Respiratory acidosis induced ST-segment elevation.

Acidosis has been reported to cause ST-segment elevation. We presented a woman with a history of rectal adenocarcinoma experienced cardiac arrest during the contrast-enhanced computed tomography examination. When spontaneous circulation returned, arterial blood gas revealed she had severe respiratory acidosis, and bedside electrocardiogram showed ST-segment elevation in anterior precordial leads. Emergent coronary angiography was normal. Echocardiography revealed no abnormality of cardiac cavity size, segmental wall motion, or pericardial echo. Carcinoma metastasis in the peritoneal cavity and lungs was detected on the contrast-enhanced computed tomography scan while the heart was not involved. The ST-segment regressed and the respiratory acidosis was corrected after she received mechanical ventilation which strongly suggested the association between acidosis and the electrocardiogram changes.

Acute and long-term management of severe bronchiectasis with high flow nasal therapy: A case report.

Bronchiectasis (BE) is a long-term, chronic lung condition featured by widened and scarred airways. These can alter the physiological mucociliary clearance, making it difficult to clear mucus and microorganisms, leading to frequent exacerbations. High flow nasal therapy (HFNT) is a noninvasive respiratory support that delivers heated and humidified gas eventually enriched with oxygen, through a nasal cannula.  Humidification is crucial for adequate airways mucociliary clearance, improving ciliary function and consequently reducing airways inflammation and recurrent infections. HFNT has been mostly used in patients with acute hypoxemic respiratory failure and in selected patients with chronic respiratory failure due to COPD. Still, evidence about its use in acute and long-term home setting in patients with clinically relevant BE are lacking. We report a case of severe widespread BE, already on top medical therapy and pulmonary rehabilitation, still suffering from difficult mucus expectoration and recurrent exacerbations, who has been additionally treated with HFNT, both in hospital and domiciliary, reporting significant improvements on relevant clinical and patient-centered outcomes. Thus, HFNT may confer additional benefits as an add-on treatment of patients with severe BE and respiratory failure.

Detection of Chronic Hypoventilation Among Infants With Robin Sequence Using Capillary Blood Gas Sampling.

OBJECTIVES/HYPOTHESIS: To describe the use of capillary blood gas (CBG) sampling to detect and quantify hypoventilation in infants with Robin sequence (RS). METHODS: Case series with chart review at two institutions. Infants with RS presenting over a 10-year period were identified using departmental databases. CBG values obtained during infancy or until airway intervention (AI) were reviewed. RESULTS: From 2008 to 2018, 111 infants with RS were identified as having had been assessed and managed from birth or transfer until discharge home and having CBG data available. In most cases, CBG sampling was obtained every other day until intervention or discharge. A total of 81 (73%) infants required AI: 72 (89%) underwent mandibular distraction osteogenesis, five (6%) underwent tracheotomy, and four (5%) were discharged home with a nasopharyngeal airway. The mean PCO2 at day of life (DOL) 7-30 for the AI group was 52.7 mmHg (95% confidence interval: 51.7-53.7) and for the no AI group was 45.9 mmHg (44.8-47.0; P < .0001). The mean HCO3 at DOL 7-30 for the AI group was 29.8 mEq/L (29.4-30.1) and for the no AI group was 27.0 mEq/L (26.5-27.4; P < .0001). Receiver operating characteristic curves were created for maximum PCO2 and HCO3 values and cutoffs were established by optimizing a balance of sensitivity and specificity. Infants requiring AI surpassed the PCO2 and HCO3 cutoff at a median of DOL 9. CONCLUSIONS: Among infants with RS and hypoventilation, objective measures of respiratory acidosis may be apparent by DOL 9. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2789-2794, 2021.

Comparison of volume-controlled, pressure-controlled, and pressure-controlled volume-guaranteed ventilation during robot-assisted laparoscopic gynecologic surgery in the Trendelenburg position.

Background: Pressure-controlled ventilation volume-guaranteed (PCV-VG) is being increasingly used for ventilation during general anesthesia. Carbon dioxide (CO2) pneumoperitoneum in the Trendelenburg position is routinely used during robot-assisted laparoscopic gynecologic surgery. Here, we hypothesized that PCV-VG would reduce peak inspiratory pressure (Ppeak), compared to volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV). Methods: In total, 60 patients were enrolled in this study and randomly assigned to receive VCV, PCV, or PCV-VG. Hemodynamic variables, respiratory variables, and arterial blood gases were measured in the supine position 15 minutes after the induction of anesthesia (T0), 30 and 60 minutes after CO2 pneumoperitoneum and Trendelenburg positioning (T1 and T2, respectively), and 15 minutes after placement in the supine position at the end of anesthesia (T3). Results: The Ppeak was higher in the VCV group than in the PCV and PCV-VG groups (p=0.011). Mean inspiratory pressure (Pmean) was higher in the PCV and PCV-VG groups than in the VCV group (p<0.001). Dynamic lung compliance (Cdyn) was lower in the VCV group than in the PCV and PCV-VG groups (p=0.001). Conclusion: Compared to VCV, PCV and PCV-VG provided lower Ppeak, higher Pmean, and improved Cdyn, without significant differences in hemodynamic variables or arterial blood gas results during robot-assisted laparoscopic gynecologic surgery with Trendelenburg position.

