April 2021 Critical Care Case of the Month: Abnormal Acid-Base Balance in a Post-Partum Woman

Mohammad Abdelaziz Mahmoud, MD, DO

Andrea N. Pruett, BS

Emanuel Medical Center

Turlock, CA 95382

History of Present Illness

A 29-year-old healthy woman, who is 8 weeks postpartum, presented to the emergency department with severe shortness of breath, fast shallow breathing, nausea, several episodes of nonbloody nonbilious emesis, abdominal pain and malaise for 1 week. The patient delivered a healthy boy at full-term by spontaneous vaginal delivery. Her pregnancy was uneventful. She denied smoking or use of alcohol.

Physical Exam

On presentation to the emergency department her blood pressure was found to be 121/71, temperature 36.8°C, pulse 110 beats per minute, respiratory rate 20 breaths per minute and SpO2 saturation of 99% while breathing ambient air. Physical exam was remarkable except for dry mucous membranes, sinus tachycardia, and tachypnea with mild epigastric tenderness with light palpation.

Which of the following should be done? (Click on the correct answer to be directed to the second of five pages)

1. Complete blood count (CBC)
2. Metabolic panel
3. Chest x-ray
4. Arterial blood gases (ABGs)
5. All of the above

Cite as: Mahmoud MA, Pruett AN. April 2021 Critical Care Case of the Month: Abnormal Acid-Base Balance in a Post-Partum Woman. Southwest J Pulm Crit Care. 2021;22(4):81-85. doi: https://doi.org/10.13175/swjpcc007-21 PDF.

First-Attempt Endotracheal Intubation Success Rate Using A Telescoping Steel Bougie

Evan D. Schmitz, MD

La Jolla, CA USA

Kevin Park, MD, MBA, FCCP 

MLK Community Medical Group

Compton, CA USA 

Abstract

Background

There has been a renewed interest in using the plastic intubation bougie to facilitate first-attempt endotracheal intubation success. The sterile single-use telescopic steel bougie (AIROD) was invented to overcome the limitations of the plastic bougie which is easily deformed during storage.  

Methods

This is a retrospective study involving critically ill patients who were intubated with the AIROD in the intensive care unit at a single institution. The purpose of this case series is to compare the success rate of the AIROD to the generally accepted success rate for the traditional plastic bougie of 96%.

Results

A total of 54 patients were enrolled at a single ICU over a 10 months period. All patients were critically ill with 76% having a difficult airway, Cormack-Lehane grade view 2 or greater in 60%, and ARDS secondary to COVID-19 in 54%. The primary outcome of first-attempt intubation success in critically ill patients intubated in the ICU with the AIROD was 97% with a 95% confidence interval of 0.89 to 0.99. The average time for intubation of all airway classifications was 15 seconds.

Conclusion

The AIROD first-attempt intubation success rate was found to be similar to the rate for the traditional plastic bougie.

Introduction

The BEAM (Bougie Use in Emergency Airway Management) trial, renewed interest in the use of a bougie rather than a stylet (1). In the BEAM trial, first-attempt endotracheal intubation success using a plastic bougie was compared to a stylet during laryngoscopy in an emergency department. First-attempt success was achieved in in 98% compared to 87% in all patients. In patients with at least one difficult airway characteristic, first-pass success using a plastic bougie was 96% compared to 82% using a stylet.

In 2019, the sterilized single-use telescopic steel bougie, AIROD (AIRODMedical; FL, USA), was introduced to the USA market (Figure 1).

Figure 1. A: AIROD closed. B: AIROD open. C: AIROD with an endotracheal tube loaded on the distal end.

The thin surgical steel construction of the AIROD allows it to bend slightly while maintaining its integrity to help manipulate oropharyngeal tissue without causing trauma. The AIROD can guide a 6.5 mm or larger endotracheal tube into the trachea. To do so, the AIROD is introduced into the oropharynx alongside a laryngoscope, either direct or video, and advanced just past the vocal cords. An endotracheal tube is then slid down over the AIROD and into the trachea securing the airway to allow for mechanical ventilation. The AIROD telescopes from one foot when closed to two feet when opened, offering many storage options.

