Transient Apnea Research Articles

409. TWO-STAGE OPERATIVE PROCEDURE FOR A BENIGN, COMPLICATED TRACHEOESOPHAGEAL FISTULA CAUSED BY FOREIGN BODY IMPACTION

Abstract Background Benign Tracheoesophageal fistula (TOF) caused by foreign body impaction is a rare condition requiring technical expertise. There are choices available based on the individual patient's situation, including endoscopic management, local resection and defect closure, and, in rare cases, esophagectomy. Methods A 58-year-old male had a history of artificial tooth dislodgement that got impacted in the esophagus, resulting in dysphagia. Endoscopy showed an impacted denture with an underlying transmural esophageal perforation, closed with clips and an endoloop. Two weeks later, partially covered SEMS was placed. Failure to retrieve the SEMS after repeated attempts due to tissue ingrowths, he was referred for management. CECT showed a stent in situ with a small air-filled cavity left lateral to the tracheal bifurcation. Bronchoscopy revealed the compression of the posterior tracheal wall and the presence of an endoclip in the posterior wall of the left main bronchus (LMB). Results The patient was planned for a two-stage operation. In the first stage, esophagus was mobilized along with the stent and the fistulous tract was excised. The esophagus was divided at both ends in the thorax. Up to this part, the procedure was done with single-port VATS without CO2 and in the left semi-prone position with a bronchial blocker in the right main bronchus. The fistula with the LMB was closed with an intercostal muscle flap and a bovine pericardial patch with transient apnoea. During this part, we extended the incision in the fourth space to raise the flap. Cervical esophagostomy was matured, and a feeding jejunostomy was created. The postoperative phase was uneventful, and he was discharged on the 5th postoperative day. After 4 weeks, we did the second phase of surgery, where we made a 4 cm retrosternal gastric conduit and performed the hand-sewn anastomosis with the cervical esophagus, which was taken down from the skin. The patient had an uneventful postoperative course and was allowed to be taken orally on day five and discharged subsequently two days later. Conclusions TOF demands a multidisciplinary treatment strategy. Successful outcomes are determined by patient triage, delineation of the location and size of the defect, mediastinal contamination, and the availability of expertise.

Hypothermia and rewarming times during general anesthesia in Hispaniolan Amazon parrots (Amazona ventralis): A comparative study between isoflurane, sevoflurane and desflurane

ObjectiveTo evaluate induced hypothermia and rewarming times in Hispaniolan Amazon parrots (HAP; Amazona ventralis) anesthetized using isoflurane, sevoflurane or desflurane, and to describe selected cardiovascular and respiratory effects. Study designRandomized, balanced, crossover experimental study. AnimalsA group of 12 adult HAP. MethodsParrots were premedicated with intramuscular butorphanol (0.5 mg kg–1) and anesthetized with the three inhalants with a 7 day washout period between events. Anesthesia was induced using isoflurane at 4 vol%, sevoflurane at 6 vol% or desflurane 12 vol% carried in oxygen, delivered via face mask. After orotracheal intubation, anesthesia maintenance was with end-tidal concentrations of 1.4–2% (Fe′Iso), 2.4–3% (Fe′Sevo) and 8.5–9.2% (Fe′Des). Hypothermia was defined as an esophageal temperature (BT) below 37.8 °C. External heat support was provided when BT dropped to 37.5 °C. Time for temperature decrease from 38.9 °C to 37.5 °C (T1), time to first increase in BT above 37.5 °C (T2) and time from external heat support to achieving 38.9 °C (T3) were recorded and compared via Friedman tests with post hoc Dunn’s test. Heart rate, respiratory rate and end-tidal carbon dioxide, amongst other variables, were evaluated. ResultsAll inhalants caused hypothermia (T1): isoflurane, 12 (2–37) minutes [median (range)]; sevoflurane, 12 (4–18) minutes; desflurane, 11.5 (6–24) minutes, with no significant differences between treatments (p > 0.05). T2 was significantly (p = 0.042) longer for sevoflurane than for desflurane but not isoflurane. Transient apnea was observed with all inhalants, including 25% of birds anesthetized with sevoflurane. Second-degree atrioventricular block and ventricular escape beats occurred with all inhalants with hypothermia potentially exacerbating cardiac arrhythmias. Conclusions and clinical relevanceHypothermia rapidly developed in butorphanol-sedated HAP anesthetized using isoflurane, sevoflurane or desflurane. Sevoflurane prolonged warming time. Hypothermia may be associated with an increased likelihood of bradyarrhythmia in parrots anesthetized with inhalants.