The effect of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) severity on cellular bioenergetic function.

Myalgic encephalomyelitis/ Chronic fatigue syndrome (ME/CFS) has been associated with abnormalities in mitochondrial function. In this study we have analysed previous bioenergetics data in peripheral blood mononuclear cells (PBMCs) using new techniques in order to further elucidate differences between ME/CFS and healthy control cohorts. We stratified our ME/CFS cohort into two individual cohorts representing moderately and severely affected patients in order to determine if disease severity is associated with bioenergetic function in PBMCs. Both ME/CFS cohorts showed reduced mitochondrial function when compared to a healthy control cohort. This shows that disease severity does not correlate with mitochondrial function and even those with a moderate form of the disease show evidence of mitochondrial dysfunction. Equations devised by another research group have enabled us to calculate ATP-linked respiration rates and glycolytic parameters. Parameters of glycolytic function were calculated by taking into account respiratory acidification. This revealed severely affected ME/CFS patients to have higher rates of respiratory acidification and showed the importance of accounting for respiratory acidification when calculating parameters of glycolytic function. Analysis of previously published glycolysis data, after taking into account respiratory acidification, showed severely affected patients have reduced glycolysis compared to moderately affected patients and healthy controls. Rates of ATP-linked respiration were also calculated and shown to be lower in both ME/CFS cohorts. This study shows that severely affected patients have mitochondrial and glycolytic impairments, which sets them apart from moderately affected patients who only have mitochondrial impairment. This may explain why these patients present with a more severe phenotype.

Respiratory acidosis during bronchoscopy-guided percutaneous dilatational tracheostomy: impact of ventilator settings and endotracheal tube size.

BACKGROUND: The current study investigates the effect of bronchoscopy-guided percutaneous dilatational tracheostomy (PDT) on the evolution of respiratory acidosis depending on endotracheal tube (ET) sizes. In addition, the impact of increasing tidal volumes during the intervention was investigated. METHODS: Two groups of ICU-patients undergoing bronchoscopy-guided PDT with varying tidal volumes and tube sizes were consecutively investigated: 6 ml/kg (N = 29, mean age 57.4 ± 14.5 years) and 12 ml/kg predicted body weight (N = 34, mean age 59.5 ± 12.8 years). RESULTS: The mean intervention time during all procedures was 10 ± 3 min. The combination of low tidal volumes and ETs of 7.5 mm internal diameter resulted in the most profound increase in PaCO2 (32.2 ± 11.6 mmHg) and decrease in pH-value (- 0.18 ± 0.05). In contrast, the combination of high tidal volumes and ETs of 8.5 mm internal diameter resulted in the least profound increase in PaCO2 (8.8 ± 9.0 mmHg) and decrease of pH (- 0.05 ± 0.04). The intervention-related increase in PaCO2 was significantly lower when using higher tidal volumes for larger ET: internal diameter 7.5, 8.0 and 8.5: P > 0.05, =0.006 and = 0.002, respectively. Transcutaneous PCO2 monitoring revealed steadily worsening hypercapnia during the intervention with a high correlation of 0.87 and a low bias of 0.7 ± 9.4 mmHg according to the Bland-Altman analysis when compared to PaCO2 measurements. CONCLUSIONS: Profound respiratory acidosis following bronchoscopy-guided PDT evolves in a rapid and dynamic process. Increasing the tidal volume from 6 to 12 ml/kg PBW was capable of attenuating the evolution of respiratory acidosis, but this effect was only evident when using larger ETs. TRIAL REGISTRATION: DRKS00011004 . Registered 20th September 2016.

Anesthesia for Pygopagus Conjoined Twins During Single-Twin and Simultaneous Pneumoperitoneum: A Case Report.

