fisiol e anat ponv.ponv anatomy and physiology,risk of

Fisiologia ed anatomia del PONV

Importance of the issue

• PONV is :– A limiting factor in the early discharge of ambulatory surgical

patients– The leading cause of unanticipated hospital admission

• PONV may:– Increase recovery room time– Expand nursing care– Increase total health care costs– Cause high level of patient discomfort---

pain,hematoma,wound dehiscence…– Cause high level of patient dissatisfaction– KO!!!

Macario A, Weinger M,Carney S, Kim A.Which clinical anesthesia outcomes are important to

avoid?Anesth.Analg.1999;89:652-8.

02468

101214161820

rank valore relativo

vomitogagging sul tubodolorenausearicordo senza doloredebolezza residuabrividomal di golasonnolenza

Dal + indesiderabile

Al meno indesiderabile

distribute $100 among the 10 outcomes, proportionally more money being allocated

to the more undesirable outcomes. The dollar allocations were used to

determine the relative value of each outcome.

Sintomi accusati dai pazienti a casa dopo interventi eseguiti in regime di day surgery(da

Wu et al.,Anesthesiology 2002).

dolorenauseavomitocefaleasonnolenzagir.di testafatica

Quali problemi preferirebbero evitare i pazienti

sottoposti a day surgery? (da Jenkins, K.; Grady, D.; Wong, J.;

Correa, R.; Armanious, S.; Chung, F.*Post-operative recovery: day surgery patients' preferences

Br. J. Anaesth. 2001; 86:272-274)

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doloretossire sul tubo etvomitonauseadisorientamentomal di golabrividosonnolenzasete

Valori relativi !

Beauregard L, Pomp A, Choinière M. Severity and impact of pain after day-surgery Can J

Anaesth 1998 / 45 / 304-11

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dolore PONV gir.testa sonnolenza cefalea mal di gola raucedine fatica

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Sintomi accusati dai pazienti a casa dopo interventi eseguiti in regime di day surgery(da

Wu et al.,Anesthesiology 2002).

dolorenauseavomitocefaleasonnolenzagir.di testafatica

Quali problemi preferirebbero evitare i pazienti

sottoposti a day surgery? (da Jenkins, K.; Grady, D.; Wong, J.;

Correa, R.; Armanious, S.; Chung, F.*Post-operative recovery: day surgery patients' preferences

Br. J. Anaesth. 2001; 86:272-274)

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25

30

doloretossire sul tubo etvomitonauseadisorientamentomal di golabrividosonnolenzasete

Valori relativi !

Beauregard L, Pomp A, Choinière M. Severity and impact of pain after day-surgery Can J

Anaesth 1998 / 45 / 304-11

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dolore PONV gir.testa sonnolenza cefalea mal di gola raucedine fatica

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Servizio di Anestesia e Rianimazione Ospedale di Faenza(RA)

Methodological questions(from Visserer et al…)

• definitions of PONV:– nausea only, – nausea and vomiting– vomiting only.

• Diversity in methods of data collection• Emetic symptoms can be quantified as:

– retrospective self-report– established through explicit questioning– observed on site by a third party. – As a consequence of the effects of both suggestion and increased

detection, repeatedly questioning patients about PONV might result in a higher percentage of patients reporting PONV and receiving antiemetic therapy than would be the case in normal practice.

• So is PONV still a problem? It's been the most common problem in anesthesia for decades; you would think that we would have a handle on it, right? And the problem is that every time someone goes out and does a study and looks at "the big bad world," where thousands and thousands of patients are being done, it still comes out to be 25% to 30% after general anesthesia. That's the way it always is. No one believes me when I tell them this; as a matter of fact, I didn't believe my practice was that bad either in Miami, Florida, and I went to the PACU nurses and I said, "What's our incidence of PONV?" I don't know, 8%, 10% probably. And then when we studied it because we do a lot of actual clinical studies, it turns out it's 30%. If you actually ask and you actually follow the patients for a significant amount of time, you find out that no matter how good you think you're doing, you're not actually doing as good as you think. So I want you to keep that in mind; just have a little bit of an open mind about what the true incidence is. Most people don't think that they're having this incidence and I'm going to show you why.