Several publications have demonstrated that the AIROD is a safe and effective tool for endotracheal intubation (2-5). In this manuscript we extend those observations.

Methods

A retrospective analysis of all endotracheal intubations that were performed with the AIROD in the ICU at a single institution (Mercy One Hospital in Sioux City, IA) between October 18, 2020 and January 1, 2020 were included.

A successful first-attempt intubation was defined as the placement of an endotracheal tube into the trachea upon the initial insertion of the laryngoscope into the oropharynx. If the laryngoscope had to be removed and a second-attempt performed, it was considered a failure. Airways were graded using the Cormack-Lehane grade view (Appendix 1).

A difficult airway was defined as the presence of body fluids obscuring the laryngeal view, airway obstruction or edema, obesity, short neck, small mandible, large tongue, facial trauma, stiff neck or the need for cervical spine immobilization (2). Intubation time was defined as the time from insertion of the laryngoscope to placement of an endotracheal tube with its cuff inflated.

Results

Patient characteristics are shown in Table 1. 

Table 1. Characteristics and outcomes of the critically ill patients intubated with the AIROD in the ICU.

A total of 54 patients with an average age of 62 years were included in the study. All patients were in critical condition. The average patient was obese with a BMI of 31.2 kg/m2. A difficult airway was present in 76% of the patients and 54% of the patients had COVID-19 infection. In total, 63% of the patients were male and 37% were female. Using the Cormack-Lehane grade view: 20% had a grade 4 view, 10% had a grade 3 view, and 30% had a grade 2 view.

Intubation first-attempt success rate was 97%. Subgroup analysis of first-attempt intubation success using the AIROD to intubate in patients with a difficult airway was 96%.

The average intubation time in the patients that were timed was 15 seconds (33/54 patients were timed). Of the patients with a difficult airway, the average time to intubate was also 15 seconds.

A bronchoscopy performed on 17% of the patients just after intubation revealed no evidence of tracheobronchial trauma.

Discussion

The patients intubated with the AIROD in the ICU had a first-attempt success rate of 97%. The first-attempt success rate for endotracheal intubation of the critically ill has been reported at only 70% (6,7). This corresponds to an absolute risk reduction of 27% in failure to intubate patients during the first-attempt with the use of the AIROD during the intubation of patients in critical condition.

Even when compared to patients who were not critically ill and were intubated with a plastic bougie in the emergency department in the BEAM trial (1), the first-attempt success rate with the AIROD was 97% vs. 98. In those patients who were critically ill and also had a difficult airway, the first-attempt intubation success rate with the AIROD was at 97% vs. 96% in all patients (not just the critically ill) with a difficult airway.

In this study, the average time to intubation in all critically ill patients was 15 seconds using the AIROD. For those patients who were critically ill and had a difficult airway, the time to intubation was also 15 seconds. A previous publication on consecutive COVID-19 patients with ARDS intubated using the AIROD also had an intubation time of 15 seconds (2). In the BEAM trial, the median time to intubation using the plastic bougie in all types of patients intubated in the emergency department was 38 seconds (1). In all critically ill patients, the AIROD was 23 seconds faster. Intubation with the AIROD took 40% of the time in those patients who were critically ill, including those with a difficult airway, as opposed to the plastic bougie. The decrease in time securing the airway may have an impact on overall decompensation and possible outcomes of the disease process. Further studies between low intubation time and disease outcome remain an area to be studied in the future. The decrease in intubation time using the AIROD was not accompanied by adverse events such as cardiac arrest or tissue damage.

