Nasopharyngeal Oxygen Research Articles

Role of modified nasopharyngeal oxygen therapy in apnoeic oxygenation under general anaesthesia: a single-centre, randomized controlled clinical study

Apnoeic oxygenation is not only important for patients who cannot be intubated/ventilated, but also can be routinely employed when planning to secure the airway.We aimed to compare safe apnoea times between patients receiving modified nasopharyngeal oxygen therapy and those receiving high-flow nasal oxygen therapy (HFNO) following the induction of general anaesthesia.This was a single-centre, randomized controlled clinical study. Eighty-four female patients undergoing elective laparoscopic gynaecological surgery under general anaesthesia were randomly assigned to the high-flow nasal oxygen therapy group (Group HFNO) or the modified nasopharyngeal oxygen therapy group (Group Naso). A Kaplan–Meier survival curve was used to describe the apnoeic oxygenation time.The safe apnoea time of the patients in the Group Naso was higher than that of the patients in the Group HFNO (20 (19.3 to 20.0) vs. 16.5 (12.9 to 20) minutes, P < 0.05). The incidence of SpO2 < 95% in the Group Naso was lower than that in the Group HFNO; hazard ratio 0.3 (95% confidence interval 0.2 to 0.6, P < 0.0001). Modified nasopharyngeal oxygen therapy which uses far less oxygen than HFNO is a convenient and effective method of apnoeic oxygenation in normal female patients.Trial registration: https://www.chictr.org.cn, ChiCTR2000039433; date of registration: 28/10/2020.

Long-term management and outcomes of tracheobronchial stent by flexible bronchoscopy in infants

Tracheobronchial (TB) lumen narrowing may require prolonged positive-pressure ventilation, endotracheal tube intubation or even surgical interventions. Therapeutic flexible bronchoscopy (TFB) of balloon-expandable metallic stent (BEMS) placement and subsequent forceps, laser and balloon dilatation management might be less invasive and helpful. This study aimed to analyse the placement, follow-up management with TFB and long-term outcomes in small infants with BEMS. This retrospective study reviewed the medical records and associated TFB videos of infants with a maximum body weight (BW) of 5.0 kg who had TB BEMS placement from January 2005 to December 2017 at our institution. All TFB procedures were supported with a novel noninvasive ventilation, nasopharyngeal oxygen with intermittent nose closure and abdominal compression. Forty-one BEMSs were placed in 24 infants. The mean BW and mean age were 4.0 ± 0.7 kg and 4.9 ± 2.4 months, respectively. There were 20, 8 and 13 stents located in trachea, carina and main-stem bronchi, respectively. Seven infants with 13 stents died without obvious stent-related mortality. Seven stents in five infants were successfully retrieved by rigid endoscopy (RE). At placement, the diameters of 28 tracheal and 21 bronchial stents were 7.5 ± 1.1 (4-10) and 5.4 ± 0.9 (4-8) mm, respectively. These implanted BEMSs could be gradually and significantly (p < 0.01) expanded. At the end of the follow-up period, all the remaining 21 stents in 12 infants were functional. The diameters of the 14 remaining tracheal and 13 remaining bronchial stents were 9.6 ± 2.0 (8-14) and 7.2 ± 1.4 (4-10) mm, respectively. BEMSs are practical and effective in selected small infants with benign TB narrowing and can be safely implanted and managed with TFB, and finally retrieved by RE.

Magnitude of Airway Problems at a University Teaching and Referral Hospital Recovery Room of Low Resource Setting-A Cross Sectional Study