• You can get up to 80% with high-risk procedures using emetogenic anesthetics. Laparoscopic gynecologic surgery: there was one paper published using a lot of narcotics and desflurane that had an incidence above 80%. So if you really mix things up and get in the worst of all worlds, you can almost guarantee your patient's going to get PONV.

• And we just talked how everybody's estimate of PONV is less than the actual occurrence and that's a lot because once the patient leaves the recovery room, we don't really think that much about the patient. Once we send them out the door, whether it's to go home or whether it is to go to the floor, we don't always say, "Five hours after you left me, did you have nausea and vomiting?" You just want to know that they're doing okay

Oh,ma i dati sono vecchi di 13 anni…..

Pediatric incidence

Figure 6 summarises the sites of actions of the drugs that influence PONV.

Risk and consequences of vomiting

• Muscular contraction of the effort:– Suture tension,stitches ,deiscence

• Regurgitation• Aspiration pneumonia

– Electrolyre imbalance,dehydration– Delay of oral intake

• Economic burden:– Nurses time ,call,cleaning up

– Drugs for ponv

– Laundry

– Discharge delay

– Unplanned hospitalization..bed blocking….reduced surgical throughput

PONV calculator

PONV risk scoring systems

• Palazzo &Evans(BJA 1993):– Logit postop sickness=-5.03+2.24(postop opioids)

+3.97(previous sickness history)+2.4(gender)+0.78(history of motion sickness )-3.2(gender*previous sickness history)

• Koivuranta(Anaesthesia 1997)– Score=0.93(if female)+0.82(if previousPONV)+0.75(if

duration of surgery >60 min)+0.61(if non smoker)+0.59(if history of motion sickness)


Independent predictors of PONV Sinclair et al.Can PONV be predicted?Anesthesiology

1999;91:109-18• age A 10-yr increase in age was associated with a 13% decrease in the likelihood of PONV.

• sex Men had one third the risk for PONV compared with women.

• smoking status Smokers had two thirds the risk for PONV compared with nonsmokers

• history of previous PONV, had a threefold increase in the likelihood PONV compared with patients with no previous PONV.

• type of anesthesia: General anesthesia increased the likelihood of PONV 11 times compared with other types of anesthesia.

• duration of anesthesia, direct association between the duration of anesthesia and the risk for PONV. A 30-min increase in duration predicted a 59% increase in the incidence of PONV

• type of surgery :– plastic surgery had a sevenfold increase in the risk for PONV.– orthopedic shoulder surgery, ophthalmologic, or ENT procedures had a four- to sixfold

increase.– orthopedic (nonshoulder) and gynecologic (non-D&C) procedures had a threefold

increase in the risk for PONV. Compared with the reference group, which includes general surgery, gynecologic dilation and curettage (D&C), urologic surgery, neurosurgery, and chronic pain blockENT

– dental surgery 14.3%, orthopedic 7.6%,plastic surgery 7.4%.Urologic, gynecologic, neurologic, or general surgery had an incidence of PONV corresponding to the overall average 4%

•


Logistic regression da:Sinclair et al.Can PONV be predicted?Anesthesiology 1999;91:109-18

• P=1/1+e esponente

• con il segno neg. all’esponente la probabilità aumenta perché e elevato ad esp negativo diminuisce sempre + con il risultato che 1+e tende a 1 e dunque P=1/1,ossia 100%

• Con il segno positivo all’esponente e aumenta sempre + e allora 1+e aumenta e dunque il denominatore dell’equazione aumenta e dunque 1/un numero in aumento fa scendere la probabilità perché viene 1/5,cioè 20%,1/10=10%,ecc…..