During multiple intubations, the AIROD was used to lift the epiglottis and move the oropharyngeal tissue that was obscuring the vocal cords out of the way, improving the view of the vocal cords and allowing for successful tracheal intubation. The AIROD was also able to move copious secretions blocking the view of the glottis in a few patients including those patients receiving chest compressions. Even during blind intubation, including one time when the light on the laryngoscope failed, the AIROD provided tactile sensation to the tracheal rings known as “tracheal clicks” that helped ensure correct tracheal placement of the endotracheal tube (2).

This study is limited by its small sample size and retrospective nature, and by that fact that not all intubations were timed because of the emergent nature of some of the intubations. The inventor of the AIROD did most of the intubations and others might not achieve equal results. A prospective trial on the timing of first-pass intubation success using the AIROD would be most useful to confirm the findings in this study.

In conclusion, the AIROD first-attempt intubation success rate was found to be similar to the rate for the traditional plastic bougie. Direct inspection of the oropharynx during intubation confirmed no significant trauma occurred during intubation.

Conflicts of Interest

Evan D. Schmitz, MD is the inventor of the AIROD and was the primary operator for most of the intubations mentioned in this study. No financial assistance was provided for this study. The AIROD instruments were donated to the hospital from AIRODMedical.com.

Acknowledgments

The author thanks H. Carole Schmitz, Carol Fountain and Abra Gibson for their editorial comments.

References

1. Driver BE, Prekker ME, Klein LR, Reardon RF, Miner JR, Fagerstrom ET, Cleghorn MR, McGill JW, Cole JB. Effect of Use of a Bougie vs Endotracheal Tube and Stylet on First-Attempt Intubation Success Among Patients With Difficult Airways Undergoing Emergency Intubation: A Randomized Clinical Trial. JAMA. 2018 Jun 5;319(21):2179-2189. [CrossRef] [PubMed]
2. Schmitz ED. Decreasing COVID-19 patient risk and improving operator safety with the AIROD during endotracheal intubation. J of Emergency Services. EMSAirway. 11/2020.
3. Schmitz ED. AIROD Case Series: A new bougie for endotracheal intubation. J Emerg Trauma Care. 2020;5(2):20. [CrossRef]
4. Schmitz ED. Single-use telescopic bougie: case series. Southwest J Pulm Crit Care. 2020;20(2):64-68. [CrossRef]
5. Schmitz ED, Park K. Emergency intubation of a critically ill patient with a difficult airway and avoidance of cricothyrotomy using the AIROD. J of Emergency Services. EMSAirway. 01/2021. [CrossRef]
6. Collins SR. Direct and indirect laryngoscopy: equipment and techniques. Respir Care. 2014 Jun;59(6):850-62; discussion 862-4. [CrossRef] [PubMed]
7. Higgs A, McGrath BA, Goddard C, Rangasami J, Suntharalingam G, Gale R, Cook TM; Difficult Airway Society; Intensive Care Society; Faculty of Intensive Care Medicine; Royal College of Anaesthetists. Guidelines for the management of tracheal intubation in critically ill adults. Br J Anaesth. 2018 Feb;120(2):323-352. [CrossRef] [PubMed]

Cite as: Schmitz ED, Park K. First-Attempt Endotracheal Intubation Success Rate Using A Telescoping Steel Bougie. Southwest J Pulm Crit Care. 2021;22(1):36-40. doi: https://doi.org/10.13175/swjpcc004-21 PDF

January 2021 Critical Care Case of the Month: A 35-Year-Old Man Found Down on the Street

John J. Lee, BS

Ling Yi Obrand, MD

Janet Campion, MD

University of Arizona School of Medicine

Tucson, AZ, USA

History of Present Illness

A 35-year-old African-American man with a history of alcohol abuse presented to Emergency Department after he was found down. He was seen by a passerby on the street who witnessed the patient fall with a possible convulsive event. He was brought in by ambulance and was unconscious and unresponsive.

PMH, SH, and FH

The patient had a history of prior ICU admission in Yuma with septic shock secondary to a dental procedure requiring a tracheostomy in 2018. He also had a history of alcohol intoxication requiring an ED visit about 10 years ago and history of sickle cell trait. Per chart review, the patient took no home medications. Further history was unable to be obtained due to the patient's condition.