Effects of high dose Fentanyl in combination with hypoxia or ketamine in adult female goats

The worsening opioid epidemic in the United States continues to claim >80,000 lives each year. Synthetic opioids such as fentanyl are highly useful in the clinical management of pain but at high doses are thought to cause death through opioid-induced respiratory depression (OIRD), impairment of the alveolar to arterial oxygen (A-a O2) gradient and though upper airway and respiratory pump muscles activation causing airway dysfunction and/or Wooden Chest Syndrome (WCS). These negative effects of high dose opioids may be exacerbated when individuals use additional drugs such as ketamine or by an existing hypoxia. We have shown previously that low (sub-lethal) doses of fentanyl (25-125 μg/kg; IV) cause transient apnea (<30 sec), a brief suppression of breathing frequency (FB; <5 min), increased tidal volume (VT), upper airway and pump muscle activity, and an increased A-a O2 gradient with an overall stimulatory effect on ventilation for up to 90 min post-injection (PMID: 37885800). Here we tested the hypothesis that the physiological effects of high doses of fentanyl will be exacerbated when combined with pre-treatment of either mild hypoxia (FIO2=0.12) or IV ketamine (10 mg/kg). Adult female goats (n=3) were surgically instrumented with electromyographic (EMG) wires in airway (genioglossus and thyropharyngeal) and respiratory pump (diaphragm, transverse abdominus and intercostal) muscles and the carotid arteries relocated subcutaneously and allowed 2 weeks for recovery. Arterial blood samples were obtained through a carotid catheter and all injections were via a catheter in the jugular. Following a 30-minute control period, goats were given IV saline (vehicle) or fentanyl (50–500 μg/kg). In most goats, fentanyl doses of 200-250 μg/kg cause immediate apnea up to 60 sec in duration and decreased FB (~40%) and PaO2 (~35 mmHg) while increasing PaCO2 (~70mmHg) along with an EMG activation and increased A-a O2 gradient. These effects tended to be less severe at a given dose when injections were performed during mild hypoxia (15 min; n=2) but were exacerbated by pretreatment with ketamine (n=1). These data suggest high doses of fentanyl in goats cause similar life-threatening features as in humans, and that these effects seem to be mitigated by hypoxic ventilatory stimulation but exacerbated by polypharmacy with ketamine. NIH DA050571. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Brainstem anesthesia during awake craniotomy: illustrative case.

Awake craniotomy (AC) is performed to remove the lesions near or in eloquent areas, during which the patients are alert and without any airway instrument. Apnea is a severe complication in AC. Here, the authors describe a case of sudden apnea induced by unexpected local anesthesia of the brainstem during AC. A 42-year-old male underwent AC for a large, recurrent, bilateral frontal lobe mass and experienced transient apnea and loss of brainstem reflexes during the surgery. The patient recovered spontaneous breath rhythm just a few minutes after the removal of a lidocaine cotton pledget, which was found near the patient's midbrain. Then the patient awoke and cooperated to finish the surgery. The administration of a local anesthetic subdurally in AC is common but risky. The scouring action of cerebral spinal fluid can spread those agents and cause unexpected brainstem anesthesia. A lower concentration of the anesthetic and keeping away from the cistern can make it safer.

Comparison of propofol infusion rate required to abolish swallowing or pedal withdrawal reflexes in dogs.