We present the case of the first stage of separation of 9-month-old pygopagus conjoined twins who demonstrated minimal shared vasculature on preoperative imaging and no cross-sedation or cross-neuromuscular blockade during separate inductions of anesthesia. Laparoscopy was implemented in 1 twin at a time, then in both twins simultaneously. Despite insufflation of a single-twin's abdomen, both twins demonstrated hypercapnia and signs of a concomitant respiratory acidosis because of carbon dioxide diffusion through a shared peritoneal membrane. This is the first documented case of simultaneous laparoscopy-induced pneumoperitoneum in pygopagus conjoined twins.

Noninvasive Ventilation as a Temporizing Measure in Critical Fixed Central Airway Obstruction: A Case Report.

BACKGROUND: Critical central airway obstruction (CAO) requires emergent airway intervention, but current guidelines lack specific recommendations for airway management in the emergency department (ED) while awaiting rigid bronchoscopy. There are few reports of the use of noninvasive ventilation (NIV) in tracheomalacia, but its use as a temporizing treatment option in fixed, malignant CAO has not, to the best of our knowledge, been reported. CASE REPORT: An 84-year-old woman presented to the ED in respiratory distress, too breathless to speak and using her accessory muscles of respiration, with bilateral rhonchi throughout the lung fields. Point-of-care arterial blood gas revealed severe hypercapnia, and NIV was initiated to treat a presumed bronchitis with hypercapnic respiratory failure. Chest radiography revealed a paratracheal mass with tracheal deviation and compression. A diagnosis of critical CAO was made. While arranging for rigid bronchoscopic stenting, the patient was kept on NIV to good effect. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Recommendations for emergent treatment of life-threatening, critical CAO before bronchoscopic intervention are not well established. Furthermore, reports of NIV use in CAO are rare. We suggest that emergency physicians consider NIV as a temporizing measure for critical CAO while awaiting availability of bronchoscopy.

[Impact of telmisartan on glomerular filtration in laparoscopic surgery. A double blinded randomised controlled study]. / Impacto de telmisartán en la filtración glomerular en cirugía laparoscópica. Estudio aleatorizado doble ciego.

BACKGROUND: Laparoscopic surgery has begun to replace a great number of procedures that were previously practiced using open or conventional techniques. This is due to the minimal invasion, small incisions, and short time recovery. However, it has come to knowledge, that the increase in intra-abdominal pressure due to carbon dioxide pneumoperitoneum during laparoscopic surgery causes cardiovascular, respiratory, endocrine, and renal alterations. OBJECTIVE: To evaluate the nephroprotective effect of telmisartan, an angiotensin II AT1 receptor antagonist, on glomerular filtration in laparoscopic surgery. MATERIAL AND METHODS: Analytical prospective, randomised, double-blind study was conducted on patients undergoing elective laparoscopic cholecystectomy. They were randomised into 2 groups, with the treatment group receiving a single dose of 40mg telmisartan orally 2hours prior to surgery, and the placebo group. RESULTS: There were 20 patients in each group (n=40), with a mean age of 32.65 years in the treatment group. Plasma creatinine did not show any significant change in the different time lapse in which blood samples were taken, but creatinine clearance at the end of surgery (196.415±56.507 vs. 150.1995±75.081; p=0.034), and at 2 h postoperative period (162.105±44.756 vs. 113.235±31.228; p≤0.001) was statistically significant, which supports an increase in renal function in the telmisartan group. CONCLUSION: The use of telmisartan, an angiotensin II AT1 receptor antagonist, offers renal protection during laparoscopic surgery.

Effect of lung-protective ventilation-induced respiratory acidosis on the duration of neuromuscular blockade by rocuronium.

PURPOSE: The purpose of this study was to elucidate whether lung-protective ventilation-induced respiratory acidosis increased the duration of neuromuscular blockade by rocuronium. METHODS: A total of 72 patients were enrolled. After the induction of general anesthesia, rocuronium 0.6 mg/kg real body weight was administered. Tidal volume and positive end-expiratory pressure were randomly assigned as either 10 ml/kg predicted body weight and 0 cmH2O (group S) or 6 ml/kg and 5 cmH2O (group L), respectively. Respiratory rate was started at 10/min. Neuromuscular blockade was monitored by acceleromyography at the adductor pollicis with train-of-four stimulation. The time from the initial bolus injection of rocuronium to first recovery of the first twitch was defined as DUR1. Immediately, rocuronium 0.15 mg/kg was administered. The time from first recovery of the first twitch to second recovery of the first twitch was defined as DUR2. We also measured arterial pH (pH1 and pH2, respectively). RESULTS: Data from 66 patients (33 each in groups L and S) were eventually available. pH1 and pH2 were significantly lower in group L compared with group S [pH1: 7.308 (7.288-7.334) vs. 7.439 (7.423-7.466); p < 0.01, pH2: 7.306 (7.285-7.330) vs. 7.453 (7.436-7.476); p < 0.01]. DUR1 and DUR2 were significantly prolonged in group L compared with group S [DUR1: 31 (24-36) vs. 24 (20-30) min; p = 0.029, DUR2: 19 (15-22) vs. 15 (12-17) min; p = 0.020]. CONCLUSIONS: Lung-protective ventilation-induced respiratory acidosis increased the duration of neuromuscular blockade by rocuronium.