Physical Examination

On arrival the patient had a core temperature of 41°C, systolic blood pressure in the 70s-80s, heart rate of 185, respiratory rate of 19, and an oxygen saturation of 99% on room air. Patient was not able to answer any questions.

On examination, the patient had a Glascow Coma Scale of 6 (no eye response, no verbal response, and normal flexion). Pupils were 4 mm bilaterally and reactive to light. The remainder of his HEENT was unremarkable with no meningismus reported. Pulmonary exam showed rapid, shallow breathing and coarse breath sounds with no crackles, wheezes, or rhonchi. Heart examination showed tachycardia with no murmurs or extra heart sounds. Abdomen was soft and nondistended. Skin was diaphoretic without cyanosis, clubbing, or edema.

Laboratory, Radiology and EKG

Initial laboratory testing was significant for a potassium level of 7.5 mmol/L, creatinine level of 1.96 mg/dL which was increased from baseline of 0.93 mg/dL, CK level of 2344 U/L, AST 93 U/L, ALT 62 U/L, and total bilirubin 2 mg/dL. Lactic acid was within normal limits. His EKG showed sinus tachycardia. His urinalysis was cloudy with protein and blood. His head CT was negative for any intracranial abnormalities or bleed.

Hospital Course

He was given 3 L of IV fluids, empiric vancomycin and piperacillin/tazobactam, and his hyperkalemia was managed with calcium gluconate, insulin and glucose. He was intubated for airway protection due to his shallow breathing and GCS of 6, started on pressor support, and was admitted to the ICU.

Based on the initial findings, what is the most likely cause of the patient’s presentation? (Click on the correct answer to be directed to the second of six pages)

1. Acute encephalitis
2. Delirium tremens
3. Heatstroke
4. Malignant hyperthermia
5. Septic shock

Cite as: Lee JJ, Obrand LY, Campion J. January 2021 Critical Care Case of the Month: A 35-Year-Old Man Found Down on the Street. Southwest J Pulm Crit Care. 2021;22:1-7. doi: https://doi.org/10.13175/swjpcc051-20 PDF 

A Case of Athabaskan Brainstem Dysgenesis Syndrome and RSV Respiratory Failure

Tanner Ellsworth

Nahid Hiermandi DO

Diana Hu MD

Lisa M. Grimaldi MD

Cardiovascular Intensive Care Unit

Phoenix Children’s Hospital

Phoenix, Arizona USA

Abstract

Athabaskan Brainstem Dysgenesis Syndrome (ABDS) is a nonlethal, homozygous HOXA1 mutation typically marked by central hypoventilation, sensorineural deafness, horizontal gaze palsy, and developmental delay. In this report, we present a case of a 27-month-old Navajo female with a new diagnosis of ABDS after multiple failed attempts at extubation following anesthesia in the setting of respiratory syncytial virus (RSV) bronchiolitis. Her case is significant because she lacks sensorineural hearing loss, a defining feature of previously documented cases thereby underscoring the challenges of diagnosing this disease. This case expands the ever-growing spectrum of homozygous HOXA1 mutations and demonstrates unique junctions for diagnosis of ABDS in the critical care setting in patients lacking key features of the disease.

Introduction

Athabaskan Brainstem Dysgenesis Syndrome (ABDS) is an autosomal recessive, nonlethal, homozygous HOXA1 mutation. Though globally rare, incidence in Southwest Athabaskan (Navajo and Apache) populations spans 1/1000 to 1/3000 births (1)(2). This can be compared to Congenital Central Hypoventilation Syndrome (CCHS) with an estimated incidence of 1/200,000 births worldwide (3).