In a prospective, randomized, experimental non-blinded study, the continuous infusions rates of propofol required to prevent swallowing (P-SR) or pedal withdrawal reflex (P-WR) were evaluated in healthy premedicated dogs. Dogs were randomly assigned to one of two treatments at weekly intervals. Following premedication with a combination of acepromazine and methadone, anesthesia was induced with propofol (4.00 mg kg-1 per min) and was maintained for 90 min. The propofol infusion rate was increased or decreased by 0.05 mg kg-1 per min based on positive or negative swallowing (P-SR) or pedal withdrawal reflexes (P-WR). Propofol induction doses were 2.12 ± 0.43 mg kg-1 (P-SR) and 2.14 ± 0.31 mg kg-1 (P-WR), which were not significantly different. The mean (±SD) propofol infusion rate was significantly higher for P-WR (0.26 ± 0.10 mg kg-1 per min) when compared to P-SR (0.22 ± 0.12 mg kg-1 per min). During the last 30 min, the mean propofol infusion rates were 0.09 ± 0.02 and 0.18 ± 0.03 mg kg-1 per min for P-SR and P-WR, respectively. There were no significant differences between treatments with respect to heart rate (HR), respiratory rate, arterial blood pressure, end-tidal CO2 partial pressure, hemoglobin oxygen saturation, partial pressures of oxygen or pH. Transient apnea lasting up to three minutes was observed in three dogs with each treatment. Propofol infusion rate of 0.22 ± 0.12 mg kg-1 per min can be used in premedicated dogs requiring tracheal intubation and undergoing mechanical ventilation, non-painful procedures or painful procedures with local anesthetic techniques.

Pro-opiomelanocortin neurons in the nucleus of the solitary tract mediate endorphinergic endogenous analgesia in mice.

The nucleus of the solitary tract (NTS) contains pro-opiomelanocortin (POMC) neurons that are 1 of the 2 major sources of β-endorphin in the brain. The functional role of these NTS POMC neurons in nociceptive and cardiorespiratory function is debated. We have shown that NTS POMC optogenetic activation produces bradycardia and transient apnoea in a working heart-brainstem preparation and chemogenetic activation with an engineered ion channel (PSAM) produced opioidergic analgesia in vivo. To better define the role of the NTS POMC neurons in behaving animals, we adopted in vivo optogenetics (ChrimsonR) and excitatory/inhibitory chemogenetic DREADD (hM3Dq/hM4Di) strategies in POMC-Cre mice. We show that optogenetic activation of NTS POMC neurons produces time-locked, graded, transient bradycardia and bradypnoea in anaesthetised mice that is naloxone sensitive (1 mg/kg, i.p.), suggesting a role of β-endorphin. Both optogenetic and chemogenetic activation of NTS POMC neurons produces sustained thermal analgesia in behaving mice that can be blocked by naloxone. It also produced analgesia in an inflammatory pain model (carrageenan) but not in a neuropathic pain model (tibial nerve transection). Inhibiting NTS POMC neurons does not produce any effect on basal nociception but inhibits stress-induced analgesia (unlike inhibition of arcuate POMC neurons). Activation of NTS POMC neuronal populations in conscious mice did not cause respiratory depression, anxiety, or locomotor deficit (in open field) or affective preference. These findings indicate that NTS POMC neurons play a key role in the generation of endorphinergic endogenous analgesia and can also regulate cardiorespiratory function.

Using a combination of midazolam and butorphanol is a safe and effective reversible field sedation protocol for Weddell seal (Leptonychotes weddellii) pups.

Weddell seals (Leptonychotes weddellii) are a well-studied species of phocid with an apparent sensitivity to immobilising agents. Mortality as high as 31% has been reported during field immobilisation. This study investigated the use of a benzodiazepine in combination with an opioid agonist/antagonist for sedation in Weddell seal pups as part of a physiological study. During the 2017 and 2019 Antarctic pupping seasons, 18 Weddell seal pups were sedated by intramuscular administration of a combination of midazolam and butorphanol or intravenous midazolam alone. Individuals were sedated at 1, 3, 5 and 7 weeks of age. Naltrexone and flumazenil were used to reverse sedation. The combination was 100% effective in providing appropriate sedation for the intended procedures. Analyses were performed to investigate relationships between dose administered, age, individual reactions, adverse effects and changes in dive physiology. Transient apnoea (10-60 seconds) was the most frequently observed adverse effect. No sedation-associated morbidity or mortality occurred. The sample size is small and there is no pharmacokinetic information for either sedative or reversal in phocid species. The combination of midazolam (0.2-0.3mg/kg) and butorphanol (0.1-0.2mg/kg) provided safe and effective sedation, with reversible effects, in Weddell seal pups.