Formula di Sinclair• P=1/1+e esponente

• Esponente=-5,97+(-0,14 *age)+(-1,03*sex)+(-0,42*smoke)+(1,14*PONV history)+(0,46*duration)+(2,36*GA)+(1,48*ENT)+(1,77*ophtalm)+(1,90*plastic)+(1,20 Gynecol non DC)+(1,04 ort knee)

+(1,78*ortshoulder)+(0.94 ort other)

• Age = age in years/10; • Sex = 1 if male and 0 if female; • Smoke = 1 if smoker and 0 if nonsmoker; • PONV History = 1 if previous PONV and 0 if no previous PONV; • Duration = duration of surgery in 30-min increments; • GA = 1 if general anesthesia and 0 if other type of anesthesia; • ENT = 1 if ENT and 0 if other type of surgery; • Ophthalm = 1 if ophthalmology and 0 if other type of surgery; • Plastic = 1 if plastic surgery and 0 if other type of surgery; • GynNonDC = 1 if gynecologic non D&C procedure and 0 if other type of surgery; • OrtKnee = 1 if orthopedic procedure involving knee and 0 if other type of surgery; • OrtShoulder = 1 if orthopedic procedure involving the shoulder and 0 if other type of surgery; • OrtOther = 1 if orthopedic procedure involving neither knee nor shoulder and 0 if other type of

surgery.


Importance of the work by Sinclair et al…

• Fitting the model to the data, we can obtain the maximum likelihood estimate of the parameters for each variable. Based on the maximum likelihood estimates from the final models, it is possible to calculate an expected risk of occurrence of the specific adverse event for any patient.

•


Examples

• The risk for patient 1, a 30-yr-old woman with a history of smoking and previous PONV undergoing a 1-h shoulder (orthopedic) operation with general anesthesia is 35.2%.

• • The risk for patient 2, a 40-yr-old nonsmoking man with no previous PONV

undergoing a 1-h knee arthroscopy (orthopedic) without general anesthesia is 0.4%. • • The risk for patient 3, a 70-yr-old smoking man with no previous PONV

undergoing a 1-h cataract surgery (ophthalmologic) without general anesthesia is 0.3%.

• • The risk for patient 4, a 32-yr-old nonsmoking woman with previous PONV

undergoing a 30-min laparoscopy (gynecologic) with general anesthesia is 22.1% • • The risk for patient 5, a 22-yr-old woman with a history of smoking and previous

PONV undergoing a 90-min bilateral breast augmentation (plastic surgery) with general anesthesia is 52%.


Risk Factors

• Non-anesthetic factors

• Anesthetic related factors

• Postoperative factors


Risk factors da Samba 2007:1

• Patient specific • Female gender• Non smoking status• Hx of ponv/motion sickness



• Anesthetic risk factors– Use of intraop volatile anesth

– Use of intraop and postop opioids

– Use of intraop N2O



• Surgical risk factors• Duration of surgery

– Each 30 min increase in duration of surgery increases the risk by 60%,so that a baseline risk of 10% increases to 16% after 30 min

• Type of surgery – Laparoscopy;laparotomy;breast,strabismu

s,plastic,maxillofacial,gynecological,abdominal,neurologic ,opthalmologic,urologic


Risk Factors

• Age

• Gender• Body habitus• Hx motion sickness• Hx PONV

• Anxiety

• Concomitant disease

• Operative procedure• Duration of surgery

Non-anesthetic Factors


Risk Factors

• Preanesthetic medication

• Gastric distension• Gastric suctioning• Anesthetic technique

• Anesthetic agents

Anesthetic Related Factors


Risk Factors

• Pain• Dizziness• Ambulation

• Oral intake

• Opioids

Postoperative Factors


Postoperative Nausea and Vomiting:Anesthetic Related Factors

• Nitrous oxide

• Volatile anesthetics

• NMB reversal

• Propofol


Risk FactorsNitrous Oxide and PONV

Omission of Nitrous Oxide during Anesthesia Reduces the Incidence of Postoperative Nausea and Vomiting. A Meta-Analysis