Background: Airway management is a basic life-saving intervention which is used when the patient’s breathing effort is compromised due to various reasons. Postsurgical patients are at risk of developing airway problems due to co-morbidities, intraoperative complications, surgery and anaesthetic drug effects. The severity of illness, analgesic drugs like narcotics and postoperative standard of monitoring may impact on breathing process of the patients. We aimed to assess the magnitude of airway problems at the recovery room. Methods and material: Cross sectional study conducted at a referral hospital recovery room, 2014. Standardized checklist used for data collection. All patients with airway problem who admitted at the recovery room during the study period were included in the study. Descriptive statistics and Chi-square were used. Results: One hundred seventy seven patients developed airway problems over five months duration. Of these, 47.5%, 32.2%, and 20.3% patients developed mild, moderate and severe airway problems respectively. The major airway problems were desaturation (62.7%), respiratory arrest (14.7%), aspiration (18.1%), bronchospasm (3.4%) and laryngospasm (1.1%) respectively. Factors associated with severity of airway problems were ASA status (P=0.031), type of trauma (P=0.026), intraoperative analgesia (P=0.020) and type of patient (P=0.049). The interventions made were ETTI or LMA (35%) patients, nasopharyngeal airway insertion (21.5%), oral airway (14.1%), oxygen supplementation (10.2%), surgical airway (9.6%), recovery position (7.3%) and emergency airway manoeuvre (2.3%) respectively. Anaesthetists involved in airway management in 30.5% of patients. Conclusion: The magnitude of airway problem was high. We recommend the availability of well trained staff for airway management and fulfilment of basic equipments and drugs for patient monitoring and resuscitation. High airway problems are an alarm for the need for well-equipped recovery room with well trained staff, patient monitoring and resuscitation materials.

Four vital capacity breaths can delay the onset of haemoglobin desaturation following nasopharyngeal oxygen insufflation

Four vital capacity breaths can delay the onset of haemoglobin desaturation following nasopharyngeal oxygen insufflation

Retrieval of tracheobronchial foreign bodies by short flexible endoscopy in children

ObjectivesFlexible endoscopy (FE) is frequently used to diagnose tracheobronchial foreign bodies (TBFB). However, it is still controversial for retrieval of TBFB in pediatric field. This study aims at reporting and evaluating our experiences of using short-length FE with a non-invasive ventilation (NIV) technique and intensive care unit (ICU) support in retrieving pediatric TBFB. MethodsA retrospective review of the hospital database and FE videos of pediatric patients aged less than 18 year-old who were diagnosed of TBFB and managed in our hospital over a 17-year period (1999–2015). The demographic data were collected and analyzed. A NIV technique of providing nasopharyngeal oxygen with intermittent nose closure and abdominal compression was routinely performed in procedural sedated patients throughout the whole FE procedures. ResultsSixty-six consecutive patients with 76 TBFB were enrolled. Among them, 72 (94.7%) TBFB in 64 patients were successfully retrieved at the first attempt of FE immediately after the diagnosis was made. There were 13 iatrogenic TBFB in patients who already had coexisting airway problems. The median age was 16 months (range 1.5 months–17 years) and the median body weight was 10.5 kg (range 3.5–48.5 kg). Seventy (70/72, 97.2%) TBFB were retrieved by short-length FE and among them, 55 procedures (55/72, 76.4%) used FE with no working channel. No significant acute or late adverse effects were noted. The mean retrieval procedural time was 23.6 ± 15.1 min. ConclusionUsing short-length FE with this NIV technique, appropriate sedation and ICU support is a safe, simple and effective modality for the retrieval of TBFB immediately after confirming the diagnosis in pediatric patients.

Randomized trial of a novel double lumen nasopharyngeal catheter versus traditional nasal cannula during total intravenous anesthesia for gastrointestinal procedures

Study objectivePatients undergoing general anesthesia routinely experience episodes of hypoxemia. There are multiple causes of procedural oxygen desaturation including upper airway obstruction and central hypoventilation. We hypothesize that oxygen supplementation via nasopharyngeal catheter (NPC) will decrease the number of episodes of hypoxemia as compared to traditional NC oxygen supplementation in patients undergoing general anesthesia provided by an anesthesia provider for gastrointestinal endoscopy procedures. DesignRandomized control trial. SettingEndoscopy suite. PatientsSixty patients undergoing intravenous general anesthesia for endoscopic gastrointestinal procedures that did not require endotracheal intubation were enrolled. InterventionsPatients were randomized to receive supplemental oxygen by either a standard nasal cannula or a nasopharyngeal catheter. Initial oxygen flow rate was 4l/min and titrated at the anesthesia provider's discretion. Intravenous anesthetic consisted of a propofol infusion. MeasurementsHypoxemia was defined as a pulse oximetry reading of <92%. Secondary outcomes included number of airway assist maneuvers such as jaw lift or other airway interventions. Main resultsOf the 60 enrolled patients; three subjects in the NPC group were excluded from further analysis. There was no difference between group in age, ASA classification, Body Mass Index, oropharyngeal classification or total propofol dose.Patients who received nasopharyngeal oxygen supplementation were less likely to experience a clinically significant oxygen desaturation event 3 of 27 (11.0%) versus 12 of 30 subjects (40.0%), p=0.013. Interventions to assists with airway management were required for fewer patients in the NPC group 4 (14.8%) versus the NC group, 17 (56.7%), p=0.001. ConclusionOxygen supplementation via a nasopharyngeal catheter during intravenous general anesthesia resulted in significantly fewer episodes of hypoxemia and number of airway assist maneuvers. Future studies are needed to assess the utility of NPC in other clinical environments where supplemental oxygen is required in the setting of potential airway obstruction.