Evaluation of Heller's reaction and the urine dipstick method alone or in combination to detect proteinuria in sheep

Urine dipstick and Heller's reaction are easy first-line screening tests for the detection of proteinuria; however, the performance of these methods in alkaline ovine urine is largely unknown. The aim of this study was to evaluate the diagnostic performance of Heller's reaction alone or in combination with dipstick for the detection of proteinuria in sheep, using the urine protein to creatinine ratio (UP/C) with two cut-off values as the reference method. Ninety-eight urine samples were collected from sheep using the transient apnea method. Heller's reaction, the dipstick method, and the UP/C ratio were used to assess proteinuria. The results were statistically analyzed twice, based on two different UP/C cut-off values of 0.2 and 0.5. Cohen's kappa value was used to determine the agreement between the UP/C ratios and Heller's reaction, the dipstick method, or the combination of methods. Sensitivity, specificity, and positive and negative likelihood ratios were calculated. ROC curves were also generated, and the areas under the curve (AUC) were evaluated to determine the optimal threshold for the numerical values of the two methods. Heller's reaction is more specific (96.67% and 96.00% when the cut-off value is 0.2 and 0.5, respectively) than the dipstick method, while the dipstick method was more sensitive (91.18% and 91.30%, when the cut-off value was 0.2 and 0.5, respectively) than Heller's reaction for the detection of proteinuria. Both tests were accurate when any grade >0 was considered positive. Proteinuria can almost be excluded in ovine urine samples with negative Heller's reaction and dipstick test.

High-flow nasal cannula (HFNC) oxygenation for sclerotherapy of facial and upper airway vascular malformations in pediatric patients: Case series.

We report anesthesia management of sclerotherapy for vascular malformations (VMs) of the upper airway and face of pediatric patients conducted under sedation using a high-flow nasal cannula (HFNC) oxygen delivery system. Sclerotherapy procedures were carried out in six patients (five males, one female; age group: 5-12 years). The patients were sedated with midazolam, fentanyl, ketamine, and graded doses of propofol along with continuous oxygen delivery using HFNC. There were no episodes of oxygen desaturation, tongue fall or obstruction of the airway, interruption of procedure for assisted ventilation, and postoperative nausea and vomiting (PONV). Only two patients showed transient apnea for 10 and 15 s but did not require ventilatory assistance. HFNC provides effective oxygenation in pediatric patients undergoing sclerotherapy of VMs of the upper airway and face under sedation.

Breathing rhythm stability is higher after intravenous injection of codeine relative to fentanyl in cats

Codeine is one of the opioids of abuse that is available by prescription, and fentanyl is the leading opioid drug of abuse. Both codeine and fentanyl are µ‐opioid agonists that are strong respiratory depressants. However, unlike fentanyl, codeine also binds to nicotinic receptors. We hypothesized that influence of these drugs on the stability of breathing would differ due to the relative non‐specificity of codeine. Ten anesthetized, spontaneously breathing adult cats were tracheotomized, and EMG activity was recorded from inspiratory muscles. Dose responses to codeine (n=5, 0.1 – 10 mg/kg, i.v.) or fentanyl (n=5, 0.1 – 10 ng/kg, i.v.) were performed in separate groups of animals. Total breathing cycle time (Ttot) was measured for 30 breaths at each dose. Measurements of Ttot were taken more than 5 minutes following administration of the drugs. Poincaré plots were constructed for Ttot, where an ellipse was fit to the data (Ɵ=45°). The ratio (SD1/SD2) was computed at each dose, where SD1 was the length the ellipse perpendicular to the line of identity, and SD2 was the length along the line of identity. SD1 is associated with short‐term variability and SD2 with long‐term variability of the data. The dose response relationships showed similar increases in Ttot from vehicle to the highest dose between codeine and fentanyl (codeine: 2.4 ± 0.2 s to 4.4 ± 1.0 s; fentanyl: 2.5 ± 0.4 s to 5.4 ± 0.5 s). Transient apnea (< 60 s) was commonly observed immediately following doses of codeine that were larger than 1 mg/kg, but was not observed after any dose of fentanyl. SD1/SD2 differed between the two drugs, where SD1/SD2 did not change across doses for codeine, and SD1/SD2 decreased significantly in a dose‐dependent manner from 0.3 ng/kg (0.77 ± 0.10) to the 3 ng/kg dose (0.32 ± 0.7) for fentanyl. The shift in the SD1/SD2 ratio after fentanyl was driven more by changes in SD2 (81% compared to vehicle) rather than SD1 (‐17% compared to vehicle). We conclude that codeine induces relatively similar changes of short and long‐term variability of Ttot, whereas fentanyl preferentially reduces long‐term variability of Ttot. Alterations in long‐term variability are more consistent with a potential for network reconfiguration rather than the respiratory network correcting for breath‐to‐breath requirements. Our data suggest that a Poincaré plot may be a sensitive metric of the disruption of respiratory control dynamics for the µ‐receptor selective fentanyl relative to the µ‐opioid agonist/nicotinic ligand codeine.