ABDS is marked by central hypoventilation, sensorineural deafness, horizontal gaze palsy, and developmental delay (2). Other features include cardiac outflow tract anomalies, swallowing dysfunction, vocal cord paralysis, facial paresis, seizures, hypotonia, and cerebrovascular maldevelopment (4)(5). Affected individuals span a broad spectrum with many asymptomatic cases. Similar syndromes include Moebius syndrome and Bosley-Salih-Alorainy Syndrome, though both lack central hypoventilation (5). Central hypoventilation in children should include consideration for primary neuromuscular, lung, or cardiac disease, along with brainstem lesions, CCHS, asphyxia, infection, trauma, tumor, and infarction (6). As more Athabaskan individuals leave reservations, medical professionals must gain familiarity with the spectrum of HOXA1 mutations to prevent avoidable complications and expedite appropriate therapies.

We present a 27-month-old Navajo female with a new diagnosis of ABDS after several failed attempts at extubation following anesthesia in the setting of respiratory syncytial virus (RSV) bronchiolitis.

Case Description

A 27-month-old Navajo female with global developmental delay, patent ductus arteriosus (PDA), and sleep apnea presented with an acute, febrile respiratory illness confirmed as RSV bronchiolitis. She was admitted to a rural hospital for supportive care including supplemental oxygen and methylprednisolone.

Birth and developmental history were significant for transient poor feeding, poor visual tracking since birth, three failed newborn hearing exams with a subsequent pass, and global developmental delay, evidenced by inability to ambulate independently or speak more than two words.

At the rural hospital, persistent hypoxemia prompted a cardiac evaluation with echocardiography that revealed left ventricular hypertrophy, a tortuous aortic arch with moderate obstruction, and a small PDA with left-to-right shunting. Considering these findings, she was transferred to a tertiary pediatric hospital for further workup and management.

On the pediatric floor, blood gas analyses showed hypercarbia with metabolic compensation, suspicious for chronic hypoventilation. She consistently demonstrated generalized hypotonia and inconsistent tracking, specifically restricted lateral eye movements. Persistent hypoxemia and abnormal echocardiogram prompted further cardiac evaluation. On hospital day (HD) 3, a cardiac CT under general endotracheal anesthesia confirmed coarctation of the aorta and hypoplastic transverse arch. She was unable to be extubated due to persistent hypoxia and hypercarbia and was transferred to the cardiovascular intensive care unit.

Extubation attempts were initially deferred due to Moraxella tracheitis, treated with antibiotics and airway clearance. She weaned ventilator settings and was extubated to non-invasive support with bilevel positive airway pressure (BiPAP) on HD7. Within hours, she developed hypercarbia due to hypoventilation with a blood pH of 6.98 requiring reintubation.

Persistent central hypoventilation, hypercarbia, and cardiac outflow tract anomaly prompted investigation for ABDS. Brain MRI showed diffuse parenchymal volume loss with no brainstem abnormalities. Brainstem Auditory Evoked Response (BAER) testing showed no evidence of sensorineural hearing loss. Chromosome microarray testing confirmed homozygous HOXA1 mutation, consistent with ABDS.

Ventilator settings were again weaned, caffeine therapy initiated, and sedation medications discontinued for several days to avoid exacerbation of central hypoventilation. Unfortunately, repeat extubation failed due to stridor and hypoventilation, so she was reintubated and underwent an airway evaluation that revealed posterior vocal fold granulomas, which were debrided.

On HD33, the patient was successfully extubated to BiPAP. She weaned to room air during the day and BiPAP at night which she continued after discharge on HD57.

Discussion

In the critical care setting, familiarity with ABDS is important because patients can present with severe symptomatology out of proportion to their underlying disease. Minor respiratory illnesses or anesthesia can greatly exacerbate central hypoventilation and potentially lead to prolonged endotracheal intubation, mechanical ventilation, and associated complications such as ventilator-associated pneumonia, airway trauma, and habituation to sedation medications (2). Patients like this, who lack certain key features of ABDS—namely sensorineural deafness—are particularly challenging since diagnosis can be delayed (2). This case further illuminates the spectrum of homozygous HOXA1 mutations and emphasizes the importance of maintaining a high index of suspicion for ABDS in Athabaskan patients to anticipate the illness course and provide tailored medical care.