Nasopharyngeal oxygen with intermittent nose-close and abdomen-compression: A novel resuscitation technique in a piglet model

To evaluate the efficacy of a simple and novel cardiopulmonary resuscitation (CPR) technique, nasopharyngeal oxygen with intermittent nose-close and abdomen-compression (NPO(2) -NC-AC) in an animal model. Prospective piglet study. In an animal physiology laboratory of a medical university. PIGLETS: Six healthy piglets <14 days old. Spontaneous breathing of the anesthetized piglets (n = 6) was medically ceased until severe bradycardia (<20 beat/min). NPO(2) -NC-AC CPR trial was then initiated by delivering NPO(2) at 1.0-1.5 L/kg/min and intermittently performing the NC-AC maneuver: (1) NC for inspiration, occluded nostrils for 1 sec; and (2) AC for expiration, released nostrils, and compressed the abdomen for 1 sec. NC-AC was repeated at a rate of 30/min for 5 min. This CPR trial was repeated three times in each piglet. Cardiopulmonary variables were monitored, recorded, and compared. A total of 18 CPR trials were performed. All of these acute life-threatening asphyxia events rapidly improved within 1 min of CPR. Cardiopulmonary variables recovered to the baseline levels and oxygenation continually increased. The intratracheal pressure (P(tr) ) values of positive end expiratory pressure and peak inspiratory pressure values were 4.3 ± 0.8 cmH(2) O and 26.2 ± 4.1 cmH(2) O, respectively. Chest wall movement was observed when the P(tr) reached 17.5 ± 3.1 cmH(2) O. All six piglets fully recovered after 63.8 ± 7.2 min of experiment without additional support. NPO(2) -NC-AC is a simple and effective CPR technique for severe acute cardiopulmonary asphyxia in piglets. It may be clinically applicable for supportive or rescue use.

Comparison between rigid and flexible laser supraglottoplasty in the treatment of severe laryngomalacia in infants

Objective Traditionally, laser supraglottoplasty for the treatment of severe laryngomalacia (SLM) is via rigid endoscopy (RE). Potassium-titanyl-phosphate (KTP) laser fiber can pass through a flexible endoscopy (FE) and cauterize tissue. This study is designed to evaluate and compare clinical variables between these two techniques in the treatment of SLM in infants. Methods A retrospective study includes four-year period of consecutive infants who received laser supraglottoplasty. In the first two years (2006–2007), conventional RE CO 2-laser with general anesthesia and endotracheal intubation were used. In the latter two years (2008–2009), a novel technique of FE KTP-laser with intravenous sedation, nasopharyngeal oxygen and a noninvasive respiratory support (if indicated), without any artificial airway was used immediately after the diagnostic FE. After laser surgery, infants were followed for three months. Clinical variables were analyzed and compared. Results A total of 57 infants (27 in RE group, 30 in FE group) were enrolled. Basic variables were similar between both groups. Clinical improvement was comparable with 88.9% and 93.3% in the RE and FE groups, respectively. There are no significant differences in mean number of laser surgery, major complications, duration of post-laser respiratory support and hospitalization days, body weight percentile between the two groups. However, the durations of waiting time, operation, ET intubation and total hospital days were significantly less in the FE group. Conclusions FE technique has similar success rate but more convenient and cost-effective than the RE technique. It may to be a practical alternative therapy for infants with SLM.