Effects of mechanical ventilation versus apnea on bi-ventricular pressure-volume loop recording.

Respiration changes intrathoracic pressure and lung volumes in a cyclic manner, which affect cardiac function. Invasive ventricular pressure-volume (PV) loops can be recorded during ongoing mechanical ventilation or in transient apnea. No consensus exists considering ventilatory mode during PV loop recording. The objective of this study was to investigate the magnitude of any systematic difference of bi-ventricular PV loop variables recorded during mechanical ventilation versus apnea. PV loops were recorded simultaneously from the right ventricle and left ventricle in a closed chest porcine model during mechanical ventilation and in transient apnea (n=72). Variables were compared by regression analyses. Mechanical ventilation versus apnea affected regression coefficients for important PV variables including right ventricular stroke volume (1.22, 95% CI [1.08-1.36], p=0.003), right ventricular ejection fraction (0.90, 95% CI [0.81-1.00], p=0.043) and right ventricular arterial elastance (0.61, 95%CI [0.55-0.68], p<0.0001). Right ventricular pressures and volumes were parallelly shifted with Y-intercepts different from 0. Few left ventricular variables were affected, mainly first derivatives of pressure (dP/dt(max): 0.96, 95% CI [0.92-0.99], p=0.016, and dP/dt(min): 0.92, 95% CI [0.86-0.99], p=0.026), which might be due to decreased heart rate in apnea (Y-intercept -6.88, 95% CI [-12.22; -1.54], p=0.012). We conclude, that right ventricular stroke volume, ejection fraction and arterial elastance were mostly affected by apnea compared to mechanical ventilation. The results motivate future standardization of respiratory modality when measuring PV relationships.

A Co-Induction Technique Utilizing 4% Sevoflurane Followed by 0.75 mg/kg Propofol in Elderly Patients Undergoing Minimally Invasive Procedures: A Prospective Randomized Control Study.

Background and Objectives: Elderly patients constitute a large segment of healthcare receivers. Considering the functional deterioration of multiple organ systems with aging, achieving a safe perioperative approach is challenging. Our aim is to study the safety and effectiveness of a genuinely regimented co-induction technique in order to minimize anesthesia-related complications. Materials and Methods: One hundred and five patients were assigned to three groups according to the induction technique: propofol, sevoflurane and co-induction group. Inclusion criteria: patients with age ≥65 and American Society of Anesthesiologists physical status classification (ASA) II-III who underwent endoscopic urological procedures. The propofol group received a dose of 1.5 mg kg−1 of propofol over two minutes for induction. The sevoflurane group received 8% of sevoflurane and 100% oxygen through a plastic facemask with the fresh gas flow set at 8 L min−1. The co-induction group received 4% sevoflurane through plastic facemask for two minutes, followed by a 0.75 mg kg−1 dose of propofol. After ensuring full range jaw relaxation, the laryngeal mask airway (LMA) was inserted. Results: Overall, the co-induction technique had a favorable profile in terms of respiratory adverse events, while the sevoflurane group had a favorable profile in terms of hemodynamic stability. Furthermore, 24 (68.6%) patients receiving inhalational sevoflurane had episodes of transient apnea, which constitutes 77.4% of the 31 episodes of transient apnea in the studied sample (p < 0.001). Moreover, six (17.1%) patients in the sevoflurane group had an episode of partial laryngospasm (p = 0.034). Compared with the co-induction group, we found that the propofol group had significantly less systolic and diastolic blood pressures in the second minute, with p values of (0.018) and (0.015), respectively. Conclusions: The co-induction technique utilizing 4% sevoflurane at 8 L min−1 flow of oxygen inhaled over two minutes followed by 0.75 mg kg−1 of propofol achieved less respiratory adverse events compared with the sevoflurane group, and less hemodynamic instability compared with the propofol group.

