficult in bilateral simultaneous surgery. Spinal anesthesia can be used to reduce the quantity of the local anesthetic, and intrathecal morphine can be used to prolong the pain relief. However, intrathecal morphine can cause itching and late respiratory depression. Respiratory depression did not occur in either of the present patients, although case 2 experienced some itching. In conclusion, combined bilateral femoral nerve block with spinal anesthesia poses minimal hindrance to postoperative anticoagulation therapy and enables control of postoperative pain in patients undergoing bilateral simultaneous total knee arthroplasty.

Optical imaging of propofol-induced central respiratory depression in medulla-spinal cord preparations from newborn rats.

1. Propofol (2,6-diisopropylphenol) is an intravenous anaesthetic used for the induction and maintenance of general anaesthesia; it also potently and dose-dependently depresses respiration. The aim of the present study was to analyse propofol-induced changes in spatiotemporal patterns of inspiratory-related neural activity and to investigate the involvement of the GABAA receptor by using an optical imaging technique. 2. The brain stems and spinal cords of 0-1-day-old Wistar rats were isolated and stained using a fluorescent voltage-sensitive dye. Neuronal activity in the preparation was detected using an optical recording apparatus containing a charge-coupled device (CCD)-based camera. 3. Bath-applied propofol (7.5 µmol/L) decreased the C4 burst rate to 45.9% of baseline. Although optical signals corresponding to membrane depolarization during the pre-inspiratory phase in the parafacial region of the ventral medulla decreased to 28.7% of baseline following propofol application, those during the inspiratory phase in the caudal part of the rostral ventrolateral medulla did not. 4. The inhibitory effect of bath-applied propofol was reversed by 2 µmol/L bicuculline. 5. Changes in optical signals corresponding to the population activity of pre-inspiratory neurons were parallel to changes in the C4 burst rate. 6. The results suggest that propofol decreases the inspiratory burst rate by reducing the activity of pre-inspiratory neurons and that GABAA receptor activation plays a role in propofol-induced central respiratory depression. These results are consistent with those of previous electrophysiological studies.

Ultrasound-guided medial mid-thigh approach to sciatic nerve block with a patient in a supine position.

We report the use of a 'medial mid-thigh approach (medial approach),' a new approach for performing ultrasound-guided sciatic nerve blockade (SNB) with patients in a supine position. Fifty-four patients undergoing knee surgery under general anesthesia and a combined femoral nerve block (FNB) and SNB were included in the study. After FNB, an ultrasound-guided medial approach was used to perform the SNB. The patient was placed in a supine position, and the hip and knee joints were flexed with the leg rotating externally. A linear ultrasound transducer was positioned perpendicular to the skin at the level of the upper mid-thigh. The sciatic nerve was identified in all patients using ultrasound imaging, and the distance to the nerve was 3.0-5.5 cm. A combined ultrasound- and nerve stimulator-guided SNB was then performed, and 0.375% ropivacaine was administered. The block was successful in all patients, and the mean duration of the sensory and motor blockade was 11.9 and 8.2 h, respectively. In this study, the medial approach was highly successful and easy to perform. As performing a simultaneous FNB and SNB with patients in a supine position has several potential advantages, future studies should compare this approach with other more proximal approaches for performing SNB.

[Peripheral nerve blocks for a patient with spondylolysis undergoing anterior cruciate ligament reconstruction].

A 24-year-old man, 178 cm tall and weighting 82 kg, underwent anterior cruciate ligament reconstruction. We gave general anesthesia and ultrasound-guided combined femoral and sciatic nerve block. Neuraxial blocks increase the risk of neuropathy in the patient with spondylolysis compared with peripheral nerve blocks. In this report, we describe the successful postoperative pain control with peripheral nerve blocks to a patient with spondylolysis.

[Ultrasound-guided rectus sheath blockade is a safe and accurate method for emergency ileostomy for patients with coagulopathy].