The Effects of Lung Protective Ventilation or Hypercapnic Acidosis on Gas Exchange and Lung Injury in Surfactant Deficient Rabbits.

BACKGROUND: Permissive hypercapnia has been shown to reduce lung injury in subjects with surfactant deficiency. Experimental studies suggest that hypercapnic acidosis by itself rather than decreased tidal volume may be a key protective factor. OBJECTIVES: To study the differential effects of a lung protective ventilatory strategy or hypercapnic acidosis on gas exchange, hemodynamics and lung injury in an animal model of surfactant deficiency. METHODS: 30 anesthetized, surfactant-depleted rabbits were mechanically ventilated (FiO2 = 0.8, PEEP = 7cmH2O) and randomized into three groups: Normoventilation-Normocapnia (NN)-group: tidal volume (Vt) = 7.5 ml/kg, target PaCO2 = 40 mmHg; Normoventilation-Hypercapnia (NH)-group: Vt = 7.5 ml/kg, target PaCO2 = 80 mmHg by increasing FiCO2; and a Hypoventilation-Hypercapnia (HH)-group: Vt = 4.5 ml/kg, target PaCO2 = 80 mmHg. Plasma lactate and interleukin (IL)-8 were measured every 2 h. Animals were sacrificed after 6 h to perform bronchoalveolar lavage (BAL), to measure lung wet-to-dry weight, lung tissue IL-8, and to obtain lung histology. RESULTS: PaO2 was significantly higher in the HH-group compared to the NN-group (p<0.05), with values of the NH-group between the HH- and NN-groups. Other markers of lung injury (wet-dry-weight, BAL-Protein, histology-score, plasma-IL-8 and lung tissue IL-8) resulted in significantly lower values for the HH-group compared to the NN-group and trends for the NH-group towards lower values compared to the NN-group. Lactate was significantly lower in both hypercapnia groups compared to the NN-group. CONCLUSION: Whereas hypercapnic acidosis may have some beneficial effects, a significant effect on lung injury and systemic inflammatory response is dependent upon a lower tidal volume rather than resultant arterial CO2 tensions and pH alone.

Low-flow veno-venous extracorporeal CO2 removal: first clinical experience in lung transplant recipients.

BACKGROUND: Low-flow extracorporeal CO2 removal devices are easy to setup and manage and may provide valuable ventilation support. METHODS: We employed a new device (ProLUNG) recently introduced into the clinical arsenal that exploits a simple hemoperfusion technique sustained by blood flows lower than 500 ml/min to remove CO2 from the venous blood. It was used as an adjunctive support to mechanical ventilation during and after four lung transplantations in our center. RESULTS: Two patients with cystic fibrosis, one with pulmonary fibrosis, and one with emphysema were included. They underwent lung transplantation and presented hypercapnia and respiratory acidosis before, during, or after the surgical procedure. After 1 h of treatment with the ProLUNG circuit, all patients showed reduced CO2 levels and increased pH; these variables remained stable until the end of treatment. CONCLUSIONS: Our data suggest that this new device is effective in removing CO2 and stabilizing the pH.

Extracorporeal membrane oxygenation can provide cardiopulmonary support during bronchoscopic clearance of airways after sand aspiration.

BACKGROUND: Sand aspiration occurs in situations of cave-in burial and near-drowning. Sand in the tracheobronchial airways adheres to the mucosa and can cause tracheal and bronchial obstruction, which can be life-threatening even with intensive management. In previous case reports of airway obstruction caused by sand aspiration, fiber optic or rigid bronchoscopy has been effective in removing loose sand, but removal of sand particles lodged in smaller airways has proven challenging and time-consuming. CASE REPORT: In this case report of sand aspiration with acute pulmonary failure, the use of extracorporeal membrane oxygenation for respiratory support allowed more effective removal of sand particles by rigid bronchoscopy and lavage with less patient compromise. CONCLUSION: Our case of sand aspiration is unique in that the patient presents with complex medical problems (mixed respiratory and metabolic acidosis), hypothermia, hypoxemia, and neoplastic conditions. The fact that she survived the sand aspiration and a long inter-hospital transport time (90 min) with inadequate ventilation and oxygenation without apparent ill effects suggests that the measures we took to resuscitate her and extract the sand from her airways were reasonable and appropriate.