Neonatal Anemia with Spontaneous Grade II Intra-ventricular Hemorrhage

Background: Intra-ventricular hemorrhage (IVH), also known as intra-ventricular bleeding, is a bleeding into the brain's ventricular system, where the cerebrospinal fluid is produced and circulates through towards the subarachnoid space. It can result from physical trauma or from hemorrhaging in stroke. It is a significant finding in a neonatal intensive care incubator's babies with sudden onset of anemia. It attracts our attention to the importance of this issue & its burden complication in the future. Subject & method: We report a case of full term male baby aged 10 days, delivered by caesarean section who was admitted to neonatal intensive care unit (NICU) with fits & transient apnea. Bedside trans-cranial ultrasound is the main tool of investigation in NICU. Conventional therapy centers on managing hypertension and intracranial pressure while correcting coagulopathy and avoiding complications such as re-bleeding and hydrocephalus. Result: There is an association between neonatal anemia & occurrence of spontaneous intra-ventricular hemorrhage. Conclusion: IVH may be a devastating complication of anemia & bedside trans-cranial ultrasound is a valuable tool in detecting the degree of intra-ventricular hemorrhage and so patient outcome.

Description of Adverse Events in a Cohort of Dance Festival Attendees with Stimulant-Induced Severe Agitation Treated with Dissociative-Dose Ketamine

Background Emergency clinicians often treat severe agitation resulting from intoxicants, psychiatric illness, and other CNS or systemic diseases. Recreational drugs–especially stimulants–are frequently used by attendees of electronic dance music festivals (EDMFs), and festivalgoers may become dangerously agitated and pose an immediate threat to themselves and others. Although benzodiazepines and antipsychotics are classically used to treat severe agitation, these medications are burdened by safety concerns including respiratory depression and cardiac arrhythmias. The effects of ketamine when used to treat severe agitation in an exclusive cohort of patients with psychostimulant drug-induced toxicity (PDIT) has not previously been reported, and existing literature describes a widely variant safety profile when ketamine is used for sedation of the agitated patient. Objective To describe ketamine’s adverse event profile when used to treat patients with severe agitation resulting from PDIT. Methods This is a retrospective, observational study enrolling consecutive patients who presented for medical attention at a large outdoor EDMF over a period of eight days on two consecutive weekends in the summer of 2017. The EDMF had an estimated attendance of 40,000 per weekend. A medical tent was set up on-site; patients were managed by a team of EMS providers, nurses and emergency physicians. Medications used, adverse events and the need for repeat dosing were abstracted from prehospital care reports. Results Over the course of eight days, 1081 of 1186 patients who were evaluated in the medical tent had a recorded chief complaint. 274 of these patients (25.3%) had a chief complaint of altered mental status. In patients presenting with AMS, 68 patients (24.8%) had severe agitation that was treated with dissociative-dose (≥4 mg/kg) intramuscular ketamine. The mean initial dose of ketamine was 308 mg. There were four serious adverse events (5.9%): Two patients (2.9%) had copious hypersalivation treated with atropine, one patient (1.5%) had transient apnea requiring assisted ventilation, and one patient (1.5%) was intubated and transported to the hospital. 42 patients (61.8%) required redosing of calming medications. All patients who received ketamine except the single patient who was intubated and transported were observed in the medical tent until resolution of symptoms and discharged back to the festival. Conclusion In this cohort of festival attendees who developed stimulant-induced severe agitation and were treated with dissociative-dose ketamine, serious adverse events occurred in 5.9% of patients including one patient who was intubated.

Modifying Ways to Perform ICU Tracheostomies in COVID-19 Patients: Approach to a Safe and Secure Method.

Background This study outlines the unique modifications to surgical tracheostomy procedure to combat the extraordinary situation the world has found itself in due to COVID 19 pandemic. We explain the modifications employed to the operative setup, anesthetic considerations and surgical procedure to enable us to provide timely and safe tracheostomy to the COVID ICU patients requiring it, while simultaneously maximally protecting our surgical personnel from the deadly exposure. Methods- We conducted 55 surgical tracheostomies in severely sick ICU patients with the modifications deemed fit to achieve safe procedure for both the patient and the operating team. We analyzed the hospital record data of these patients and the surgical teams COVID 19 status to assesss the efficacy of our procedural modifications. Discussion- The COVID 19 pandemic has thrown the entire medical fraternity into a dilemma as to how to provide the best possible care to the patients while protecting ourselves from its grip. Severely sick COVID patients often require tracheostomy for improved prognosis. We performed bedside open surgical tracheostomy and induced transient apnoea periprocedur along with carinal intubation. By making these simple and cost effective modifications to the procedure, we have ensured that patients get tracheostomised as and when required but not at the cost of the health and lives of our health care workers.