Conclusion

Overall, as Athabaskan individuals spread geographically, this case underscores the importance of widespread familiarity with ABDS for physicians. Basic knowledge of the features of ABDS will help identify individuals who may present with events such as infection or anesthesia that unmask an underlying abnormality, and their care can be directed at the unique challenges they present.

References

1. Erickson RP. Southwestern Athabaskan (Navajo and Apache) genetic diseases. Genet Med. 1999 May-Jun;1(4):151-7. [CrossRef] [PubMed]
2. Holve S, Friedman B, Hoyme HE, Tarby TJ, Johnstone SJ, Erickson RP, Clericuzio CL, Cunniff C. Athabascan brainstem dysgenesis syndrome. Am J Med Genet A. 2003 Jul 15;120A(2):169-73. [CrossRef] [PubMed]
3. Bardanzellu F, Pintus MC, Fanos V, Marcialis MA. Neonatal Congenital Central Hypoventilation Syndrome: Why We Should not Sleep on it. Literature Review of Forty-two Neonatal Onset Cases. Curr Pediatr Rev. 2019;15(3):139-153. [CrossRef] [PubMed]
4. Bosley TM, Alorainy IA, Salih MA, Aldhalaan HM, Abu-Amero KK, Oystreck DT, Tischfield MA, Engle EC, Erickson RP. The clinical spectrum of homozygous HOXA1 mutations. Am J Med Genet A. 2008 May 15;146A(10):1235-40. [CrossRef] [PubMed]
5. Erickson RP. Autosomal recessive diseases among the Athabaskans of the southwestern United States: recent advances and implications for the future. Am J Med Genet A. 2009 Nov;149A(11):2602-11. [CrossRef] [PubMed]
6. Weese-Mayer, DE, Marazita, ML, Rand, CM, et al. Congenital central hypoventilation syndrome. 2004 Jan 28. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1427/

Cite as: Ellsworth T, Hiermandi N, Hu D, Grimaldi LM. A Case of Athabaskan Brainstem Dysgenesis Syndrome and RSV Respiratory Failure. Southwest J Pulm Crit Care. 2020;21(5):124-6. doi: https://doi.org/10.13175/swjpcc053-20 PDF 

October 2020 Critical Care Case of the Month: Unexplained Encephalopathy Following Elective Plastic Surgery

Natalie Held, MD and Carolyn Welsh, MD

University of Colorado Division of Pulmonary Sciences and Critical Care Medicine

Aurora, CO USA

A 29-year-old woman with no significant medical history presents to the hospital due to progressive encephalopathy, 5 days after undergoing an elective abdominoplasty with abdominal liposuction and breast augmentation. She is somnolent on exam, and is hypoxic to ~60% saturation on room air. She is emergently intubated in the emergency department prior to being admitted to the MICU, and is started on broad-spectrum antibiotics and n-acetyl cysteine (NAC). She has evidence of acute liver failure but her initial work-up for acute liver failure is entirely unrevealing, and her liver function and hemodynamics improve without additional intervention over the initial 3 days of hospitalization. Unfortunately, her mental status does not improve. Despite weaning of all sedation, she shows limited signs of awareness. A lumbar puncture, CT of the head, and electroencephalogram (EEG) are performed and are unremarkable.

What should be done next? (Click on the correct answer to be directed to the second of six pages)

1. Brain magnetic resonance (MRI) imaging
2. Myelography
3. Neurology consultation
4. 1 and 3
5. All of the above

Cite as: Held N, Welsh C. October 2020 Critical Care Case of the Month: Unexplained Encephalopathy Following Elective Plastic Surgery. Southwest J Pulm Crit Care. 2020;21(4):73-9. doi: https://doi.org/10.13175/swjpcc041-20 PDF