Divatia et al. Anesthesiology 1996;85:1055-1062

Twenty-Four of Twenty-Seven Studies Show a Greater Incidence of Emesis Associated with Nitrous Oxide than with Alternative Anesthetics

Hartung. Anesth Analg 1996;83:114-116

Omitting Nitrous Oxide in General Anaesthesia: Meta-Analysis of Intraoperative Awareness and Postoperative Emesis in Randomized Controlled Trials

Tramer et al. BJA 1996;76:186-193


Risk FactorsNitrous Oxide and PONV

• Decreases POV significantly only if the baseline risk is high

• Does not affect nausea or complete control of emesis

• Increases the incidence of intraoperative awareness

Omitting nitrous oxide from general anesthesia:

Tramer et al. BJA 1996;76:186-193

The value of hydration


Intravenous Fluid Therapy

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30 min 60 min DIS Day 1Time

Inci

den

ce %

Low Infusion High Infusion

*

Yogendran S, et al. Anesth Analg 1995;80:682-686High Infusion = 20 ml/kg

Low Infusion = 2 ml/kg

Incidence of Postop Nausea


P-6 Acupuncture Point Stimulation

TAES Sham PlaceboPACU 25 17 28

45 min 36 51 32

90 min 27* 51 33

120 min 27 40 41

4 hr 26* 52 35

6 hr 22*† 47 43

9 hr 18*† 42 47

Control of Nausea

Zarate E, et al. Anesth Analg 2001;92:629-35

* compared to sham

† compared to placebo


Supplemental Oxygen

• Greif R, Laciny S, Rapf B, et al. Supplemental oxygen reduces the incidence of postoperative nausea and vomiting. Anesthesiology 1999;91:1246-52.

• Goll V, Ozan A, Greif R, et al. Ondansetron is no more effective than supplemental intraoperative oxygen for prevention of postoperative nausea and vomiting. Anesth Analg 2001;92:112-17.


Supplemental Oxygen30 % Oxygen 80% Oxygen P Value

Male/Female 57/62 41/71 0.110

0-6 hr PONV (%) 15.1 8 0.141

nausea (%) 15.1 8 0.077

vomiting (%) 1.7 0 0.169

6-24 hr PONV (%) 22.2 19.9 0.045

nausea (%) 17.6 8.9 0.066

vomiting (%) 5.9 1.8 0.108

0-24 hr PONV (%) 30.3 17 0.027

nausea (%) 27.7 16 0.034

vomiting (%) 5.9 1.8 0.108

Greif et al. Anesthesiology 1999;91:1246-1252


Supplemental Oxygen30 % Oxygen 80% Oxygen Ondansetron

Patients (female) 80 79 71

0-6 hr PONV (%) 36 20 27

nausea (%) 35 20 27

vomiting (%) 19 9 14

6-24 hr PONV (%) 13 4 6

nausea (%) 11 4 6

vomiting (%) 9 4 1

0-24 hr PONV (%) 44 22* 30

nausea (%) 41 22* 30

vomiting (%) 26 10* 15Goll et al. Anesth Analg 2001;92:112-117


Pain and PONVEffects % of Total Patients

Pain relieved, nausea relieved 68.5

Pain reduced, nausea relieved 11.5

Pain relieved, nausea persisted 9.5

Pain persisted, nausea persisted 10.5

Andersen et al. Can Anaesth Soc J 23:366-369, 1976

Transdermal scopolamine side effects

• NO in a glaucoma patient

• No in a patient who has voiding problems

• It hasn't been approved in children

• don't cut the patch

• It has to be applied correctly

• can cause dry mouth.

Pharmacogenomics

fisiol e anat ponv.ponv anatomy and physiology,risk of

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