Evaluation of subcutaneous administration of alfaxalone-midazolam and dexmedetomidine-midazolam for sedation of ball pythons (Python regius).

To evaluate SC administration of alfaxalone-midazolam and dexmedetomidine-midazolam for sedation of ball pythons (Python regius). 12 healthy juvenile ball pythons. In a randomized crossover study, each snake was administered a combination of alfaxalone (5 mg/kg [2.3 mg/lb]) and midazolam (0.5 mg/kg [0.23 mg/lb]) and a combination of dexmedetomidine (0.05 mg/kg [0.023 mg/lb]) and midazolam (0.5 mg/kg), SC, with a washout period of at least 7 days between protocols. Respiratory and heart rates and various reflexes and behaviors were assessed and compared between protocols. Forty-five minutes after protocol administration, sedation was reversed by SC administration of flumazenil (0.05 mg/kg) alone or in combination with atipamezole (0.5 mg/kg; dexmedetomidine-midazolam protocol only). Because of difficulties with visual assessment of respiratory effort after sedative administration, the experiment was repeated for a subset of 3 ball pythons, with plethysmography used to assess respiration. Both protocols induced a similar level of moderate sedation with no adverse effects aside from transient apnea. Cardiopulmonary depression was more profound, but time to recovery after reversal was significantly shorter, for the dexmedetomidine-midazolam protocol than for the alfaxalone-midazolam protocol. Plethysmographic findings were consistent with visual observations and suggested that snakes compensated for a decrease in respiratory rate by increasing tidal volume amplitude. Results indicated that both protocols induced clinically relevant sedation in ball pythons and should be useful for minor procedures such as venipuncture and diagnostic imaging. However, caution should be used when sedating snakes with compromised cardiopulmonary function. (J Am Vet Med Assoc 2020;256:573-579.

Safety and Efficacy of a Propofol and Ketamine Based Procedural Sedation Protocol in Children with Cerebral Palsy Undergoing Botulinum Toxin A Injections.

Pediatric patients with cerebral palsy often undergo intramuscular botulinum toxin (BoNT-A) injections. These injections can be painful and may require procedural sedation. An ideal sedation protocol has yet to be elucidated. To investigate the safety and efficacy of a propofol and ketamine based sedation protocol in pediatric patients with cerebral palsy requiring BoNT-A injections. Retrospective chart review. The sedations took place in a procedural sedation suite at a tertiary children's hospital from February 2013 through September 2017. 164 patients with diagnoses of cerebral palsy undergoing propofol and ketamine based sedation for injections with botulinum toxin A. An initial bolus of 0.5 mg/kg ketamine followed by a 2 mg/kg bolus of propofol was administered with supplemental boluses of propofol as needed to achieve deep sedation during the intramuscular BoNT-A injections. Propofol dosages, adverse events, serious adverse events, and sedation time parameters were reviewed. 345 sedations were successfully performed on 164 patients. The median total dose of propofol was 4.7 mg/kg (interquartile range [IQR]: 3.5, 6.3). Adverse events were encountered in 10.1% of procedures including hypoxemia responsive to supplemental oxygen (9.6%) and transient apnea (1.4%). The mean procedure time, recovery time, and total sedation time were 10, 11 and 33 minutes, respectively. With regard to patient variables, including age, weight, dose of propofol, sedation time, and Gross Motor Function Classification System classification, there was no association with increased incidence of adverse events. Our sedation protocol of propofol and ketamine is safe and effective in children with cerebral palsy undergoing procedural sedation for intramuscular injections with BoNT-A. The adverse events encountered appeared to be related to airway and respiratory complications secondary to musculoskeletal deformities, emphasizing the importance of airway monitoring and management in these patients. IV.