Obstructive ileus is a life-threatening gastrointestinal condition that requires emergency operation. Patients with obstructive ileus sometimes develop coagulopathy. In such cases, central neuraxial blockade should be avoided. Rectus sheath blockade (RSB) is one of the popular methods for abdominal wall surgery. Ultrasound imaging of the rectus sheath may facilitate successful RSB by indicating the presence and location of rectus abdominis. Two patients presented with ileus secondary to rectal or sigmoid cancer and underwent emergency ileostomy. The patients had mild coagulopathy [platelet count, 77,000 microl(-1) in case 1, and platelet count, 98,000 microl(-1) in case 2]. Each patient underwent general anesthesia using propofol and remifentanil. They were given 0.5% ropivacaine 20ml for RSB under ultrasound-guidance. Their hemodynamics was stable and they did not need another muscle relaxant during operation, except succinylcholine during induction. RSB is useful for abdominal operations. In addition, ultrasonogrhaphy facilitates the prediction of depth of the posterior rectus sheath and improves the accuracy of local anesthetic placement. We conclude that RSB is effective for improving postoperative pain and intraoperative muscle relaxation of the abdominal wall. Ultrasound-guided RSB is an alternative method to central neuraxial blockade.

[Ultrasound-guided combined femoral-obturator nerve block for the knee arthroscopic surgery of meniscal lesions: case report].

We report successful management of anesthesia in two cases of knee arthroscopic surgery of meniscal lesions using ultrasound-guided combined femoral-obturator nerve block with inhalation anesthesia. The blocks were performed with 30 ml of 0.5% ropivacaine under ultrasonographic visualization. The perioperative courses were uneventful and there was no complaint about postoperative pain. Unlike spinal or epidural anesthesia, combined femoral-obturator nerve block has advantages of no muscle weakness in healthy lower limbs, no urinary retention, and no post dural puncture headache. Our technique relieved postoperative pain effectively because knee joint is innervated by the femoral and obturator nerves in great measure. Ultrasound-guided femoral and obturator nerve block is easier and more successful than sciatic nerve block. General anesthesia with combined femoral-obturator nerve block could be a useful technique with less complication for knee arthroscopic surgery.

[Ultrasound-guided rectus sheath block for upper abdominal surgery].

Upper abdominal surgery leads to severe postoperative pain. Insufficient postoperative analgesia accompanies a high incidence of complications. Therefore, postoperative analgesia is very important. The epidural analgesia has many advantages. However it has a high risk of epidural hematoma in anticoagulated patients. Rectus sheath block provided safer and more reliable analgesia in recent years, by the development of ultrasound tools. We experienced two cases of the rectus sheath block in upper abdominal surgery under ultrasound guidance. Ultrasound guided rectus sheath block can reduce the risk of peritoneal puncture, bleeding, and other complications. Rectus sheath block is very effective to reduce postoperative pain in upper abdominal surgery as an alternative method to epidural anesthesia in anticoagulated patients.

Efforts to reduce the length of stay in a low-intensity ICU: Changes in the ICU brought about by collaboration between Certified Nurse Specialists as head nurses and intensivists.

Certified Nurse Specialists (CNS) are advanced practice nurses that often play a role in management. This study aims to investigate whether cooperation between CNSs in the position of Intensive Care Unit (ICU) head nurse and intensivists change the length of stay for ICU patients. A single centered retrospective cohort study design was followed. A multivariable regression analysis was performed to determine whether there is a difference in patients' length of ICU stay for two years before and after CNS as ICU head nurse and an intensivist started collaborating. The patients' diagnosis, age, gender, scheduled/emergency admission, surgical history, length of ICU stay, usage of ventilator, and details of ICU treatment were collected from the institution's electronic medical records. During the study period (April 2015 to March 2019), 3,135 patients were admitted to ICU, with 1,471 in the before collaboration group and 1,664 in the after-collaboration group. Collaboration between the CNS as head nurse and intensivists was significantly associated with shorter length of ICU stay (coefficient -0.03 [95% CI, -0.05-0.01], p < 0.001, t-statistic -3.29). Our main finding illustrates that in low-intensity ICUs, collaboration between CNSs as head nurses and intensivists may reduce patients' length of ICU stay.

