BANG BANG

What is OSA? Why does OSA matter? And does STOP BANG help us truly identify OSA?

OSA is:

• cessation of airflow >10sec, 5+x/hr + 4% desat in SaO2
• definitions vary, but >15x /hr is diagnostistic
• dx by polysomnography
• Apnea/hypopnea index (AHI), which is derived from the total number of apneas and hypopneas divided by the total sleep time (mild up to 15, severe >30)

 

Obstructive Sleep Apnea (OSA) matters because:

• harder to intubate, harder to ventilate
• increased prevalance of cardiac disease: Afib, arrhythmias, stroke, CHF, cardiomyopathy, pulmonary hypertension, CAD
• periop complications higher, including airway obstruction, hypoxemia, atelectasis, pneumonia
• more sensitive to respiratory depressant effect of opioids and hypnotics

Source: http://www.ncbi.nlm.nih.gov/pubmed/18339794

Is STOP BANG Helpful?

The literature shows…

“The sensitivities of the STOP questionnaire with apnea-hypopnea index greater than 5, greater than 15, and greater than 30 as cutoffs were 65.6, 74.3, and 79.5%, respectively. When incorporating body mass index, age, neck circumference, and gender into the STOP questionnaire, sensitivities were increased to 83.6, 92.9, and 100% with the same apnea-hypopnea index cutoffs.”

See: http://www.ncbi.nlm.nih.gov/pubmed/18431116

And what are these complications?

Mostly pulmonary, with a few possible cardiac events mixed in as noted in this study in Chest, cited in Miller’s 8th edition( http://journal.publications.chestnet.org/article.aspx?articleid=1085863#t4)

 

Variables	ODI4%	Age, yr	Sex	BMI, kg/m2	Type of Surgery	Complication
ODI 4%< 5	0.2	27	F	46.7	Laparoscopic gastric bypass surgery	Transient episodes of unspecified tachyarrhythmia during the first 3 postoperative days
	3.0	52	F	59.4	Laparoscopy with conversion to open ventral herniorrhaphy and adhesiolysis	Hypoxemia treated with supplemental oxygen and BPAP
ODI 4%≥ 5	5.5	49	F	26.2	Total abdominal hysterectomy and right salpingoophorectomy cystoscopy with placement of ureteral catheters	Hypoxemia was observed on postoperative day 3 and treated with oxygen supplementation; atelectasis was noted
	6.0	49	F	39.1	Total abdominal hysterectomy and bilateral oophorectomy	Intraperitoneal bleeding was treated with embolization
	6.2	39	F	44.9	Laparoscopic gastric bypass surgery	Intraperitoneal bleeding which resolved without surgery
	7.6	61	M	33.5	Sigmoid colon resection	Hypoxemia and hypotension.
	12.9	64	M	37.0	Mitral valve replacement	Hypotension and junctional escape rhythm
	13.0	57	M	38.9	Laparoscopic colonic polypectomy	Atelectasis
	14.5	58	F	41.6	Total abdominal hysterectomy and bilateral oophorectomy	Atelectasis
	18.6	62	M	37.3	Left inguinal herniorrhaphy	Wheezing observed which required treatment with bronchodilators
	24.6	49	F	28.1	Total abdominal hysterectomy and bilateral oophorectomy	Pneumonia
	26.3	53	F	47.9	Gastric bypass surgery	GI bleeding
	31.9	50	M	29.6	Radical prostatectomy	Hypoxemia treated with CPAP
	34.1	62	F	31.4	Total abdominal hysterectomy and bilateral oophorectomy	Atelectasis
	34.2	69	M	36.9	Laparoscopic right hemicolectomy	Pulmonary embolism; superior mesenteric vein thrombosis
	36.4	55	F	49.5	Exploratory laparotomy, adhesiolysis, small bowel resection, partial hepatic resection, gastric bypass	Chest pain (MI was ruled out)
	82.4	66	F	46.8	Total abdominal hysterectomy and bilateral oophorectomy	Hypoxemia treated with CPAP

*

F = female; M = male; BPAP = bilevel positive airway pressure. See Table 1 for abbreviation not used in the text.

Midazolam for PONV

From Wick, Elizabeth, and Christopher L. Wu. “The Effect of Intravenous Midazolam on Postoperative Nausea and Vomiting: A Meta-Analysis.” (2015).

The gist: Midaz at any point reduces PONV by up to 40%!

BACKGROUND: Research has shown that high-risk surgical patients benefit from a multimodal therapeutic approach to prevent postoperative nausea and vomiting (PONV). Our group sought to investigate the effect of administering IV midazolam on PONV.
METHODS: This meta-analysis included 12 randomized controlled trials (n = 841) of adults undergoing a variety of surgical procedures that investigated the effect of both preoperative and intraoperative IV midazolam on PONV in patients undergoing general anesthesia.
RESULTS: Administration of IV midazolam was associated with significantly reduced PONV (risk ratio [RR] = 0.55; 95% confidence interval [CI], 0.43–0.70), nausea (RR = 0.62; 95% CI, 0.40–0.94), vomiting (RR = 0.61; 95% CI, 0.45–0.82), and rescue antiemetic administration (RR = 0.49; 95% CI, 0.37–0.65) within 24 hours. Individual subgroup analyses of trials excluding the use of thiopental for induction, trials of either female sex or high-risk surgery, trials involving nitrous oxide maintenance, and trials using midazolam in combination with known antiemetics all yielded similar reductions in PONV end points within 24 hours of surgery.
CONCLUSIONS: Administration of preoperative or intraoperative IV midazolam is associated with a significant decrease in overall PONV, nausea, vomiting, and rescue antiemetic use. Providers may consider the administration of IV midazolam as part of a multimodal approach in preventing PONV.