Response to nasopharyngeal oxygen administration in horses with lung disease

Guidelines for administration of oxygen to standing horses are unavailable because previous investigations of the efficacy of oxygen administration to increase arterial oxygenation in standing horses have produced equivocal results. To determine the effect of nasal oxygen supplementation on inspired and arterial blood gas tensions in control horses and those with moderate to severe recurrent airway obstruction (RAO). Normal horses (n = 6) and horses during an attack of RAO induced by stabling (n = 6) were studied. Oxygen was administered through either one or 2 cannulae, passed via the nares into the nasopharynx to the level of the medial canthus of each eye. Intratracheal inspired oxygen and carbon dioxide concentration and arterial blood gas tensions were measured at baseline and during delivery of 5, 10, 15, 20 and 30 l/min oxygen. Nasal cannulae and all but the highest oxygen flow rates were well tolerated. Fractional inspired oxygen concentration (F(I)O2) increased with flow but was significantly lower at all flow rates in horses with RAO compared with controls. Arterial oxygen tension (PaO2) was significantly increased (P < 0.001) by all flow rates, but was always lower in RAO-affected animals. At 30 l/min, PaO2 increased to 319 +/- 31 mmHg in control horses and 264 +/- 69 mmHg in horses with RAO. Additionally, a large arterial to end-tidal gradient for CO2 in RAO-affected horses was observed, indicating increased alveolar deadspace ventilation in these animals. The use of nasal cannulae to deliver oxygen effectively increases both F(I)O2 and PaO2 in horses with moderate to severe RAO. Oxygen flow rates up to 20 l/min are well tolerated, but flow rates of 30 l/min produce occasional coughing or gagging. Oxygen therapy delivered by means of an intranasal cannula is a highly effective means of increasing arterial oxygen tension in horses with respiratory disease. Generally, flows of 10-20 l/min should be effective. If higher flows (20-30 l/min) are necessary, they should be delivered by means of 2 cannulae.

Fatal pneumoperitoneum caused by nasopharyngeal oxygen delivery after transoesophageal echocardiography for cardiac surgery

We report a case of fatal post-operative pneumoperitoneum in a patient who had undergone urgent mitral valve surgery. In the absence of a proven cause of the pneumoperitoneum (refusal by the family of an autopsy), we can only propose a hypothesis for its origin. The most probable one is that forceful or sustained retrograde flexion of the transoesophageal echocardiographic probe created a lower oesophagus or gastric rupture and that oxygen flow administered by the nasal cannula went straight to the abdominal cavity, leading to tension pneumoperitoneum.

Evaluation of Nasopharyngeal Oxygen, Nasal Prongs and Facemask Oxygen Therapy Devices in Adult Patients: A Randomised Crossover Trial

Nasopharyngeal oxygen (NPO) therapy may overcome some of the difficulties associated with nasal prongs and facemask oxygen delivery devices. In response to a lack of published studies of NPO therapy in adults, we conducted a prospective randomised crossover trial to compare the effectiveness of NPO, nasal prongs (NP) and facemasks (FM) when used in an adult population (n = 37) from the intensive care unit and general hospital wards. We measured oxygen saturation (SpO2) using pulse oximetry, oxygen flow (litres per minute), respiration rate (per minute) and comfort using a horizontal visual analogue scale. All three devices were effective in maintaining a SpO2 of > or = 95% (NP 97.0 +/- 1.9, NPO 97.7 +/- 1.7, FM 98.8 +/- 1.3%). NPO therapy consumed less oxygen than NP and FM therapy (NP 2.6 +/- 1.0, NPO 2.2 +/- 0.9, FM 6.1 +/- 0.4 l/min, P < 0.001). There was no significant difference in patients' respiratory rates (NP 19.9 +/- 3.2, NPO 19.9 +/- 3.0, FM 19.8 +/- 3.1 per minute, P = 0.491). In terms of comfort, patients rated NP higher than NPO and FM using a horizontal visual analogue scale (100 mm = most comfortable) (NP 65.5 +/- 14.3, NPO 62.8 +/- 19.4, FM 49.4 +/- 21.4 mm, P < 0.001). We conclude that for adult patients, nasal prongs and nasopharyngeal oxygen therapy consume less oxygen and provide greater comfort than facemasks while still maintaining SpO2 > or = 95%.