Impact of having a certified nurse specialist in critical care nursing as head nurse on ICU patient outcomes.

OBJECTIVES: This study evaluated the impact of the presence of a certified nurse specialist in critical care (CNS) as ICU head nurse in an open ICU on clinical outcomes. METHODS: The presence of a CNS as ICU head nurse was implemented in practice in April 2017. To evaluate the impact on patient outcomes before and after the implementation, patients were divided into two groups: before (April 2014 to March 2017; 1988 patients) and after (April 2017 to March 2019; 1664 patients). Patients' demographic data were collected from the ICU database. RESULTS: Multivariable logistic regression analysis revealed that the presence of a CNS as ICU head nurse was associated with lower ICU mortality (odds ratio (OR): 0.52, 95% CI: 0.36-0.73, p < .001) and fewer patients receiving mechanical ventilation in the ICU (OR: 0.20, 95% CI: 0.15-0.26, p < .001). CONCLUSION: CNSs are defined as one type of advanced practice nurses. Having a CNS as a head nurse in the ICU may have helped improve patient outcomes by leveraging these practical skills in nursing management.

Neural mechanisms of sevoflurane-induced respiratory depression in newborn rats.

BACKGROUND: Sevoflurane-induced respiratory depression has been reported to be due to the action on medullary respiratory and phrenic motor neurons. These results were obtained from extracellular recordings of the neurons. Here, the authors made intracellular recordings of respiratory neurons and analyzed their membrane properties during sevoflurane application. Furthermore, they clarified the role of gamma-aminobutyric acid type A receptors in sevoflurane-induced respiratory depression. METHODS: In the isolated brainstem-spinal cord of newborn rat, the authors recorded the C4 nerve burst as an index of inspiratory activity. The preparation was superfused with a solution containing sevoflurane alone or sevoflurane plus the gamma-aminobutyric acid type A receptor antagonist picrotoxin or bicuculline. Neuronal activities were also recorded using patch clamp techniques. RESULTS: Sevoflurane decreased C4 burst rate and amplitude. Separate perfusion of sevoflurane to the medulla and to the spinal cord decreased C4 burst rate and amplitude, respectively. Both picrotoxin and bicuculline attenuated the reduction of C4 burst rate. Sevoflurane reduced both intraburst firing frequency and membrane resistance of respiratory neurons except for inspiratory neurons. CONCLUSION: Under the influence of sevoflurane, the region containing inspiratory neurons, i.e., the pre-Bötzinger complex, may determine the inspiratory rhythm, because reduced C4 bursts were still synchronized with the bursts of inspiratory neurons within the pre-Bötzinger complex. In contrast, the sevoflurane-induced decrease in C4 burst amplitude is mediated through the inhibition of phrenic motor neurons. gamma-Aminobutyric acid type A receptors may be involved in the sevoflurane-induced respiratory depression within the medulla, but not within the spinal cord.

[The antiemetic effect of dexamethasone during continuous subcutaneous infusion of morphine for postoperative pain relief].

BACKGROUND: Dexamethasone is known to reduce the incidence of postoperative nausea and vomiting, associated with perioperative intrathecal, epidural, or intravenous morphine. However, the effect of dexamethasone on subcutaneous morphine is unclear. Therefore, we evaluated the antiemetic effect of intravenous dexamethasone during continuous subcutaneous infusion of morphine for postoperative pain relief. METHODS: Twenty patients scheduled for spinal surgery under general anesthesia were enrolled in this randomized, double-blind, and placebo-controlled study. The dexamethasone group (n=10) received dexamethasone 8 mg and the saline group (n=10) received the same amount of saline before the induction of anesthesia. Anesthesia was maintained with propofol and fentanyl. Postoperative pain was treated with continuous subcutaneous morphine via a patient-controlled analgesia device. Postoperatively patients were assessed during 48 hours for nausea and vomiting. RESULTS: Nausea or vomiting ascribable to the subcutaneous morphine developed in 40% of the patients in each group (P:NS). CONCLUSIONS: Our results suggest that the single dose of dexamethasone (8 mg) does not reduce postoperative nausea and vomiting associated with continuous subcutaneous infusion of morphine after spinal surgery.