Harmonization of lateral fluid-percussion injury model production and post-injury monitoring in a preclinical multicenter biomarker discovery study on post-traumatic epileptogenesis

Multi-center preclinical studies can facilitate the discovery of biomarkers of antiepileptogenesis and thus facilitate the diagnosis and treatment development of patients at risk of developing post-traumatic epilepsy. However, these studies are often limited by the difficulty in harmonizing experimental protocols between laboratories. Here, we assess whether the production of traumatic brain injury (TBI) using the lateral fluid-percussion injury (FPI) in adult male Sprague-Dawley rats (12 weeks at the time of injury) was harmonized between three laboratories - located in the University of Eastern Finland (UEF), Monash University in Melbourne, Australia (Melbourne) and The University of California, Los Angeles, USA (UCLA). These laboratories are part of the international multicenter-based project, the Epilepsy Bioinformatics Study for Antiepileptogenesis Therapy (EpiBioS4Rx). Lateral FPI was induced in adult male Sprague-Dawley rats. The success of methodological harmonization was assessed by performing inter-site comparison of injury parameters including duration of anesthesia during surgery, impact pressure, post-impact transient apnea, post-impact seizure-like behavior, acute mortality (<72 h post-injury), time to self-right after the impact, and severity of the injury (assessed with the neuroscore). The data was collected using Common Data Elements and Case Report Forms. The acute mortality was 15% (UEF), 50% (Melbourne) and 57% (UCLA) (p < 0.001). The sites differed in the duration of anesthesia, the shortest being at UEF < Melbourne < UCLA (p < 0.001). The impact pressure used also differed between the sites, the highest being in UEF > Melbourne > UCLA (p < 0.001). The impact pressure associated with the severity of the functional deficits (low neuroscore) (P < 0.05) only at UEF, but not at any of the other sites. Additionally, the sites differed in the duration of post-impact transient apnea (p < 0.001) and time to self-right (P < 0.001), the highest values in both parameters was registered in Melbourne. Post-impact seizure-like behavior was observed in 51% (UEF), 25% (Melbourne) and 2% (UCLA) of rats (p < 0.001). Despite the differences in means when all sites were compared there was significant overlap in injury parameters between the sites. The data reflects the technical difficulties in the production of lateral FPI across multiple sites. On the other hand, the data can be used to model the heterogeneity in human cohorts with closed-head injury. Our animal cohort will provide a good starting point to investigate the factors associated with epileptogenesis after lateral FPI.

Early infancy-onset stimulation-induced myoclonic seizures in three siblings with inherited glycosylphosphatidylinositol (GPI) anchor deficiency.

Inherited glycosylphosphatidylinositol anchor deficiency causes a variety of clinical symptoms, including epilepsy, however, little information is available regarding seizures as a symptom. We report three siblings with inherited glycosylphosphatidylinositol anchor deficiency with PIGL gene mutations. The phenotypes of the subjects were not consistent with CHIME syndrome or Mabry syndrome, as reported in previous studies. All shared some clinical manifestations, including transient apnoea as neonates, dysmorphic facial features, and intellectual disability. Between one week and 3 months of life, all patients developed myoclonic seizures. Myoclonic jerks were easily evoked by sudden unexpected acoustic or tactile stimuli. None showed elevation of serum alkaline phosphatase. Vitamin B6 was given to one of the three siblings, but failed to suppress seizures. The presence of early infancy-onset stimulation-induced myoclonic seizures combined with dysmorphic facial features should lead physicians to consider the possibility of inherited glycosylphosphatidylinositol anchor deficiency.

Comparison of the Influence of Sedation with Either of Xylazine or Acepromazine on Nephrographic Opacification in Dogs

The effect of chemical restraints with either 2.0mg/kg intramuscular injection of xylazine hydrochloride or 0.1mg/kg intramuscular injection of acepromazine during standard excretory urography was studied in five adult local dogs receiving 800mgI/kg intravenous injection of 76% Urograffin®. Radiographs were obtained immediately, at 10 mins, 20 mins and 40 mins post injection of Urograffin, while scores ranging from 1-4 was assigned to nephrographic densities. Also, respiratory rates (RR), heart rates (HR) and pulse rates (PR) were determined before sedation, after sedation, immediately after contrast agent administration and at 10 minutes interval during the 40 minutes duration of urography. In addition, adverse effects associated with injection of the drugs were noted as at when they occurred. In this study, sedation with xylazine was associated with few adverse effects such as transient apnoea and arrhythmia. Nephrographic opacification score was significantly (P