Supplementation of pre‐oxygenation in morbidly obese patients using nasopharyngeal oxygen insufflation

During apnoea following induction of anaesthesia, morbidly obese patients may suffer a rapid decrease in oxygen saturation. This study compares pre-oxygenation alone with pre-oxygenation followed by nasopharyngeal oxygen insufflation on the onset of desaturation occurring during the subsequent apnoea. A randomised controlled trial was performed in 34 morbidly obese patients undergoing gastric bypass or gastric band surgery. Seventeen patients received nasopharyngeal oxygen supplementation following pre-oxygenation (Study group, body mass index = 41.8 (6.9) kg.m(-2)), and the other 17 patients received pre-oxygenation alone (Control group, body mass index = 42.7 (5.4) kg.m(-2)). Time from the onset of apnoea until S(p)o(2) fell to 95% was compared between the two groups with a cut-off of 4 min. In the control group, the S(p)o(2) fell from 100% to 95% during the subsequent apnoea in 145 (27) s, with a significantly negative correlation (r(2) = 0.66, p < 0.05) between the time to desaturation to 95% and the body mass index. In the study group, the S(p)o(2) was maintained in 16 of 17 patients at 100% for 4 min when apnoea was terminated. In conclusion, nasopharyngeal oxygen insufflation following pre-oxygenation in morbidly obese patients delays the onset of oxyhaemoglobin desaturation during the subsequent apnoea.

Effect of Nasopharyngeal Oxygen Insufflation on Time-to-Hypoxia

Airway management, particularly rapid sequence intubation, relies on effective preoperative oxygenation. Preoxygenation denitrogenates the functional

Nasopharyngeal oxygen insufflation following pre‐oxygenation using the four deep breath technique

This paper evaluates the effectiveness of nasopharyngeal oxygen insufflation following preoxygenation using the four deep breath technique within 30 s, on the onset of haemoglobin desaturation during the subsequent apnoea. Thirty ASA I or II patients were randomly allocated to one of two groups. In the study group (n = 15), pre-oxygenation was followed by insufflation of oxygen at a flow of 5 l.min(-1) via a nasopharyngeal catheter commenced at the onset of apnoea. In the control group, pre-oxygenation was not followed by nasopharyngeal oxygen insufflation (n = 15). In the control group, SpO2 fell to 95% within a mean (SD) apnoea time of 3.65 (1.15) min, whereas in the study group, SpO2 was maintained in all patients at 100% throughout the 6 min of apnoea, at which point apnoea was terminated and positive pressure ventilation commenced. We conclude that nasopharyngeal oxygen insufflation following pre-oxygenation using the four deep breath technique can delay the onset of haemoglobin desaturation for a significant period of time during the subsequent apnoea.

Nasopharyngeal oxygen (NPO) as a safe and comfortable alternative to face mask oxygen therapy

Nasopharyngeal oxygen (NPO) therapy is an emerging alternative to conventional face mask oxygen administration. It warrants consideration for treating hypoxaemia when face mask therapy is impractical or when patient intolerance or non-compliance regularly interrupt treatment. The effectiveness of the NPO route has been validated in post anaesthetic care and paediatric intensive care units (PICUs), but use in the adult ICU remains minimal. Recent research in the adult ICU setting 1 has shown the nasopharyngeal route to be as effective as face mask oxygen administration in alleviating mild to moderate hypoxaemia, and is significantly more comfortable for patients. Therefore, NPO, administered via a fine catheter advanced into the nasopharynx, should be considered when face masks (FMs) or nasal prongs (NPs) are impractical or poorly tolerated and, because of its effectiveness and improved comfort, in patients for whom traditional non-invasive oxygen therapy is indicated. Implications for resource utilisation and costs also exist.

Nasopharyngeal Oxygen in Adult Intensive Care—Lower Flows and Increased Comfort

Nasopharyngeal oxygen therapy, the delivery of supplementary oxygen into the nasopharynx via a fine catheter placed through the nose, is a simple technique used in postoperative anaesthetic care units and paediatric intensive care, but never described in the setting of adult intensive care. In a prospective crossover design, we compared nasopharyngeal oxygen therapy with semi-rigid plastic mask (Hudson Mask) in 50 unintubated adult patients receiving supplemental oxygen. We measured oxygen flow rate to achieve cutaneous saturations 93 to 96%, and patient comfort by visual analogue score. Nasopharyngeal oxygen therapy consumed significantly less oxygen than mask administration (3.0+/-0.9 vs 6.7+/-2.1 l/min, P<0.001) and was associated with significantly higher comfort than the mask (7.5+/-1.6 cm vs 5.2+/-1.8, P<0.001).