Effects of neuromuscular blocking agents on central respiratory control in the isolated brainstem-spinal cord of neonatal rat.

Although neuromuscular blocking agents (NMBAs) function as muscular nicotinic acetylcholine receptor (nAChR) antagonists, several studies have shown that they block neuronal nAChRs as well, which led us to hypothesize that these agents can affect neuronal nAChRs expressed in respiratory centers. To test this hypothesis, we studied the effects of two NMBAs on respiratory activity and respiratory neurons in brainstem-spinal cord preparations from neonatal rats. The application of either D-tubocurarine or vecuronium resulted in dose-dependent reductions in C4 respiratory rate. These reductions were concomitant with reductions in the depolarizing cycle rate of inspiratory (Insp) neurons; the depolarizing cycle rate of preinspiratory (Pre-I) neurons, however, was not affected. We also detected C4 burst activity during the depolarizing phase in Pre-I neurons, even during NMBA-induced respiratory depression. Both NMBAs inhibited drive potential amplitude and intraburst firing frequency in Insp and Pre-I neurons. These agents also induced a hyperpolarization and an increase in membrane resistance in Pre-I neurons, however they had no effect on these membrane properties in Insp neurons. Our findings indicate that these agents suppress central respiratory activity mainly through their inhibitory effects on Pre-I neurons and the Pre-I to Insp neuron synaptic drive, and that nAChRs are involved in central respiratory control.

Electrical stimulation of the rabbit pulmonary artery increases respiratory output.

This study was conducted to test the hypothesis that the pulmonary artery is involved in neural respiratory control and to identify the involved topographical region, if any. Six adult rabbits were anesthetized, artificially ventilated, and the chest was opened. The outer surface of the extra-pulmonary portion of the pulmonary artery was electrically stimulated by monitoring phrenic nerve activity. Phrenic nerve activity increased in three of the six rabbits when the proximal dorsal surface of the pulmonary trunk was stimulated. This positive response was abolished after bilateral vagotomy. In histological examinations we found densely grouped cells, i.e. pulmonary glomic tissue, with a fine nerve bundle in the tissue adjacent to the dorsal surface of the pulmonary trunk where electrical stimulation elicited respiratory augmentation. We suggest that there is a neural substrate which is involved in respiratory control inside the wall of or in the region adjacent to the proximal dorsal surface of the pulmonary trunk. Further studies to anatomically identify the neural substrate and clarify its physiological role in respiratory control are necessary.

Antagonism of morphine-induced central respiratory depression by donepezil in the anesthetized rabbit.

Morphine is often used in cancer pain and postoperative analgesic management but induces respiratory depression. Therefore, there is an ongoing search for drug candidates that can antagonize morphine-induced respiratory depression but have no effect on morphine-induced analgesia. Acetylcholine is an excitatory neurotransmitter in central respiratory control and physostigmine antagonizes morphine-induced respiratory depression. However, physostigmine has not been applied in clinical practice because it has a short action time, among other characteristics. We therefore asked whether donepezil (a long-acting acetylcholinesterase inhibitor used in the treatment of Alzheimer's disease) can antagonize morphine-induced respiratory depression. Using the anesthetized rabbit as our model, we measured phrenic nerve discharge as an index of respiratory rate and amplitude. We compared control indices with discharges after the injection of morphine and after the injection of donepezil. Morphine-induced depression of respiratory rate and respiratory amplitude was partly antagonized by donepezil without any effect on blood pressure and end-tidal C02. In the other experiment, apneic threshold PaC02 was also compared. Morphine increased the phrenic nerve apnea threshold but this was antagonized by donepezil. These findings indicate that systemically administered donepezil partially restores morphine-induced respiratory depression and morphine-deteriorated phrenic nerve apnea threshold in the anesthetized rabbit.

Association of nicotinic acetylcholine receptors with central respiratory control in isolated brainstem-spinal cord preparation of neonatal rats.