Efficacy of high-flow oxygen by nasal cannula with active humidification in a patient with acute respiratory failure of neuromuscular origin.

The treatment of choice for patients with respiratory failure of neuromuscular origin, especially in patients with hypercapnic respiratory acidosis, is noninvasive ventilation (NIV). Endotracheal intubation and invasive ventilation are indicated for patients with severe respiratory compromise or failure of NIV. In recent years, high-flow oxygen therapy and active humidification devices have been introduced, and emerging evidence suggests that high-flow oxygen may be effective in various clinical settings, such as acute respiratory failure, after cardiac surgery, during sedation and analgesia, in acute heart failure, in hypoxemic respiratory distress, in do-not-intubate patients, in patients with chronic cough and copious secretions, pulmonary fibrosis, or cancer, in critical areas and the emergency department. We report on a patient with amyotrophic lateral sclerosis who arrived at the emergency department with acute hypercapnic respiratory failure. She did not tolerate NIV and refused intubation, but was treated successfully with heated, humidified oxygen via high-flow nasal cannula. Arterial blood analysis after an hour on high-flow nasal cannula showed improved pH, P(aCO2), and awareness. The respiratory acidosis was corrected, and she was discharged after 5 days of hospitalization. Her response to high-flow nasal cannula was similar to that expected with NIV. We discuss the mechanisms of action of heated, humidified high-flow oxygen therapy.

Bilineal inheritance of PKD1 abnormalities mimicking autosomal recessive polycystic disease.

BACKGROUND: Dominant polycystic kidney disease is common and usually presents clinically in adulthood. Recessive polycystic kidney disease is much less common and frequently presents antenatally or in the neonatal period with severe renal involvement. These are usually thought of as clinically distinct entities but diagnostic confusion is not infrequent. CASE-DIAGNOSIS/TREATMENT: We describe an infant with antenatally diagnosed massive renal enlargement and oligohydramnios with no resolvable cysts on ultrasound scanning. He underwent bilateral nephrectomy because of respiratory compromise and poor renal function but died subsequently of overwhelming sepsis. Genetic analysis revealed that he had bilineal inheritance of abnormalities of PKD1 and no demonstrable abnormalities of PKD2 or PKHD1. CONCLUSIONS: Biallelic inheritance of abnormalities of PKD1 may causextremely severe disease resembling autosomal recessive polycystic kidney disease (ARPKD) which can result indiagnostic confusion. Accurate diagnosis is essential forgenetic counseling [corrected].

Hypercapnic acidosis transiently weakens hypoxic pulmonary vasoconstriction without affecting endogenous pulmonary nitric oxide production.

PURPOSE: Hypercapnic acidosis often occurs in critically ill patients and during protective mechanical ventilation; however, the effect of hypercapnic acidosis on endogenous nitric oxide (NO) production and hypoxic pulmonary vasoconstriction (HPV) presents conflicting results. The aim of this study is to test the hypothesis that hypercapnic acidosis augments HPV without changing endogenous NO production in both hyperoxic and hypoxic lung regions in pigs. METHODS: Sixteen healthy anesthetized pigs were separately ventilated with hypoxic gas to the left lower lobe (LLL) and hyperoxic gas to the rest of the lung. Eight pigs received 10% carbon dioxide (CO(2)) inhalation to both lung regions (hypercapnia group), and eight pigs formed the control group. NO concentration in exhaled air (ENO), nitric oxide synthase (NOS) activity, cyclic guanosine monophosphate (cGMP) in lung tissue, and regional pulmonary blood flow were measured. RESULTS: There were no differences between the groups for ENO, Ca(2+)-independent or Ca(2+)-dependent NOS activity, or cGMP in hypoxic or hyperoxic lung regions. Relative perfusion to LLL (Q (LLL)/Q (T)) was reduced similarly in both groups when LLL hypoxia was induced. During the first 90 min of hypercapnia, Q (LLL)/Q (T) increased from 6% (1%) [mean (standard deviation, SD)] to 9% (2%) (p < 0.01), and then decreased to the same level as the control group, where Q (LLL)/Q (T) remained unchanged. Cardiac output increased during hypercapnia (p < 0.01), resulting in increased oxygen delivery (p < 0.01), despite decreased PaO(2) (p < 0.01)(.) CONCLUSIONS: Hypercapnic acidosis does not potentiate HPV, but rather transiently weakens HPV, and does not affect endogenous NO production in either hypoxic or hyperoxic lung regions.