Nasopharyngeal oxygen therapy produces positive end-expiratory pressure in infants.

The World Health Organisation recommends nasopharyngeal catheters as a safe and efficient method of oxygen administration in infants. However, little is known about the mechanisms of the improvement in oxygenation. The aim of the present study was to determine whether nasopharyngeal oxygen therapy produces positive end-expiratory pressure (PEEP). Nine spontaneously breathing infants (median age 13 months, range 10 days to 20 months) after heart surgery were investigated. All patients had normal pulmonary blood flow at the time of the study (Qp:Qs=1:1). Oxygen (oxygen fraction 1.0) was delivered by an 8 F catheter inserted into the nasopharynx (tip just visible below the soft palate). The pulmonary mechanics were analysed using a single compartment model of the respiratory system. Oesophageal pressure (Pes) at end-expiration, dynamic lung compliance (C(L)) and resistance (R(L)), minute ventilation, PaCO2 and PaO2 were measured at baseline without a nasopharyngeal catheter or oxygen, and at oxygen flows of 0.5 l/min, 1.0 l/min and 2.0 l/min. All the flows generated significant increases in PEEP. Mean difference in PEEP (SD, paired t-test versus baseline): 1.6 cm H2O (1.4, P=0.008) with 0.5 l/min of oxygen; 2.8 cm H2O (2.7, P=0.014) with 1.0 l/min of oxygen; and 4.0 cm H2O (2.9, P = 0.004) with 2.0 l/min of oxygen. There was a significant correlation between all the nasopharyngeal flows (in ml/kg per min) and the generated PEEP (P<0.001) and between the C(L) values and the generated PEEP (P < 0.05). There was no significant difference in PaCO2 and R(L). Minute ventilation was significantly less with nasopharyngeal oxygen than at baseline. As expected, PaO2 increased significantly with increasing oxygen flows. Administration of oxygen through an 8 F nasopharyngeal catheter at flow rates recommended by the World Health Organisation (0.5 l/min in newborns, 1.0 l/min in infants) produces moderate amounts of positive end-expiratory pressure. The levels achieved may contribute to an improvement in oxygenation by altering the visco-elastic properties of the lung.

Tension pneumo‐orbitus and pneumocephalus induced by a nasal oxygen cannula: Report on two paediatric cases

The present paper highlights the potential dangers of misplaced nasopharyngeal oxygen cannulae causing secondary pneumo-orbitus and pneumocephalus in two paediatric patients. While this complication is uncommon, early recognition allows prompt and appropriate intervention, with cessation of nasal oxygen, cannula removal, early investigation with computed tomography (CT) head/orbit scan and orbital or cranial decompression, if required. Early CT imaging identifies medial orbital or paranasal sinus fractures, the presence of sinusitis, associated intracranial air and assessment of the degree of orbital or intracranial tension. Antibiotics are not usually required for this type of clean injury unless pre-existing sinusitis is identified. In both cases, direct orbital decompression was performed with excellent results after identification of marked unilateral tense exophthalmos, delayed pupillary reactions to light and ophthalmopegia.

Oxygenation during local anaesthesia for cataract surgery

The oxygenation of 48 elderly patients scheduled for cataract surgery under local anaesthesia was studied using pulse oximetry and nasopharyngeal oxygen measurement. After a control period the patients breathed supplemental oxygen 2 l/min and later 4 l/min, via either a face mask or a nasal catheter. The effects of the two oxygen flow levels and oxygen delivery methods on oxygenation were assessed. The lowest oxygen saturation values were seen after retrobulbar block before the patients were transferred to the operating room. The surgical draping did not cause hypoxaemia and the 2 l/min oxygen flow was sufficient to cause hyperoxaemia in all patients. The face mask and nasal catheter appeared to be equally good in oxygenating the patients.

Pneumocephalus caused by a nasopharyngeal oxygen catheter

Many patients on spontaneous breathing require extra oxygen. This can be administered by several methods. One common method is via a nasopharyngeal catheter introduced through one nostril. An unusual and serious complication of this is described