Nicotine exposure is a risk factor in several breathing disorders Nicotinic acetylcholine receptors (nAChRs) exist in the ventrolateral medulla, an important site for respiratory control. We examined the effects of nicotinic acetylcholine neurotransmission on central respiratory control by addition of a nAChR agonist or one of various antagonists into superfusion medium in the isolated brainstem-spinal cord from neonatal rats. Ventral C4 neuronal activity was monitored as central respiratory output, and activities of respiratory neurons in the ventrolateral medulla were recorded in whole-cell configuration. RJR-2403 (0.1-10 mM), alpha4beta2 nAChR agonist induced dose-dependent increases in respiratory frequency. Non-selective nAChR antagonist mecamylamine (0.1-100 mM), alpha4beta2 antagonist dihydro-beta-erythroidine (0.1-100 mM), alpha7 antagonist methyllycaconitine (0.1-100 mM), and a-bungarotoxin (0.01-10 mM) all induced dose-dependent reductions in C4 respiratory rate. We next examined effects of 20 mM dihydro-beta-erythroidine and 20mM methyllycaconitine on respiratory neurons. Dihydro-beta-erythroidine induces hyperpolarization and decreases intraburst firing frequency of inspiratory and preinspiratory neurons. In contrast, methyllycaconitine has no effect on the membrane potential of inspiratory neurons, but does decrease their intraburst firing frequency while inducing hyperpolarization and decreasing intraburst firing frequency in preinspiratory neurons. These findings indicate that alpha4beta2 nAChR is involved in both inspiratory and preinspiratory neurons, whereas alpha7 nAChR functions only in preinspiratory neurons to modulate C4 respiratory rate.

Effects of neuromuscular blocking agents on central respiratory chemosensitivity in newborn rats.

Neuromuscular blocking agents suppress central respiratory activity through their inhibitory effects on preinspiratory neurons and the synaptic drive from preinspiratory neurons to inspiratory neurons. Central CO2-chemosensitive areas, which partly consist of CO2-excited neurons, in the rostral ventrolateral medulla are thought to provide tonic drive to the central respiratory network and involve cholinergic mechanisms, which led us to hypothesize that neuromuscular blocking agents can inhibit CO2-excited neurons and attenuate respiratory CO2 responsiveness. To test this hypothesis, we used isolated brainstem-spinal cord preparations from newborn rats. The increase of C4 burst frequency induced by a hypercapnic superfusate, i.e. respiratory CO2 responsiveness, was suppressed by the application of neuromuscular blocking agents, either d-tubocurarine (10, 100 microM) or vecuronium (100 microM). These agents (40 microM) also induced hyperpolarization and decreases in firing frequency of CO2-excited neurons in the rostral ventrolateral medulla. Our results demonstrate that neuromuscular blocking agents inhibit CO2-excited tonic firing neurons and attenuate respiratory CO2 responsiveness.

A neuronal mechanism of propofol-induced central respiratory depression in newborn rats.

The neural mechanisms of propofol-induced central respiratory depression remain poorly understood. In the present study, we studied these mechanisms and the involvement of gamma-aminobutyric acid (GABA)A receptors in propofol-induced central respiratory depression. The brainstem and the cervical spinal cord of 1- to 4-day-old rats were isolated, and preparations were maintained in vitro with oxygenated artificial cerebrospinal fluid. Rhythmic inspiratory burst activity was recorded from the C4 spinal ventral root. The activity of respiratory neurons in the ventrolateral medulla was recorded using a perforated patch-clamp technique. We found that bath-applied propofol decreased C4 inspiratory burst rate, which could be reversed by the administration of a GABAA antagonist, bicuculline. Propofol caused resting membrane potentials to hyperpolarize and suppressed the firing of action potentials in preinspiratory and expiratory neurons. In contrast, propofol had little effect on resting membrane potentials and action potential firing in inspiratory neurons. Our findings suggest that the depressive effects of propofol are, at least in part, mediated by the agonistic action of propofol on GABAA receptors. It is likely that the GABAA receptor-mediated hyperpolarization of preinspiratory neurons serves as the neuronal basis of propofol-induced respiratory depression in the newborn rat.